P-WAVE SIGNAL-AVERAGED ELECTROCARDIOGRAM IN PATIENTS WITH IDIOPATHIC MITRAL-VALVE PROLAPSE SYNDROME AND SUPRAVENTRICULAR ARRHYTHMIAS

The aim of the study was to assess whether the P-wave triggered signal -averaged ECG (SAECG) used in patients with idiopathic mitral valve pr olapse syndrome could predict the risk of the development of supravent ricular arrhythmias. Fifty patients with idiopathic mitral valve prola pse syndrome (15 men, 35 women, mean age: 37 +/- 9 years) were prospec tively studied. P-wave triggered SAECG was recorded with a commerciall y available system (HIPEC-200HA Aerotel). The following parameters wer e calculated: the root-mean-square voltage for the terminal 10, 20, 30 ms of filtered P-wave (RMS 10,20,30) and time duration of filtered P- wave (PWD). Nine patients with mitral valve prolapse syndrome (18%) re vealed the occurrence of supraventricular arrhythmias on Holter monito ring whereas of the remaining 41 (82%), no clinically relevant suprave ntricular arrhythmias were detected. We found PWD values to be signifi cantly longer in patients with supraventricular arrhythmias when compa red with those without arrhythmias: 119.8 +/- 6.9 ms vs. 111.7 +/- 12. 1 ms, respectively, P < 0.02. We conclude that P-wave triggered SAECG could be a useful technique for detecting patients with idiopathic mit ral valve prolapse syndrome at risk of paroxysmal supraventricular arr hythmias.