Acute and Chronic Treatment for SVT DrJo Jo Hai
Supraventricular Tachycardia SVT -generally reserved for AVNRT, AT, AP mediated tachycardia Can be narrow / wide complex Acute treatment -principally determined by whether it is narrow / wide complex tachycardia
Acute Management
HaemodynamicallyUnstable Cardioversion/ Defibrillation
Common Narrow Complex Tachycardia AV nodal reentrant tachycardia OrthodromicAV reentrant tachycardia Atrial tachycardia CP1077722-3
RP Classification of Narrow Complex Short RP (RP < PR) Tachycardias Long RP (RP > PR) RP <70 ms - Typical AVNRT RP >70ms AVNRT or OAVRT You can t exclude Atrial tachycardia Junction tachycardia is always a ddx to typical AVNRT Sinus tachycardia Atrial tachycardia Atypical AVNRT Permanent junctional reciprocating tachycardia
Others P wave morphology Septal: narrow and sharp Free wall: Bifid and wide Polarity of P on II, III, avf Mode of induction & termination etc Patient s demographics Medical / surgical history
Vagal maneuvers / Adenosine Both diagnostic and therapeutic
Vagal maneuvers / Adenosine Carina Blomström-Lundqvist, JACC 2003
AV nodal reentrant tachycardia OrthodromicAV reentrant tachycardia Atrial tachycardia CP1077722-3
Occasionally can terminate the atrial activity Last atrial firing conducts through AVN to the ventricle and ends with QRS If the last beat ends with P => concomitant AVN blockade HIGHLY UNLIKELY!!!
Other Agents Longer acting AVN blockers IV BB IV CCB Class I / Class III agents IV Procainamide IV Flecainide Add AVN blockers!
Any SVT with BBB SVT with Wide QRS AntidromicAV reentrant tachycardia Accessory pathway Any SVT (inclaf) with AP Accessory pathway Risk of rapid conduction and sudden cardiac death!!! CP1077722-20
Carina Blomström-Lundqvist, JACC 2003
Carina Blomström-Lundqvist, JACC 2003
Definite SVT SVT with BBB As for narrow complex tachycardia Pre-excited SVT Class I / Class III agents IV Procainamide IV Flecainide Add AVN blockers!
Unknown Wide Complex Tachycardia IV Amiodarone(espif LVEF poor) IV Sotalol IV Lidocaine IV Procainamide
If any doubt / treatment unsuccessful Cardioversion/ Defibrillation
Chronic Management
AV Node Reentry Determined by frequency and tolerability of attacks Vagal maneuvers Pill-in-the-pocket BB + CCB Flecainide LA BB, CCB Class IC and class III agents Always add AVN blockers with class IC agents Digoxin CP1077722-7
AV Node Reentry Complete suppression by medical treatment ~30% Catheter ablation >95% effective Risk of AVB ~1% Risk of recurrence ~3-7% Can be offered as 1 st line treatment if patient prefers Preferred treatment if medically refractory or poorly tolerated CP1077722-7
Pathway-mediated tachycardia Wolff-Parkinson-White Syndrome = Preexcitation + tachycardia With Pre-excitation: Class IC / Class III agents can be considered Without Pre-excitation: BB can also be considered (Class Iib recommendation) Vagal maneuvers / pill-in-the-pocket (BB + CCB) in patients with infrequent attacks and without pre-excitation By all means avoid CCB and digoxin!!!
Pathway-mediated tachycardia Effectiveness of medical treatment ~70-90% Catheter ablation >95% effective Risk depends on site (L vs R? distance from AVJ?) Serious Cx ~1-2% Most common Tamponade and AV block Risk of recurrence ~5% CP1077722-7
Accessory Pathway Preferred treatment except in patients with infrequent attacks and without pre-excitation The only acceptable treatment in patients with pre-excited AF and rapid conduction (CL <250 ms) or poorly tolerated AVRT CP1077722-7
Asymptomatic Pre-excitation Risk of SCD ~0.15-0.39 in 3-10 yrs Risk Factors Shortest RR <250ms during AF Multiple AP Ebstein s anomaly Familial WPW Catheter ablation can be considered CP1077722-7
Atrial Tachycardia BB, CCB is the 1 st line treatment Class IC / Class III agents can be considered No therapy is acceptable if nonsustained and asymptomatic CP1077722-7
Atrial Tachycardia Catheter ablation is the 1 st line treatment for recurrent or incessant AT Success rate 89% R > L Recurrence Single > multiple Inc with age Serious Cx ~ 1% Most common perforation, phrenic nerve palsy, SN dysfx CP1077722-7
Summary Diagnostic clues for narrow and wide complex SVT Acute and chronic medical management of SVT Catheter ablation is almost always an alternative option!