[Chronic cardiac insufficiency, a disease of adaptation].

Cardiac hypertrophy due to a mechanical overload is not a disease per se but the physiological reaction of the heart to a disease which is usually arterial hypertension and/or coronary insufficiency. It results from the put into play of several changes in gene expression, frequently species-specific, which explain the thermodynamic improvement of the cardiac function and the physiological adaptation of the heart to the new environmental requirements. Some of these modifications can have detrimental consequences and explain the modifications of ventricular compliance and the high incidence of arrhythmias in ventricular hypertrophy. The most important changes in the genetic expression which have been reported so far after pressure overload are located on contractile proteins and on membrane proteins.