Reversal of left ventricular hypertrophy by propranolol in hypertensive rats.

BACKGROUND Hypertension contributes significantly to the development of left ventricular hypertrophy. Left ventricular hypertrophy is associated with increased incidence of sudden cardiac death. Recognition and management of hypertension is, therefore, imperative. OBJECTIVE To establish whether propranolol can reverse left ventricular hypertrophy in hypertensive rats. METHODS Hypertension was induced in male albino rats by giving them 1% NaCl solution as their only drink for four weeks. Propranolol was then administered orally to one of the four groups of rats used in this study. Systolic blood pressure of each rat was measured twice a week using a modified tail-cuff method. Each rat was then sacrificed, its heart excised from the chest cavity and geometric studies carried on the left ventricle. RESULTS Excessive intake of sodium salt by the rats caused an increase in their systolic blood pressure which was accompanied by left ventricular hypertrophy. The elevated blood pressure (139.4 +/- 0.5 mm Hg) was, however, brought back to normal (108.4 +/- 0.2 mm Hg) by propranolol. Data on weight, thickness, and volume of the left ventricle strongly indicated that propranolol can reverse ventricular hypertrophy. CONCLUSION Propranolol reverses left ventricular hypertrophy besides lowering elevated systolic blood pressure in rats.