CHARACTERISTICS OF PULMONARY-ARTERY PRESSURE WAVE-FORM FOR DIFFERENTIAL-DIAGNOSIS OF CHRONIC PULMONARY THROMBOEMBOLISM AND PRIMARY PULMONARY-HYPERTENSION

Objectives. The accurate diagnosis of chronic pulmonary thromboembolis m (CPTE) is a prerequisite for life-saving surgical interventions. To help in the differential diagnosis of CPTE and primary pulmonary hyper tension (PPH), rye characterized the configuration of the pulmonary ar tery pressure waveform. Background Because CPTE predominantly involves the proximal arteries, whereas PPH involves the peripheral arteries, we hypothesized that patients with CPTE would have stiff or high resis tance proximal arteries, whereas those affected by PPH would have high resistance peripheral arteries. These differences in the primary lesi ons would make arterial pulsatility relative to mean pressure larger i n CPTE than in PPH. Methods. In 34 patients with either CPTE (n = 22) or PPH (n = 12) whose pulmonary systolic pressure was greater than or equal to 50 mm Hg, we measured pulmonary artery pressure using a fluid -filled system that included a balloon-tipped flow directed catheter. Results. To quantify the magnitude of pulsatility relative to mean pre ssure, we normalized pulse pressure by mean pressure, hereinafter refe rred to as fractional pulse pressure (PPf. PPf was markedly higher in CPTE than in PPH (mean [+/- SD] 1.41 +/- 0.20 and 0.80 +/- 0.18, respe ctively, p < 0.001) and was diagnostic in separating the two groups wi thout overlap. Similarly, the coefficient of variation of pulmonary ar tery pressure also separated the two groups without overlap (0.45 +/- 0.06 and 0.25 +/- 0.06, respectively, p < 0.001). Fractional time to h alf the area under the pressure curve separated the two groups reasona bly well (0.35 +/- 0.02 and 0.43 +/- 0.03, respectively, p < 0.001). C onclusions. The analysis of pulsatility of pulmonary artery pressure i s useful in the differential diagnosis of CPTE and PPH. (C) 1997 by th e American College of Cardiology.