The role of clonidine in hypertensive heart disease. Influence on myocardial contractility and left ventricular afterload.
The hemodynamic and contractile effects of clonidine were studied in hypertrophied hearts of spontaneously hypertensive rats (Okamoto-Aoki strain, SHR). The hemodynamic pattern was characterized by dose-dependent decreases in systolic blood pressure and systolic wall stress, ie, the afterload imposed upon the left ventricle, whereas left ventricular ejection fraction and stroke volume were unchanged. Even at extremely high doses (10(-5)M/L) there was found no depression of isometric tension development and maximum isotonic shortening velocity of the isolated LV papillary muscle. It is concluded that clonidine may be beneficial in hypertensive heart disease, if ventricular unloading associated with a reduction in myocardial energy demand is desired.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D006332:Cardiomegaly / Q000188:drug therapy*; D003000:Clonidine / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013318:Stroke Volume / Q000187:drug effects
D003000:Clonidine