LEFT-VENTRICULAR FUNCTION AFTER REPEATED EPISODES OF VENTRICULAR-FIBRILLATION AND DEFIBRILLATION ASSESSED BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Background Investigators studying the effects of cardioverter-defibril lators on left ventricular systolic function have given only minor att ention to the diastolic effects. Objectives The purpose of this study was to investigate the impact of repeated episodes of ventricular fibr illation and defibrillation on systolic function and diastolic filling of the left ventricle during non-thoracotomy implantation of a cardio verter-defibrillator. Methods Systolic function and diastolic filling of the left ventricle were assessed peri-operatively on a beat-by-beat basis using a transoesophageal echo-Doppler technique in 12 patients during greater than or equal to 4 episodes of ventricular fibrillation and defibrillation. Systolic function was assessed from the fractiona l area change and diastolic filling from the EIA ratio. Arterial blood pressure and the ECG were recorded continuously. Results Blood pressu re and heart rate did not change significantly throughout the procedur e. The systolic function, similarly, was not significantly affected; t he only changes were seen in the first two beats after defibrillation when the mean fractional area increased from 0 . 2 +/- 0 . 01 to 0 . 4 +/- 0 . 02 and 0 . 3 +/- 0 . 02, respectively (P<0 . 001). Diastolic filling was, however, impaired as reflected by a decrease in the E/A r atio from 2 . 6 +/- 0 . 5 before to 1 . 6 +/- 0 . 4 (P<0 . 01) after r epeated threshold tests. Conclusions While the combined ischaemic and electrical trauma caused by repeated episodes of ventricular fibrillat ion and defibrillation during the implantation of a cardioverter-defib rillator did not cause any systolic dysfunction, diastolic filling was significantly impaired.