Solutions which, upon administration, will temporarily arrest cardiac activity. They are used in the performance of heart surgery.
A procedure to stop the contraction of MYOCARDIUM during HEART SURGERY. It is usually achieved with the use of chemicals (CARDIOPLEGIC SOLUTIONS) or cold temperature (such as chilled perfusate).
Damage to the MYOCARDIUM resulting from MYOCARDIAL REPERFUSION (restoration of blood flow to ischemic areas of the HEART.) Reperfusion takes place when there is spontaneous thrombolysis, THROMBOLYTIC THERAPY, collateral flow from other coronary vascular beds, or reversal of vasospasm.
Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.
The hollow, muscular organ that maintains the circulation of the blood.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Devices for the compression of a blood vessel by application around an extremity to control the circulation and prevent the flow of blood to or from the distal area. (From Dorland, 28th ed)
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Contractile activity of the MYOCARDIUM.

Myocardial protection: the rebirth of potassium-based cardioplegia. (1/132)

The introduction of open-heart surgery more than 4 decades ago signaled a new era in medicine. For the 1st time, previously untreatable cardiac anomalies became amenable to surgical therapy. The use of the heart-lung machine seemed to grant the surgeon unlimited time in which to operate inside the heart. Still frustrated by poor operating conditions and the threat of air embolism, Denis Melrose introduced elective cardiac arrest in 1955. His use of a potassium citrate solution seemed to offer a safe method to effect a quiet, bloodless field. However, a few years after its inception, numerous reports began to question the safety of this approach, and the Melrose technique was abandoned in the early 1960s. Nearly 15 years elapsed before potassium-based cardioplegia regained popularity. During this period, topical hypothermia, coronary perfusion with intermittent aortic occlusion, and normothermic ischemia were evaluated and discarded. A few European investigators like Hoelscher, Bretschneider, and Kirsch had maintained their interest in chemical cardioplegia, and it was through their efforts that future researchers like Hearse and Gay spearheaded the return to potassium-based cardioplegia, which today forms the core of the cardiac surgeon's myocardial protective armamentarium and has contributed towards lowering operative mortality rates.  (+info)

Induction of immune tolerance in adult rabbits undergoing heterotopic cardiac transplantation. (2/132)

OBJECTIVE: To induce experimental immune tolerance in rabbits and observe its effects on heterotopic cardiac transplantation. METHODS: Donor's splenic lymphocytes pretreated with platinum metal chelator were injected into the recipient's mesenteric-portal vein. Cyclosporin A was perfused through the donor's heart. RESULTS: The injection of donor's splenic lymphocytes before transplantation could significantly prolong the survival time of the heterotopically transplanted heart. The effect of two injections was better than that of one. Radioactive tracer studies showed that the 99mTc-HMPAO tagged lymphocytes injected into the recipient rabbit were later concentrated in the liver, though initially they were distributed in multiple organs. The induced immune tolerance was antigen-specific, and it neither affect the other immune functions of the lymphatic system prominently nor exert any harmful effect on the recipient's liver and renal functions. The perfusion of cyclosporin A through the donor heart could block the glycosyl groups, such as D-glucose, D-mannose or N-acetyl-galactosamine on the surface of the myocardial cells, thus might change the antigenic expression, effectively preventing rejection of the graft by the host, and might be considered as a new method to block graft rejection in cardiac transplantation. The combined use of the above-mentioned two methods acted on both the host and the donor, thus reducing the exposed antigens on the donor organ as well as the immune reaction against the donor antigens, and resulting in synergistic effect in inducing immune tolerance in adult rabbits, and resulting in relatively long-term survival of transplanted hearts. CONCLUSION: This report may provide the experimental basis for inducing immune tolerance in clinical transplantation.  (+info)

Emerging concepts in the management of acute myocardial infarction in patients with diabetes mellitus. (3/132)

Although fibrinolysis has improved survival of patients after myocardial infarction (MI), such therapy is less likely to be administered to patients with diabetes. Furthermore, these patients present later (15 min) than nondiabetics. Moreover, even with the use of early potent fibrinolytic agents, patients with diabetes continued to suffer excessive morbidity and mortality. This finding is not related to the ability of fibrinolytic agents to restore complete reperfusion or increased risk of reocclusion of the infarct-related artery. Instead, the impaired ventricular performance at the noninfarct areas and metabolic derangements during the acute phase of MI may account for the adverse outcome. The efficacy of percutaneous coronary revascularization procedures for treatment of acute MI requires further evaluation. Therapeutic approaches should consider correcting these abnormalities to afford greater survival benefit for this subset of high-risk patients.  (+info)

Intercalated clear cells or pale cells in the sinus node of canine hearts? An ultrastructural study. (4/132)

Two types of sinus nodal cells were responsible for the main differences in the literature concerning the ultrastructure of the sinuatrial node: the intercalated clear cells and pale cells. Canine hearts were arrested by (1) aortic cross clamping, (2) coronary perfusion with the cardioplegic solution St. Thomas, and (3) coronary perfusion with the cardioplegic solution HTK (Custodiol(R)). After fixation by immersion or perfusion the sinus node tissue was prepared for electron microscopy. Following cardioplegic arrest and perfusion fixation, three nodal cell types in the non-ischemic sinuatrial node were observed: typical nodal cells, transitional cells, and intercalated clear cells. Less than 1% of the non-ischemic sinuatrial cells were intercalated clear cells, surrounded by typical nodal cells or transitional cells. The contractile apparatus of the intercalated clear cells was extremely poorly developed. Great structural variations in the mitochondria were observed in intercalated clear cells, variations that would not appear under conditions of ischemia. In contrast, after 15-25 min of ischemia at 25 degrees C the appearance of the sinus nodal cells was strikingly different from that of the non-ischemic sinuatrial cells. More than 10% of the nodal cells showed typical ischemic alterations, e.g., mitochondrial swelling, clumping of nuclear chromatin, loss of glycogen particles, and cell swelling in varying degrees. Because they look very pale, these nodal cells have been described as pale cells in the literature. Intercalated clear cells appear mainly in non-ischemic nodal tissue. Pale cells are ischemically damaged sinus nodal cells.  (+info)

Reduced cytosolic Ca(2+) loading and improved cardiac function after cardioplegic cold storage of guinea pig isolated hearts. (5/132)

BACKGROUND: Hypothermia is cardioprotective, but it causes Ca(2+) loading and reduced function on rewarming. The aim was to associate changes in cytosolic Ca(2+) with function in intact hearts before, during, and after cold storage with or without cardioplegia (CP). METHODS AND RESULTS: Guinea pig hearts were initially perfused at 37 degrees C with Krebs-Ringer's (KR) solution (in mmol/L: Ca(2+) 2.5, K(+) 5, Mg(2+) 2.4). One group was perfused with CP solution (Ca(2+) 2.5, K(+) 18, Mg(2+) 7.2) during cooling and storage at 3 degrees C for 4 hours; another was perfused with KR. LV pressure (LVP), dP/dt, O(2) consumption, and cardiac efficiency were monitored. Cytosolic phasic [Ca(2+)] was calculated from indo 1 fluorescence signals obtained at the LV free wall. Cooling with KR increased diastolic and phasic [Ca(2+)], whereas cooling with CP suppressed phasic [Ca(2+)] and reduced the rise in diastolic [Ca(2+)]. Reperfusion with warm KR increased phasic [Ca(2+)] 86% more after CP at 20 minutes and did not increase diastolic [Ca(2+)] at 60 minutes, compared with a 20% increase in phasic [Ca(2+)] after KR. During early and later reperfusion after CP, there was a 126% and 50% better return of LVP than after KR; during later reperfusion, O(2) consumption was 23% higher and cardiac efficiency was 38% higher after CP than after KR. CONCLUSIONS: CP decreases the rise in cardiac diastolic [Ca(2+)] observed during cold storage in KR. Decreased diastolic [Ca(2+)] and increased systolic [Ca(2+)] after CP improves function on reperfusion because of reduced Ca(2+) loading during and immediately after cold CP storage.  (+info)

Leukocyte-depleted continuous blood cardioplegia for coronary artery bypass grafting. (6/132)

Many cardiac surgeries are performed with blood cardioplegia. However, some studies suggest that activated neutrophils form blood cardioplegia can cause reperfusion injury. In this study we assessed myocardial protection using a leukocyte-depleted cardioplegic solution. Patients undergoing elective coronary artery bypass grafting (CABG) with continuous blood cardioplegia were divided into two groups: the LD group, which received leukocyte-depleted blood cardioplegia (n = 11); and the control group, which received nonfiltered blood cardioplegia (n = 11). IL-6, IL-8, CK-MB, and troponin T were measured in the coronary sinus blood immediately after the release of the aortic cross-clamp. Cytokine concentrations were also measured upon the patient's return to the ICU. The total dopamine and dobutamine doses, hemodynamic measurements after surgery, and the leukocyte filtration rate were also measured. During antegrade cardioplegia infusion, leukocytes were almost completely removed (filtration rate: 85.8+/-4.0%). However, during terminal warm cardioplegia, leukocyte removal decreased (filtration rate: 39.9+/-7.8%). Immediately after the release of the aortic cross-clamp, plasma CK-MB and troponin T concentrations were significantly lower in the LD group (17.7+/-1.9 U/l and 0.017+/-0.002 ng/ml, respectively) than in the control group (30.3+/-3.6 U/l and 0.072+/-0.029 ng/ml, respectively). The IL-6 and IL-8 concentrations were similar in the LD group and the control group. After the return to the ICU, the CK-MB and troponin T concentrations were similar in the two groups. No significant differences were found in the total doses of dopamine or dobutamine after surgery in the two groups (99+/-77 vs 101+/-128 microg/kg/min). No significant differences were found in the hemodynamic parameters after surgery in the two groups. In patients undergoing CABG with continuous blood cardioplegia, leukocyte-depleted blood cardioplegic solution may attenuate reperfusion injury.  (+info)

Does cardioplegia type affect outcome and survival in patients with advanced left ventricular dysfunction? Results from the CABG Patch Trial. (7/132)

BACKGROUND: There is controversy regarding which cardioplegic solution, temperature, and route of administration provides superior protection. The CABG Patch Trial enrolled a high-risk group of coronary artery disease patients with an ejection fraction of <36%. Thus, they constitute an ideal group to benefit most from optimal cardioplegic protection. METHODS AND RESULTS: All patients randomized into the trial were compared with respect to the use of blood and crystalloid cardioplegia. In addition, a questionnaire was sent to surgeons requesting blood cardioplegic temperature and route. Patients receiving crystalloid cardioplegia versus those receiving blood cardioplegia were found to have significantly more operative deaths (2% versus 0.3%, P:=0.02), postoperative myocardial infarctions (10% versus 2%, P:<0.001), shock (13% versus 7%, P:=0. 013), and postoperative conduction defects (21.6% versus 12.4%, P:=0. 001). Despite this, early death (6% crystalloid versus 4% blood cardioplegia) and late death (24% crystalloid versus 21% blood cardioplegia) statistics were not significantly different. Patients receiving normothermic blood had less postoperative right ventricular dysfunction (10%) than did patients receiving cold blood (25%) or cold blood with warm reperfusion (30%) (P:=0.004). There was no significant difference in early or late death. Finally, patients who received combined antegrade and retrograde cardioplegia had significantly less inotrope use (71% versus 84%, P:=0.002), right ventricular dysfunction (23% versus 41%, P:=0.001), and postoperative balloon pump use (12% versus 19%, P:=0.02) than did those who received antegrade cardioplegia. There was no difference in survival. CONCLUSIONS: Blood cardioplegia and combined antegrade and retrograde cardioplegia are superior to crystalloid and antegrade cardioplegia alone for postoperative morbidity. Despite this, there is no significant difference in early or late survival.  (+info)

Cardioplegic strategies for calcium control: low Ca(2+), high Mg(2+), citrate, or Na(+)/H(+) exchange inhibitor HOE-642. (8/132)

BACKGROUND: Ca(2+) overload plays an important role in the pathogenesis of cardioplegic ischemia-reperfusion injury. The standard technique to control Ca(2+) overload has been to reduce Ca(2+) in the cardioplegic solution (CP). Recent reports suggest that Na(+)/H(+) exchange inhibitors can also prevent Ca(2+) overload. We compared 4 crystalloid CPs that might minimize Ca(2+) overload in comparison with standard Mg(2+)-containing CP: (1) low Ca(2+) CP (0.25 mmol/L), (2) citrate CP/normal Mg(2+) (1 mmol/L Mg(2+)), (3) citrate CP/high Mg(2+) (9 mmol/L Mg(2+)), and (4) the addition of the Na(+)/H(+) exchange inhibitor HOE-642 (Cariporide). We also tested the effect of citrate titration in vitro on the level of free Ca(2+) and Mg(2+) in CPs. METHODS AND RESULTS: Isolated working rat heart preparations were perfused with oxygenated Krebs-Henseleit buffer and subjected to 60 minutes of 37 degrees C arrest and reperfusion with CPs with different Ca(2+) concentrations. Cardiac performance, including aortic flow (AF), was measured before and after ischemia. Myocardial high-energy phosphates were measured after reperfusion. The in vitro addition of citrate to CP (2%, 21 mmol/L) produced parallel reductions in Mg(2+) and Ca(2+). Because only Ca(2+) was required to be low, the further addition of Mg(2+) increased free Mg(2+), but the highest level achieved was 9 mmol/L. Citrate CP significantly impaired postischemic function (AF 58.3+/-2. 5% without citrate versus 41.6+/-3% for citrate with normal Mg(2+), P:<0.05, versus 22.4+/-6.2% for citrate with high Mg(2+), P:<0.05). Low-Ca(2+) CP (0.25 mmol/L Ca(2+)) significantly improved the recovery of postischemic function in comparison with standard CP (1.0 mmol/L Ca(2+)) (AF 47.6+/-1.7% versus 58.3+/-2.5%, P:<0.05). The addition of HOE-642 (1 micromol/L) to CP significantly improved postischemia function (47.6+/-1.7% without HOE-642 versus 62.4+/-1. 7% with HOE-642, P:<0.05). Postischemia cardiac high-energy phosphate levels were unaffected by Ca(2+) manipulation. CONCLUSIONS: (1) A lowered Ca(2+) concentration in CP is beneficial in Mg(2+)-containing cardioplegia. (2) The use of citrate to chelate Ca(2+) is detrimental in the crystalloid-perfused isolated working rat heart, especially with high Mg(2+). (3) The mechanism of citrate action is complex, and its use limits precise simultaneous control of Ca(2+) and Mg(2+). (4) HOE-642 in CP is as efficacious in preservation of the ischemic myocardium as is the direct reduction in Ca(2+).  (+info)

Cardioplegic solutions are specially formulated liquids used in medical procedures to induce cardiac arrest and protect the heart muscle during open-heart surgery. These solutions typically contain a combination of electrolytes, such as potassium and magnesium, which stop the heart from beating by interrupting its electrical activity. They may also include energy substrates, buffers, and other components to maintain the health and function of the heart cells during the period of arrest. The specific formulation of cardioplegic solutions can vary depending on the needs of the patient and the preferences of the medical team.

Induced heart arrest, also known as controlled cardiac arrest or planned cardiac arrest, is a deliberate medical intervention where cardiac activity is temporarily stopped through the use of medications or electrical disruption. This procedure is typically carried out during a surgical procedure, such as open-heart surgery, where the heart needs to be stilled to allow surgeons to work on it safely.

The most common method used to induce heart arrest is by administering a medication called potassium chloride, which stops the heart's electrical activity. Alternatively, an electrical shock may be delivered to the heart to achieve the same effect. Once the procedure is complete, the heart can be restarted using various resuscitation techniques, such as defibrillation or medication administration.

It's important to note that induced heart arrest is a carefully monitored and controlled medical procedure carried out by trained healthcare professionals in a hospital setting. It should not be confused with sudden cardiac arrest, which is an unexpected and often unpredictable event that occurs outside of a medical setting.

Myocardial reperfusion injury is a pathological process that occurs when blood flow is restored to the heart muscle (myocardium) after a period of ischemia or reduced oxygen supply, such as during a myocardial infarction (heart attack). The restoration of blood flow, although necessary to salvage the dying tissue, can itself cause further damage to the heart muscle. This paradoxical phenomenon is known as myocardial reperfusion injury.

The mechanisms behind myocardial reperfusion injury are complex and involve several processes, including:

1. Oxidative stress: The sudden influx of oxygen into the previously ischemic tissue leads to an overproduction of reactive oxygen species (ROS), which can damage cellular structures, such as proteins, lipids, and DNA.
2. Calcium overload: During reperfusion, there is an increase in calcium influx into the cardiomyocytes (heart muscle cells). This elevated intracellular calcium level can disrupt normal cellular functions, leading to further damage.
3. Inflammation: Reperfusion triggers an immune response, with the recruitment of inflammatory cells, such as neutrophils and monocytes, to the site of injury. These cells release cytokines and other mediators that can exacerbate tissue damage.
4. Mitochondrial dysfunction: The restoration of blood flow can cause mitochondria, the powerhouses of the cell, to malfunction, leading to the release of pro-apoptotic factors and contributing to cell death.
5. Vasoconstriction and microvascular obstruction: During reperfusion, there may be vasoconstriction of the small blood vessels (microvasculature) in the heart, which can further limit blood flow and contribute to tissue damage.

Myocardial reperfusion injury is a significant concern because it can negate some of the benefits of early reperfusion therapy, such as thrombolysis or primary percutaneous coronary intervention (PCI), used to treat acute myocardial infarction. Strategies to minimize myocardial reperfusion injury are an area of active research and include pharmacological interventions, ischemic preconditioning, and remote ischemic conditioning.

Cardiopulmonary bypass (CPB) is a medical procedure that temporarily takes over the functions of the heart and lungs during major heart surgery. It allows the surgeon to operate on a still, bloodless heart.

During CPB, the patient's blood is circulated outside the body with the help of a heart-lung machine. The machine pumps the blood through a oxygenator, where it is oxygenated and then returned to the body. This bypasses the heart and lungs, hence the name "cardiopulmonary bypass."

CPB involves several components, including a pump, oxygenator, heat exchanger, and tubing. The patient's blood is drained from the heart through cannulas (tubes) and passed through the oxygenator, where it is oxygenated and carbon dioxide is removed. The oxygenated blood is then warmed to body temperature in a heat exchanger before being pumped back into the body.

While on CPB, the patient's heart is stopped with the help of cardioplegia solution, which is infused directly into the coronary arteries. This helps to protect the heart muscle during surgery. The surgeon can then operate on a still and bloodless heart, allowing for more precise surgical repair.

After the surgery is complete, the patient is gradually weaned off CPB, and the heart is restarted with the help of electrical stimulation or medication. The patient's condition is closely monitored during this time to ensure that their heart and lungs are functioning properly.

While CPB has revolutionized heart surgery and allowed for more complex procedures to be performed, it is not without risks. These include bleeding, infection, stroke, kidney damage, and inflammation. However, with advances in technology and technique, the risks associated with CPB have been significantly reduced over time.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

Potassium chloride is an essential electrolyte that is often used in medical settings as a medication. It's a white, crystalline salt that is highly soluble in water and has a salty taste. In the body, potassium chloride plays a crucial role in maintaining fluid and electrolyte balance, nerve function, and muscle contraction.

Medically, potassium chloride is commonly used to treat or prevent low potassium levels (hypokalemia) in the blood. Hypokalemia can occur due to various reasons such as certain medications, kidney diseases, vomiting, diarrhea, or excessive sweating. Potassium chloride is available in various forms, including tablets, capsules, and liquids, and it's usually taken by mouth.

It's important to note that potassium chloride should be used with caution and under the supervision of a healthcare provider, as high levels of potassium (hyperkalemia) can be harmful and even life-threatening. Hyperkalemia can cause symptoms such as muscle weakness, irregular heartbeat, and cardiac arrest.

Coronary artery bypass surgery, also known as coronary artery bypass grafting (CABG), is a surgical procedure used to improve blood flow to the heart in patients with severe coronary artery disease. This condition occurs when the coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of fatty deposits, called plaques.

During CABG surgery, a healthy blood vessel from another part of the body is grafted, or attached, to the coronary artery, creating a new pathway for oxygen-rich blood to flow around the blocked or narrowed portion of the artery and reach the heart muscle. This bypass helps to restore normal blood flow and reduce the risk of angina (chest pain), shortness of breath, and other symptoms associated with coronary artery disease.

There are different types of CABG surgery, including traditional on-pump CABG, off-pump CABG, and minimally invasive CABG. The choice of procedure depends on various factors, such as the patient's overall health, the number and location of blocked arteries, and the presence of other medical conditions.

It is important to note that while CABG surgery can significantly improve symptoms and quality of life in patients with severe coronary artery disease, it does not cure the underlying condition. Lifestyle modifications, such as regular exercise, a healthy diet, smoking cessation, and medication therapy, are essential for long-term management and prevention of further progression of the disease.

In medical terms, the heart is a muscular organ located in the thoracic cavity that functions as a pump to circulate blood throughout the body. It's responsible for delivering oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. The human heart is divided into four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it out to the rest of the body. The heart's rhythmic contractions and relaxations are regulated by a complex electrical conduction system.

In the context of medical terminology, "solutions" refers to a homogeneous mixture of two or more substances, in which one substance (the solute) is uniformly distributed within another substance (the solvent). The solvent is typically the greater component of the solution and is capable of dissolving the solute.

Solutions can be classified based on the physical state of the solvent and solute. For instance, a solution in which both the solvent and solute are liquids is called a liquid solution or simply a solution. A solid solution is one where the solvent is a solid and the solute is either a gas, liquid, or solid. Similarly, a gas solution refers to a mixture where the solvent is a gas and the solute can be a gas, liquid, or solid.

In medical applications, solutions are often used as vehicles for administering medications, such as intravenous (IV) fluids, oral rehydration solutions, eye drops, and topical creams or ointments. The composition of these solutions is carefully controlled to ensure the appropriate concentration and delivery of the active ingredients.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

A tourniquet is a device or material used to apply pressure around an extremity, typically an arm or leg, with the goal of controlling severe bleeding (hemorrhage) by compressing blood vessels and limiting arterial flow. Tourniquets are usually applied as a last resort when direct pressure and elevation have failed to stop life-threatening bleeding. They should be used cautiously because they can cause tissue damage, nerve injury, or even amputation if left on for too long. In a medical setting, tourniquets are often applied by healthcare professionals in emergency situations; however, there are also specialized tourniquets available for use by trained individuals in the military, first responder communities, and civilians who have undergone proper training.

Potassium is a essential mineral and an important electrolyte that is widely distributed in the human body. The majority of potassium in the body (approximately 98%) is found within cells, with the remaining 2% present in blood serum and other bodily fluids. Potassium plays a crucial role in various physiological processes, including:

1. Regulation of fluid balance and maintenance of normal blood pressure through its effects on vascular tone and sodium excretion.
2. Facilitation of nerve impulse transmission and muscle contraction by participating in the generation and propagation of action potentials.
3. Protein synthesis, enzyme activation, and glycogen metabolism.
4. Regulation of acid-base balance through its role in buffering systems.

The normal serum potassium concentration ranges from 3.5 to 5.0 mEq/L (milliequivalents per liter) or mmol/L (millimoles per liter). Potassium levels outside this range can have significant clinical consequences, with both hypokalemia (low potassium levels) and hyperkalemia (high potassium levels) potentially leading to serious complications such as cardiac arrhythmias, muscle weakness, and respiratory failure.

Potassium is primarily obtained through the diet, with rich sources including fruits (e.g., bananas, oranges, and apricots), vegetables (e.g., leafy greens, potatoes, and tomatoes), legumes, nuts, dairy products, and meat. In cases of deficiency or increased needs, potassium supplements may be recommended under the guidance of a healthcare professional.

Myocardial contraction refers to the rhythmic and forceful shortening of heart muscle cells (myocytes) in the myocardium, which is the muscular wall of the heart. This process is initiated by electrical signals generated by the sinoatrial node, causing a wave of depolarization that spreads throughout the heart.

During myocardial contraction, calcium ions flow into the myocytes, triggering the interaction between actin and myosin filaments, which are the contractile proteins in the muscle cells. This interaction causes the myofilaments to slide past each other, resulting in the shortening of the sarcomeres (the functional units of muscle contraction) and ultimately leading to the contraction of the heart muscle.

Myocardial contraction is essential for pumping blood throughout the body and maintaining adequate circulation to vital organs. Any impairment in myocardial contractility can lead to various cardiac disorders, such as heart failure, cardiomyopathy, and arrhythmias.

Whilst there are several cardioplegic solutions commercially available; there are no clear advantages of one cardioplegic ... Cardioplegic solution is the means by which the ischemic myocardium is protected from cell death. This is achieved by reducing ... Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of ... When solution is introduced into the aortic root (with an aortic cross-clamp on the distal aorta to limit systemic circulation ...
With the addition of extra potassium salt, it can be used to prepare a cardioplegic solution. Tyrode's solution was invented by ... The solution was a modification of Ringer-Locke's solution. Tyrode's solution is often used for irrigation of the peritoneum. ... Tyrode's solution is a solution that is roughly isotonic with interstitial fluid and used in physiological experiments and ... Lactated Ringer's solution Tyrode's solution (www.whonamedit.com) Llewellys F. Barker, "The Obesities -- Their Origins and Some ...
... and a new cardioplegic solution. He continued developing new simplified techniques to rapidly and safely distribute ... They discussed Buckberg's journey as a researcher dedicated to finding solutions to heart disease and its complications - ... solutions which, once adopted by the healthcare field, could transform heart treatments and improve outcomes for people ... Additional studies conducted by his team showed that employing blood cardioplegic techniques in surgical treatment of patients ...
A clamp is placed on the aorta between the cardioplegic catheter and aortic cannula, so that the flow of cardioplegic solution ... They then insert the graft within the pericardium, sometimes attached to the cardioplegic catheter. The anastomosis of the LIMA ... and a catheter which temporarily arrests the heart using a solution high in potassium. Another purse string is placed in the ...
... pharmaceutical solutions MeSH D27.720.280.775.322 - cardioplegic solutions MeSH D27.720.280.775.483 - dialysis solutions MeSH ... cardioplegic solutions MeSH D27.505.954.411.222 - cardiotonic agents MeSH D27.505.954.411.320 - fibrinolytic agents MeSH ... ophthalmic solutions MeSH D27.720.280.775.822 - sclerosing solutions MeSH D27.720.280.779 - powders MeSH D27.720.280.785 - ... contact lens solutions MeSH D27.505.954.122.425.300 - dental disinfectants MeSH D27.505.954.158 - anti-inflammatory agents MeSH ...
A cardioplegic solution is used to stop the heart from beating and combination with hypothermia reduces oxygen demand of the ... asystole is desired and induced during cardiopulmonary bypass through a cardioplegia solution containing very high amounts of ...
... known as cardioplegic cardiac arrest. Del Nido developed the solution while working at the University of Pittsburgh in the ... Del Nido is the eponym of the del Nido cardioplegia, a solution infused during open-heart surgery to temporarily stop the heart ... It consists of a base solution of Plasma-lyte A, which has an electrolyte composition similar to that of extracellular fluid. ... The sodium bicarbonate component of cardioplegia, in addition to its role in this reaction, as a buffering solution to assist ...
... pharmaceutical solutions MeSH D26.776.708.160 - cardioplegic solutions MeSH D26.776.708.322 - dialysis solutions MeSH D26.776. ... contact lens solutions MeSH D26.776.314 - hypertonic solutions MeSH D26.776.314.420 - glucose solution, hypertonic MeSH D26.776 ... saline solution, hypertonic MeSH D26.776.399 - hypotonic solutions MeSH D26.776.498 - isotonic solutions MeSH D26.776.675 - ... ophthalmic solutions MeSH D26.776.708.822 - sclerosing solutions MeSH D26.776.741 - rehydration solutions MeSH D26.878.250 - ...
Cardioplegic drugs may be administered to ensure the heart stops beating completely (asystole), which is protective of both the ... Safar and Bellamy proposed flushing cold solution through blood vessels of patients with deadly bleeding, and leaving them in a ... Glucose is eliminated from all intravenous solutions to reduce the risk of hyperglycemia. In order for accurate hemodynamic ...
Cardioplegic Induction Solution Fresenius Please note that due to the South African MEDICINES AND RELATED SUBSTANCES CONTROL ...
Cardioprotection during cardiac surgery: impact of temperature of cardioplegic solution on microRNA profile in a pig model of ...
Whilst there are several cardioplegic solutions commercially available; there are no clear advantages of one cardioplegic ... Cardioplegic solution is the means by which the ischemic myocardium is protected from cell death. This is achieved by reducing ... Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of ... When solution is introduced into the aortic root (with an aortic cross-clamp on the distal aorta to limit systemic circulation ...
Myocardial protection was performed by moderated hypothermia and cold cardioplegic solution.. Closing annular abscess: in fact ...
1986) Magnesium in cardioplegic solutions as assessed by 31P NMR spectroscopy. Magnesium-Bulletin Academic article ... 1986) Magnesium in cardioplegic solutions as assessed by 31P NMR spectroscopy. Magnesium-Bulletin Academic article ...
... part crystalloid solution. The addition of blood to the cardioplegic solution enhances oxygen delivery, especially at the ... and the addition of verapamil and nicardipine to a standard potassium cardioplegic solution may improve postischemic cardiac ... Blood cardioplegia solution is typically a mixture of four (4) parts of oxygenated blood and one (1) ... Given the relatively low circulating blood volume of newborns and infants compared with that of adults, the priming solution in ...
The aorta was occluded using an arterial clamp, and cardioplegic solution was immediately and rapidly infused into the coronary ... The cardioplegic solution was administered at 10 mL/kg every 20 minutes. ... A 5-Fr catheter inserted into the aortic root through a preplaced purse-string suture was used to administer cardioplegic ... To place a catheter for cardioplegic infusion, the aortic root was elevated, and a 6-0 polyvinylidene fluoride suture purse- ...
Thomas Hospital cardioplegic solution (Plegisol). Results of a clinical study. Eur J Cardiothorac.Surg 1991;5:74-81. View ... Biochemical and functional effects of creatine phosphate in cardioplegic solution during aortic valve surgery--a clinical study ... Evaluation of the stability of creatine in solution prepared from effervescent creatine formulations. AAPS PharmSciTech 2003;4: ...
Hyperkalemia typically occurs from the use of cardioplegic solutions but usually resolves on its own. Because hyperkalemia does ...
Myocardial protection in pediatric cardiac surgery - deep look to the most often used cardioplegic solutions. https://doi.org/ ...
The cardioplegic solution and the heart are sometimes cooled slightly to enhance tolerance of ischemia; the patients body is ... Then the aorta is cross-clamped and the heart is stopped by injection of a cardioplegic solution (crystalloid or more commonly ...
... without high potassium and as cardioplegic additive to high potassium solutions. Adenosine cardioplegia and potassium ... The preservation solution and the portable preservation unit that emerged from this experimental study were thoroughly ... Six positive aspects of cardiac preservation have emerged from this study: - (1) A clear fluid hyperosmolar solution was ... of even high concentrations of adenosine to limit ventricular fibrillation in the baboon exclude its use as cardioplegic agent ...
Myocardial Effects of Captopril and Lisinopril Addition to the Prime Solution and Cardioplegic Solution on Rat Heart under in ...
This is an advantage over other cardioplegic solutions that may have to be re administered every 20-30 minutes. ... Custodiol solution is administered in a single-dose, allowing the operation to be done continuously. ...
The patients received 1.6 L cardioplegic Bretschneider solution on average. Blood gas and urine samples obtained were analyzed ... Histidine and other amino acids in blood and urine after administration of Bretschneider solution (HTK) for cardioplegic arrest ... Bretschneider (histidine-tryptophan-ketoglutarate, HTK) solution employed for induction of cardioplegic arrest possesses a high ...
Cardioplegic Solutions. *Cardiopulmonary Bypass. *Cardiovascular Diseases. *Carrier State. *Case-Control Studies. *Caspases ...
... placing the heart in a cardioplegic solution, which consisted in the sterile medium of a potassium chloride solution (in mM): ... Dynamic light scattering (DLS) was used to quantify the PSD of the nanoparticles (NPs) in aqueous solutions. Their PSD was ... Electrophoretic light scattering (ELS) was used to determine the zeta potential of the NPs dispersed in aqueous solutions ... The time between cutting the diaphragm and placing the heart in the solution took less than 60 s in order to avoid ischemia. ...
It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (Reynolds JEF(Ed): ... It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (Reynolds JEF(Ed): ...
It is usually achieved with the use of chemicals (CARDIOPLEGIC SOLUTIONS) or cold temperature (such as chilled perfusate).. ... Isotonic Solutions. Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared ... Solutions in water or alcohol have a deep blue color. Methylene blue is used as a bacteriologic stain and as an indicator. It ... Any liquid used to replace blood plasma, usually a saline solution, often with serum albumins, dextrans or other preparations. ...
Cardioplegic Solutions * Cardiotonic Agents * Central Nervous System Depressants * Central Nervous System Stimulants ...
... the effectiveness of myocardial protection in infants under the age of one year using new intracellular cardioplegic solution ... He made a great contribution to the solution of the problem of coronary heart disease surgical treatment. ...
... the effectiveness of myocardial protection in infants under the age of one year using new intracellular cardioplegic solution ... He made a great contribution to the solution of the problem of coronary heart disease surgical treatment. ...
... the effectiveness of myocardial protection in infants under the age of one year using new intracellular cardioplegic solution ... He made a great contribution to the solution of the problem of coronary heart disease surgical treatment. ...
... oxygenated cardioplegic solution containing erythrocytes, nutrition and hormones 63,83; the perfusion was intermittently ... Taking extended risks in donor selection is one alternative solution 2, donations after circulatory death (DCD) are another 3-5 ... Since there exist no drugs or vaccines, "early weaning" is the only solution at the present time, as it prevents the nasal ... An emerging and promising solution is xenotransplantation of genetically multi-modified (GM) pig hearts. Recent studies have ...
... which were stored in cardioplegic solution (subgroup 1c).. Results. The use of cold cardioplegic solution makes it possible to ... The obtained samples immediately after harvesting from the patient were randomly placed into a sterile cardioplegic solution ... Depending on the solution in which the samples were stored, the veins of the first group were subdivided into 2 subgroups: 40 ... To analyze and evaluate the effect of solutions for storage and storage times on the morphological characteristics of the human ...
It can also make amino acid solutions, paracetamol infusion solutions, iopamidol and contrast media for radiology, cardioplegic ... anticoagulant solutions, organ preservation solutions, anesthetics, analgesics, markers, and a variety of other medications, ... veterinary solutions, life-saving medicinal items like adrenaline and noradrenaline, and dialysis solutions. ... Depending on the pharmacy, a 375-milliliter supply of Potassium Phosphate intravenous solution (3 mmol/mL (with potassium 4.4 ...
... the effectiveness of myocardial protection in infants under the age of one year using new intracellular cardioplegic solution ... He made a great contribution to the solution of the problem of coronary heart disease surgical treatment. ...
C14.280.484.150.70.160.500 Cardioplegic Solutions D27.720.280.775.322 D27.720.752.322 Career Mobility I1.880.840.200 I1.880. ... Z1.542.816.124 Dialysis Solutions D27.720.280.775.483 D27.720.752.483 Diet Surveys E5.318.308.585.550.350 E5.318.308.667.350 ... Sclerosing Solutions D27.720.280.775.822 D27.720.752.822 Secondary Prevention E2.897 Secularism I1.880.448 I1.880.853.350 ... I1.880.853.150.500.280 Ophthalmic Solutions D26.255.775.645 D27.720.752.608 D27.720.280.775.645 Optic Chiasm A8.186.211.730. ...
  • Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of cardiac cells. (wikipedia.org)
  • This study was designed to investigate the role of adenosine, an endogenous cardioprotectant agent, without high potassium and as cardioplegic additive to high potassium solutions. (uct.ac.za)
  • In view of the limited cardioprotection achieved with the combination of adenosine and high potassium further studies should aim for additional interventions to induce cardioplegia with adenosine and normokalemic solutions. (uct.ac.za)
  • c) intracellular sodium and water contents were dissociated from myocardial viability and recovery from cold ischemia in potassium and magnesium cardioplegic solutions. (tau.ac.il)
  • A study of the effectiveness of myocardial protection in infants under the age of one year using new intracellular cardioplegic solution 'Bockeria - Boldyreva', created in the SCCVS under Bockeria's guidance, is continued. (cvsnews-journal.com)
  • The main goals of hypothermic cardioplegia are: Immediate and sustained electromechanical quiescence Rapid and sustained homogeneous myocardial cooling Maintenance of therapeutic additives in effective concentrations Periodic washout of metabolic inhibitors The most common procedure for accomplishing asystole is infusing cold cardioplegic solution into the coronary circulation. (wikipedia.org)
  • The aorta was occluded using an arterial clamp, and cardioplegic solution was immediately and rapidly infused into the coronary artery to produce diastolic cardio-arrest. (vin.com)
  • He made a great contribution to the solution of the problem of coronary heart disease surgical treatment. (cvsnews-journal.com)
  • Then the aorta is cross-clamped and the heart is stopped by injection of a cardioplegic solution (crystalloid or more commonly blood-based) that also contains substances that help myocardial cells tolerate ischemia and reperfusion. (msdmanuals.com)
  • Cellular parameters were measured by multinuclear NMR spectroscopy in isolated rat hearts during 12 h of ischemia at 4°C and 2 h of normothermic reperfusion with an isoosmotic Krebs-Henseleit (KH) solution. (tau.ac.il)
  • Cardioplegia is a solution given to the heart during cardiac surgery, to minimize the damage caused by myocardial ischemia while the heart is paused. (wikipedia.org)
  • It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (nih.gov)
  • Most commonly, however, the word cardioplegia refers to the solution used to bring about asystole of the heart, or heart paralysis. (wikipedia.org)
  • As the cardioplegia solution distributes to the entire myocardium, the ECG will change and eventually asystole will ensue. (wikipedia.org)
  • To place a catheter for cardioplegic infusion, the aortic root was elevated, and a 6-0 polyvinylidene fluoride suture purse-string suture placed. (vin.com)
  • It can also make amino acid solutions, paracetamol infusion solutions, iopamidol and contrast media for radiology, cardioplegic solutions in bags, antibiotics in bags, veterinary solutions, life-saving medicinal items like adrenaline and noradrenaline, and dialysis solutions. (pipelinepharma.com)
  • They manufacture a variety of generic pharmaceuticals, infusion therapy, and parenteral nutrition solutions, and medical devices that are crucial in the treatment of critically ill patients and those suffering from chronic illnesses. (pipelinepharma.com)
  • The CPB circuit was filled with 20% D-mannitol (5 mL/kg), 7% sodium bicarbonate (2 mL/kg), heparin sodium (500 U), and acetate Ringer's solution. (vin.com)
  • Given the relatively low circulating blood volume of newborns and infants compared with that of adults, the priming solution in the CPB circuit plays an important role in hemodilution. (medscape.com)
  • Then the aorta is cross-clamped and the heart is stopped by injection of a cardioplegic solution (crystalloid or more commonly blood-based) that also contains substances that help myocardial cells tolerate ischemia and reperfusion. (msdmanuals.com)
  • 1] Rohinson LA , Harwood DL , Dmaha N. Lowering the calcium concentration in St. Thomas Hospital Cardioplegic Solution improves protection during hypothermic ischemia [J]. J Thorac Cardiovasc Surg , 1991, 101: 314- 315. (xml-journal.net)
  • Calcium and cardioplegic protection of the ischemic immature heart [J]. Ann Thorac Surg , 1994, 11 (2) :108- 109. (xml-journal.net)
  • CONCLUSIONS: With our findings, we believe that CC and BC solutions do not have a significant difference in terms of myocardial protection during bypass operations. (bvsalud.org)
  • In group 2, nisoldipine was added to the cardioplegic solution at a concentration of 0.1 mg/kg in 7 hearts. (umn.edu)
  • The temperature was gradually reduced to 27-30°C, and the heart was arrested by a cardioplegic solution (K+30mmol.1-' at 4°C) after aortic cross clamping. (docksci.com)
  • Group 1 consisted of 6 hearts, which received St. Thomas II cardioplegic solution. (umn.edu)
  • Methods: The explanted hearts were suspended from Langendorff apparatus and were perfused with Krebs-Henseleit solution. (umn.edu)
  • bed into the left ventricle, from where or intramyocardial, However, when a Most patients with calcification of it could reach any part of the body cyst is located in subendocardial en- the cyst wall remain asymptomatic for through systemic circulation [1-3]. (who.int)