K. Yamamoto et al., CONTRIBUTION OF CHAMBER COMPLIANCE AND LEFT-VENTRICULAR MINIMUM PRESSURE TO ABNORMAL LEFT-VENTRICULAR FILLING DYNAMICS, Japanese Circulation Journal, 58(1), 1994, pp. 57-68
This study was designed to clarify whether changes in transmitral flow
velocity patterns in left ventricular (LV) dysfunction are determined
primarily by changes in left atrial (LA) pressure and LV relaxation,
and, if not, to determine the contribution of changes in other paramet
ers. Two levels of acute LV dysfunction were produced in 11 dogs by co
ronary microembolization, and pulsed Doppler transmitral now velocity
patterns and hemodynamic parameters were recorded. The mean ratio of p
eak early diastolic filling velocity (E) to peak late diastolic fillin
g velocity decreased with mild LV dysfunction (LV end-diastolic pressu
re of between 12 and 17 mmHg), and redistribution of diastolic filling
to early diastole was observed with severe LV dysfunction (LV end-dia
stolic pressure of greater than or equal to 18 mmHg). Changes in E cor
related best with those in the LA-LV pressure gradient integral. Multi
ple linear regression analysis of the changes in possible determinants
of the pressure gradient integral, i.e., LA to LV crossover pressure,
LV time constant, LV minimum pressure, and LA and LV chamber complian
ce, yielded a highly significant correlation with the changes in E. Ho
wever, analysis of only the changes in the crossover pressure and the
time constant showed a very poor correlation. Thus, changes in chamber
compliance and LV minimum pressure, in addition to the changes in LA
pressure and LV relaxation, may significantly affect the changes in E
that are associated with LV dysfunction.