Lung Hemodynamics

Lung Hemodynamics Calculator Explanation and Clinical Context This calculator provides noninvasive echocardiographic estimates that support interpretation of pulmonary artery pressures and pulmonary vascular resistance in clinical practice. Systolic pulmonary artery pressure is estimated from the peak tricuspid regurgitation velocity using the modified Bernoulli equation and an estimate of right atrial pressure. Use this estimate as one component of a comprehensive assessment that includes symptoms, physical examination, chest imaging, and when available, right heart catheterization.

Echocardiographic estimates of mean pulmonary artery pressure are provided using accepted empirical conversions from systolic pulmonary artery pressure and by calculation from pulmonary regurgitation velocities when those signals are present. Echocardiographic pulmonary vascular resistance offers a noninvasive surrogate for invasive measurement. The echo derived formula provided here is widely used for screening and trending.

The PVR index calculated as the pressure gradient between mean pulmonary artery pressure and pulmonary capillary wedge pressure divided by cardiac index follows the physiologic definition of resistance and aligns with invasive practice. Interpret all numeric results in the clinical context. Small changes in input values may produce important changes in calculated indices.

Confirm clinically important decisions with invasive haemodynamic assessment when appropriate. Clinical interpretation summary Use systolic and mean pressure estimates to screen for elevated pulmonary pressures and to monitor response to therapy. Use echocardiographic PVR for initial noninvasive assessment of pulmonary vascular load.

Use DPG and TPG as adjuncts that may help differentiate predominant pre capillary pulmonary vascular disease from left heart related pulmonary pressure elevation. When the clinical question influences management or when noninvasive estimates are inconsistent with symptoms or exam, proceed to right heart catheterization for definitive measurements. Reference Galiè N, Channick RN, Frantz R, et al.

Guidelines for the diagnosis and treatment of pulmonary hypertension. European Heart Journal. 2022;43:3618-3731. doi reference available from guideline document.

Abbas AE, Fortuin FD, Schiller NB, et al. A simple echocardiographic method to estimate pulmonary vascular resistance. Journal of the American Society of Echocardiography.

2003;16:114-121. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults.

Journal of the American Society of Echocardiography. 2010;23:685-713. Chemla D, Castelain V, Lecarpentier Y, et al.

New formula for mean pulmonary artery pressure estimation: a comparison with direct measurements. Chest. 2004;126:1313-1319.

This educational content is not a substitute for individual clinical judgement. Please consult primary sources and local protocols when managing patients.