A noninvasive method for assessing impaired diastolic suction in patients with dilated cardiomyopathy.
BACKGROUND
Diastolic suction is a major determinant of early left ventricular filling in animal experiments. However, suction remains incompletely characterized in the clinical setting.


RESULTS
First, we validated a method for measuring the spatio-temporal distributions of diastolic intraventricular pressure gradients and differences (DIVPDs) by digital processing color Doppler M-mode recordings. In 4 pigs, the error of peak DIVPD was 0.0+/-0.2 mm Hg (intraclass correlation coefficient, 0.95) compared with micromanometry. Forty patients with dilated cardiomyopathy (DCM) and 20 healthy volunteers were studied at baseline and during dobutamine infusion. A positive DIVPD (toward the apex) originated during isovolumic relaxation, reaching its peak shortly after mitral valve opening. Peak DIVPD was less than half in patients with DCM than in control subjects (1.2+/-0.6 versus 2.5+/-0.8 mm Hg, P<0.001). Dobutamine increased DIVPD in control subjects by 44% (P<0.001) but only by 23% in patients with DCM (P=NS). DIVPDs were the consequence of 2 opposite forces: a driving force caused by local acceleration, and a reversed (opposed to filling) convective force that lowered the total DIVPD by more than one third. In turn, local acceleration correlated with E-wave velocity and ejection fraction, whereas convective deceleration correlated with E-wave velocity and ventriculo:annular disproportion. Convective deceleration was highest among patients showing a restrictive filling pattern.


CONCLUSIONS
Patients with DCM show an abnormally low diastolic suction and a blunted capacity to recruit suction with stress. By raising the ventriculo:annular disproportion, chamber remodeling proportionally increases convective deceleration and adversely affects left ventricular filling. These previously unreported mechanisms of diastolic dysfunction can be studied by using Doppler echocardiography.
Yotti
Raquel
R
Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Bermejo
Javier
J
Antoranz
J Carlos
JC
Desco
M Mar
MM
Cortina
Cristina
C
Rojo-Alvarez
José Luis
JL
Allué
Carmen
C
Martín
Laura
L
Moreno
Mar
M
Serrano
José A
JA
Muñoz
Roberto
R
García-Fernández
Miguel A
MA
D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D003971:Diastole; D004106:Dilatation / Q000009:adverse effects*; D004452:Echocardiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D016277:Ventricular Function, Left