The echocardiogram is probably the most important non-invasive test in the diagnosis of pulmonary hypertension as it will often be the investigation which will decide on further diagnostic tests for the patient. It is important to remember that although this is an important test it is not the gold standard diagnostic test for PAH. That remains the right heart catheterisation. The important measurements in the echo focus on the pulmonary artery pressure (measured by tricuspid regurgitant velocity or pressure gradient) and the RV morphology. Key parameters include the RV dimensions and RV function.
Occasionally the TRV cannot be accurately measured and in these circumstances other parameters which may indicate PAH should be assessed. These include RV morphology and pulmonary artery acceleration time. In addition echo parameters such as Tricuspid annular planar systolic excursion(TAPSE) can be used to aid in patient prognosis.
Echo can also be used to assess the underlying cause of the pulmonary hypertension. For example an enlarged LA can indicate heart failure with preserved ejection fraction and an assessment of valvular function can indicate mitral regurgitation or aortic stenosis.
In patients with hypoxaemia, an assessment using agitated saline should be made to investigate the presence of a significant right to left intracardiac shunt.
Links to further reading:
- The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS). 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. European Heart Journal (2016) 37, 13
- Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K, Solomon SD, Louie EK,Schiller NB. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registeredbranch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr 2010; 23: 685–713.
- Forfia et al. Tricuspid annular planar systolic excursion predicts survival in pulmonary hypertension.A J Respir Crit Care Med 2006;174:1034