pituitrin and Tachycardia--Paroxysmal

Various rhythm disturbances occur in the postoperative patient. Proper management requires an awareness of clinical circumstances in which they are most likely to happen. Often, the appearance of new arrhythmias in the postoperative period is a manifestation of underlying remediable medical problems. Direct antiarrhythmic therapy is unnecessary in many patients when these precipitating conditions are properly treated.

Topics: Arrhythmias, Cardiac; Atrial Fibrillation; Atrial Flutter; Bradycardia; Bundle-Branch Block; Electrocardiography; Heart Diseases; Humans; Surgical Procedures, Operative; Tachycardia; Tachycardia, Paroxysmal; Vasopressins

The mechanism of polyuria associated with paroxysmal supraventricular tachycardia (SVT) was investigated in 8 patients. SVT was induced artificially and sustained for 60 minutes. Urine and blood samples were collected every 30 minutes. During the latter half of SVT, urine flow increased twofold in the control subjects before SVT. Urinary sodium excretion increased significantly (p less than 0.01) within 30 minutes after SVT. Urinary excretion of antidiuretic hormone (ADH) decreased (p less than 0.01) during the latter half of SVT and increased (p less than 0.01) after SVT, respectively. Plasma level of ADH did not change during SVT but increased (p less than 0.05) after SVT. The concentration of plasma atrial natriuretic polypeptide (ANP) increased significantly (p less than 0.05) before SVT ended. Urinary excretion of prostaglandin E2 increased significantly (p less than 0.05) after termination of SVT. The percent changes in the urinary excretion of prostaglandin E2 were correlated (r = 0.713, p less than 0.001) with those of ADH. There was also a correlation (r = 0.6, p less than 0.001) between the percent changes in the urinary excretion of prostaglandin E2 and those of sodium. Their findings suggest that the polyuria during SVT is attributed mainly to the inhibition of ADH release and that the natriuresis after SVT is due not only to the increased ANP but also to the increased renal prostaglandin E2 probably stimulated by ADH.

Topics: Adult; Atrial Natriuretic Factor; Blood Pressure; Dinoprostone; Female; Heart Rate; Humans; Kidney; Male; Middle Aged; Natriuresis; Osmolar Concentration; Polyuria; Tachycardia, Paroxysmal; Tachycardia, Supraventricular; Vasopressins

Plasma concentrations of antidiuretic hormone (ADH) were measured in 8 patients with congestive heart failure (CHF) of NYHA functional class III-IV, before and during treatment with captopril, 6.25-25.0 mg t.i.d., added to their drug regimen. Before captopril treatment, plasma ADH was high, 2.5 times the upper limit of normal reference values. During treatment with captopril, plasma ADH levels were normalized, and remained so throughout the study, for at least 6 months. Plasma levels of angiotensin II were also reduced to a normal level. Reduction of plasma ADH during captopril treatment in CHF may partly depend on reduced angiotensin II formation, and may be beneficial by improving water balance. Atrial natriuretic peptide (ANP), was measured by radioimmunoassay in 17 patients with CHF. The highest levels were measured in the most severe CHF cases, and intermediate high values on NYHA functional class I-II patients. Plasma ANP concentrations in control patients (n = 18) without cardiac diseases ranged between 0 and 30 pg/ml. In two patients with paroxysmal supraventricular tachycardia, associated with transient polyuria, high plasma ANP concentrations were noticed during tachycardic episodes. Thus, ANP appears to be a circulating hormone in humans, and is released into the blood in clinical conditions associated with raised preload and atrial wall stretch.

Topics: Aged; Aldosterone; Angiotensin II; Atrial Natriuretic Factor; Captopril; Female; Heart Failure; Humans; Male; Middle Aged; Renin; Tachycardia, Paroxysmal; Vasopressins

Topics: Animals; Aorta, Thoracic; Central Venous Pressure; Denervation; Diuresis; Dogs; Electrocardiography; Female; Heart; Heart Atria; Heart Block; Kidney; Natriuresis; Pacemaker, Artificial; Pressoreceptors; Reflex; Sinoatrial Node; Tachycardia, Paroxysmal; Vasopressins

Topics: Aldosterone; Angiotensin II; Cardiac Output; Cardiac Volume; Cardiovascular System; Heart Atria; Humans; Hypothalamo-Hypophyseal System; Juxtaglomerular Apparatus; Kidney; Polyuria; Pressoreceptors; Renin; Tachycardia, Paroxysmal; Vasopressins

Topics: Blood Pressure; Cardiac Output; Creatine; Humans; Kidney Function Tests; Middle Aged; Polyuria; Tachycardia, Paroxysmal; Vasopressins; Water-Electrolyte Balance