Intercoronary Continuity With Bidirectional Flow: Dynamic Changes Parallel To Coronary Disease Progression - Intercoronary Continuity With Bidirectional Flow: Dynamic Changes Parallel To Coronary Disease Progression - Open Access Pub

Direct intercoronary continuity is a rare angiographic finding. We report an unusual case of a 51-year old male with coronary disease who demonstrated intermittent variability in the directions of flow as a result of changes in his coronary disease. DOI10.14302/issn.2329-9487.jhc-12-167 Direct continuity between coronary arteries is a rare congenital finding, occurring in about 0.02% of cases, based on pathological or angiographic studies 1. This entity is distinct from collateral coronary vessels, which develop gradually in the presence of obstructive coronary disease. A 51-year old male with a history of diabetes mellitus, hypertension and dyslipidaemia was hospitalized with a typical clinical history of unstable angina that had recently appeared. He underwent coronary angiography and was found to have single vessel disease, with a significant stenosis in the proximal segment of his right coronary artery (RCA). Angioplasty was performed, with the successful implantation of a bare metal stent and the patient was discharged in good health. Six months later he was readmitted. He had started to experience mild exercise-induced chest pains several weeks following his previous procedure and these had continued intermittently, culminating in a more prolonged episode associated with ST segment elevation in his electrocardiogram (ECG). These ECG changes had resolved by the time he was hospitalized. Coronary angiography was again performed. On injections into the left system, collaterals to the distal RCA were demonstrated (figure 1), arising from the left circumflex coronary artery (CX). Injections into the RCA demonstrated tight in-stent restenosis, (figure 2) and a drug eluting stent was successfully implanted. After the angioplasty, injections into the RCA were seen to retrogradely fill the CX (figure 3). The suspicion arose that maybe the left coronary artery had been inadvertently damaged during angiography, so the left coronary was again cannulated and injections performed, demonstrating entirely normal left main and CX arteries. However, the collateral flow that had previously been demonstrated from the CX to the RCA was no longer apparent. On review of the previous angiogram, it was noted that the RCA retrogradely filled the CX despite the original significant stenosis (figure 4). In essence, it became apparent that the bidirectional filling of the RCA from the CX and vice versa was in fact a direct continuity between the vessels and not collaterals, as free flow was noted from the RCA to the CX even when both arteries were completely patent. Figure 1.