Left ventricular isovolumic relaxation is a predictor of left ventricular end-diastolic pressure.
BACKGROUND
The relationship between isovolumic left ventricular (LV) relaxation and LV filling pressures remains incompletely explored. If there is a relationship between the rate of early diastolic LV relaxation and LV end-diastolic pressure, this would have important implications concerning both our understanding and, potentially, our treatment of LV diastolic dysfunction.


OBJECTIVE
To examine the baseline hemodynamic correlates of LV end-diastolic pressure in patients with both normal and abnormal LV function.


METHODS
The relationships between LV end-diastolic pressure, a variety of hemodynamic parameters (tau, the rate of LV isovolumic relaxation, LV peak positive+dP/dt, LV peak systolic pressure and heart rate), measures of LV end-systolic and end-diastolic volume, and age were determined using regression analysis techniques in 104 patients with normal LV systolic function and 90 patients with an LV ejection fraction of less than 40%.


RESULTS
Univariate analysis demonstrated a correlation between tau and LV end-diastolic pressure (r=0.743, P<0.001). There were significant univariate relationships between a number of other hemodynamic variables and LV end-diastolic pressure. A multiple regression model demonstrated that tau made the most important contribution to a model where LV end-diastolic pressure is the dependent variable. LV peak systolic pressure and heart rate also made significant contributions to the model. In 33 of these patients, when LV end-diastolic pressure was reduced using an inferior vena cava occlusion balloon, tau did not change. The acute administration of clonidine (n=11) caused an increase in LV end-diastolic pressure that was closely correlated with an observed increase in tau (r=0.843, P<0.001).


CONCLUSIONS
These observations suggest that the rate of LV isovolumic relaxation is a predictor of LV end-diastolic pressure.
Detsky
Michael E
ME
Division of Cardiology, Mount Sinai Hospital and Department of Medicine University of Toronto, Ontario, Canada.
Azevedo
Eduardo R
ER
Parker
John D
JD
D006328:Cardiac Catheterization; D003000:Clonidine; D003971:Diastole; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D017725:Ventricular Pressure
D003000:Clonidine