Correlation between Age and Electrical Axes of the Heart in Adult Nigerians

Background: P wave axis, QRS axis, T wave axis and QRS-T angle have prognostic values on cardiovascular morbidity and mortality, yet the effect of age on these important electrocardiographic parameters has not been well studied in adult Nigerians, knowing that some electrocardiographic parameters are affected by age. Objectives: This study was aimed at determining the effect of age on P frontal axis, QRS frontal axis, T frontal axis and frontal QRS-T angle among adult Nigerians. Methods: This was a retrospective study in which P frontal axis, QRS frontal axis and T frontal axis of adult patients who attended a university teaching hospital were determined from 12-lead ECG. Frontal QRS-T angle was calculated as the absolute difference between the QRS frontal axis and T wave frontal axis. The electrical axes and QRS-T angle were correlated with age. Results: There were 85 cases aged between 20 and 66 years, which included 42 males and 43 females. P frontal axis correlated positively and non-significantly with age (r = -0.032, p = 0.773), QRS frontal axis correlated negatively and significantly with age (r = -0.295, p = 0.006), T frontal axis correlated negatively and non-significantly with age (r = -0.002, p = 0.984), while frontal QRS-T angle correlated negatively and significantly with age (r = -0.266, p = 0.014). Conclusion: There were significant age related changes in both QRS frontal axis and frontal QRS-T angle. No significant age related changes were found in P frontal axis and T frontal axis.