Effects of atorvastatin on ventricular late potentials and repolarization dispersion in patients with hypercholesterolemia

Abstract

Emerging evidence suggests that statins have a favorable impact on the reduction of arrhythmia events and sudden cardiac death in patients with structural heart disease. We aimed to investigate the possibly and directly favorable effects of statins on ventricular late potentials, QT dispersion, and transmural dispersion of repolarization attained by analyzing clinical electrocardiography (ECG) risk stratification parameters in patients with hypercholesterolemia without structural heart disease. In total, 82 patients (45 females; mean age, 62 +/- 10 years) with hypercholesterolemia were enrolled in this prospective study to examine the effects of statin therapy (atorvastatin 10 mg/day for 3 months) on ECG risk stratification parameters. Surface 12-lead ECG and signal-average ECG (SAECG) were recorded before and after statin treatment. The SAECG parameters, QT dispersion, Bazett-corrected QT (QTc) dispersion, T wave peak-to-end interval (Tpe), and percentage of Tpe/QT interval were calculated and compared before and after statin therapy. Twelve-lead ambulatory 24-hour ECGs were recorded in 12 patients. The results demonstrated that after statin therapy for 3 months, serum levels of total cholesterol and low-density lipoprotein cholesterol were significantly reduced (both p values < 0.001). However, neither significant changes of each SAECG parameter nor the frequency of late potentials were demonstrated after atorvastatin therapy. In addition, no significant changes in QT dispersion, QTc dispersion, Tpe, or Tpe/QT were found. However, 24-hour ambulatory ECG revealed a flattening effect of circadian variation of QTc dispersion after atorvastatin therapy. In conclusion, the favorable antiarrhythmia effect of atorvastatin (10 mg/day) therapy cannot be directly reflected by analyzing these noninvasive ECG risk stratification parameters in low-risk patients with hypercholesterolemia.