Prognostic significance of sustained ventricular tachyarrhythmia occurring during dobutamine infusion.

The prognostic significance of a de novo sustained ventricular tachyarrhythmia occurring during a dobutamine infusion is unknown. This study was performed to determine (1) the risk of recurrent ventricular arrhythmia, (2) the safety of future dobutamine infusions, and (3) the role of electrophysiologic testing. The study population consisted of 15 patients, six with coronary artery disease, and nine with idiopathic dilated cardiomyopathy. Mean ejection fraction was 17% +/- 4.1%. The arrhythmia during the infusion was ventricular tachycardia in 13 patients and ventricular fibrillation in two patients and was not associated with preceding hemodynamic instability, electrolyte abnormality, digoxin toxicity, or antiarrhythmic drug therapy. During electrophysiologic testing, 7 of 15 patients had inducible ventricular tachycardia. All patients with inducible ventricular tachycardia were treated with either antiarrhythmic drugs, defibrillators, or ablation. Over a 12.3 +/- 5.2 month follow-up period, all 15 patients received further dobutamine treatment. Seven of 15 (47%) had a recurrent sustained ventricular tachyarrhythmia. Although three of seven recurrences occurred during a dobutamine infusion, all three of these patients had hemodynamically unstable conditions and were receiving high-dose (> 10 micrograms/kg/min) therapy at the time of recurrence. The other four recurrent arrhythmias were not associated with clear precipitating factors. Ejection fraction, origin of left ventricular dysfunction, and inducibility at baseline electrophysiologic testing did not predict arrhythmia recurrence. The de novo occurrence of a sustained ventricular tachyarrhythmia during dobutamine infusion is associated with a significant risk of arrhythmia recurrence (47%), which can occur in the presence or absence of dobutamine therapy.(ABSTRACT TRUNCATED AT 250 WORDS)