Unexpected, sustained ventricular tachyarrhythmia after cardiac operations.

Unexpected, sustained ventricular tachyarrhythmia after cardiac operations is differentiated from sustained ventricular tachycardia and ventricular fibrillation from known antecedent causes, such as recent or perioperative myocardial infarction, low cardiac output, preoperative ventricular arrhythmia, sympathomimetic drugs, drug toxicity, and metabolic abnormalities. Sixteen of 2364 patients (0.68%) who underwent heart operations met strict exclusion criteria for unexpected sustained ventricular tachyarrhythmia that occurred 1 hour to 12 days after operation. Recurrent ventricular tachyarrhythmias occurred in 12 patients; three died (21%), despite resuscitation from the initial episode. All patients had significant preoperative left ventricular dysfunction and 14 had ejection fractions below 30%. Fifteen of the 16 patients had monomorphic ventricular tachycardia at the initial episode. Empirically prescribed therapy was not effective in suppressing ventricular tachyarrhythmias inducible by programmed stimulation during postevent electrophysiologic studies in 10 of the 13 survivors. Inducibility was eventually prevented by drugs in nine patients, three patients received automatic implantable cardiac defibrillators, and one patient underwent successful catheter ablation of ventricular tachycardia. No patient died of recurrent ventricular tachyarrhythmias during the follow-up of 8 to 55 (mean 29) months after hospital discharge.