Supraventriculartachyarrhythmias

Václav DurdilKardiologická klinika UK 2.LF a FN Motol

Definition

Supraventricular tachyarrhythmia (=SVT)Different heart rhythm than sinus rhythm

Rate of contractions is more than 100 per minute

Atrial myocardium is needed to sustain the arrhythmia

Mechanism of origin

● Focal (ectopic) activity ○ trigerred activity○ enhanced automaticity

● Reentry○ macroreentry○ microreentry

● Sinoatrial node● Atrial myocardium● Atrioventricular node

Place of origin

Focal activityEarly afterdepolarizations Delayed afterdepolarizationsEnhanced automaticity

ReentryTwo requirements:

● anatomic barrier● zone of slow conduction

ClassificationSinoatrial node Focal Inappropriate sinus tachycardia

Reentry Sinus nodal reentrant tachycardia (SNRT)

Atrial myocardium

Focal Focal atrial tachycardia (FAT)

Reentry Atrial flutter (AFL)

Atrial fibrillation (AFib)

Atrioventricular node

Focal Junctional ectopic tachycardia (JET)

Reentry AV nodal reentrant tachycardia (AVNRT)

AV reentrant tachycardia (AVRT)

SymptomsPalpitations (feeling of irregular heart beats)

● Regularity○ Regular - AVNRT, AVRT, FAT○ Irregular - atrial fibrillation or flutter

● Beginning and end○ Sudden - reentry tachycardia○ Gradual - focal atrial tachycardia, sinus tachycardia

● Vagal maneuvers reaction○ Yes = reentry dependent on AV node

Dizziness, pre collapse state, exceptionally syncope

Atrial flutterTypical (cavotricuspid isthmus dependent)

Atypical (non-isthmus dependent)

Typical atrial flutter

Atypický flutter síní

AVNRTTypical = slow-fast

Atypical = fast-slow, slow-slow

AVNRTRP<100ms

AVNRT

AVNRT

AVRT = atrio-ventricular reentrant tachycardiaOrthodromic AVRT

Antidromic AVRT

Preexcitation

Preexcitation

AVRT RP>100ms

Atrial fibrillation

Atrial fibrillation

Therapy

● Pharmacological = antiarrhythmic drugs● Non-pharmacological = catheter ablation

, propafenon

blocks accessory pathway

blocks AV node

all above effects

blocks AV node

, metoprolol

, ajmalin, prajmalin

blocks ectopy

Catheter ablation of AVNRT

Catheter ablation of AVRT

Catheter ablation of typical atrial flutter