The effects of prazosin in severe congestive heart failure. An echocardiographic study.

Twelve patients with severe chronic congestive heart failure (CHF) received prazosin in a dose of 4 to 20 mg daily for a period of 2 months, in addition to cardiac glycoside and diuretic drugs. After this treatment left ventricular end-diastolic diameter decreased from 5.7 +/- 0.4 to 5.4 +/- 0.4 cm (p less than 0.001), left ventricular end-systolic diameter decreased from 4.3 +/- 0.5 to 4 +/- 0.5 (p less than 0.001), left ventricular stroke excursion increased from 1.03 +/- 0.11 to 1.27 +/- 0.15 cm (p less than 0.01), the ejection fraction increased from 24.9 +/- 2.1 to 32.2 +/- 2.8 (p less than 0.001) and the mean velocity of circumferential fiber shortening increased from 0.68 +/- 0.06 to 0.79 +/- 0.08 circumferences/s (p = 0.06). Prazosin treatment clearly relieved dyspnea and fatigue. Three patients improved from Class IV to Class III, four patients improved from Class IV to Class II and 3 patients from Class III to Class II.

Exercise testing for assessing the effectiveness of digitalis therapy in compensated heart diseases.

Exercise pulse rate (EPR) during a 6-minute exercise testing and recovery pulse rate (RPR) 5 minutes following the test were determined in three groups of subjects before and after rapid digitalization. Ten normal subjects showed no significant changes in heart rate after rapid digitalization. EPR and RPR decreased and FPR/RPR ratio increased significantly after administration of the cardiac glycoside in 7 patients with congestive heart failure. A similar response was found in 25 out of 36 patients with compensated heart disease (69.4%). Such a response suggests a beneficial effect of chronic digitalis therapy in cardiac patients without heart failure.

The sick sinus syndrome. Clinical and electrocardiographic spectrum of nine patients.

The paper presents a report on the clinical and electrographic spectrum of nine patients with the sick sinus syndrome with severe symptoms of clinical disturbances and serious disorders of impulse formation and conduction. Seven patients had syncope associated with sinus bradycardia, sinoatrial block or atrial fibrillation with slow ventricular rate. Prolonged episodes of atrial and ventricular asystole occurred and were interrupted by junctional escape beats. Paroxysmal atrial fibrillation and flutter were foun in three patients and infrahisian block in four. Atropine induced a slight acceleration of the heart rate in all the patients studied while the post-suppression S-A node recovery time was prolonged in four.

The monophasic action potentials of the intact canine heart.

Monophasic action potentials were recorded in 7 mongrel dogs, endocavitarily, from heart in situ and from the epicardial surface with open chest thus revealing the characteristic configuration of the different chambers. The duration of the monophasic action potential showed a good correlation with the cycle length, demonstrated during endocavitary electrostimulation.