Table 1

Baseline Observations and Tachycardia Features Prospectively Selected for Evaluationlegend

Baseline Observations and Tachycardia Features
Baseline Observations
 1. Ventricular preexcitation during sinus rhythm
 2. Dual AV nodal physiology
 3. VA block cycle length >600 ms at baseline
 4. Extranodal response to Para-Hisian pacing during sinus rhythm
Tachycardia Features
 1. Induction dependent on a critical AH interval
 2. Isoproterenol required to sustain tachycardia
 3. Tachycardia cycle length ≥500 ms
 4. Septal VA interval >70 ms
 5. Eccentric atrial activation
 6. Spontaneous AV block during tachycardia
 7. Spontaneous termination with AV block
 8. Development of bundle branch block
 9. Effect of bundle branch block on VA conduction time
  • legend AH = atrial His bundle; AV = atrioventricular; VA = ventriculoatrial.