Improvement of the cardiac function after electrical cardioversion of atrial fibrillation. Echocardiographic study in patients with and without mitral stenosis.

The improvement of the cardiac function after electrical cardioversion of atrial fibrillation has been studied by echocardiography by few authors and only in patients without mitral stenosis. Moreover, discordant results have been obtained. We have studied nine patients with mitral valve disease as well as nine other patients with ischemic heart disease. Both groups were cardioverted within five days of onset of atrial fibrillation, and appropriate echocardiographic measurements were made one hour before and two hours after cardioversion. We found a significant decrease of left atrial diameter in both groups, as well as a significant increase of the end-diastolic diameter and volume of left ventricle and an improvement of the cardiac index. These changes were significantly more pronounced in patients with mitral valve disease and they appear in accordance with the improvement of the cardiac function demonstrated with invasive hemodynamic studies after cardioversion to sinus rhythm. In the group of patients with mitral valve disease and a very dilated left atrium (more than 6 cm. of diameter) atrial fibrillation recurred within the next twelve months. In spite of the limitations of M-mode approach for calculating left ventricular volumes, echocardiography appears to be sensitive and useful for evaluating in the single patient the changes in left ventricular performance after cardioversion of atrial fibrillation to sinus rhythm.