Transthoracic high frequency (7.5 MHz) echocardiographic assessment of coronary vascular reserve and its relation to left ventricular mass
JJ Ross Jr,
JF Ren,
W Land,
K Chandrasekaran,
and
GS Mintz
Department of Medicine, Hahnemann University Hospital, Philadelphia, Pennsylvania 19102.
Transthoracic high frequency (7.5 MHz) ultrasonography can visualize the distal left anterior descending coronary artery. Thirty-seven patients were studied before and after administration of 0.4 mg sublingual nitroglycerin to determine whether this technique could quantitatively record changes in coronary artery diameter after intervention. Left anterior descending coronary artery diameter increased from 2.2 to 2.8 mm (p less than 0.05). The vasodilator response of this artery was compared with left ventricular mass index in normal subjects, patients with congestive cardiomyopathy and those with end-stage renal disease and left ventricular hypertrophy. Left anterior descending artery diameter increased 55% in normal subjects, 27% in patients with dilated cardiomyopathy and 10% in those with end-stage renal disease with left ventricular hypertrophy. These results demonstrate that high frequency ultrasound can detect nitroglycerin-induced changes in left anterior descending artery diameter. The percent increase is related to the diameter before nitroglycerin administration, which is related to the underlying diagnosis and left ventricular mass index.
