title: A noninvasive method for assessing impaired diastolic suction in patients with dilated cardiomyopathy.
abstract: 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.
authors.affiliation: Department of Cardiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Yotti
authors.forename: Javier
authors.initials: J
authors.lastname: Bermejo
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Antoranz
authors.forename: M Mar
authors.initials: MM
authors.lastname: Desco
authors.forename: Cristina
authors.initials: C
authors.lastname: Cortina
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rojo-Alvarez
authors.forename: Carmen
authors.initials: C
authors.lastname: Allué
authors.forename: Laura
authors.initials: L
authors.lastname: Martín
authors.forename: Mar
authors.initials: M
authors.lastname: Moreno
authors.forename: José A
authors.initials: JA
authors.lastname: Serrano
authors.forename: Roberto
authors.initials: R
authors.lastname: Muñoz
authors.forename: Miguel A
authors.initials: MA
authors.lastname: García-Fernández
mesh_terms: 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