To determine the value of dispersion of ventricular repolarization as a diagnostic tool to assess the risk for ventricular arrhythmias in patients with rheumatoid arthritis (RA).
We examined 42 patients with RA (age 44+/-4.8 yrs; 32 women and 10 men) and 42 age matched healthy subjects as the control group. Repolarization dispersion variables were calculated based on the difference between maximal and minimal values of QT, QTc, JT, and JTc (QTd, QTc-d, JTd, and JTc-d, respectively) from 12 lead electrocardiographic (ECG) recording at 50 mm/s. The frequency of ventricular arrhythmias by means of 24 h ambulatory ECG monitoring was investigated. A grade of > 3 ventricular arrhythmias according to modified Lown and Wolf classification was accepted as complex arrhythmias.
We found QT and QTc intervals 392+/-20 and 409+/-38 ms in patients; values in controls were 387+/-22 and 400+/-14 ms, respectively; p > 0.05. QTd, QTc-d, JTd, and JTc-d intervals were 61.6+/-1.6, 77.6+/-1.1, 72.5+/-1.8, and 93.3+/-1.5 ms in patients and 40.3+/-0.9, 55+/-1.2, 42.6+/-0.4, and 52.9+/-0.8 ms in controls, respectively; p < 0.001. Thirty-two of the patients had complex premature ventricular complexes during 24 h ECG and the prevalence of premature ventricular complexes was found to be higher than in controls (p < 0.001). No correlation was found between complex premature ventricular complexes and QT, but there was a correlation between complex premature ventricular complexes and dispersion variables in patients with RA.
Striking increases in QT dispersion indicating regional inhomogeneity of ventricular repolarization were noted in patients with RA. QT dispersion might be a useful marker of cardiovascular morbidity and mortality due to complex ventricular arrhythmias in patients with RA.