CARDIOVASCULAR RESPONSE TO EXERCISE
The heart responds to exercise principally by adrenergic stimulation and vagal withdrawal, which increase heart rate and contractility, and by peripheral circulatory alterations (Table 1-2). The increase in heart rate usually accounts for the majority of the increase in cardiac output. Increased contractility contributes to the increase in cardiac output by increasing the stroke volume.
Vessels supplying exercising muscles dilate, whereas the remaining vascular beds vasocon-strict. Isometric and isotonic exercises affect the cardiovascular system somewhat differently. The predominant response to isometric exercise (e.g., weight lifting) is an increase in peripheral vasoconstriction with a subsequent increase in arterial pressure. In contrast, isotonic exercise (e.g., jogging) reduces systemic vascular resistance primarily in exercising muscles, which improves cardiac output. Those who exercise regularly obtain a cardiac training effect, with a lower resting heart rate and a greater capacity to increase cardiac output during exercise.
- CIRCULATORY PHYSIOLOGY
- MICROSCOPIC ANATOMY
- VENTRICULAR SEPTAL DEFECT
- PATENT DUCTUS ARTERIOSUS
- PHYSIOLOGY OF THE SYSTEMIC CIRCULATION
- MYOCARDIAL METABOLISM
- CONGENITAL HEART DISEASE
- PHYSIOLOGY OF THE CORONARY CIRCULATION
- ACYATJOTIC LESIONS
- ATRIAL SEPTAL DEFECT
- EVALUATION OF THE PATIENT WITH CARDIOVASCULAR DISEASE
- ELECTROPHYSIOLOGY
- GROSS ANATOMY
- SHOCK
- MANAGEMENT OF ACUTE PULMONARY EDEMA
- PHYSIOLOGY OF THE PULMONARY CIRCULATION
- CARDIAC DEVELOPMENT
- CARDIOVASCULAR RESPONSE TO EXERCISE
- SYMPATHOMIMETIC AMINES
- NONPHARMACOLOQICAL MANAGEMENT OF HEART FAILURE
- HIGH-OUTPUT STATES