Ventricular Fibrillation From Spontaneous Coronary Artery Dissection in a Patient With Atrioventricular Nodal Re-entrant Tachycardia: Rationale for Implantable Cardioverter Defibrillator Therapy.

Ventricular fibrillation (VF) management requires identification of the underlying cause and consideration of implantable cardioverter defibrillator (ICD) therapy; these decisions are complicated when the aetiology is unclear. We present a 41-year-old woman with lifelong atrioventricular nodal re-entrant tachycardia (AVNRT) who experienced cardiac arrest secondary to VF. Multimodality cardiac imaging identified features suggestive of spontaneous coronary artery dissection (SCAD) with transient vessel healing but a new apical scar. Given the scar-related arrhythmogenic substrate, risk of SCAD recurrence, and prior AVNRT episodes degenerating into polymorphic ventricular tachycardia (PMVT), a single-chamber ICD was implanted. This case highlights the need to avoid diagnostic anchoring on the pre-existing arrhythmia as the cause for cardiac arrest and demonstrates the value of imaging in identifying SCAD as the cause and in guiding ICD decision-making.