Novel echocardiographic approach to the accurate measurement of pulmonary vascular resistance based on a theoretical formula in patients with left heart failure -- pilot study.
BACKGROUND
Several non-invasive methods for measuring pulmonary vascular resistance (PVR) have been proposed to date, but they remain empirical, lacking sufficient accuracy to be used in clinical practice. The aims of this study were to propose a novel echocardiographic measurement of PVR based on a theoretical formula and investigate the feasibilty and accuracy of this method in patients with heart failure.


RESULTS
Echocardiography was performed in 27 patients before right heart catheterization. Peak tricuspid regurgitation pressure gradient (TRPG), pulmonary regurgitation pressure gradient in end-diastole (PRPGed), and cardiac output derived from the time-velocity integral and the diameter in the left ventricular outflow tract (COLVOT) were measured. PVR based on a theoretical formula (PVRtheo) was calculated as (TRPG-PRPGed)/3COLVOTin Wood units (WU). The results were compared with PVR obtained by right heart catheterization (PVRcath) using linear regression and Bland-Altman analysis. Mean PVRcathwas 2.4±1.4 WU. PVRtheocorrelated well with PVRcath(r=0.83, P<0.001). On Bland-Altman analysis the mean difference was 0.1±0.7 WU. The limits of agreements were smaller than for other non-invasive estimations previously reported.


CONCLUSIONS
The new echocardiographic approach based on a theoretical formula provides a non-invasive and accurate assessment of PVR in patients with heart failure.
Kansai Rosai Hospital Cardiovascular Center.
Takashi
T
Kanda
Masashi
M
Fujita
Osamu
O
Iida
Masaharu
M
Masuda
Shin
S
Okamoto
Takayuki
T
Ishihara
Kiyonori
K
Nanto
Tatsuya
T
Shiraki
Mitsuyoshi
M
Takahara
Yasushi
Y
Sakata
Masaaki
M
Uematsu
D000368:Aged; D006328:Cardiac Catheterization; D015150:Echocardiography, Doppler / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results; D013997:Time Factors; D014655:Vascular Resistance