Transthoracic Doppler echocardiographic assessment of left anterior descending coronary artery and intramyocardial small coronary artery flow in patients with hypertrophic cardiomyopathy.
OBJECTIVE
Transthoracic Doppler echocardiography with a high frequency transducer can visualize blood flow velocities in the left anterior descending coronary artery (LAD) and the intramyocardial small coronary artery in humans. However, the clinical utility for coronary circulation has not been established. To evaluate the reliability of transthoracic Doppler echocardiography for measuring coronary flow velocity, we firstly evaluated the coronary flow velocity and coronary flow reserve in the LAD in patients with coronary artery disease, and secondly evaluated the flow velocity in the intramyocardial small coronary artery in patients with hypertrophic cardiomyopathy.


METHODS
Transthoracic Doppler echocardiographic LAD flow velocity was simultaneously recorded with Doppler guide wire before and after papaverin or adenosine triphosphate (ATP) infusion in 18 patients with coronary artery disease (mean age 61 years) during cardiac catheterization. Intramyocardial small coronary artery flow velocity by transthoracic Doppler echocardiography was examined in another 51 patients (mean age 53 years) with hypertrophic cardiomyopathy and 31 normal subjects (mean age 62 years).


RESULTS
There were good correlations of coronary flow reserve measured by papaverin (r = 0.87) and ATP (r = 0.80) administration between the transthoracic Doppler echocardiography and Doppler flow wire methods in patients with coronary artery disease. Averaged diastolic peak flow velocity [77 +/- 36 (mean +/- SD) cm/sec] and time velocity integral (27 +/- 11 cm) in the small coronary artery in patients with hypertrophic cardiomyopathy were significantly higher (p < 0.05) than those in the LAD (46 +/- 20 cm/sec and 19 +/- 11 cm), respectively. However, there were no significant differences of flow velocities in the control subjects between averaged diastolic peak flow velocity (31 +/- 10 cm/sec) and time velocity integral (11 +/- 5 cm) in the small coronary artery and those in the LAD (32 +/- 11 cm/sec and 12 +/- 5 cm), respectively. Systolic reversal flow in the small coronary artery was observed in 41 patients with hypertrophic cardiomyopathy, but not in the controls.


CONCLUSIONS
Transthoracic Doppler echocardiography using a high frequency transducer is a useful technique for noninvasive investigation of flow velocity dynamics in the LAD and intramyocardial small coronary artery in patients with hypertrophic cardiomyopathy.
Minagoe
S
S
First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima 890-8520, Japan.
D001783:Blood Flow Velocity; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D015150:Echocardiography, Doppler; D018618:Echocardiography, Doppler, Color; D006801:Humans; D008875:Middle Aged; D018084:Ultrasonography, Interventional