SIGNAL-AVERAGED ECC IN PATIENTS WITH ANTIDEPRESSANT THERAPY

The signal-averaged electrocardiography (SAECG) identifies patients at risk of ventricular arrhythmias and sudden cardiac death. Since the s imilarity has been known of the pharmacology of class I antiarrhythmic s and tricyclic antidepressants, the potential proarrhythmic effects o f antidepressants has become a particular problem. The influence of so dium channel blocking antidepressant drugs on the SAECG time-domain pa rameters was evaluated, using high-pass filters of 25 Hz and 40 Hz. SA ECG was performed in 11 depressed patients with normal cardiac status before and for 4 weeks after antidepressant initiation. At the filter setting of 25 Hz, a significant worsening of all studied SAECG paramet ers (filtered QRS duration, low-amplitude signal duration, root mean s quare voltage in the first and in the last 40 ms of the filtered QRS) was found in our patient group. Using a 40 Hz high-pass filter, the re sults were similar. Antidepressant therapy significantly prolonged fil tered QRS duration, significantly reduced root mean square voltages in the first and in the last 40 ms of the filtered QRS and non-significa ntly prolonged low amplitude signal duration. Amitriptyline and maprot iline induced late potentials (LP) in 2 patients at 40 Hz high pass fi lter setting. No patient had LP at 25-250 Hz. Our pilot study indicate s that sodium channel blocking antidepressant drugs may affect SAECG v ariables similarly to class I antiarrhythmics. SAECG might be useful i n categorizing of antidepressant agents and risk stratification of psy chiatric patients.