The Effect of Electromagnetic Fields Emitted from Mobile Phone on qt Intervals and Dispersion Among Hypertensive Subjects

Background: There is increasing public concern about the possible health risks associated with the electromagnetic field emitted by mobile phones with conflicting data about these risks. Prolonged QT interval and or increased dispersion have been associated with increased cardiovascular risk and mortality in health and diseased states even among hypertensives. Aim: To study the effects of electromagnetic field emitted from mobile phone on QT intervals and dispersions among hypertensives. Subjects and Methods: 100 hypertensive patients were compared with age and sex matched controls. Five sets of 12 lead resting ECGs were obtained from each participant, baseline ECG obtained without mobile phone. ECGs were obtained during 4 experimental settings: Mobile phone over the precordium turned ON not ringing, then in RINGING mode; then at the hip level turned ON and lastly on hip RINGING.QT interval and dispersion were manually measured from each of the ECGs. Results: Overall, there tended to be the longest QT intervals with the phone ringing on the precordium of hypertensive patients, though this was not statistically significant with ANOVA. However there was significant prolongation of the QTc intervals in hypertensives with the phone ringing on precordium compared to hip QTc (432.84+24.38 vs 430.72 +26.40 ms, p= 0.038); QTcmax (455.04+27.78 vs 450.28+27.77msecs p=0.002). This trend was absent however with QT dispersions. All the baseline QT intervals were longer in hypertensives compared with controls. Conclusion: Short-term exposure to electromagnetic field emitted by mobile phone interferes with QT intervals in hypertensive patients particularly when ringing on the precordium.