A case report of non-dominant right coronary artery occlusion: not always benign!

Background: Non-dominant right coronary artery (RCA) occlusion is uncommon and usually affects a small area of the myocardium. Rarely, it can complicate fatal outcomes such as shock, cardiac arrest, bradyarrhythmia, or tachyarrhythmia.

Case Summary: A 50-year-old man with no significant medical history presented with ventricular fibrillation (VF) cardiac arrest. He required prolonged cardiopulmonary resuscitation and multiple defibrillation shocks to achieve return of spontaneous circulation. ST elevation was noted on inferior leads. Due to refractory VF, extracorporeal membrane oxygenation (ECMO) was initiated followed by coronary angiography which demonstrated 100% acute occlusion of proximal RCA (small non-dominant), 90% stenosis of ramus intermedius (RI), and 80% stenosis of obtuse marginal (OM) arteries. Left ventricular ejection fraction was 35%. Percutaneous coronary intervention (PCI) of the RCA was performed with drug eluting stent. He had excellent clinical recovery without any neurological deficits. The ECMO was weaned off and decannulated within three days. Guideline directed medical therapy was administered. He remained hemodynamically stable and underwent staged PCI of RI and OM to achieve complete revascularization.

Discussion: Non-dominant RCA lesions are usually considered benign. However, when acute RCA occlusion results in cardiac arrest as seen in our patient, prompt revascularization is necessary. Treatment of cardiogenic shock with appropriate pharmacological and mechanical therapies is important, such as ECMO in our patient.