Protective intercoronary continuity

Abstract

Intercoronary continuity, a congenital open-ended continuity with bidirectional blood flow between two major epicardial coronary arteries, is a rare variation in the coronary anatomy. It has been speculated by Esente et al. (1983) that such type of open-ended circulation may prevent the development of myocardial infarction if severe obstruction of one of the coronary arteries develops, but this has never been reported. A 48-year-old male suffered chest pain suggestive of acute myocardial infarction. The 12-lead electrocardiogram, 5 days later on presentation to our hospital, was normal and the Troponin T test was negative. In view of the history, suggestive of acute coronary syndrome, a coronary angiogram was done. Coronary angiogram revealed total occlusion of the proximal left anterior descending artery (Fig.1A), and the left circumflex artery did not show any significant coronary artery disease. There was insignificant disease of the right coronary artery and almost the whole left anterior descending artery was filling retrogradely (Rentrop III flow) from the posterior descending artery (Fig. 1B) through an intercoronary continuity. Intercoronary arterial connections can be either collateral coronary circulation (coronary anastomosis between branches of the main coronary arteries) or intercoronary continuity (direct continuity between the main coronary arteries). In both types of intercoronary arterial connection blood flow is usually bidirectional. The true prevalence of intercoronary continuity is unknown. Atak et al. (2002) reported one case among 7,986 coronary angiograms. Arat-Ozkan et al. (2004) described one case among 12,674 angiograms performed. In the postmortem study by Reig et al. (1995) of 100 human hearts from individuals with an average age of 61 years, 7 cases of intercoronary artery were described. Reig et al. (1995) reported that intercoronary continuity is found either as continuity between the anterior and posterior interventricular arteries in the distal portion of the posterior interventricular groove or as continuity between the distal right coronary artery and the left circumflex arteries in the posterior atrioventricular groove. Angiographically intercoronary continuity has to be distinguished from the coronary collaterals. The features that favor the presence of intercoronary continuity include the presence of a single straight epicardial vessel connecting the terminal portions of major epicardial vessels in the interventricular or atrioventricular groove and the connecting vessel size of more than 1 mm in diameter. The diameter of the collateral vessels is usually less than 300 lm and they arise at an angle from the primary vessel. Collaterals are usually present in association with critical narrowing of a coronary vessel whereas intercoronary continuity is usually described in association with angiographically normal vessels. But in case of any doubt, the final arbiter becomes the histological examination of the concerned vessel at postmortem. A collateral vessel has the appearance ...

Intercoronary Continuity: A Case Report

“…However, this large anastomotic connection might have a potential role in protecting the myocardium in the presence of significant stenosis in either of the parent arteries. 3,4 To support this hypothesis, our case had totally occluded LAD and severe stenosis in the proximal RCA, but she was hemodynamically stabile and could survive. Moreover, despite the significant stenosis in the proximal RCA, inferior ischemia was not detected during the myocardial perfusion.…”

Intercoronary continuity between the right and circumflex coronary arteries causing myocardial ischemia

“…Intercoronary continuity is a congenital open-ended connection with bidirectional flow between two major epicardial coronary arteries. [2] Atak et al [3] and Arat-Ozkan et al [4] reported their individual cases among 7,086 and 12,674 angiograms, respectively. In a postmortem study of 100 human hearts, it was detected in seven cases.…”

“…[6] Intercoronary connection is a single straight epicardial vessel with a diameter of ≥1 mm and composed of layers of a typical muscular artery, connecting the terminal portions of major epicardial vessels. [2] Although some authors speculated that these connections may have a potential protective role in the myocardium against obstructive CAD, [1] their functional significance remains unclear. Our case of inter-coronary continuity was associated with myocardial ischemia, which we think is the first reported feature in the literature.…”