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Atrial FlutterNeural ConductionHeart Conduction SystemCatheter AblationAction PotentialsAtrial FibrillationMyelin SheathElectrocardiographyAxonsTricuspid ValveHeart BlockRanvier's NodesPeripheral NervesHeart AtriaElectrophysiologyElectrophysiologic Techniques, CardiacSciatic NerveAnti-Arrhythmia AgentsConnexin 43PropafenoneCardiac Pacing, ArtificialPericarditisNerve FibersProcainamideElectric StimulationElectric CountershockBody Surface Potential MappingTetrodotoxinImpulse Control DisordersAtrioventricular NodeRefractory Period, ElectrophysiologicalTachycardia, SupraventricularAtrial Function, RightAtrial FunctionDisopyramideFlecainideTachycardiaVena Cava, InferiorAmiodaroneArrhythmias, CardiacTachycardia, ParoxysmalAtrial Premature ComplexesTachycardia, Ectopic AtrialPulmonary VeinsCryosurgeryTime FactorsHydrops FetalisDogsTreatment OutcomeCoronary SinusRecurrenceFollow-Up StudiesSick Sinus SyndromeFluoroscopyTachycardia, Atrioventricular Nodal ReentryBundle of HisTachycardia, Sinoatrial Nodal ReentryAtrial Function, LeftCardiac CathetersWolff-Parkinson-White SyndromeButylscopolammonium BromideAtrioventricular BlockFetal DiseasesElectrocardiography, AmbulatorySinoatrial NodeProspective StudiesNeurons, AfferentVenae CavaeSotalolEchocardiography, TransesophagealHeart DiseasesArrhythmia, SinusCatsMechanoreceptorsAtrial AppendageEdrophoniumHeart RateBone ConductionMedian NerveMotor NeuronsVibrationDigoxinAtrial SeptumEndocardiumCardiac CatheterizationPostoperative ComplicationsEchocardiographyHeartHeart Defects, CongenitalElectrodesEquipment DesignPacemaker, ArtificialSulfonamidesDysgeusiaEvoked PotentialsUlnar NerveVagus NerveSurgery, Computer-AssistedAzygos VeinRetrospective Studies
FibrillationAtriaAtrioventricular nodeVentriclesVentricular rateReentryArrhythmiaNodeMitralBlockageFibersCardiac impulsePathwayActivatesWallsOccursTissueIrregularSystemHeartIncludeFormBodyTachycardiaLeft atrialAbnormalPrematureAbnormallyHeartbeatsElectricalCardiacContractilityContractionsPathwaysNodalRhythmAberrantReentrantRight atriumEpisodesRepolarizationMyocardiumOriginatesBeatsBundle brancDependsBlockMarkedly
Fibrillation16
Atria11
  • As a strategy, surgically debulking the atria is limited by its invasive nature and the potential for disrupting long-term atrial transport function. (medscape.com)
  • This second theory of AF depends on the importance of areas of the atria that harbor focal impulses or localized reentry. (medscape.com)
  • This impulse activates the upper chambers of the heart (atria). (msdmanuals.com)
  • A specialized cluster of cells called the atrioventricular node conducts electrical impulses from the heart's upper chambers (the atria) to the lower chambers (the ventricles). (nih.gov)
  • Impulses move through the atrioventricular node during each heartbeat, stimulating the ventricles to contract slightly later than the atria. (nih.gov)
  • The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. (nih.gov)
  • The atrioventricular node is an area of specialized tissue between the atria and the ventricles of the heart , which conducts the normal electrical impulse from the atria to the ventricles. (wikidoc.org)
  • The reason it is important to delay the cardiac impulse is to ensure that the atria have ejected their blood into the ventricles before the ventricles contract. (wikidoc.org)
  • From the SA node, the impulse spreads across the upper chambers of the heart to reach the atrial ventricular (AV) node located between the atria and lower ventricles. (orlandocvi.com)
  • 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)
  • Both atria contract together, as do the ventricles, but atrial contraction occurs first. (medscape.com)
Atrioventricular node4
Ventricles2
  • The difference between SA node block and SA node suppression is that in SA node block an electrical impulse is generated by the SA node that doesn't conduct to the ventricles. (the-medical-dictionary.com)
  • After leaving the AV node, impulses spread across the pumping chambers of the heart, the ventricles. (orlandocvi.com)
Ventricular rate3
  • For most people who are not being treated, every second atrial impulse gets to the ventricules, resulting in a ventricular rate of about 150 beats per minute. (msdmanuals.com)
  • Typically, the ventricular rate is half the atrial rate. (nih.gov)
  • the ventricular rate may be less when AV conduction is incomplete. (rjmatthewsmd.com)
Reentry1
  • Pathophysiologically, atrial flutter is a form of atrial reentry in which there is a premature electrical impulse creates a self-propagating circuit. (nih.gov)
Arrhythmia1
  • As has been the case in the history of electrophysiology, one of the best ways to confirm the (causative) importance of an area or impulse is when ablation of that area terminates the arrhythmia. (medscape.com)
Node10
  • Each heartbeat begins with an impulse from the heart's pacemaker (sinus or sinoatrial node). (msdmanuals.com)
  • This is because if an individual had complete block at this level of the conduction system (which is uncommon), the secondary pacemaker of the heart would be at the AV node, which would fire at 40 to 60 beats a minute, which is enough to retain consciousness in the resting state. (the-medical-dictionary.com)
  • In SA node suppression, on the other hand, the SA node doesn't generate an electrical impulse because it is reset by the electrical impulse that enters the SA node. (the-medical-dictionary.com)
  • An important property that is unique to the AV node is decremental conduction , in which the more frequently the node is stimulated, the slower it conducts. (wikidoc.org)
  • Electrical impulses originate from specialized cells called the sinoatrial (SA) node, which is the hearts natural pacemaker. (orlandocvi.com)
  • An AV-junctional rhythm , or atrioventricular nodal bradycardia, is usually caused by the absence of the electrical impulse from the sinus node . (wikipedia.org)
  • [4] This dysrhythmia also may occur when the electrical impulses from the SA node fail to reach the AV node because of SA or AV block . (wikipedia.org)
  • [4] Impulses originating within or below the bundle of His in the AV node will produce a wide QRS complex with heart rates between 20 and 40 BPM. (wikipedia.org)
  • The SA node is located less than 1 mm from the epicardial surface, laterally in the right atrial sulcus terminalis at the junction of the anteromedial aspect of the superior vena cava (SVC) and the right atrium (RA). (medscape.com)
  • The human SA node contains a more than 3-fold greater density of beta-adrenergic and muscarinic cholinergic receptors than the adjacent atrial tissue. (medscape.com)
Mitral2
  • The chronic and recurrent ones are related to underlying structural causes like atrial disease or mitral disease. (rjmatthewsmd.com)
  • C. They tend to be recucurrent when an underlying structural cause such as atrial disease or mitral disease is the dominant pathophysiologic factor. (rjmatthewsmd.com)
Blockage1
Fibers1
  • The conducting system of the heart consists of cardiac muscle cells and conducting fibers (not nervous tissue) that are specialized for initiating impulses and conducting them rapidly through the heart (see the image below). (medscape.com)
Cardiac impulse1
  • The Bachmann bundle is a large muscle bundle that appears to conduct the cardiac impulse preferentially from the RA to the LA. (medscape.com)
Pathway3
  • G. There is a slow conduction pathway as well as a fast one. (rjmatthewsmd.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)
  • Anatomic evidence suggests the presence of 3 intra-atrial pathways: (1) anterior internodal pathway, (2) middle internodal tract, and (3) posterior internodal tract. (medscape.com)
Activates1
  • Cardioversion involves a high energy shock to the heart muscle which activates all of the cardiac muscle and conduction tissue simultaneously. (orlandocvi.com)
Walls1
  • The resulting electrical activity is chaotic rather than organized and thus, the atrial walls quiver rather than contract. (msdmanuals.com)
Occurs1
  • This is a safety mechanism when a lack of electrical impulse or stimuli from the atrium occurs. (wikipedia.org)
Tissue1
  • These groups of internodal tissue are best referred to as internodal atrial myocardium, not tracts, as they do not appear to be histologically discrete specialized tracts. (medscape.com)
Irregular1
System2
Heart5
Include1
  • Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, and fainting (syncope). (nih.gov)
Form1
  • Human AF may be sustained by localized sources in the form of either electrical rotors or focal impulses. (medscape.com)
Body1
  • It is at the apex of a triangle formed by the tricuspid annulus and the tendon of Todaro, which originates in the central fibrous body and passes posteriorly through the atrial septum to continue with the eustachian valve (see the images below). (medscape.com)
Tachycardia5
  • Atrial flutter is a regular narrow-complex tachycardia characterized by a rapid atrial rate (typically around 300/min), atrioventricular (AV) node conduction block with a ventricular response of approximately 150/minute , and a "sawtooth" pattern on an electrocardiogram (ECG). (lecturio.com)
  • This type of rhythm includes paroxysmal atrial tachycardia (PAT). (cvphysiology.com)
  • Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation). (lookformedical.com)
  • In sustained ventricular tachycardia, there are consecutive impulses that arise from the ventricles at a heart rate of 100 beats or more per minute until stopped by drug treatment or electrical conversion. (findmeacure.com)
  • In tachycardia, an irregular electrical signal (impulse) starting in the upper or lower chambers of the heart causes the heart to beat faster. (mayoclinic.org)
Left atrial2
  • Measures of Disease Frequency with left atrial enlargement, or with left ventricular or biventricular heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. (lecturio.com)
  • Sinus rhythm at hospital discharge, lower left atrial size in the preoperative period and bipolar radiofrequency were associated with a greater chance of sinus rhythm after one year. (bjcvs.org)
Abnormal3
  • The following figure shows QRS complexes having an abnormal shape and prolonged duration because ventricular depolarization does not follow normal conduction pathways. (cvphysiology.com)
  • It is caused by abnormal impulse generation. (lookformedical.com)
  • You can think of "aberrancy" as abnormal conduction. (answersonweb.com)
Premature3
Abnormally2
  • Conduction delay or block can be physiologic if the atrial rate is abnormally fast or pathologic at normal atrial rates. (medscape.com)
  • Aberrant ventricular conduction is a common electrocardiographic (EKG) manifestation that occurs when the supraventricular electrical impulse is conducted abnormally through the ventricular conducting system. (answersonweb.com)
Heartbeats1
  • Atrial flutter is similar to A-fib , but heartbeats are more organized. (mayoclinic.org)
Electrical6
  • The resulting electrical activity is chaotic rather than organized and thus, the atrial walls quiver rather than contract. (msdmanuals.com)
  • The electrical impulses are shown on the screen as a line with waves on it. (freshrn.com)
  • Rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. (lookformedical.com)
  • We investigated short-term effects of particulate matter ≤ 2.5 μm in aerodynamic diameter (PM 2.5 ) and ozone (O 3 ) on cardiac electrical impulse propagation and repolarization as recorded in surface electrocardiograms (ECG). (biomedcentral.com)
  • The cardiac conduction system initiates and conducts electrical impulses as recorded in the electrocardiogram (ECG). (biomedcentral.com)
  • To coordinate these two tasks, the heart has an electrical conduction system composed of specialized myocardial cells (henceforth referred to as conduction cells). (ecgwaves.com)
Cardiac6
  • An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart. (lookformedical.com)
  • The evidence of air pollution effects on the cardiac conduction system is incomplete yet. (biomedcentral.com)
  • In patients undergoing cardiac catheterization, short-term exposure to air pollution was associated with increased HR and delays in atrioventricular conduction, ventricular depolarization and repolarization. (biomedcentral.com)
  • Hypothesizing that air pollution exposure would be associated with cardiac conduction delay, we performed this study to investigate the short-term effects of PM 2.5 and O 3 on the electrocardiographic intervals reflecting impulse propagation and repolarization in high-risk patients from a cardiovascular cohort. (biomedcentral.com)
  • Disruptions in the conduction of these impulses affect contractility of the heart as well as the volume of blood pumped by the heart each minute (cardiac output). (nurseslabs.com)
  • Aberrant conduction occurs when the length of the cardiac cycle is changed without a compensatory change in the length of the refractory period. (answersonweb.com)
Contractility1
  • As a result of the above effects, atrial contractility is lost causing an inability to completely empty blood from atrial appendage leading to the risk of clot formation and subsequent thromboembolic events. (nih.gov)
Contractions1
  • It is caused by rapid, uncontrolled atrial contractions and uncoordinated ventricular responses. (lecturio.com)
Pathways1
  • The technique is used most often to ablate the AV junction and/or accessory pathways in order to interrupt AV conduction and produce AV block in the treatment of various tachyarrhythmias. (lookformedical.com)
Nodal1
  • First-degree AV nodal block - the conduction velocity is slowed so that the PR interval is increased to greater than 0.20 seconds. (cvphysiology.com)
Rhythm2
  • Atrial rate and rhythm may be completely normal (green arrows indicate P waves, although in the last beat it is obscured by the QRS), but ventricular rate will be reduced, the extent of which depends on the location of the site generating the ventricular rhythm. (cvphysiology.com)
  • AV block is generally defined based on a regular atrial rhythm. (medscape.com)
Aberrant6
Reentrant1
Right atrium1
  • Atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). (lecturio.com)
Episodes1
Repolarization1
  • Note that the ECG rarely shows atrial recovery (repolarization) since it coincides with ventricular depolarization (i.e. (ecgwaves.com)
Myocardium2
  • As the impulse spreads through the myocardium, it activates the cells which respond by contracting. (ecgwaves.com)
  • Conduction cells form the fiber networks that sprout into the myocardium and disseminate the action potential. (ecgwaves.com)
Originates1
  • SVT typically originates in atrial tissue and/or AV junction and utilizes the normal atrioventricular (AV) conduction system for ventricular activation. (answersonweb.com)
Beats2
  • For most people who are not being treated, every second atrial impulse gets to the ventricules, resulting in a ventricular rate of about 150 beats per minute. (msdmanuals.com)
  • Atrial flutter - sinus rate of 250-350 beats/min. (cvphysiology.com)
Bundle branc1
  • the QRS complex is usually normal width, unless there are also intraventricular conduction blocks (e.g., bundle branch block). (cvphysiology.com)
Depends1
  • The type of wave we see depends on where the impulse is located at that time. (freshrn.com)
Block1
  • During third-degree ("complete") AV block, no AV conduction occurs when it should be able to occur. (medscape.com)
Markedly1
  • Class Ic drugs markedly depress phase 0 and extremely slows conduction but has little effect on the duration of action potential. (nurseslabs.com)