Left ventricular function in systole and diastole in constrictive pericarditis

Left ventricular function was studied in systole and diastole in 30 patients with constrictive pericarditis. Left ventricular end-diastolic volume was used to divide the patients into three arbitrary groups: severe constriction (EDV < 25 ml./M.²), moderate constriction (EDV 25 to 50 ml./M.²), and mild constriction (EDV > 50 ml./M.²).The patients had high ventricular diastolic and venous filling pressures (mean LVEDP = 23 ± 7 mm. Hg, mean RVEDP = 20 ± 7 mm. Hg). Measurements related to absolute fiber shortening (stroke index, stroke work index, and left ventricular ejection rate) were reduced and linearly related to the degree of constriction as assessed by the end-diastolic volume.Measurements of relative fiber shortening or lengthening (ejection and filling fraction and circumferential fiber shortening) were normal despite great reduction in ventricular volumes.Velocity measurements, peak LV $\text{dp}\text{dt}$ and mean velocity of circumferential fiber shortening were normal or slightly reduced.These changes were reflected in the systolic time interval measurements pre-ejection phase, left ventricular ejection time, and the ratio $\text{PEP}\text{LVET}$.Diastolic function of the ventricle was abnormal; the distensibility index of the ventriculo-pericardial system ($\text{ΔV}\text{ΔP}$) was low and the passive elastic modulus in-increased. The change in compliance correlated with the degree of constriction and there was a linear relationship between compliance and EDV.The ventricle was underloaded despite the high filling pressure and stroke work index was reduced; extrinsic compression raised the diastolic pressure and reduced left ventricular volumes.