Prevalence and predictive value of electrocardiographic abnormalities in pulmonary hypertension: evidence from the pan-African pulmonary hypertension cohort (PAPUCO) study

Background: Pulmonary hypertension (PH) is prevalent in Africa and is still often diagnosed only at an advanced stage, therefore it is associated with poor quality of life and survival rates. In resource-limited settings, we assessed the diagnostic utility of standard 12-lead electrocardiograms (ECG) to detect abnormalities indicating PH. Methods: Sixty-five patients diagnosed with PH were compared with 285 heart disease-free subjects. The prevalence and diagnostic performance of ECG features indicative of PH and right heart strain were calculated. Results: Compared to the control group, all abnormalities were more frequent in the PH cohort where no patient had a completely normal ECG. The most prevalent (cases vs control) ECG abnormalities were: pathological Q wave in at least two contiguous peripheral leads (47.7 vs 6.7%), left ventricular hypertrophy (38.5 vs 9.8%) and p-pulmonale (36.9 vs 20.7%) (all p < 0.05). The sensitivity of ECG criteria for right heart strain ranged between 6.2 and 47.7%, while specificity ranged between 79.3 and 100%. Negative predictive value ranged between 81.5 and 88.9% and positive predictive value between 25 and 100%. Positive predictive value was lowest (25%) for right bundle branch block and QRS rightaxis deviation (≥ 100°), and highest (100%) for QRS axis ≥ +100° combined with R/S ratio in V1 ≥ 1 or R in V1 > 7 mm. Conclusion: When present, signs of PH on ECG strongly indicated disease, but a normal ECG cannot rule out disease. ECG patterns focusing on the R and S amplitude in V1 and right-axis deviation had good specificity and negative predictive values for PH, and warrant further investigation with echocardiography.