Mechanisms behind the postprandial increase in cardiac output: a clue obtained from transplanted hearts.

Consumption of a meal is followed by an increase in cardiac output (CO) which appears to be closely related to the concomitant increase in blood flow to the gastrointestinal organs. To gain information on the mechanism behind this increase in CO we have previously used Doppler ultrasound technique to record circulatory responses to a standardized meal in five patients with recently transplanted and thus denervated hearts. We obtained the surprising result that they reacted to the consumption of a meal with a greater increase in CO than did five matched normal controls.

Regulation of arterial blood pressure in humans during isometric muscle contraction and lower body negative pressure.

Previous studies have shown that the blood pressure response to isometric handgrip remains unchanged during reductions in preload induced by lower body negative pressure (LBNP). The purpose of the present study was to assess the beat-by-beat haemodynamic mechanisms allowing for precise control of mean arterial pressure (MAP). We have followed the cardiovascular variables involved in the regulation of MAP during isometric handgrip with and without additional application of LBNP during defined periods of the ongoing contraction.

Circulatory responses to a meal in patients with a newly transplanted heart.

It is well established that consumption of a meal releases a gradually developing and quite marked increase in blood flow to the gastrointestinal organs and a similar and simultaneous increase in cardiac output (CO). It is not known through which mechanism the pumping of the heart adjusts so accurately to the gastrointestinal flow increase. We have approached this problem by serving a standardized, mixed meal to five patients with recently transplanted and thus denervated hearts and to five sex- and age-matched controls.

[Distribution of left ventricular output].

Background: This survey focuses on distribution of cardiac output to various organs and on some dynamic changes occurring in cardiac output and its distribution.

Materials And Methods: Data presented are largely related to work carried out in our research group, where Doppler ultrasonography is widely used for measurement of cardiac output and arterial blood flow. Additional data are drawn from relevant literature, in part compiled through search in the PubMed database.