Derivation of systolic time intervals from doppler measurement of temporal arterial blood flow

During one- or two-leg bicycle exercise in three subjects the exercised limb(s) were made ischemic by occlusion cuffs inflated to 300 Torr immediately at, or 30 s before, end of 7-min exercise and kept inflated for 3 min of recovery. Mean arterial pressure (MAP) remained elevated during occluded recovery, whereas heart rate (HR) and forearm blood flow tended to recover at the same rate as in the control situation without occlusion. Systolic time intervals (STI) were negatively correlated to HR in the interval 60–120 beats/min. In spite of a variation in afterload of 30 Torr induced by occlusion the correlation between HR and STI fitted the same equations. The involvement of different size of muscle mass did not change these relationships. The elevation of MAP during ischemia of exercised muscles is due to an increased vascular tone reflexly induced from muscle chemoreceptors and not cardiac in origin. The results also demonstrate that heart contractility adapts well to the induced afterload.

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Relationship between systolic time intervals and arterial blood pressure

Clinical Cardiology ◽

10.1002/clc.4960091104 ◽

1986 ◽

Vol 9 (11) ◽

pp. 545-549 ◽

Cited By ~ 4

Author(s):

P. Cinelli ◽

M. De Scalzi ◽

V. De Leonardis ◽

S. Citi

Keyword(s):

Blood Pressure ◽

Arterial Blood Pressure ◽

Systolic Time Intervals ◽

Time Intervals ◽

Arterial Blood ◽

Systolic Time

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Relationship between maximal oxygen uptake and left ventricular function in exercise

Journal of Applied Physiology ◽

10.1152/jappl.1978.44.1.44 ◽

1978 ◽

Vol 44 (1) ◽

pp. 44-49 ◽

Cited By ~ 11

Author(s):

L. A. Wolfe ◽

D. A. Cunningham ◽

G. M. Davis ◽

H. Rosenfeld

Keyword(s):

Systolic Time Intervals ◽

Bicycle Ergometer ◽

Left Ventricular ◽

Cardiovascular Fitness ◽

Left Ventricular Ejection ◽

Time Intervals ◽

Ventricular Performance ◽

Arterial Blood ◽

Blood Pressures ◽

Systolic Time

Left ventricular systolic time intervals (STI's), cardiac output, and arterial blood pressures were measured during bicycle ergometer work in three groups of 10 young men (aged 20–33 yr) who represented average (VO2max = 42–45 ml.kg-1.min-1), moderate (VO2max = 50–56 ml.kg-1.min-1), and high (VO2max = 59–72 ml.kg-1.min-1) levels of cardiovascular fitness. The subjects were studied using noninvasive procedures at steady-state heart rate of approximately 110, 130, and 150 beats.min-1. At all exercise levels, the fitter subjects displayed slightly shorter values for the preejection period (PEP) compared with less fit groups. Significantly (P less than 0.05) larger stroke volumes, longer left ventricular ejection times (LVET), faster mean systolic ejection rates and lower PEP/LVET ratios were found in the group with the highest aerobic capacity. Although these observations appear to indicate a superior mean level of left ventricular performance in groups who represent high levels of cardiovascular fitness, it was concluded that the use of STI values by themselves to describe the cardiovascular fitness of an individual would not be warranted.

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