Pulmonary Artery Wave Intensity Analysis in Pulmonary Hypertension Due to Left Heart Disease

Abstract

<h3>Purpose</h3> Wave intensity analysis (WIA) uses simultaneous changes in the pressure and flow velocity to determine wave energy, type and timing of traveling waves in the circulation. Pulmonary artery WIA has not been studied in patients with heart failure. We hypothesise that WIA can differentiate patients with combined pre- and post-capillary pulmonary hypertension (PH) from isolated post-capillary PH. <h3>Methods</h3> Right heart catheterisation was performed using a balloon floatation catheter. Pressure and velocity data were acquired simultaneously using a dual-tipped pressure and doppler flow sensor wire. The data were processed offline using customised Matlab software. <h3>Results</h3> We studied 20 patients with heart failure [Table]. Eight patients had backward compressions wave (BCW). The representative wave intensity (dI) pattern with pressure (P) and velocity (U) profile is shown in Figure 1. The black line denotes total pressure, velocity and wave intensity, the blue dotted line denotes forward going waves and red dotted lines denotes backward going waves. Figures 1a and 1b show the groups with and without a BCW. Typically a forward compression wave (FCW) in early systole (related to right ventricular systole) is followed by a forward decompression wave (FDW) in diastole. Fig1a shows a BCW immediately following the FCW in systole, which may be indicative of wave reflection in the pulmonary circulation. Patients who displayed a BCW had significantly higher pulmonary artery pressure, TPG, PVR and significantly lower PAC. <h3>Conclusion</h3> The presence of a BCW on pulmonary WIA may identify patients with combined pre- and post-capillary PH.