Doppler-derived diastolic indices in dilated cardiomyopathy: a hemodynamic evaluation relating pre- and afterload parameters to flow velocity.
OBJECTIVE
To explain the well known finding of a normal early diastolic filling velocity in advanced grade heart failure due to dilated cardiomyopathy (DCM) exclusively by hemodynamics and to relate Doppler-flow velocity parameters to indices representing pre- and afterload.


METHODS
DCM was hypothesized to be a disorder in which pre- and afterload contribute in equal proportion to cardiac insufficiency independently from ischemic impairment of relaxation.


METHODS
Twenty patients with DCM were enroled in the study after definitive exclusion of coronary and valvular heart disease.


METHODS
Diastolic transmitral and transtricuspid Doppler readings and hemodynamic measurements were done simultaneously by two blinded observers. A Swan-Ganz catheter was employed.


RESULTS
Simple and multiple regression analyses revealed early diastolic filling velocity to depend on hemodynamic parameters representing afterload. Pulmonary capillary wedge pressure (PCWP) was found to be directly related to early diastolic filling velocity. An inverse relation between early diastolic filling velocity and parameters representing afterload (systemic vascular resistance and mean arterial pressure) was demonstrated; however the most significant correlation using multiple regression analysis was shown between mitral early diastolic peak-flow velocity (dependent) and PCWP as well as systemic vascular resistance index (independents) (r = 0.75; P < 0.001). Correspondingly, the transtricuspid early diastolic peak-flow velocity was shown to be related to the equilibrium of right atrial pressure and pulmonary vascular resistance index. The atrial diastolic flow velocity parameters were found not to be related to hemodynamic indices.


CONCLUSIONS
A definitive but not one-to-one relationship between early diastolic Doppler-flow indices and hemodynamic parameters was defined. A functional coupling of pre- and afterload can be considered the main determinant of early diastolic filling velocity in DCM.
Bartel
T
T
Med. Klinik, Charité, Humboldt-Universität zu Berlin, Germany.
Muller
S
S
Borges
A C
AC
D000328:Adult; D001783:Blood Flow Velocity; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D012044:Regression Analysis