Case report of asymptomatic very late presentation of ALCAPA syndrome: review of the literature since pathophysiology until treatment

Background Anomalous origin of the left coronary artery (LCA) from the pulmonary artery (ALCAPA) is an unusual congenital heart defect which affects approximately 1 in 300 000 live births and accounts for 0.5% of all congenital heart disease. Without surgical intervention, most patients die in infancy (nearly 90%). Case summary We present a rare case of an asymptomatic 67-year-old female. Transthoracic echocardiography demonstrated a dilated right coronary artery (RCA) and multiple collaterals. ALCAPA was confirmed by multidetector computed tomography. The left main artery was seen originating from the pulmonary artery and well-developed collaterals were visualized between the RCA and LCA. No areas of myocardial infarction were identified on cardiac magnetic resonance. Stress studies showed no inducible ischaemia. Discussion Our clinical case of an ALCAPA patient who survived and remained asymptomatic to their late 60’s, highlights the importance of well-collateralized and pressurized coronary system to maintain adequate myocardial perfusion. Physicians should be aware of this congenital anomaly as appropriate early diagnosis is crucial to prevent irreversible myocardial damage, acute ischaemia, and arrhythmias, and can improve patient outcomes. Surgical treatment is suggested irrespective of symptomatology or the presence of inducible myocardial ischaemia.

Effects of GIK (glucose–insulin–potassium) on stress-induced myocardial ischaemia

Despite the evidence in experimental animal models that insulin, or GIK (glucose–insulin–potassium), improves left ventricular function and perfusion during both acute and chronic ischaemia, clinical studies have generated conflicting results. We tested the hypothesis that pretreatment with GIK attenuates the vascular and functional effects of stress-induced myocardial ischaemia in humans. Twenty-two patients with evidence of inducible myocardial ischaemia were enrolled; 11 patients with normal ventricular function underwent two dipyridamole echocardiography tests, and 11 with regional contractility defects from previous myocardial infarction were submitted to two ECG exercise tests combined with 201Tl myocardial perfusion scintigraphy; the tests were preceded by 60 min of either normal saline or an isoglycaemic GIK infusion. On a stress echocardiogram, a 30% reduction in the severity of ischaemia was observed. On ECG ergometry, GIK infusion slightly increased the time to ischaemia (+0.6 min, P=0.07); however, the higher workload (+8%, P=0.07) was achieved at a similar rate–pressure plateau. On scintigraphy, an increase in ischaemic segments (+48%, P<0.001) was imaged mainly at the expense of viable (but non-ischaemic) and non-viable segments, which were reduced by 60%. GIK affected stress-induced left ventricular underperfusion only marginally (GIK: 39.7±2.5 compared with saline: 35.4±2.2 units, P<0.05), but significantly improved its acute reversibility (−42±4 compared with −25±4%, P<0.001). We conclude that GIK pretreatment attenuates the effect of ischaemia on myocardial contractility, slightly improves exercise tolerance and causes a more rapid and diffuse recovery of post-ischaemic reperfusion.