Unmasking Ischemic Cardiomyopathy with CMR: An Adult Case of ALCAPA

Description of Clinical Presentation: A 29-year-old woman was referred to cardiology for evaluation of dyspnea (NYHA class II). She had no cardiovascular risk factors and was not taking any medication. Physical examination was unremarkable.
Transthoracic echocardiography revealed a mildly dilated left ventricle (LV) with global hypokinesia, no regional wall motion abnormalities, and mildly reduced ejection fraction (EF: 49%).

Diagnostic Techniques and Their Most Important Findings: Cardiac magnetic resonance (CMR) was performed as part of the heart failure with reduced ejection fraction (HFrEF) workup. It demonstrated a mildly dilated LV with hypokinesia in the mid anterior and mid anteroseptal segments, and mildly reduced systolic function (EF: 48%). On phase-sensitive inversion recovery (PSIR) imaging, subendocardial late gadolinium enhancement was observed in the basal anterior segment ( < 25% transmurality) and in the mid anterior, mid anteroseptal, and apical septal segments ( < 50% transmurality). Unexpectedly, steady-state free precession (SSFP) sequences also revealed an ectatic right coronary artery, visualized in the three- and four-chamber views and at the aortic root short axis, as well as a connection between an epicardial vessel and the right ventricular outflow tract with inward flow into the RVOT. Computed tomography coronary angiography confirmed an anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), while invasive coronary angiography excluded additional coronary abnormalities. The patient subsequently underwent coronary artery bypass surgery with the left internal mammary artery grafted to the mid left anterior descending artery, along with surgical ligation of the anomalous left anterior descending (LAD) artery origin from the pulmonary trunk. At three-month follow-up, the patient was asymptomatic. Repeat CMR showed a non-dilated left ventricle with normal systolic function and persistence of the subendocardial scar previously described.

Learning Points from this Case:

• CMR plays a pivotal role in differentiating ischemic from non-ischemic cardiomyopathy through precise tissue characterization.


• The presence of a subendocardial scar in a coronary distribution mandates exclusion of an ischemic cause, even in young patients without conventional risk factors.


• In this case, CMR findings guided further evaluation, leading to the diagnosis of ALCAPA, a rare but surgically correctable anomaly.


• CMR also provides valuable viability assessment, as subendocardial scars with transmurality < 50% are associated with recovery of contractility after revascularization.

SSFP image in oblique LVOT (a) and oblique RVOT (b) showing ectatic origin of RCA from aortic root and LAD from pulmonary artery. Ao, aorta; RCA, right coronary artery; PA, pulmonary artery; LAD, left anterior descending.
PSIR imaging in SA (a-e) and in 2-Chamber view (f) showing a subendocardial scar in LAD territory.
Coronary CT. Different multiplanar reconstructions: axial (a), sagital (b) and coronal (c) showing origin of LAD from pulmonary artery. Ao, aorta; PA, pulmonary artery; LAD, left anterior descending.