Physical Activity and Ventricular Arrhythmias
Physical Activity and Ventricular Arrhythmias
The purpose of the study is to determine the effect of aerobic interval training in patients
 with an implantable cardioverter defibrillator (ICD) on physical fitness, quality of life and
 the amount of serious ventricular arrhythmic events on short and long term.
In this study, participants will be randomly assigned to either take part in the exercise
 program or serve as control and live as usual. At baseline study visit, study researchers
 will review medical records to collect various information, including the reason for needing
 an ICD, the type and settings of the ICD, medication use and medical history etc. All
 participants will undergo blood collection, complete a questionnaire to assess quality of
 life and undergo examination with echocardiography and ECG. The ICD will be programmed
 accordingly to international guidelines regarding ICD-therapy and optimal monitoring, before
 each participant complete an exercise treadmill test to determine VO2 peak. They will wear a
 Holter monitor to record heart activity 48 hours before the test and 24 hours after the test.
 All participants will then be observed for 2 months before being randomly assigned to either
 intervention or control. During this observation period, they will wear a fitness activity
 tracker wristband to evaluate degree of physical activity and a Holter monitor to register
 number of premature ventricular contractions. Participants taking part in the interval
 training group will perform aerobic interval training 4 x 4 minutes intervals, 3 times a week
 for 12 weeks (week 1-12), whereas participants taking part in the control group will carry on
 with usual daily life with no lifestyle recommendations. All participants will then undergo a
 new period of observation (week 13-20) and repeat the tests and examinations performed at
 baseline and during the observation period prior to intervention/control.
Inclusion Criteria:

 -  Patients with ICD and dilated cardiomyopathy or coronary heart disease as cause for
 implantation

 -  ICD implanted at St Olavs hospital, Trondheim

 In case of difficulties with patient inclusion for the study, the criteria might be
 broadened to include patients with idiopathic ventricular arrhythmia as cause for
 implantation.

 Exclusion Criteria:

 -  inability to accomplish the exercise program due to serious comorbidity or to
 participate in regular training within the next 3 months due to other reasons

 -  signs of severe cardiac ischemia or persistent ventricular tachycardia during
 individualized treadmill O2 peak test, which after individual assessment is to be
 found at risk

 -  comorbidity where endurance training at more than moderate intensity is discouraged

 -  severe cardiac valve disease

 -  planned surgery within the next 3 months

 -  inability to give informed consent