Combined intra-cavitary course of left anterior descending artery and myocardial bridge of right coronary artery in right ventricle hypertrophy: a case report.

Background: Intra-cavitary (IC) coronary course is a rare anatomical variant that has become more commonly reported in the last decade. While the condition is generally benign and often discovered incidentally during coronary computed tomography angiography (CCTA), these arteries are vulnerable to injury during cardiac interventions. It is unclear whether right ventricle (RV) pathology, such as dilatation or hypertrophy, plays a role in this condition.

Case Summary: A patient in their fifties with a medical history of rheumatic heart disease and atrial fibrillation presented with dyspnoea and orthopnea but denied any previous chest pain. Upon examination, the patient exhibited slow atrial fibrillation and generalized anasarca. Echocardiography revealed severe mitral stenosis, tricuspid regurgitation, pulmonary hypertension, and a significantly dilated and impaired RV. Before surgery, a CCTA was performed and revealed an abnormal mid-left anterior descending (LAD) course through the RV cavity with complete systolic attenuation. This finding was later confirmed through invasive angiography. Additionally, the right coronary artery (RCA) showed a mid-segment myocardial bridge (MB). The patient was scheduled for mitral and tricuspid valves' surgery with no planned intervention to the LAD or RCA.

Discussion: Coronary IC course is a rare finding that poses a risk of arterial injury during invasive cardiac procedures. It is important for all cardiac interventionists to be familiar with this diagnosis and the potential hazards during cardiac interventions. Further research is needed to determine whether RV dilatation or hypertrophy can exacerbate coronary IC course or MB.