The Diagnostic Accuracy of an Electrocardiogram in Pulmonary Hypertension and the Role of “R V1, V2 + S I, aVL − S V1”

<b>Background</b>: Pulmonary hypertension (PH) can cause characteristic electrocardiographic (ECG) changes due to right ventricular hypertrophy and/or strain. The aims of the present study were to explore the diagnostic accuracy of ECG parameters for the diagnosis of PH, applying the recently adjusted mean pulmonary artery pressure (mPAP) threshold of >20 mmHg, and to determine the role of "R V1, V2 + S I, aVL - S V1". <b>Methods</b>: Between July 2012 and November 2023, 100 patients without PH, with pulmonary arterial hypertension, or with chronic thromboembolic pulmonary hypertension were retrospectively enrolled. <b>Results</b>: The sensitivity and specificity of the ECG parameters for the diagnosis of PH varied from 3 to 98% and from 3 to 100% (means: 39% and 87%). After optimising the parameters' cut-offs, the mean sensitivity (39% to 66%) increased significantly but the mean specificity (87% to 74%) slightly decreased. "R V1, V2 + S I, aVL - S V1" was able to predict an mPAP >20 mmHg (OR: 34.33; <i>p</i> < 0.001) and a pulmonary vascular resistance >5 WU (OR: 17.14, <i>p</i> < 0.001) but could not predict all-cause mortality. <b>Conclusions</b>: Even with improved cut-offs, ECG parameters alone are not able to reliably diagnose or exclude PH because of their low sensitivity. However, they still might be helpful to reveal a suspicion of PH, especially in early diagnostic stages, e.g., in primary care with general practitioners or non-specialised cardiologists and pulmonologists. "R V1, V2 + S I, aVL - S V1" was able to predict the diagnosis of (severe) PH but could not predict all-cause mortality. Nevertheless, it can still be useful in risk stratification.