Introduction: Little is known about the roles of wave travel and wave reflection in the development of right ventricular dysfunction. The objective of this study is to apply wave intensity analysis (WIA) in the pulmonary artery to assess right ventriculo-arterial function and coupling in man.

Methods: Right heart catheterisation was performed using a pressure and Doppler flow sensor tipped catheter to obtain simultaneous pressure and flow velocity measurements in the pulmonary artery (PA). Recordings were made at rest as well as during a modified Valsalva manoeuvre and handgrip exercise. WIA was subsequently applied to the acquired data.

Results: 7 patients (48 ± 14 years, 5 male) undergoing cardiac catheterisation and with normal mean pulmonary arterial pressure (17 ± 3 mmHg) and without significant cardiovascular disease or lung disease were studied. In the main PA, WIA showed a forward (proximally originating) compression wave in early systole caused by right ventricular ejection and a forward expansion wave prior to closure of the pulmonary valve that decreased the arterial pressure and flow in late systole. Backward (reflecting) waves were minimal. Wave speed was 2.64 ± 1.39 m/s. The wave pattern was unchanged by respiration and handgrip exercise, however, during Valsalva manoeuvre the magnitude of the waves reduced.

Conclusion:Contrary to previous work in animals, our data show that minimal backward waves are present in the pulmonary artery indicating well matched ventriculo-arterial coupling in individuals without pulmonary artery disease. Patients with pulmonary hypertension will be assessed in the continuation of this study.