Simultaneous cardio-cerebral ultrasonic measurement technique for assessing the interrelationship between cardiac and cerebral circulations in elderly subjects: a preliminary study.
To assess the interrelationship between the cardiac and cerebral circulations, simultaneous measurements of cardiac output (CO) and common carotid blood flow volume (CCBFV) was performed by M-mode echocardiography of the left ventricle, and quantitative ultrasonic Doppler blood flowmetry of the common carotid artery. The subjects studied were 12 healthy persons living in a home for the elderly ranging in age from 62 to 99 years. These subjects were divided into two groups: those who were in their 90s (Group I, 5 females) with a mean age of 93.6 +/- 3.5 years (mean +/- SD), and those who were in their 60s to 80s (Group II, 1 male and 6 females) with a mean age of 77.1 +/- 8.1 years. The average CO in Group I was 2.85 +/- 0.37 L/min, and 4.18 +/- 0.52 L/min in Group II. The average CCBFV was 4.74 +/- 0.64 dl/min in Group I, and 4.44 +/- 1.01 dl/min in Group II. The ratio of CCBFV to CO was 16.6 +/- 1.32% in Group I, and 10.6 +/- 1.45% in group II. Good linear correlations of y = 1.44x +0.65 (r = 0.82) in Group I and y = 1.58x - 2.15 (r = 0.81, p less than 0.05) in Group II were observed between CO (x) and CCBFV (y). No such close correlations were observed between CCBFV and other indices of left ventricular function such as circumferential fiber shortening or fractional shortening of the diameter of the left ventricle (r less than or equal to 0.56, p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)