Coronary Artery Ectasia and Systolic Flow Cessation in Hypertrophic Cardiomyopathy
A 24-year-old woman was evaluated for exertional dyspnea and chest pain. Echocardiography showed marked apical, septal (14 mm), and anterolateral (21 mm) hypertrophy with normal inferior and posterior wall thickness (Figure 1⇓). The patient underwent right and left heart catheterization, with coronary and biventricular angiography. The cardiac index was 2.2 L · min−1 · m−2. The left ventricular pressure was 100/0 to 10 mm Hg, without evidence of an intracavitary gradient. Right anterior oblique ventriculography demonstrated a subtotal obliteration of the left ventricular cavity during systole (Figure 2⇓). Simultaneous right and left ventricular angiography revealed a massively thickened interventricular septum (Figure 3⇓). Coronary angiography showed no hemodynamically relevant fixed stenosis. The striking finding was the dilation and pronounced tortuosity of the coronary arteries, particularly the left anterior descending arterial (LAD) system (Figure 4⇓, bottom), without signs of a coronary artery-to-left ventricular fistula. The coronary perfusion pattern of the LAD showed marked dynamic changes: the dye propagation occurred only during ventricular diastole; during systole, radiocontrast flow practically ceased, with apparent obliteration of the vascular lumen. Figure 4⇓ shows the left coronary arterial system during the same cardiac cycle: during systole, the LAD system is “squeezed empty” (Figure 4⇓, top), while the same vessels are rapidly filled during the subsequent diastole (Figure 4⇓, bottom). The dynamic changes of luminal diameter are illustrated quantitatively in Figure 5⇓. The caliber of a compressed and noncompressed branch of the LAD (Figure 4⇓, top and bottom, arrows) was measured frame by frame (12.5 frames per second) during three consecutive cardiac cycles by digital image analysis (CASS II, CVA4v5.2).
The vascular ectasia was most pronounced in the vessels supplying the hypertrophic myocardium, suggesting that the vascular dilation was causally related to functional and/or structural changes of the left ventricular wall. The coronary ectasia associated with hypertrophic cardiomyopathy appears to be morphologically and etiologically distinct from coronary aneurysms in vasculitis and coronary artery disease. In hypertrophic cardiomyopathy, the phasic characteristics of coronary arterial blood flow may be exaggerated to the extent that even systolic flow reversal has been described.1 However, it is unusual to see these phasic variations in luminal diameter during coronary angiography. The systolic obliteration of the distal LAD system in the present patient suggests that the abnormally high wall tension of the hypertrophic left ventricular apex and septum may act functionally as a giant “muscle bridge,” causing systolic blood flow cessation.2 High intraluminal pressure during ventricular systole caused by peripheral flow obstruction may have contributed to the ectatic morphology of the LAD.
The clinical symptom of angina in the presence of massive coronary ectasia could be explained by the mismatch between the metabolic demand of the hypertrophic myocardium and the regional blood supply3 compromised by intermittent coronary flow obstruction and possibly coexistent small-vessel disease.4 5
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to Dr Hugh A. McAllister, Jr, St Luke’s Episcopal Hospital and Texas Heart Institute, 6720 Bertner Ave, MC1–267, Houston, TX 77030.
- Copyright © 1998 by American Heart Association
Brugada P, Bar FW, de Zwaan C, Roy D, Green M, Wellens HJ. “Sawfish” systolic narrowing of the left anterior descending coronary artery: an angiographic sign of hypertrophic cardiomyopathy. Circulation. 1982;66:800–803.
Nienaber CA, Gambhir SS, Mody FV, Ratib O, Huang SC, Phelps ME, Schelbert HR. Regional myocardial blood flow and glucose utilization in symptomatic patients with hypertrophic cardiomyopathy. Circulation. 1993;87:1580–1590.
Dissmann R, Schultheiss H. Ischemia in patients with hypertrophic cardiomyopathy: various causes and symptoms and the difficulties of ischemia screening tests. Eur Heart J. 1996;17:982–984.