Multiparametric electrocardiographic evaluation of left ventricular hypertrophy in idiopathic and hypertensive cardiomyopathy.

BACKGROUND: Electrophysiological abnormalities underlying the increased arrhythmogenicity of left ventricular hypertrophy (LVH) are still under investigation. The aim of this study was to assess non-invasively the electrophysiologic alterations in two different types of LVH, METHODS: Multiparametric non-invasive ECG analysis (R-R interval, QRS and QT intervals, QT dispersion, T-wave complexity, activation-recovery interval [ARI] dispersion, standard deviation of RR intervals [SDNN], filtered QRS duration [fQRS], root-mean-square voltage of the terminal 40 ms of the fQRS [RMS40] and low amplitude signal duration (< 40 microV) in the terminal portion of the fQRS [LAS]) was performed in 57 patients with hypertensive LVH and hypertrophic cardiomyopathy (HCM), and in 105 healthy subjects.

RESULTS: The R-R interval and SDNN were similar in hypertrophic patients and controls. QRS and QT intervals were longer in hypertrophic patients without any differences between hypertensive LVH and HCM. QT dispersion, T-wave complexity and fQRS were greater in hypertrophic patients; QT dispersion was the greatest in HCM. ARI dispersion was lesser in hypertrophic patients without any differences between subgroups of LVH. fQRS showed a trend toward higher values in hypertensive patients. LAS at 25 Hz had a trend toward lower values in HCM patients, while LAS at 40 Hz and RMS40 showed no difference between controls and hypertrophic patients. Left ventricular mass index was not correlated with any of the above-mentioned parameters.

CONCLUSIONS: The QT interval and dispersion did not identify the type of hypertrophy. Similarly, ARI dispersion which explores local variations of repolarization duration, and T-wave complexity could not distinguish patients with hypertensive LVH from those with HCM indicating that multiparametric ECG data are affected more by the presence of LVH, than by its type.