Sinus myocardium conduction. Medical search. Frequent questions

Many class III antidysrhythmic agents have been shown to be effective in maintaining sinus rhythm after conversion from atrial tachycardia. (medscape.com)
60) is a narrow complex rhythm that often supersedes a clinically bradycardic sinus node rate (see images below). (medscape.com)
Accelerated junctional rhythm is a result of enhanced automaticity of the AVN that supersedes the sinus node rate. (medscape.com)
During this rhythm, the AVN is firing faster than the sinus node, resulting in a regular narrow complex rhythm. (medscape.com)
Changes in autonomic tone or the presence of sinus node disease that is causing an inappropriate slowing of the sinus node may exacerbate this rhythm. (medscape.com)
Nowadays, flecainide is recommended as one of the first line therapies for pharmacological conversion as well as maintenance of sinus rhythm in patients with atrial fibrillation and/or supraventricular tachycardias. (wjgnet.com)
Diltiazem converts paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm by interrupting the reentry circuit in AV nodal reentrant tachycardias and reciprocating tachycardias, e.g. (nih.gov)
By comparing the two ECGs, it can be seen that the first ECG showed a sinus tachycardia with an IVCD that was also present at baseline during normal sinus rhythm. (manualofmedicine.com)
During normal sinus rhythm, the canine SAN is functionally insulated from the surrounding atrial myocardium except for 2 (or more) narrow superior and inferior sinoatrial exit pathways separated by 12.8±4.1 mm. (wustl.edu)
A critical transmural activation delay determined during sinus rhythm (SR) may identify VT substrates in RVCM. (bvsalud.org)
A total of 445 electrograms were recorded in sinus rhythm (range: 30-186) using the MR-EP system including 138 electrograms from LGE regions. (kcl.ac.uk)
hence the electrical activity is called as sinus rhythm and its propagation is called as conduction. (parkhospital.in)
In a sinus rhythm normal the heart beats 60-100 times a minute. (parkhospital.in)
ECG showed normal sinus rhythm. (neurology.org)
The normal sequence of electrical activation of the chambers of the heart is called sinus rhythm. (health.am)
Sinus rhythm is a term used in medicine to describe the normal beating of the heart, as measured by an electrocardiogram ( ECG ). (wikidoc.org)
There are typically five distinct waves (identified by the letters P, Q, R, S, and T) in a single beat of the heart in sinus rhythm, and they occur in a specific order, over specific periods of time, with specific relative sizes. (wikidoc.org)
While there is a significant range within which variations in rhythm are considered normal, anything that deviates from sinus rhythm by more than a certain amount may be indicative of heart disease . (wikidoc.org)
Sinus rhythm is characterized by a usual rate of anywhere between 60-100 bpm. (wikidoc.org)
In normal sinus rhythm, electrical impulses from the SA node travel to the AV node with successful contraction of the two atria . (wikidoc.org)
In Normal Sinus Rhythm the pacemaker impulse is formed in the SA node which is located near the junction of the superior vena cava and right atrium. (wikidoc.org)
The sinus rhythm and persAF conditions are implemented using the Courtemanche formalism. (udem.edu.co)

The AV node (AVN) has intrinsic automaticity that allows it to initiate and depolarize the myocardium during periods of significant sinus bradycardia or complete heart block. (medscape.com)
Junctional bradycardia due to profound sinus node dysfunction. (medscape.com)
Junctional rhythms are common in patients with sick sinus syndrome or in patients who have significant bradycardia that allows the AV nodal region to determine the heart rate. (medscape.com)
Electrophysiological measurements in Popdc1 null mutants revealed a stressinduced and age-dependent sinus bradycardia, which was due to an increase in sinus pauses and independent of the nature of stress. (uni-wuerzburg.de)
The combination of atrial tachyarrhythmias and atrioventricular nodal conduction disturbances defines tachycardia-bradycardia syndrome. (biomedcentral.com)
Electrocardiogram of a 23-year-old patient in Israel with Q fever, showing a left bundle branch block with sinus bradycardia of 35 bpm. (cdc.gov)
Mutations in the human cardiac sodium channel ( SCN5A ) cause one type of long-QT syndrome (LQT3), and these individuals may also have sinus pauses and sinus bradycardia in addition to the characteristic prolongation of the QT interval. (medilib.ir)

The predilection of cardiac sarcoid involvement of the interventricular septum causes atrioventricular (AV) conduction system blocks in many patients with cardiac sarcoidosis. (merckmanuals.com)
Atrioventricular (AV) block is the disturbance in conduction of atrial impulse through the AV conducting system, i.e., the AV node, the bundle of His or His-Purkinje system. (yourarticlelibrary.com)
The atrioventricular node delays impulses for ~0.1 second before allowing impulses through to the His-Purkinje conduction system, which spreads impulses to the ventricular walls. (wikidoc.org)

Cardiac tissue is characterized by structural and cellular heterogeneities that play an important role in the cardiac conduction system. (udem.edu.co)

The therapeutic benefits of diltiazem in supraventricular tachycardias are related to its ability to slow AV nodal conduction time and prolong AV nodal refractoriness. (nih.gov)
A Holter electrocardiogram (ECG) performed 3 weeks before her admission revealed the presence of salvos of supraventricular extrasystoles and multiple supraventricular tachycardia episodes without any conduction disorder (Fig. 3 ). (biomedcentral.com)
By applying a set of basic questions it is possible to distinguish sinus rhythms from ectopic rhythms, supraventricular rhythms from ventricular rhythms / abnormal conduction, etc. (vin.com)

The sinus node is an accumulation of specialized myocardial cells located in the wall of the right atrium. (ecgbuddy.com)
In a limited number of studies of patients with compromised myocardium (severe congestive heart failure, acute myocardial infarction, hypertrophic cardiomyopathy), administration of intravenous diltiazem produced no significant effect on contractility, left ventricular end diastolic pressure, or pulmonary capillary wedge pressure. (nih.gov)
It lowers the automatism of the sinus node, reduces heart rate, slows AV conduction, reduces contractility and myocardial excitability, reduces cardiac output, reduces the need for oxygen in the myocardium. (bestpharmbuy.com)
The myocardial conducting cells (1 percent of the cells) form the conduction system of the heart. (lumenlearning.com)
Myocardial conduction cells initiate and propagate the action potential (the electrical impulse) that travels throughout the heart and triggers the contractions that propel the blood. (lumenlearning.com)

Sinus tachycardia is always physiologic, the result of sympathetic activation or elevated catecholamines. (manualofmedicine.com)
It is likely that the sinus tachycardia is the result of the episode of delirium, which is generally associated with sympathetic activation. (manualofmedicine.com)
Mild sinus slowing may be observed initially fol-lowed by sinus tachycardia. (brainkart.com)

This is the property of the AV node that prevents rapid conduction to the ventricle in cases of rapid atrial rhythms, such as atrial fibrillation or atrial flutter . (wikidoc.org)

Therefore, the QRS complex manifests a nonspecific intraventricular conduction delay (IVCD) , which is the result of diffuse impulse slowing through the normal His-Purkinje system. (manualofmedicine.com)
hence this is an intraventricular conduction delay (IVCD). (manualofmedicine.com)
Resynchronization of the intraventricular conduction can be achieved by introducing an additional lead through the coronary venous sinus to stimulate the left ventricle (biventricular pacing, BVP). (biomedcentral.com)

The bundle of His and Purkinje fibres are specialised cardiomyocytes that function in the conduction system. (wikipedia.org)
The Purkinje fibers which transport the information into the ventricular myocardium. (ecgbuddy.com)
As explained already, the electrical excitement spreads from cell to cell, starting from the sinus node and then traveling to the right and left atria and the AV node, and then into the right and left ventricle via the high-speed electric tracts of the Tawara branches and the Purkinje fibers. (ecgbuddy.com)
As the QRS complex has an IVCD, the activation of the ventricle uses the normal His-Purkinje system with slowed conduction. (manualofmedicine.com)
This means that spread of conduction has not taken place via the bundle branches and Purkinje system, but instead by passive cell-to-cell conduction, which is much slower. (vin.com)

citation needed] The function of the right heart, is to collect de-oxygenated blood, in the right atrium, from the body via the superior vena cava, inferior vena cava and from the coronary sinus and pump it, through the tricuspid valve, via the right ventricle, through the semilunar pulmonary valve and into the pulmonary artery in the pulmonary circulation where carbon dioxide can be exchanged for oxygen in the lungs. (wikipedia.org)
This escape mechanism, with a rate of 40-60 beats per minute, produces a narrow QRS complex because the ventricle is depolarized using the normal conduction pathway. (medscape.com)
Class IB antiarrhythmic agent that increases electrical stimulation threshold of the ventricle, suppressing automaticity of conduction through the tissue. (medscape.com)
2. There are many anatomic considerations suggesting the morphologically left ventricle (LV) may well be a better systemic pump than the morphologically right ventricle (RV) which, if true, would favor the arterial switch procedure as opposed to an atrial switch operation: (1) The LV consists almost entirely of the sinus or pumping portion, and has only a minimal distal infundibular (conal) component. (nih.gov)
In contrast, with a left bundle branch block, the activation of the left ventricle is not along the normal conduction system, but occurs via an abnormal pathway directly utilizing the ventricular myocardium. (manualofmedicine.com)
The dilatation of the left ventricle frequently induces intracardiac conduction delays resulting in asynchronous left ventricular motion. (biomedcentral.com)
The right ventricle receives blood from the right atrium across the tricuspid valve, which is located in the large anterolateral (ie, sinus) portion of the right ventricle. (medscape.com)
The inflow tract (sinus) and outflow tract (infundibulum) of the right ventricle are widely separated. (medscape.com)
Ventricular septal defects (VSDs) commonly occur in the area between the sinus and the outlet tract of the right ventricle. (medscape.com)
Coronary sinus, normally located between the LEFT ATRIUM and LEFT VENTRICLE on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures. (bvsalud.org)

G. There is a slow conduction pathway as well as a fast one. (rjmatthewsmd.com)
Sites of low voltage and slow conduction identified using the system were registered and compared to regions of late gadolinium enhancement (LGE) on MRI. (kcl.ac.uk)

The pacemaker cells make up just (1% of cells) and form the conduction system of the heart. (wikipedia.org)
The expression of Popdc1-LacZ transgene as well as Popdc1 protein was elevated in the ventricular conduction system compared to the ventricular working myocardium. (uni-wuerzburg.de)
7) The LV has two conduction system radiations, whereas the RV has only one. (nih.gov)
Since the activation is along the normal conduction system, abnormalities of the left ventricular myocardium can be identified. (manualofmedicine.com)
Pacemaker cells (e.g., sinus node) of the conduction system of the heart autonomously and spontaneously generate an action potential (AP). (thecore9.com)
The conduction system transmits the AP throughout the myocardium. (thecore9.com)
We evaluated a novel real-time MR-EP system to perform endocardial voltage mapping and assessment of delayed conduction in a porcine ischaemia-reperfusion model. (kcl.ac.uk)
Low-voltage zones and regions of delayed conduction determined using a real-time MR-EP system are moderately associated with LGE areas identified on MRI. (kcl.ac.uk)
In cardiac sarcoidosis, the conducting system and/or myocardium are typically involved in patients with clinically apparent cardiac sarcoidosis, but valvular, papillary muscle, and pericardial involvement may also occur. (merckmanuals.com)
Heart valves are controlled by pressure changes within each chamber and contraction and relaxation are controlled by the heart's conduction system. (health.am)
There is a delay in conduction of every impulse through the AV conducting system (Fig. 6.2a). (yourarticlelibrary.com)
The conduction of impulse through the AV conducting system becomes increasingly difficult and ultimately an impulse fails to conduct to the ventricles. (yourarticlelibrary.com)
After this, the AV conduction system recovers and the sequence is repeated in a cyclic manner (Fig. 6.3). (yourarticlelibrary.com)
There is regular or irregular interruption of conduction through AV conducting system (Fig. 6.4a). (yourarticlelibrary.com)
It is characterized by complete and permanent failure of conduction through AV conducting system (Fig. 6.5a). (yourarticlelibrary.com)
Cardiac amyloidosis may affect the way electrical signals move through the heart (conduction system). (medlineplus.gov)
Conduction system pacing in pediatric and congenital heart disease. (stanfordchildrens.org)
Conduction system pacing (CSP) has evolved rapidly to become the pacing method of choice for many adults with structurally normal hearts. (stanfordchildrens.org)
Studies in this population have repeatedly demonstrated superior hemodynamics and outcomes compared to conventional pacing with the recruitment of the native conduction system. (stanfordchildrens.org)

In this article we will discuss about the Disturbances in Conduction of Impulse. (yourarticlelibrary.com)

When there is a disturbance in the normal conduction through the fast pathway, the slow pathway may be activated to conduct the excitation wave to the bundle of His, as well as retrograde back to the fast one, and then back again down the slow pathway continuously to produce the PSVT (see Figure 1). (rjmatthewsmd.com)
Thus, the site of origin of excitation and conduction pathway(s) within the SAN of these mammals remains unknown. (wustl.edu)

Cardiac excitation starts in the sinus node. (ecgbuddy.com)
During ventricular excitation, the atrium is already re-polarized and is thus ready to receive the next wave of excitation from the sinus node. (ecgbuddy.com)
After a 49±22 ms conduction delay within the SAN, excitation reached the atrial myocardium via superior and/or inferior sinoatrial exit pathways 8.8±3.2 mm from the leading pacemaker site. (wustl.edu)

It has no effect on the sinus node recovery time or on the sinoatrial conduction time in patients without SA nodal dysfunction. (nih.gov)
Sick sinus syndrome (SSS) is a sinoatrial dysfunction mostly related to sinoatrial node and surrounding atrial myocardium senescence. (biomedcentral.com)
Involvement of the sinus node artery may produce the bradyarrhythmias of sinus nodal dysfunction. (merckmanuals.com)
Sinus node dysfunction (SND), also historically referred to as sick sinus syndrome, is the term used to describe the inability of the SA node to generate a heart rate that meets the physiologic needs of an individual. (medilib.ir)
See "Sinus node dysfunction: Clinical manifestations, diagnosis, and evaluation" and "Sinus node dysfunction: Treatment" . (medilib.ir)

The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium . (daviddarling.info)
The heart wall consists of the epicardium (inner layer), the myocardium (middle layer comprised of cardiac muscle tissue), and the endocardium (lining of the myocardium that covers the heart valves). (health.am)

Less commonly, the AV junction develops abnormal automaticity and exceeds the sinus node rate at a time when the sinus rate would be normal (see image below). (medscape.com)
Rarely, the AVN develops enhanced automaticity and overtakes a "normal" sinus node. (medscape.com)

The coronary sinus drains coronary venous blood into the anteroinferior portion of the right atrium. (medscape.com)
The coronary sinus drains blood from the coronary arteries into the right atrium. (health.am)
HN - 2008 BX - Granulosa Cells, Cumulus MH - Coronary Sinus UI - D054326 MN - A07.231.908.194.500 MS - A short vein that collects about two thirds of the venous blood from the MYOCARDIUM and drains into the RIGHT ATRIUM. (bvsalud.org)

HN - 2008 MH - Superior Sagittal Sinus UI - D054063 MN - A07.231.908.224.667 MS - The long large endothelium-lined venous channel on the top outer surface of the brain. (bvsalud.org)
HN - 2008 MH - Transverse Sinuses UI - D054064 MN - A07.231.908.224.833 MS - The two large endothelium-lined venous channels that begin at the internal occipital protuberance at the back and lower part of the CRANIUM and travels laterally and forward ending in the internal jugular vein (JUGULAR VEINS). (bvsalud.org)

Conduction disorders occur when the electrical activity generated in the sinus node in the right atrium fails to propagate to the ventricles, eventually, it results in a failure in adequate contractility of ventricles to pump out sufficient blood. (parkhospital.in)

Your heart is four-chambered with two atria and two ventricles and is made up of the myocardium, the heart muscle that enables the heart to pump blood. (parkhospital.in)
The impulse now spreads leftward and inferiorly through the atria (at first only in the RA, then in both RA and LA and finally only in the LA). Small fascicles of tissue which resemble conduction tissue can be demonstrated in the atria, called intra-atrial pathways which connect both atria and help organize atrial depolarization. (wikidoc.org)
HN - 2008 BX - Lateral Sinus MH - Atrial Septum UI - D054087 MN - A07.541.459.249 MS - The thin membrane-like muscular structure separating the right and the left upper chambers (HEART ATRIA) of a heart. (bvsalud.org)

Depolarization then spreads slowly through the ventricular myocardium. (ecgbuddy.com)

Prolongs action potential and refractory period in myocardium and inhibits adrenergic stimulation. (medscape.com)
Diltiazem prolongs the sinus cycle length. (nih.gov)

Pacemaker testing 5 months and 12 months later showed no restoration of normal conduction. (cdc.gov)

The walls of the heart are largely made from myocardium, which is a special kind of muscle tissue. (daviddarling.info)
In contrast, expression in atrial tissue was equivalent to the expression in the sinus node. (uni-wuerzburg.de)

Q fever should be suspected in unexplained conduction abnormalities, especially in febrile young patients residing in disease-endemic areas. (cdc.gov)
Abnormal rhythms (or arrhythmias ) may arise from abnormalities of impulse formation, or impulse conduction (or sometimes both). (vin.com)

Histological examinations with the help of the sinus node marker HCN4 revealed structural alterations in the inferior part of the sinus node in 8 months old Popdc1-mice. (uni-wuerzburg.de)
The heart also has a coronary sinus valve and an inferior vena cava valve , not discussed here. (wikipedia.org)
Mapping of sinus node activation indicates that at faster rates, the SA impulse originates in the superior portion of the SA node, or extranodally, while at slower rates, it arises from the inferior portion of the node or, once again, extranodally [ 7 ]. (medilib.ir)

Diltiazem exhibits frequency (use) dependent effects on AV nodal conduction such that it may selectively reduce the heart rate during tachycardias involving the AV node with little or no effect on normal AV nodal conduction at normal heart rates. (nih.gov)
Using an electrical threshold of 1.5 mV to define abnormal myocardium, the total DSC, scar DSC, and normal myocardium DSC between voltage maps and LGE scar maps was 79.0 ± 6.0%, 35.0 ± 10.1%, and 90.4 ± 8.6%, respectively. (kcl.ac.uk)

Near the lower back of the CRANIUM, the superior sagittal sinus deviates to one side (usually the right) and continues on as a TRANSVERSE SINUS. (bvsalud.org)

It can be a feature of sick sinus syndrome. (yourarticlelibrary.com)

Studies in cells expressing either wild type or LQT3 channels showed that an increase in a persistent inward current in the mutated channels reduced the sinus rate directly and could also result in the failure to repolarize completely [ 6 ]. (medilib.ir)

This alters the electrical activity of the heart and decreases cardiac conduction velocity (dromotropic effect). (trc-p.nl)

Sometimes there is a conduction disorder (interference in the conduction of these electrical signals) due to which there is a heart block. (parkhospital.in)
Therefore, the proposed model can be a useful tool for modeling electrical and structural properties during cardiac conduction. (udem.edu.co)
Another electrical property is conductivity, which is characterized by a conduction and activation process, where the action potential, by the all-or-nothing law, travels throughout the heart. (bvsalud.org)

the ventricular rate may be less when AV conduction is incomplete. (rjmatthewsmd.com)

Internally, the sinus area and infundibulum contain coarse trabeculations. (medscape.com)

The waveforms should be measured in detail, selecting sinus complexes from a lead II recording. (vin.com)

Anatomy63

Organisms12

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Analytical, Diagnostic and Therapeutic Techniques and Equipment46

Psychiatry and Psychology2

Phenomena and Processes32

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Atrioventricular3

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