Ventricular arrhythmias during exercise testing and 24-hour ECG tape recording in patients with ischaemic heart disease and in normal individuals.

The occurrence of ventricular arrhythmias (VA) during resting ECG, maximal bicycle exercise testing and 24-hour ECG tape recording (24-ETR) was studied in 24 patients and 24 matched normal persons. The patients were on treatment with beta-receptor blocking agents or verapamil for ischaemic heart disease (IHD), verified by coronary angiography. The matched persons showed no signs of heart disease. VA did not occur in any of those studied on a 60-second resting ECG. During exercise testing, one patient and six normal subjects had VA. During 24-ETR, VA were found in 16 patients and 11 normal persons. The maximum heart rate during exercise and the average heart rate during ETR did not differ significantly between individuals with and without VA in the groups of patients and normal subjects, respectively. It is concluded that in IHD patients receiving beta-blocking agents or verapamil, 24-ETR is a more reliable indicator of VA than exercise ECG testing. In normal individuals the two methods are of similar value.