Pulmonary arterial compliance: a physiological variable still searching for clinical relevance?

The fundamental physiological disturbance in pulmonary hypertension is an increase in right ventricular (RV) afterload, regardless of disease aetiology. Although a complete description of the arterial afterload can be constructed using complex impedance analysis in the frequency domain, more simple measures are required for clinical use. In general, there are two major factors which modulate the RV afterload, a steady component and a pulsatile component which are often represented by pulmonary vascular resistance (PVR) and pulmonary arterial compliance (PAC), respectively (figure 1). Furthermore, the pulmonary circulation is highly pulsatile and it is estimated that the pulsatile component of the pulmonary arterial load accounts for 25% of RV power, as compared with 10% in a systemic left ventricle–aorta coupled system.1 Thus, it stands to reason that assessment of PAC should be of both physiological and clinical relevance. Figure 1Right ventricular afterload consists of...
Source: Heart - Category: Cardiology Authors: Tags: Editorials Source Type: research