Influence of Ventriculoatrial Timing on Hemodynamics and Symptoms During Supraventricular Tachycardia

AIMS: Patients with reentrant supraventricular tachycardia (SVT) are often highly symptomatic and the mechanism of symptoms is not well understood. We hypothesized that variation in ventriculoatrial interval (QRS to P) modulates the left atrial pressure and symptoms during tachycardia. METHODS AND RESULTS: Three hundred twenty-six patients awaiting electrophysiological study completed a questionnaire regarding "neck pounding" or "shirt flapping" during tachycardia. Mean left atrial pressure was measured during simulated atrioventricular reentry tachycardia (AVRT) and atrioventricular nodal reentry tachycardia (AVNRT) in 18 patients. Pulmonary venous flow reversal was assessed using transesophageal echocardiography in 12 dogs when pacing at 220 bpm with different VA delays (0 to 250 ms). "Shirt flapping" is present more often during AVNRT than during AVRT (58.6% vs 43.8%, respectively, P < 0.05). Simulated AVNRT is associated with higher left atrial pressure compared with AVRT (19.4 +/- 4.8 mmHg vs 13.7 +/- 3.9 mmHg, respectively, P < 0.05). In dogs, pulmonary venous flow reversal during atrial systole was observed with significantly decreasing amplitude as VA delays increased: 668 +/- 167% at 0 ms; 492 +/- 138% at 100 ms; 278 +/- 148% at 180/ms; and 134 +/- 91% at 220 ms. CONCLUSION: "Shirt flapping" and "neck pounding" frequently occur during AVNRT. LA contractions during AV valve closure increase left atrial pressure and may explain differences in certain symptoms between AVNRT and AVRT.