ECG demonstrating the three specific electrocardiographic characteristics of right ventricular overload, the ‘Chronic Thromboembolic Pulmonary Hypertension (CTEPH) rule out criteria’. ① Right bundle branch block: rSR’ of RSr’ pattern in lead V1 with a QRS duration ≥120 ms; ② R:S >1 in lead V1 with R>0.5 mV and ③ right QRS axis deviation QRS axis >90°. Reprinted from “To screen or not to screen for chronic thromboembolic pulmonary hypertension after acute pulmonary embolism” (26), Vol 151, Yvonne M. Ende-Verhaar, Menno V. Huisman, Frederikus A. Klok, Pages No.7, Copyright [2017], with permission from Elsevier. ECG, electrocardiography.