Noninvasive assessment of the right ventricular filling pressure gradient.
BACKGROUND
The physiological basis of right ventricular (RV) diastolic function remains incompletely studied in humans. The driving force responsible for RV filling, the pressure gradient along the RV inlet from the right atrium to the RV apex, has never been measured in the clinical setting.


RESULTS
We validated a method for measuring the RV filling pressure difference (RVFPD) from color Doppler M-mode recordings in 12 pigs undergoing interventions on RV preload, afterload, and lusitropic states (error, -0.1+/-0.4 mm Hg compared with micromanometers; intraclass correlation coefficient, 0.88). Peak early RVFPD correlated directly with mean right atrial pressure and inversely with the time constant of RV relaxation. In 21 patients with dilated cardiomyopathy, the peak RVFPD was 1.0 mm Hg (95% CI, 0.8 to 1.2), significantly lower than in age-matched control subjects (1.4 mm Hg; 95% CI, 1.2 to 1.6). In another population of 19 young healthy volunteers, the peak RVFPD was 2.3 mm Hg (95% CI, 2.0 to 2.6), which was reduced by nitroglycerine and esmolol and was augmented by volume overload and atropine infusions. RVFPD was generated almost exclusively by inertial forces.


CONCLUSIONS
For the first time, the RV driving filling force can be accurately measured noninvasively in the clinical setting, and the method is sensitive to detect the effects of preload, chronotropic, and lusitropic states. In patients with dilated cardiomyopathy, the RV filling force is markedly reduced, indicating severely impaired RV relaxation. These findings suggest that this is a useful tool for improving the clinical assessment of RV diastolic function.
Department of Cardiology, Hospital General Universitario Gregorio Marañón, Dr Esquerdo 46, 28007 Madrid, Spain.
Cristina
C
Cortina
Javier
J
Bermejo
Raquel
R
Yotti
M Mar
MM
Desco
Daniel
D
Rodríguez-Pérez
J Carlos
JC
Antoranz
José Luis
JL
Rojo-Alvarez
Damien
D
Garcia
Miguel A
MA
García-Fernández
Francisco
F
Fernández-Avilés
D000818:Animals; D001794:Blood Pressure; D015150:Echocardiography, Doppler; D007091:Image Processing, Computer-Assisted; D023421:Models, Animal; D015203:Reproducibility of Results; D013552:Swine; D016278:Ventricular Function, Right / Q000502:physiology*