Extremely rare coronary anomaly as cause of palpitations: a case report of single right coronary artery-multimodality imaging and its impact on treatment decisions.

Background: We report the case of a 63-year-old white Caucasian male patient admitted to the clinic because of atypical angina and palpitations. Other comorbidities included hypertension, hyperuricaemia, and hypercholesterolaemia. He was admitted to a tertiary cardiac centre for deepened diagnostics of his complaints. Case summary: Echocardiography revealed no pathology, but due to high calcium score (Agatston > 400 units), signs of arrhythmia during exercise, and atypical angina complaints, further investigations were performed. Invasive coronary angiography revealed stenosis up to 53% in the middle part of the right coronary artery (RCA), and computed tomography angiography showed no left coronary artery, only malignant-coursed vessel, running from the proximal part of the RCA. Single-photon emission tomography findings allowed to come to a decision not to perform invasive treatment (coronary artery bypass grafting), due to acceptable perfusion and viability of the heart muscle. Discussion: Single coronary artery is an extremely rare anomaly. This requires highly individualized diagnostic approaches, which include multiple imaging modalities, as each adds different information. While the only coronary vessel was narrowed in 53%, no significant ischaemia was detected. Left ventricular function remained preserved.