Cardiovascular and electrocardiographic changes in Nigerians with a normal pregnancy.

Introduction: Pregnancy is associated with major haemodynamic and cardiac changes, which can mimic or precipitate cardiac diseases. There is a paucity of this kind of data among pregnant Nigerian women. This study was aimed at describing the cardiovascular and electrocardiographic changes found among healthy pregnant Nigerian women.

Methods: This was an age-matched control study of 69 consecutive normal pregnant and 70 healthy non-pregnant controls. The study protocol included history, physical examination and 12-lead electrocardiography.

Results: Diastolic blood pressure < 60 mmHg was significantly commoner among pregnant subjects than controls (64.7 vs 24.3%, respectively, p < 0.005). Mean heart rate was higher among pregnant women (88.34 ± 11.46 bpm) than the controls (75.16 ± 12.22 bpm, p = 0.020). Pregnant subjects also had a higher proportion of left ventricular hypertrophy (LVH) (10.2 vs 0%, p < 0.05) than non-pregnant controls. Abnormal cardiac findings included a loud second heart sound (P(2)), missed beats and systolic murmurs (41.2% in pregnant subjects vs 12.9% in non-pregnant controls, p < 0.05). Negroid-pattern ST-segment elevation was commoner among controls (24.3%) than pregnant subjects (2.9%, p < 0.005). Arrhythmias were rare among the study participants.

Conclusion: Significant findings on examination were low diastolic blood pressure and a systolic ejection murmur. However, ECG changes showed a normal frontal-plane QRS axis, normal PR interval, significantly rare normal Negroidpattern ST elevation, significant LVH based on Araoye RI > 12 mm and a rarity of all forms of arrhythmias. These data may help resolve some cardiac diagnostic difficulties during pregnancy.