Provocable Pressure Gradient Across an Anomalous Left Main Coronary Artery
A Unique Diagnostic Tool
A 14-year-old girl presented with progressive fatigue. She had a family history of Marfan syndrome, and a previous evaluation had revealed only an anomalous origin of the left main coronary artery. Although previously negative, a recent technetium Cardiolite stress test demonstrated a mild reversible lateral wall defect. Before making a commitment to operate, the surgeon requested confirmation of the physiological significance of the anomaly. MRI displayed the left main coronary artery originating from the right coronary cusp (Figure 1). In the cardiac catheterization laboratory, the ostium of the anomalous left main coronary artery was cannulated (Figure 2), and a 0.014-in pressure wire (RADI Medical) was placed in the left anterior descending artery. No baseline pressure gradient was observed (Figure 3, left). Adenosine was infused intravenously (140 μg · kg−1 · min−1), and a fractional flow reserve (FFR) of 0.87 was measured (Figure 3, middle). After pressures returned to baseline, a dobutamine infusion was begun, with doses increasing from 10 to 40 mg · kg−1 · min−1 (Figure 3, right). The FFR was 0.86 at peak dobutamine infusion. Although neither of the FFRs reached the established ischemic threshold (≤0.75), the hemodynamic abnormality of the anomalous coronary ostium was demonstrated. Given the potential for sudden death and a dynamic provocable pressure gradient across the left main ostium, surgery was performed.