Assessment of Electrocardiogram among Adult Nigerians: High Blood Pressure versus Normal Blood Pressure

Aims: This study assessed the electrocardiogram (ECG) variables of apparently healthy adult Nigerians (≥18 years) who presented for medical screening to determine the effects of high blood pressure (HBP) on the heart's electrical activities.

Study Design: This was a descriptive retrospective study.

Place and Duration of Study: This study was conducted at the ECG library of the Department of Physiological Sciences, Obafemi Awolowo University, Ile-Ife, over 5 weeks.

Methodology: ECGs obtained from the participants through a standard protocol from 2013 to 2015 were selected, sorted, and stratified into two categories (A and B) based on the blood pressure level. Group A contained 250 ECGs of individuals with high blood pressure (SBP ≥130mmHg and/or DBP ≥80mmHg) while Group B contained 250 ECGs of age-and-sex-matched individuals with normal blood pressure (SBP <130mmHg and/or DBP<80mmHg). Variables extracted from each ECG include age, gender, height, weight, blood pressure, ECG variables, and patterns.

Results: HBP did not significantly alter P wave variables except for morphology (χ2=16.65, P=.005). Across the left lateral leads, QRS voltage(mm) was significantly higher among Group A than Group B; I (8.99 ± 3.54, 7.54±3.00; t = 4.89, P < .001), aVL (5.07± 3.97, 3.83± 3.07; t=3.91, P<.001), V5 (19.18±7.18,16.98±6.45; t=3.60, P <.001) and V6(16.14±5.95, 14.10±5.23; t =4.07, P<.001). The ventricular rate in bpm (77.46 ±14, 70.26 ± 12.48; t=5.99, P =.001) and QTc in ms (424.56±29.24,409.16 ± 22.23; t=0.56, P<.001) were significantly higher in Group A than Group B respectively.

Conclusion: In conclusion, HBP significantly altered cardiac electrical activities and the changes are detectable through routine ECG screening of asymptomatic adults. ECG is recommended as a routine test for adult Nigerians with HBP.