[Disorders of cardiac rhythm and the changes in Q-T interval in mitral valve prolapse syndrome].

To study the incidence and nature of cardiac arrhythmias and the changes in the corrected Q-T interval, 60 patients with the prolapsed mitral valve syndrome were examined. All the patients underwent resting ECG and leg isometric exercise. 24-hour ECG monitoring was performed in 48 patients. The latter technique was found to be the most informative tool for detecting cardiac arrhythmias (66.8%). Prolonged corrected Q-T interval (more than 440 msec) was more frequently revealed in leg isometric exercise (41.6%) than in resting ECG (26.6%) and 24-hour monitoring (29.2%). Its degree was directly related to the severity of cardiac arrhythmias in patients with the prolapsed mitral valve syndrome.