PMID: 3768071Jul 1, 1986Paper

Myocardial and ventricular mechanics as influenced by disopyramide

Arzneimittel-Forschung
M VogtR Jacob

Abstract

The effects of disopyramide (D) on the mechanics of isolated myocardium as well as on the whole ventricle were examined in the rat model. Moreover bipolar leads of the apex and an area at the base of the left ventricle were set up to get indications for changes in the spread of excitation. D in concentrations of 10(-8) to 10(-4) mol/l did not affect the diastolic elastic properties of isolated myocardium. Isometric contraction amplitude was nearly unaltered, while rate of isometric contraction and relaxation were slightly increased. In the whole ventricle in situ D (2 to 10 mg/kg b.w. administered i.v.) induced a dose-dependent decrease in left ventricular isovolumetric peak pressure (16%), max.pos. dP/dt (40%) and max.neg. dP/dt (30%; for highest doses respectively), while time to peak pressure and relaxation time 90% were prolonged. Therapeutic dose of D (2 mg/kg b.w.i.v.) induced no decrease in essential systolic parameters of the whole ventricle under auxotonic conditions. Left ventricular pressure, dP/dt max.pos. and neg., left ventricular end-diastolic pressure and cardiac output were nearly unaltered. Heart rate showed a tendency to decrease, while total time of contraction and left ventricular ejection time increased. H...Continue Reading

Related Concepts

Related Feeds

Antiarrhythmic Agents: Mechanisms of Action

Understanding the mechanism of action of antiarrhythmic agents is essential in developing new medications as treatment of cardiac arrhythmias is currently limited by the reduced availability of safe and effective drugs. Discover the latest research on Antiarrhythmic Agents: Mechanism of Action here.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Anti-Arrhythmic Drug Therapies

Anti-arrhythmic drugs are used to prevent abnormal heart rhythms. These medications are used in conditions including, ventricular tachycardia, ventricular fibrillation and atrial fibrillation. Discover the latest research on anti-arrhythmic drug therapies here.