title: Assessment of the effect of coronary artery bypass grafting on left ventricular performance by Doppler measurement of the aortic blood velocity during exercise.
abstract: The effect of coronary artery bypass grafting (CABG) on left ventricular (LV) function is studied noninvasively in 30 male patients with a mean age o 55.4 years using the continuous-wave Doppler technique of transcutaneous aortovelography (TAV). With a transducer applied in the suprasternal notch the main-stream aortic blood velocity recordings were obtained before and at maximum-tolerated supine exercise both prior to, and six weeks after, CABG. From the TAV recordings the stroke distance (Sd: or the systolic velocity integral which is a measure of the stroke volume) and minute distance (Md: or the measure of cardiac output) were derived as well as the percentage changes in these parameters with exercise (% delta Sd and % delta Md successively). Whereas no significant change following CABG was observed in the resting values for Sd, a significant improvement in the maximal exercise values for Sd and Md as well as the % delta Sd and % delta Md was noticed after CABG (p less than 0.001). Prior to CABG the % delta Sd (an indicator of left ventricular function) was significantly lower in 13 patients with a history of an old myocardial infarction (MI). The % delta Sd in these 13 patients was also significantly lower than that in the 17 patients without a history of MI though the improvement in the % delta Sd following CABG was similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D001011:Aorta / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000503:physiopathology; D005069:Evaluation Studies as Topic; D005080:Exercise Test; D006321:Heart / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications; D012212:Rheology; D014159:Transducers
chemical_list: D000319:Adrenergic beta-Antagonists