This study describes prospective cardiac arrest survivors admitted to a tertiary center in Copenhagen during a 1-year period

Patients underwent extensive evaluation, however, many patients (37%) did not receive a diagnosis

Family history did not predict etiology among cardiac arrest survivors

In 9 of 16 patients categorized as ‘idiopathic ventricular fibrillation’ supplemental ECG recordings suggested the presence of channelopathies as the cause of the cardiac arrest

Performing the ‘brisk standing’ test to induce postural sinus tachycardia and ‘elevation of precordial leads V1–2’ may be reasonable diagnostic tricks among cardiac arrest survivors in whom no diagnosis can be reached despite extensive evaluation