The importance of performing an exercise stress test in survivors of an unexplained cardiac arrest

In survivors of a cardiac arrest, a thorough investigation into the cause of the cardiac arrest is important. The diagnosis ‘idiopathic ventricular fibrillation’ (IVF) is used, if no underlying disease could be found. From earlier research and practical experience, we know that the investigation after a cardiac arrest is sometimes not completely performed, leading to an incorrect diagnosis of IVF which in turn means a patient may not receive adequate treatment for the real underlying disease. The exercise test is an example of a diagnostic test that is quite often omitted.

In this article, we describe three patients in whom the diagnosis of ‘catecholaminergic polymorphic ventricular tachycardia’ (CPVT), a heritable disease in which abnormal and life-threatening heart rhythms occur during exercise or heightened emotion such as anger or excitement, was missed as a result of not doing an exercise test. What these patients had in common was that all were young and otherwise healthy when they suddenly collapsed and had to be resuscitated. Upon arrival  at hospital, initial tests showed no abnormalities or problems that may have caused the collapse, except for an unusually long recovery interval (QT interval) on the electrocardiogram (ECG), which can be caused by the cardiac arrest itself or by long QT syndrome, among other things. As no other clues were found during their hospital stay, the patients were diagnosed with long QT syndrome. When an exercise test was later performed, either as part of a routine cardiological exam, or after a second opinion, CPVT was diagnosed. As a result of the delayed diagnosis, these patients did not receive the correct treatment, which is obviously less optimal for the patient and it may also lead to inadequate follow-up of family members. We conclude that the exercise test must be performed in the assessment of an otherwise unexplained cardiac arrest.

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Bergeman AT, Robyns T, Amin AS, Wilde AAM, van der Werf C.

Neth Heart J. 2023 Nov;31(11):444-451. PMID: 37347419.