Stimulation of the cardiopulmonary baroreflex enhances ventricular contractility in awake dogs: a mathematical analysis study
| Autor: | Masashi Ichinose, Donal S. O'Leary, Mohsen Moslehpour, Robert L. Hammond, Ramakrishna Mukkamala, Sell Evan, Javier A. Sala-Mercado, Xiaoxiao Chen |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
medicine.medical_specialty
Time Factors Baroreceptor Central Venous Pressure Physiology Heart Ventricles Adrenergic beta-Antagonists Hemodynamics Pressoreceptors Stimulation Baroreflex Dogs Heart Rate Physiology (medical) Internal medicine Heart rate medicine Animals Wakefulness Neural Control business.industry Models Cardiovascular Central venous pressure Myocardial Contraction medicine.anatomical_structure Anesthesia Models Animal cardiovascular system Vascular resistance Cardiology Vascular Resistance business |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 307:R455-R464 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.00510.2013 |
| Popis: | The cardiopulmonary baroreflex responds to an increase in central venous pressure (CVP) by decreasing total peripheral resistance and increasing heart rate (HR) in dogs. However, the direction of ventricular contractility change is not well understood. The aim was to elucidate the cardiopulmonary baroreflex control of ventricular contractility during normal physiological conditions via a mathematical analysis. Spontaneous beat-to-beat fluctuations in maximal ventricular elastance ( Emax), which is perhaps the best available index of ventricular contractility, CVP, arterial blood pressure (ABP), and HR were measured from awake dogs at rest before and after β-adrenergic receptor blockade. An autoregressive exogenous input model was employed to jointly identify the three causal transfer functions relating beat-to-beat fluctuations in CVP to Emax (CVP → Emax), which characterizes the cardiopulmonary baroreflex control of ventricular contractility, ABP to Emax, which characterizes the arterial baroreflex control of ventricular contractility, and HR to Emax, which characterizes the force-frequency relation. The CVP → Emax transfer function showed a static gain of 0.037 ± 0.010 ml−1 (different from zero; P < 0.05) and an overall time constant of 3.2 ± 1.2 s. Hence, Emax would increase and reach steady state in ∼16 s in response to a step increase in CVP, without any change to ABP or HR, due to the cardiopulmonary baroreflex. Following β-adrenergic receptor blockade, the CVP → Emax transfer function showed a static gain of 0.0007 ± 0.0113 ml−1 (different from control; P < 0.10). Hence, Emax would change little in steady state in response to a step increase in CVP. Stimulation of the cardiopulmonary baroreflex increases ventricular contractility through β-adrenergic receptor system mediation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|