Prodromal ventricular premature beats preceded by a diastolic wave.

In a prospective study of quinidine syncope, 71 patients with atrial fibrillation/flutter were ECG monitored for four days after the start of quinidine therapy. Six patients developed ventricular tachycardia (VT) or ventricular fibrillation (VF) during the first 48 hours in sinus rhythm. Q-T prolongation was seen in most patients with and without VT/VF and was non-predictive in this respect. However, a diastolic wave (DW) of larger amplitude than the preceding T wave usually followed by a ventricular premature beat (VPB) appeared in five of the six VT/VF patients (13-185 min before the first event) and in none of the remaining 63 patients reaching sinus rhythm. For comparison, two of our own cases and nine from the literature with idiopathic long Q-T or alternating T wave syndromes were studied for these DW-VPBs. They were found in all ten cases with a VPB recording, but among 19 patients with acute myocardial infarction and VT/VF no such case was seen. As VT/VF was more common after large and VPB after small amplitude DWs, it is discussed whether the DW not only precedes but also initiates the ventricular tachyarrhythmias.