NPPB and chronic thromboembolic pulmonary hypertension: In the absence of three specific ECG characteristics suggestive of right ventricular overload (Fig. 2) and a normal age- and gender-adjusted NT-proBNP level, CTEPH is considered excluded with a sensitivity of more than 90%.8, 9Hence, only patients with abnormal rule-out criteria need to be referred for echocardiography.1By this design, CTEPH diagnostic resources can be focused not only on patients with clear symptoms of CTEPH but also on those with a high pre-test probability of CTEPH, with a limited number of required echocardiographs.