NONINVASIVE ESTIMATION OF PULMONARY ARTERIAL WEDGE PRESSURE WITH DOPPLER TRANSMITRAL FLOW VELOCITY PATTERN IN PATIENTS WITH KNOWN HEART-DISEASE

Pulmonary arterial wedge pressure (PAWP) is an important marker of car diac function. Regrettably, it requires catheterization, which can occ asionally result in serious complications. A noninvasive method of est imating PAWP would thus be helpful. Recent studies have indicated that the Doppler transmitral flow velocity pattern was strongly dependent on preload and could provide an estimate of PAWP. This study was there fore designed to evaluate the relation between Doppler transmitral flo w velocity indexes and measured PAWP in 91 patients (learning group: 7 3 men, mean age 57 +/- 13 years) with ischemic heart disease (n = 41), dilated (n = 29) or hypertrophic cardiomyopathy (n = 4), or aortic st enosis (n = 17). Multiple regression analysis was used to derive an eq uation for estimation of PAWP, which was subsequently tested in a sepa rate group of 33 patients (testing group: 28 men, mean age 58 +/- 12 y ears) with similar cardiac conditions. PAWP ranged from 4 to 48 mm Hg in the learning group and from 7 to 40 mm Hg in the testing group. In the learning group, PAWP correlated with the E/A ratio (r = 0.95), atr ial filling fraction (r = -0.80), peak E velocity (r = 0.79), isovolum ic relaxation period (r = -0.75), and deceleration time (r = -0.61). I n the learning group, PAWP was best predicted as PAWP = 18.4 + [17:1.I n(E/A ratio)]. This equation allowed prediction of PAWP within 3 mm Hg of the measured value in 24 of 33 patients (73%) in the testing group . In 8 additional patients, the equation also accurately predicted the changes in PAWP induced by volume loading or intravenous nitrates (r = 0.98). Data indicate that in patients with known heart disease, the noninvasive assessment of transmitral flow velocity pattern by Doppler echocardiography can predict PAWP with a clinically meaningful degree of accuracy.