Continuous monitoring for ventricular arrhythmias during exercise tests.

Exercise stress testing is being increasingly used to verify exercise-induced arrhythmia and to aid in assessing antiarrhythmic drug efficacy. The true prevalence of ventricular arrhythmia during exercise testing is underestimated by means other than continuous monitoring. We compared the yield of ventricular premature beats (VPBs) between a continuous recording system ("trendscription") and intermittent monitoring among 39 patients undergoing a total of 50 consecutive exercise studies. By intermittent monitoring, 22 (44%) of 50 of the exercise tests demonstrated VPBs; with trendscription, 31 (62%) exhibited such arrhythmia. Most striking, however, was a sixfold increase in the disclosure of complex and repetitive forms of VPBs (56 vs nine episodes). Thus, this form of monitoring presents a cost-efficient, on-line method that allows concentration on the patient during exercise as well as clear recording of all arrhythmic events.