Hypertrophic cardiomyopathy (HCM) is associated with sudden cardiac death and an increased risk of atrial fibrillation and subsequent embolic event. An insertable cardiac monitor will provide data on cardiac rhythm over a period of 18 months. This will provide an extended monitoring far longer than 24-48 hours of Holter monitoring as is currently usual care. Therefore, detection of arrhythmias could be used in risk stratification and decision-making with regard to offer an implantable defibrillator and anticoagulants.

Detection of non-sustained ventricular tachycardia (NSVT) and atrial fibrillation (AF) using an insertable cardiac device monitor (SJM Confirm XT) which is connected to the patients smart phone and monitored for 18 months.

Inclusion Criteria:

• hypertrophic cardiomyopathy

Exclusion Criteria:

• aortic stenosis (moderate, severe)
• hypertrophic cardiomyopathy associated with metabolic disease (e.g. Fabry) and syndromes (e.g. Noonan)
• systolic heart failure
• cardiac device (previous pacemaker, implantable defibrillator )
• history of myocardial infarction
• percutaneous coronary intervention and/or coronary artery by-pass grafting
• pulmonary vein isolation, Maze surgery, ventricular tachycardia ablation, ectopic atrial tachycardia ablation
• renal clearance below 40
• malignancy or other comorbidity with less than five years life expectancy
• pregnancy of planned within 18 months
• drug addiction, severe mental disease
• not able to participate in 18 months follow-up
• 5 years risk more than 6% according HCM risk calculator of European Society of Cardiology guidelines.