Ventricular Late Potentials in Healthy Adults

The aim of this study is to investigate signalaveraged electrocardiogram (SAECG) parameters in healthy people. For this purpose, 54 people (23 women and 31 men, age 46.17±11.95 years) with no complaints, normal blood pressure and normal resting and exercise ECG's were evaluated. Holter recording were completely normal in all subjects. SAECG recordings were done by Marquette Case 15 computarized ECG system. A mean of 256.8±15.4 beats were averaged out of 265.3±24 detected beats. Mean unfiltered QRS duration (uQRS) was 77.3±10.3 msec. Mean filtered QRS duration (fQRS) was 105.9±9.9 msec, high frequency low amplitude signal duration (HFLA) was 20.7±6.7 msec, and root mean square voltage (RMS) was 98.6±45.9 mV at 25-250 Hz BF. At 40-250 Hz. BF, mean fQRS was 96.9±8.5 msec, mean HFLA was 26.4±7.3 msec, and mean RMS was 61.5±32.6 mV. Mean fQRS was 84.5±9.2 msec, mean HFLA was 26.6±6.8 msec, mean RMS was 31.4±16.9 mV at 80-250 Hz BF. One of our subjects (1.9%) fulfilled all of the five criteria and one another (1.9%) fulfilled four. In addition three subjects (5.6%) presented with three criteria, seven (13%) presented with two criteria and 12 people (22.2%) presented one late potential criterion. fQRS durations at all BF were significantly longer in men (p<0.0001, p<0.0001 and p<0.0001, respectively). On the other hand HFLA at 25-250 Hz BF was significantly longer in women (p<0.007). SAECG parameters in healthy subjects fitted normal distribution rules, but all parameters had wide skewness and kurtosis ranges. It is to be concluded that, the great variability observed at SAECG parameters of healthy people makes the sensitivity of SAECG in predicting sudden death controversial, and more studies are needed to rejudge the predictive value of SAECG in arrhythmias.