An Analysis Of QRS Interval Of The Electrocardiogram In Asymptomatic Normal Nigerians

Abstract

Objectives: This cross-sectional study of the 12-lead electrocardiogram (ECG) was undertaken to establish the normal QRS interval of the adult Nigerian from Jos; to find significant correlation coefficients for QRS interval and the various anthropometric measurements and also to establish prediction equations for the QRS interval of the electrocardiogram.

Methods: The QRS interval was measured in 109 young healthy adult Nigerians. Males numbered ninety-five and females numbered fourteen. They were aged between 19 years and 30 years.

Results: The mean values for QRS interval in the 12-lead ECG were: Sec ± S.D (Lead 1:0.06 ± 0.01; lead II: 0.07 ± 0.01; lead III 0.07 ± 0.01; lead aVR: 0.07 ± 0.01; lead aVL: 0.07 ± 0.01; lead aVF: 0.08 ± 0.02; lead V₁: 0.10 ± 0.04; lead V₂:0.10 ± 0.01; lead V₃: 0.08 ± 0.01; lead V₄:0.07 ± 0.02; lead ± V₅: 0.07 ± 0.01; lead V₆: 0.07 ± 0.02).

Significant inverse correlation was found between:
(1) QRS interval and age in lead aVR.
(2) QRS interval and weight in lead V₃.
(3) QRS interval and the systolic blood pressure in lead V₁.
(4) QRS interval and the diastolic blood pressure in leads aVR and V₁.
(5) QRS interval and the chest circumference in lead V₃.


Conclusion : This study has demonstrated the normal range (0.06 ± 0.01 sec in lead 1 to 0.10 ± 0.01 sec in level V₂) for the QRS interval in young adult normal Nigerians in Jos and thus provided a precise guide for the interpretation of QRS interval in this city.

Key words: QRS interval, Electrocardiogram, asymptomatic, Cross-sectional study.

Highland Medical Research Journal Vol.2(2) 2004: 37-41