Organs Tag's Archives
Pathophysiology of Circulatory Failure
Circulatory failure, or the inability of the heart to provide sufficient cardiac output to satisfy tissue metabolic requirements, is the most important and most common cause of altered pharmacokinetics during cardiac emergencies. Circulatory failure may result from decreased myocardial contractility, arrhythmias that allow insufficient time for diastolic filling or impair atrioventricular synchrony, circulatory stresses such as increased afterload or hypovolaemia, valvular dysfunction, tamponade, or a variety of less common insults.
Regardless of the aetiology, circulatory failure elicits characteristic compensatory haemodynamic adjustments, mediated in large part by activation of the sympathetic nervous system [Peniel & Benowitz 1984; Benowitz & Meister 1978]. Enhanced sympathetic tone increases cardiac contractility and peripheral vascular resistance, both of which serve to maintain arterial blood pressure. The increase in peripheral vascular resistance, however, is not uniform among different vascular beds.
Arterial, Blood Pressure, Cardiac, Circulatory, Dysfunction, Effect, Heart, Metabolism, Organs, Treatment
