[Effect of stimulation on ventricular kinetics: contribution to the treatment of cardiomyopathies]. / Effet de la stimulation sur la cinétique ventriculaire: apport au traitement des myocardiopathies.

ABSTRACT

Cardiac pacing using the apex of the right ventricle as site of excitation induces asynchronous contraction between the right ventricle and the left ventricle as well as inversion of the normal left ventricular activation sequence. These two phenomena are responsible for alteration of septal kinetics and overall contractility. It has recently been demonstrated that these alterations can be used to advantage to reduce the degree of subaortic obstruction of patients suffering from hypertrophic and obstructive cardiomyopathy, and to improve their exercise tolerance. Using an opposite approach, consisting of reducing the degree of asynchronous contraction related to the presence of intraventricular conduction disorders, while optimizing atrioventricular synchronism, new pacing methods have recently been able to improve cardiac output and functional tolerance of some patients suffering from dilated cardiomyopathy. Although cardiac pacing can now be considered to be an alternative a surgery for the treatment of refractory forms of hypertrophic and obstructive cardiomyopathy, it still constitutes a research technique in the field of dilated cardiomyopathy.