Influence of drug therapy on myocardial hypertrophy in left ventricular failure.

The terminal phases of volume-overload heart failure are characterised by eccentric ventricular hypertrophy. Relatively little attention has been directed to exploring the mechanisms involved in this development. The increase in diastolic wall stress leads to replication of the sarcomeres in series. The hypertrophied myocytes has a defective contractile ability that is due to an intrinsic depression of contractility; this is restored when failure is reversed. The development of appropriate hypertrophy is dependent upon adequacy of the coronary blood supply to the failing myocytes. Reduction of preload and afterload can be expected to be more effective in reducing systolic wall stress, and hence myocardial oxygen demands, in eccentric hypertrophy than in the nonfailing heart with concentric hypertrophy. However, there is no information available on the influence of anti-heart-failure drugs on the myocardial hypertrophy associated with severe volume-overload failure. The presence of such hypertrophy carries an ominous prognosis and may be associated with the high incidence of arrhythmic sudden deaths. The detection of myocardial hypertrophy in the patient with failure emphasises the urgency of adequate reduction of the elevated preload and afterload without impairment of the coronary perfusion gradient.