An unusual case of aborted sudden cardiac death in a young woman: which is the culprit?

Background: Anomalous origin of a coronary artery (AAOCA) carries an associatedrisk of Sudden Cardiac Death (SCD) with interarterial anomalous left or right coronaryartery course (ALCA and ARCA respectively). Myocarditis, especially with extensivebrosis at MRI is also a risk factor for SCD in young population. Increasing use ofcardiac imaging techniques is enhancing myocarditis and AAOCA diagnosis, previ-ously completely skipped.Clinical case: We present a 23y/o woman without any relevant previous disease(except for BMI 15 Kg/m2) resuscitated by a relative from SCD while she wassleeping (5 DC shocks due to ventricular brillation, VF), followed by unevent-ful course and full recover. A cardiac CT scan showed an ARCA with interarte-rial course (between aorta and pulmonary artery) and moderate narrowing of RCAlumen at rest (Fig.1) and she was referred at our hospital for surgical coronary arteryre-implantation, asymptomatic with no further arrhythmias. Blood sample showednormal CBC, Troponin, C-reactive protein values. A cardiac MRI showed a pictureconsistent with a previous, subclinical, myocarditis with diffuse myocardial brosis(non-ischemic pattern) and mild reduction in ejection fraction (Fig.1). A right sidemyocardial biopsy failed to take a pathological sample due to epicardial brosisdistribution. Both cardiac tissue PCR and serum antibodies were negative for com-mon myocarditis viruses. Patient underwent an electrophysiological study withoutinduced arrhythmias. A Subcutaneous Debrillator (S-ICD) was implanted and shewas discharged with no complications.Discussion: In this peculiar case 2 diagnosis could be responsible for the abortedSCD. A recent review on AAOCA underlines the importance of ischemia in patientswith ARCA where, particularly without proximal vessel narrowing, a conservativeapproach may be reasonable. In this woman affected both by AAOCA and myocar-dial brosis the culprit disease is debatable, but in absence of recurring events, signsof ischemia and imaging criteria for malignant pattern (acute take-off, slit-like, severecompression), eventual surgery was postpone and she was protected with a S-ICD(SCD secondary prevention). Furthermore the occurrence of VF at rest is less typi-cal for AAOCA, mostly occurring during exercise. At 6 months she is asymptomaticwithout clinical events.Conclusions: We present a case of an aborted SCD with 2 possible culprit diagno-sis in which multimodality imaging is fundamental in case management and clinical decisions.