Study population: 1) mutation carriers without the hypertrophic phenotype (pre-clinical Hypertrophic Cardiomyopathy (HCM)) and in 2) patients with clinically overt HCM (clinical HCM).

Hypothesis: Cardiac troponin release after exercise can be demonstrated in both clinical and pre-clinical HCM patients.

Inclusion Criteria:

• Patients with an echocardiographically proven hypertrophic cardiomyopathy according to the ESC guidelines or individuals with a HCM associated mutation without the clinical characteristics of hypertrophic cardiomyopathy (pre-clinical HCM patients);
• Age ≥ 18 years;
• Able to comply with the protocol;
• Written informed consent.

Exclusion Criteria:

• Known significant epicardial coronary artery disease;
• Patients with LVH in the clinical setting of other disorders that explain the myocardial hypertrophy (amyloidosis, MELAS, Anderson-Fabry, WPW etc.);
• Heart failure NYHA class III-IV;
• Patients with known hemodynamic instability or syncope during exercise due to left ventricular outflow gradient or occurrence of ventricular arrhythmia;
• History of PTSMA (percutaneous transluminal septal myocardial ablation) or Morrow myectomy;
• Patients not able to complete a bicycle test;
• Any contraindication to MR imaging (MR imaging is not obligatory for assessment of the primary objective, therefore relative exclusion criterion);
• Recent (within 30 days) admittance to the hospital for any cardiac reason (myocardial infarction, heart failure, cardiac arrhythmia, etc.);
• Severe renal insufficiency (eGFR < 30 ml/min);
• Any other condition which, in the opinion of the investigator, may pose a significant hazard to the subject if he or she participates in the present study.

The study population will consist of clinical or pre-clinical HCM patients that are registered in the HCM database of the HCM outpatient clinic of University Medical Center St. Radboud. This database will be screened for eligible patients according to the in- and exclusion criteria described below.