Assessment of Coronary Flow Parameters by Transesophageal Echocardiography in Patients with Isolated Coronary Artery Ectasia: Effect of Intravenous Nitroglycerin

Background: We sought to assess coronary flow parameters in patients with isolated coronary artery ectasia (CAE) as compared to subjects with normal coronaries. Methods: Consecutively, we enrolled 30 patients with ectasia of the left anterior descending (LAD) coronary artery (study group), and 10 subjects with normal coronaries (control group). All patients underwent transesophageal echocardiography to visualize the LAD. Spectral recordings of proximal LAD flow velocities were made and velocity time integrals were calculated. The diameter of the proximal LAD was measured and LAD blood flow was calculated. Nitroglycerin (0.3 mg) was administered intravenously and measurements were repeated 5 minutes later. Results: The mean age of the whole series was 48.6 +/- 8 years, 39 (97.5%) being males. A significantly higher baseline systolic, diastolic, and total coronary blood flow was found in the study group as compared to the control group (46.1 +/- 34.3 vs. 23.1 +/- 8.2, 123.9 +/- 73.3 vs. 68.1 +/- 21.6, 170.1 +/- 97.9 vs. 91.1 +/- 26.8 cm3/min, respectively, P < 0.05 for all). Within the study group, nitroglycerin administration caused a significant decrease in peak diastolic velocity; systolic, diastolic, and total velocity time integrals; and both diastolic and total coronary blood flow (P < 0.05 for all). Meanwhile, within the control group, nitroglycerin administration caused a significant increase in the total coronary blood flow (P < 0.05). Conclusions: Patients with CAE have higher resting coronary blood flow in comparison with subjects with normal coronaries. Intravenous nitroglycerin administration causes significant reduction of coronary blood flow in ectatic coronary arteries. (Echocardiography 2010;27:1004-1010).