This study is a substudy of a planned study involving participants with an implantable cardioverter defibrillator (ICD), who will be randomly assigned to either take part in a exercise program for 12 weeks or serve as control and live as usual (Clinical Trials Unique Protocol ID: 2018/1592). In that study all participants will complete an exercise treadmill test to determine maximum oxygen uptake (VO2 peak).~In this study we wish to examine the acute effect of one single bout of high intensity exercise (i.e the VO2 peak test) on the tendency for ventricular arrhythmia. The study will evaluate changes in ICD-parameters and the number of premature ventricular contractions the first 24 hours after VO2 peak testing compared to the average number of the 48 hours prior to the test.~The study will also examine if the acute effect after VO2 peak testing alters after completing 12 weeks of aerobic interval training or control respectively.
This study will evaluate the acute effect of one single bout of high intensity exercise on the tendency for ventricular arrhythmia.