In patients with ALCAPA, a chest x-ray may demonstrate cardiomegaly with or without pulmonary vascular congestion; however, this is not diagnostic. Left ventricular hypertrophy, abnormalities of repolarization detected as ST-segment depression, and/or inversion in the inferior and lateral leads may be noted on ECG, as well as wide, deep Q waves in the lateral leads and poor R wave progression. Left ventricular dysfunction, mitral regurgitation or mitral annular dilation, and wall motion abnormalities in the setting of left heart dilatation may be seen on TTE. Enlargement of the proximal right coronary artery may reflect the development of extensive collateralization.
Although most cases may be diagnosed with echocardiography, echocardiography alone may be inadequate for establishing the diagnosis because the close course of the anomalous coronary vessel to the aortic sinus may create a false impression of normal anatomic origin. The use of color-flow Doppler ultrasonography has largely eliminated the need for cardiac catheterization by providing significantly increased diagnostic accuracy. Although it is dependent on PA pressures and the development of collateral vessels, abnormal retrograde anomalous coronary flow can be clearly demonstrated with color-flow Doppler ultrasonography. If the anomalous coronary artery arises from a branch PA, however, the diagnosis may be difficult to make using echocardiography, even when enhanced with Doppler techniques.
Although retrograde flow into the PA is most often directed in an unusual orientation, improper diagnosis of a PDA shunt or a coronary-cameral fistula may be erroneously made. Lack of collateralization may also make identification by selective right coronary arteriography or aortography difficult in the catheterization laboratory. The use of transesophageal echocardiography is seldom necessary in infants.
Although cardiac catheterization has traditionally been used as the criterion standard for diagnosing coronary artery anomalies, the angular restriction of angiographic projections and the limitations inherent in its planar imaging nature may render conventional angiography less useful for creating a clear anatomic picture when compared with newer imaging modalities. Conventional angiography is also invasive and carries a morbidity and mortality rate of 1.5% and 0.15%, respectively (especially in children).
With progressive improvement in both the resolution and technical specifications, as well as multiplanar reconstruction with maximum intensity projections and volume rendering, CCTA may be an adequate alternative diagnostic tool for detecting coronary anomalies. Although in younger patients a short investigation time and minimal follow-up using CCTA as a diagnostic modality provides practical usefulness, multiangle assessment using three-dimensional reconstruction can provide optimal vessel projection for evaluating surgical intervention; therefore, repeated exposure to radiation and contrast required for conventional angiography is minimized.
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Cite this: Shah Azmoon, Matthew Budoff, David Atkinson. Pediatric Case Challenge: Alarming Symptoms in a Toddler Who Had Myocarditis and Recently Immigrated - Medscape - Jan 17, 2023.