Electrocardiography changes and their significance during treatment of patients with intermediate-high and high-risk pulmonary embolism

Background: Electrocardiography (ECG) signs, typical or acute pulmonary embolism, and their changes can be used for the prediction of clinical and haemodynamic outcomes. Purpose: To study the predictive value of the resolution of admission ECG signs in higher risk pulmonary embolism patients for 30-day survival and for the decrease in right ventricular systolic pressure. Methods: We analysed the 12-lead ECGs at admission and daily for the first 5 days after hospitalisation in 110 intermediate-high and high-risk pulmonary embolism patients admitted to the intensive care unit of a single tertiary centre. The predictive value of the resolution of four ECG signs were analysed for 30-day survival and for the changes in right ventricular systolic pressure during hospitalisation: S-wave in the first standard lead, right bundle branch block pattern, S-wave in the aVL lead and negative T-waves in precordial leads. Results: ECG recordings showed the existence of S-wave in the I lead in 71 (64.5%), S-wave in the aVL in 77 (70%), right bundle branch block pattern in 30 (27.3%) and negative T-waves in 66 (60%) patients. All-cause 30-day in-hospital mortality was 13.6%. Among the ECG signs, only the presence of right bundle branch block at admission was significantly associated with 30-day all-cause mortality (hazard ratio (HR) adjusted for age, gender and right ventricular systolic pressure at admission was 7.7, 95% confidence interval (CI) 2.1–27.9; P=0.002). The resolution of three ECG signs during the first 5 days of hospitalisation, S-wave in the I lead (HR 26.4, 95% CI 3.1–226.6; P=0.003), S-wave in the aVL (HR 21.5, 95% CI 2.6–175.3; P=0.004) and right bundle branch block configuration (HR 5.2, 95% CI 1.3–20.8; P=0.020) were associated with 30-day survival. The intermediate-high and high-risk pulmonary embolism patients with S-wave resolution in lead aVL had 0.0% and 7.1% 30-day all-cause mortality, respectively. The patients with resolution of the S-wave in the first lead and in aVL as well as right bundle branch block had more pronounced changes in right ventricular systolic pressure at discharge (27±13 vs. 13±15 mmHg; P=0.011 for S-wave in I lead resolution, 27±12 vs. 15±17 mmHg; P=0.004 for S-wave in aVL resolution and 23±14 vs. 9±14 mmHg; P=0.040 for right bundle branch block resolution) than patients without resolution. Conclusion: Resolution of S-waves and right bundle branch block in ECG correlates with lower all-cause 30-day mortality in intermediate-high and high-risk pulmonary embolism patients. Resolution of S-waves in the first lead and in aVL and right bundle branch block correlates with a decrease of right ventricular systolic pressure.