Sinus arrhythmia effects on QT dispersion parameters in healthy individuals and coronary heart disease patients

Abstract

Aim. To study sinus arrhythmia (SA) effects on quantitative parameters of time myocardial repolarization dispersion (dQTt) in healthy people and coronary heart disease (CHD) patients, as well to assess the potential of this predictor in CHD diagnostics. Material and methods. In total, 94 healthy people aged 19–60 years, and 54 CHD patients aged 39–57 years, were examined. All participants underwent morning registration of rest electrocardiogram (ECG) in SII for 5 minutes, to measure heart rate variability (HRV), QT duration and dispersion. Results. The difference between mean QTtc dispersions in diapasons of sinus isometry, moderate and manifested SA was observed, irrespective of age. A new diagnostic parameter, dQTtc/RRVR, was proposed for normalizing dQTtc according to SA severity and HR. The predictive value of this parameter was substantially greater than that of HRV characteristics, QT and QTc duration and dispersion. Conclusion. SA and HR-normalized dQTt could be regarded as a diagnostic CHD index, independent of HRV characteristics. Sensitivity and specificity of normalized dQTt in CHD diagnostics is increasing when combined with other parameters.

Keywords

• ишемическая болезнь сердца
• диагностика
• дисперсия интервала qt
• синусовая аритмия