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Left ventricular performance during the course of a day and meals in dilated cardiomyopathy and heart failure
M P Rome1, N Majetich, P F Binkley
1Ohio State University College of Medicine, Division of Cardiology, Columbus.
Insights
Heart failure patients experience minor daily hemodynamic changes, but significant cardiovascular shifts occur after meals. Noninvasive measures often fail to detect these meal-related alterations in dilated cardiomyopathy.
Area of Science:
- Cardiology
- Physiology
Background:
- Dilated cardiomyopathy and chronic congestive heart failure significantly impact left ventricular performance.
- Understanding daily hemodynamic variations is crucial for managing heart failure.
Purpose of the Study:
- To investigate the influence of diurnal variations and meal intake on left ventricular performance.
- To assess hemodynamic changes in patients with dilated cardiomyopathy and chronic heart failure.
Main Methods:
- Invasive and noninvasive hemodynamic measurements, including systolic time intervals and echocardiography, were conducted.
- Measurements were taken over a 15-hour daytime period and during three meals in nine patients.
- Pulmonary capillary wedge pressure, cardiac output, stroke volume, and vascular resistances were monitored.
Main Results:
- Pulmonary capillary wedge pressure showed a modest decrease from afternoon to evening.
- Cardiac output and stroke volume increased significantly after meals.
- Pulmonary and systemic vascular resistances, blood pressure, and pulmonary artery pressure decreased post-meal.
- Noninvasive cardiovascular parameters generally did not reflect these meal-induced changes.
Conclusions:
- Patients with dilated cardiomyopathy and chronic heart failure exhibit modest diurnal hemodynamic fluctuations.
- Food ingestion causes notable central hemodynamic alterations in these patients.
- Noninvasive cardiovascular monitoring may not adequately capture meal-related hemodynamic changes.
Abstract:
This study was performed to examine the influence of time during the day and of meals on left ventricular performance in patients with dilated cardiomyopathy and chronic congestive heart failure. Systolic time intervals and echocardiography were performed at set intervals with concomitant hemodynamic measurements in nine patients with chronic congestive heart failure over a 15 hour daytime period and during the three meals. Pulmonary capillary wedge pressure decreased (p less than 0.05) from a non-meal resting peak of 18 +/- 8 mm Hg at 1500 hours to 16 +/- 7 mm Hg at 2200 hours. The other non-meal cardiovascular variables, invasive and noninvasive, did not change significantly during the course of the day. Cardiac output and stroke volume rose and pulmonary and systemic vascular resistances, systemic blood pressure, pulmonary artery pressure, and pulmonary capillary wedge pressure generally fell significantly after meals. Although mean PEP/LVET tended to decrease and delta p/delta t increase after meals, these numerical changes were not statistically significant and none of the other noninvasive variables were affected by meals. Patients with dilated cardiomyopathy and chronic congestive heart failure have modest changes in central hemodynamics over the course of a day with rather striking changes with food ingestion. These alterations are generally not reflected in noninvasive cardiovascular parameters.