PhD Defense: Idiopathic ventricular fibrillation: Absence of evidence is not evidence of absence

Sudden cardiac death is a major problem in the Western world. In young people, sudden cardiac arrest is often caused by ventricular fibrillation (VF). In most cases of VF, an underlying cause is found. However, in a small part of the patients, no cause for VF can be found. These patients are diagnosed with “idiopathic ventricular fibrillation” (IVF). Extensive diagnostic testing is necessary to exclude any underlying diseases.

In this dissertation, we have attempted to further unravel the mystery surrounding IVF. Using a large national IVF database, we have attempted to further unravel the characteristics of current IVF patients. In this thesis, we focussed on the value of systematic diagnostic testing in IVF and on a specific phenotype in IVF, called short-coupled VF. We were able to reveal abnormalities around the mitral valve using cardiac magnetic resonance imaging and we have applied echocardiographic deformation imaging to detect subtle myocardial abnormalities. Our research indicates that subtle myocardial disease is present in a large subset of IVF patients. At last, we performed familial cascade screening in IVF to search for cardiac abnormalities in family members, and we created a practical flowchart for diagnostic testing after sudden cardiac death of a young person.