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Tachycardia, Sinoatrial Nodal ReentryTachycardia, Atrioventricular Nodal ReentrySinoatrial NodeTachycardia, SupraventricularTachycardiaAtrioventricular NodeSinoatrial BlockTachycardia, VentricularCatheter AblationHeart Conduction SystemCryosurgeryElectrocardiographyTachycardia, SinusTachycardia, ParoxysmalTachycardia, Ectopic AtrialCardiac Pacing, ArtificialElectrophysiologic Techniques, CardiacTachycardia, ReciprocatingTachycardia, Ectopic JunctionalHeart RateHemodynamicsHeart AtriaBundle of HisAnti-Arrhythmia AgentsArrhythmias, CardiacHeart BlockPostural Orthostatic Tachycardia SyndromeBody Surface Potential MappingBradycardiaModels, CardiovascularVentricular FibrillationDogsAction PotentialsElectrophysiologyArrhythmia, SinusLabetalolEphedrineAccessory Atrioventricular BundleCarbon DioxideCapnography

Paroxysmal supraventriSinus tachycardiaVentricular tachycardiaReentrant TachycardiaWide-complex tachycardiasConductionAdenosineSupraventricular tachycardiasInstabilityMyocardialAVNRTAtriaPSVTNodeFibrillationOccursAutomaticityDisturbancesSignsPatientsRateResultReentrantSinusSupraventricular tachycardiaAtrioventricular nodalVentricular fibrillationDiltiazemOriginatesAtrial fibrillationCollapseSlowsSuddenHeartWideEvidence

Paroxysmal supraventri2

• 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)
• F. The most common form of paroxysmal supraventricular tachycardia (PSVT) is AV nodal reentry due to dual pathways of excitation in the region of the AV node (see Figure 1). (rjmatthewsmd.com)

Sinus tachycardia3

• Sinus tachycardia can be considered an automatic tachycardia, but it is rarely spontaneous and characteristically resolves when the abnormal stimulus resolves. (mhmedical.com)
• Mild sinus slowing may be observed initially fol-lowed by sinus tachycardia. (brainkart.com)
• The abrupt change from a fast, regular rhythm to a slower, irregular rhythm is evidence that the tachycardia was due to a reentrant circuit, and not sinus tachycardia. (ecgguru.com)

Ventricular tachycardia3

• In contrast, other forms of automatic tachycardia, such as atrial ectopic tachycardia, junctional ectopic tachycardia, and the automatic form of ventricular tachycardia, may be spontaneous or triggered by the aforementioned stimuli. (mhmedical.com)
• Following myocardial infarction (MI), the myocardium is prone to calcium-driven alternans, which typically precedes ventricular tachycardia and fibrillation. (frontiersin.org)
• Divided into supraventricular and ventricular tachycardia. (mims.com)

Reentrant Tachycardia3

• AV nodal reentrant tachycardia occurs most often in otherwise healthy patients. (msdmanuals.com)
• Accessory pathway reentrant tachycardia involves tracts of conducting tissue that partially or totally bypass normal AV connections (bypass tracts). (msdmanuals.com)
• Adenosine is approved for the acute management and termination of supraventricular tachyarrhythmias, in- cluding A-V nodal reentrant tachycardia and A-V recip-rocating tachycardia. (brainkart.com)

Wide-complex tachycardias1

• The general rule followed by emergency providers that "all wide-complex tachycardias are v tach until proven otherwise" has no doubt prevented deaths in situations where care providers did not agree on the origin of the tachycardia. (ecgguru.com)

Conduction6

• 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)
• 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)
• It has no effect on the sinus node recovery time or on the sinoatrial conduction time in patients without SA nodal dysfunction. (nih.gov)
• If these maneuvers are ineffective, treatment is with IV adenosine or nondihydropyridine calcium channel blockers for narrow QRS rhythms or for wide QRS rhythms known to be a reentrant SVT with aberrant conduction that requires atrioventricular nodal conduction. (msdmanuals.com)
• However, especially in the presence of congenital or acquired structural or conduction abnormalities, a subset of dysrhythmias (ie, sustained VT and VF) may pose an immediate threat to life by causing profound hemodynamic instability. (medscape.com)
• Re-entry , the other form of abnormal impulse conduction, is an important mechanism underlying supraventricular tachycardia in infants. (mhmedical.com)

Adenosine3

• Therapies that produce only transient effects, such as direct current (DC) cardioversion and administration of adenosine, do not terminate automatic tachycardias. (mhmedical.com)
• Adenosine receptors are found on myocytes in the atria and sinoatrial and A-V nodes. (brainkart.com)
• This strip shows a supraventricular tachycardia, rate 196 bpm, after adenosine was administered to the patient. (ecgguru.com)

Supraventricular tachycardias2

• Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. (msdmanuals.com)
• Supraventricular tachycardias (SPVT) usually have narrow QRS complexes, but they may be wide because of aberrant counduction through the intraventricular conducting tissue, participation of a bypass tract in the intraventricular depolarization pattern,or in the presence of a coexiting bundle branch block. (rjmatthewsmd.com)

Instability1

• Synchronized cardioversion can be done for all cases in which drugs are ineffective or there is hemodynamic instability. (msdmanuals.com)

Myocardial1

• Sustained tachyarrhythmias may eventually cause myocardial dysfunction, which is known as tachycardia-induced cardiomyopathy. (mhmedical.com)

AVNRT1

• Ear drops?AutoPap: Computer-assisted cytology interpretation system?AV: Aortic valve?AV: Atrioventricular?A-V: Arteriovenous?AVERT: Atorvastatin Versus Revascularization treatment?AVID: ?AVM: Arteriovenous Malformation?AVNRT: AV nodal reentry tachycardia?AVP: Arginine vasopressin?AVR: Aortic valve replacement?AVR: Augmented V lead, right arm (ECG)?AVRT: ?AVS: Arteriovenous shunt?AWS: Alcohol withdrawal syndrome?AXR: Abdominal X ray?AZF: Azoospermia factor genes?AZT: Azidothymidine (zidovudine)?B & O: Belladonna and opium?B Bx. (kuwaitpharmacy.com)

Atria1

• Abnormalities in impulse formation result in sinus bradycardia and tachycardia, premature atrial and ventricular contractions, and ectopic or automatic rhythms from the atria, AV node, or ventricles. (mhmedical.com)

PSVT1

• Management of PSVT due to AV nodal reentry. (rjmatthewsmd.com)

Node2

• The electrical impulse normally originates in the sinoatrial (SA) node. (mhmedical.com)
• The effects on the A-V node may result in a con-duction block and the termination of tachycardias that use the A-V node as a limb of a reentrant circuit. (brainkart.com)

Fibrillation1

• MAs may be manifested either in hemodynamic collapse or in cardiac arrest: The sudden loss of effective blood flow due to atrial fibrillation (AF) with rapid VT leads to hemodynamic collapse, and VT and VF result in cardiac arrest necessitating CPR or electric defibrillation. (medscape.com)

Occurs1

• Increased automaticity occurs when atrial, nodal, or ventricular cells display autonomous repetitive depolarization at a higher rate than is normal. (mhmedical.com)

Automaticity1

• Ventricular Premature Beats (VPB) Ventricular premature beats (VPB) are single ventricular impulses caused by reentry within the ventricle or abnormal automaticity of ventricular cells. (msdmanuals.com)

Disturbances1

• This type of tachycardia is sometimes associated with fever, hypoxemia, electrolyte disturbances, or infusion of intravenous sympathomimetic agents. (mhmedical.com)

Signs1

• It worthwhile to perform ultrasound on all chest pain patients, but particularly if there are any hemodynamic signs. (blogspot.com)

Patients1

• In 1930, Wolff, Parkinson, and White described a series of young patients who had a bundle branch block pattern on electrocardiography (ECG), a short PR interval, and paroxysms of tachycardia. (rjmatthewsmd.com)

Rate1

• The rate of an automatic tachycardia is often sensitive to changes in autonomic tone. (mhmedical.com)

Result1

• Abnormalities in any of these factors can result in bradycardia or tachycardia that are not related to any specific cardiac disorder. (mhmedical.com)

Reentrant6

• Diltiazem converts paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm by interrupting the reentry circuit in AV nodal reentrant tachycardias and reciprocating tachycardias, eg, Wolff-Parkinson-White syndrome (WPW). (nih.gov)
• Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. (msdmanuals.com)
• If these maneuvers are ineffective, treatment is with IV adenosine or nondihydropyridine calcium channel blockers for narrow QRS rhythms or for wide QRS rhythms known to be a reentrant SVT with aberrant conduction that requires atrioventricular nodal conduction. (msdmanuals.com)
• AV nodal reentrant tachycardia occurs most often in otherwise healthy patients. (msdmanuals.com)
• Accessory pathway reentrant tachycardia involves tracts of conducting tissue that partially or totally bypass normal AV connections (bypass tracts). (msdmanuals.com)
• The abrupt change from a fast, regular rhythm to a slower, irregular rhythm is evidence that the tachycardia was due to a reentrant circuit, and not sinus tachycardia. (ecgguru.com)

Sinus1

• It has no effect on the sinus node recovery time or on the sinoatrial conduction time in patients without SA nodal dysfunction. (nih.gov)

Supraventricular tachycardia1

• This strip shows a supraventricular tachycardia, rate 196 bpm, after adenosine was administered to the patient. (ecgguru.com)

Atrioventricular nodal1

• The objective of the present meta-analysis was to evaluate recent and applicable data regarding the location and variation of the atrioventricular nodal artery (AVNA) in relation to adjacent structures. (bvsalud.org)

Ventricular fibrillation1

• Observational studies and inferences from typical electrophysiology studies were initially focused on ventricular ectopy triggering ventricular tachycardia (VT), which, in turn, can degenerate into ventricular fibrillation, as a mechanisms for sudden cardiac death. (medscape.com)

Diltiazem1

• If VT is treated as SVT (using diltiazem/verapamil), hemodynamic deterioration may occur. (ekgrhythm.com)

Originates2

• If the ectopic beat originates in high nodal tissue, the QRS complex can be narrow. (medscape.com)
• A generic expression for any tachycardia that originates above the BUNDLE OF HIS. (lookformedical.com)

Atrial fibrillation1

• MAs may be manifested either in hemodynamic collapse or in cardiac arrest: The sudden loss of effective blood flow due to atrial fibrillation (AF) with rapid VT leads to hemodynamic collapse, and VT and VF result in cardiac arrest necessitating CPR or electric defibrillation. (medscape.com)

Collapse1

• VT that persists for 30 seconds or causes hemodynamic collapse is called sustained VT. (medscape.com)

Slows1

• Unlike the reentry mechanism, automatic tachycardia speeds up and slows down gradually. (lookformedical.com)

Sudden1

• 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)

Heart1

• INTRODUCTION: Radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is by evidence, safe and effective. (bvsalud.org)

Wide3

• What is a wide complex tachycardia? (ekgrhythm.com)
• What are the probabilities of a Wide Complex Tachycardia (WCT)? (ekgrhythm.com)
• However, in this age of ECG telemetry, most wide QRS tachycardia are captured and saved in central telemetry which can view all the limb leads and a V1 +/- V6. (ekgrhythm.com)

Evidence1

• In animal models, focal mechanisms without evidence of macro-reentry play a major role in the origin of ventricular arrhythmia associated with ischemic cardiomyopathy. (medscape.com)