Predictive values of the electrocardiogram in diagnosing pulmonary hypertension.

OBJECTIVE: Determination of the prevalences and predictive values of specific electrocardiograms (ECG) criteria of right ventricular hypertrophy (RVH) or right atrial enlargement for pulmonary hypertension.
METHODS: We examined the ECG and trans-thoracic echocardiograms (TTE) of 372 patients who had TTE and 12-lead ECG, performed within 24 h interval, during a 12-month period. There were 282 consecutive adults with pulmonary hypertension (pulmonary artery systolic pressure (PASP) >30 mm Hg) and 90 subjects with normal cardiac anatomy and normal PASP. The mean age of patients with pulmonary hypertension was 74.0+/-11.0 years and 66% of them were females. The control subjects had a mean age of 56.3+/-17.5 years and 58.8% were females.
RESULTS: ECG patterns focusing on the R and S amplitudes and R/S ratio in V1 were more predictive of pulmonary hypertension than ECG patterns involving leads V5 and V6. In particular, each of the following ECG patterns had good positive predictive values for pulmonary hypertension (greater than 80%): R in I less than 2 mm+S in V1</=2 mm, R/S in V1 more than 1, R/S V6 less than 1, QRS axis more than 110 degrees , qR in V1. Right axis deviation with QRS axis more than 110 degrees had the best positive predictive value of severe pulmonary hypertension (PASP>/=60 mm Hg). Electrocardiographic criterion for right atrial enlargement was not found in any of the patients with pulmonary hypertension.
CONCLUSIONS: ECG criteria of RVH were rare in patients with pulmonary hypertension. ECG patterns focusing on the R and S amplitude in V1 and right axis deviation with QRS axis deviation>/=110 degrees had excellent positive predictive values of pulmonary hypertension. However, the absence of ECG criteria of RVH could not exclude with certainty the presence of pulmonary hypertension.