Respiration-synchronous fluctuations in stroke volume, heart rate and arterial pressure in humans.
AUTOR(ES)
Toska, K
RESUMO
1. Simultaneous recordings of beat-to-beat left cardiac stroke volume (SV, pulsed ultrasound Doppler), mean arterial pressure (MAP) and heart rate (HR) were obtained in ten healthy young adults during spontaneous respiration at supine rest, before and after cholinergic blockade by atropine (0.035 mg kg-1). 2. Respiration-synchronous fluctuations in SV, HR, cardiac output (CO) and MAP were quantified by spectral analysis of the recordings of each of these variables. 3. Before atropine administration, respiration-synchronous fluctuations in HR and SV were prominent. The changes in HR and SV were inversely related and variation in SV was the main source of respiratory variability in CO. Respiration-synchronous fluctuations in MAP were mainly caused by variations in CO. 4. After cholinergic blockade, respiratory HR variations were eliminated, whereas the respiratory fluctuations in SV persisted. The fluctuations in CO and MAP increased. In this situation, mechanically induced variations in SV were not counteracted by inverse HR fluctuations and the influence on CO thus increased. 5. The main source of respiratory fluctuations in MAP in supine humans is thus variation in SV, while inverse, vagally mediated HR variations tend to reduce the fluctuations in CO and MAP.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1160498Documentos Relacionados
- THE EFFECT OF TEMPORARY OCCLUSION OF ARTERIOVENOUS FISTULAS ON HEART RATE, STROKE VOLUME, AND CARDIAC OUTPUT 1
- Fluctuations in blood flow to acral skin in humans: connection with heart rate and blood pressure variability.
- CLINICAL STUDIES OF THE BLOOD VOLUME. III. CHANGES IN BLOOD VOLUME, VENOUS PRESSURE AND BLOOD VELOCITY RATE IN CHRONIC CONGESTIVE HEART FAILURE
- HEMODYNAMIC CHANGES DURING THIOPENTAL ANESTHESIA IN HUMANS: CARDIAC OUTPUT, STROKE VOLUME, TOTAL PERIPHERAL RESISTANCE, AND INTRATHORACIC BLOOD VOLUME 12
- TOTAL RED CELL VOLUME, PLASMA VOLUME, AND SODIUM SPACE IN CONGESTIVE HEART FAILURE 1