Electrophysiologic drug testing in patients with malignant ventricular arrhythmias: importance of stimulation at more than one ventricular site.
Sixty-four patients with symptomatic ventricular tachycardia or ventricular fibrillation underwent right ventricular apical programmed stimulation and had no inducible ventricular tachycardia during drug testing. Thirty patients (Group I) did not undergo left ventricular stimulation. Left ventricular stimulation in 38 drug trials induced no ventricular tachycardia in 50% (Group IIA), nonsustained ventricular tachycardia in 24% (Group IIC). Patients in Groups I, IIA, and IIB received chronic antiarrhythmic drug therapy based on the results of electrophysiologic drug testing. Patients in Group IIC underwent further drug testing until sustained ventricular tachycardia was no longer inducible and were then entered into Group IIA or IIB; 4 patients in whom the induction of sustained ventricular tachycardia could not be suppressed by any drug regimen tested were excluded from long-term follow-up. The duration of follow-up (mean +/- standard deviation) was 15.8 +/- 1.5 months in Group I, 13.6 +/- 3.7 months in Group IIA, and 12.1 +/- 4.9 months in Group IIB. Recurrence rates of symptomatic ventricular tachycardia or sudden death were 27% in Group I, 0% in Group IIA, and 20% in Group IIB (p less than 0.02 for Group IIA versus Group I and p greater than 0.05 versus Group IIB). If only right ventricular apical stimulation is performed during electrophysiologic drug testing in patients with malignant ventricular arrhythmias, approximately 50% of drug trials may be incorrectly judged as suppressing the induction of ventricular tachycardia. Drug therapy that suppresses ventricular tachycardia induction with both right and left ventricular programmed stimulation results in a significantly better clinical response than therapy based on the results of only right ventricular apical stimulation.
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D002304:Cardiac Pacing, Artificial; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D013610:Tachycardia / Q000175:diagnosis / Q000188:drug therapy*; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000188:drug therapy*
D000889:Anti-Arrhythmia Agents