Radionuclide ventriculographic responses to graded supine and upright exercise: Critical role of the Frank-starling mechanism at submaximal exercise

Radionuclide Ventriculography in Normal Volunteers Performing Graded Supine Bicycle Exercise

“…Previous investigations have shown that the normal LVEF response to supine bicycle exercise is usually a 5 % increase, and that there is little change in diastolic vol ume [7], Our study demonstrates that LVEF progres sively rises in nearly all stages of graded supine exercise, in agreement with Steingart et al [10]. Our data show a trend for the LVEF to rise sharply during the first stage of exercise, to then stabilize and then to increase slowly in the later stages as the subjects approach maximal exer tion.…”

“…This was also noted by Schoen et al [14] and Manyari et al [16] in studies of normal subjects undergoing supine bicycle exercise. However, Steingart et al [10] reported an increase in diastolic volume in the early stages of both supine and upright exericse, with no significant changes in the later stages. Their subjects had their legs positioned at the level of the heart during supine exercise (rather than above as in our study and in Manyari's report), and this may have prevented a central redistribution of blood volume that could conceivably mask a Starling effect at low-level exertion.…”

“…LVED volume did not show any significant change. The proportional increase in exercise PFR was steeper than that of the PER.In summary: (1) the LVEF response during supine exercise is biphasic with an early plateau followed by contin uously increasing values; (2) the LVEF response to exercise is independent of sex but is dependent on baseline EF and the intensity of the exercise protocol; (3) no significant changes in LVED dimension occurred; the Frank-Starling mechanism is not employed during supine bicycle exercise, and (4) the increase in PFR appears to be independent of the increase in PER.or no change in the left ventricular end-diastolic volume [7], However, this pattern is dependent on such factors as age [8], sex [9], patient exercise position [10] and sys temic hypertension [11], Most studies have confined their analysis to the rest and peak exercise RVG, but some have also recorded the RVG changes at various intervals during and after exercise [9,10]. In this inves tigation, we recorded a number of systolic and diastolic variables during each stage of graded supine exercise in 20 clinically normal volunteers.…”

Left Ventricular Dysfunction during Dynamic Exercise in Noninsulin-Dependent Diabetic Patients with Retinopathy

“…Both deter minants increase during exercise; increase in stroke volume due to increased venous re turn would lengthen LVET [21], while in crease in ejection rate would shorten LVET. The critical role of the Frank-Starling mech anism during dynamic exercise has been demonstrated in subjects with advancing age [22] or in patients with coronary artery dis ease [23]. As heart rate response to exercise was not impaired in our patients with reti nopathy.…”

Immediate effects of bumetanide on systemic haemodynamics and left ventricular volume in acute and chronic heart failure.

“…The onset of angina pectoris is accompanied by acute but reversible left ventricular failure characterised by increased left ventricular pressure and volume; in chronic heart failure there is long-standing pressure and volume overload (McCans & Parker, 1973;Sharma et al, 1976;Rerych et al, 1978;Nechwatal et al, 1980;Freeman etal., 1981;Manyari etal., 1981;Hakki et al, 1983;Mancini et al,-1983;Manyari et al, 1983;Osbakken et al, 1983;Steingart et al, 1984). It is widely believed that the immediate and long-term benefits of diuretic therapy in such patients are due to reductions in left ventricular filling pressure and volume (Nechwatal et al, 1980).…”