Radionuclide Determined Ejection Fractions and Ventricular Volumes
Table 2 shows the initial and final right and left ventricular ejection fractions and the right and left ventricular end-diastolic volume indices for the survivors and nonsurvivors of septic shock. Survivors had a substantial depression of initial left ventricular ejection fraction at 0.31 and a depressed initial right ventricular ejection fraction of 0.35. With recovery these values increased significantly to 0.47 (p<0.001) and 0.51 (p<0.001), respectively. The initial left and right ventricular end-diastolic volume indices were substantially increased (145 ml/m2 and 124 ml/m2, respectively) and decreased toward normal with recovery (to 106 ml/m2, p = 0.012; and to 88 ml/m2, p = 0.03, respectively). Thus, survivors showed a pattern of transient biventricular depression of ejection fraction associated with transient biventricular dilatation.
In contrast, the nonsurvivors had an initial left ventricular ejection fraction of 0.40 and right ventricular ejection fraction of 0.41; these did not change significantly from initial to final studies. The initial left and right ventricular end-diastolic volume indices were 124 ml/m2 and 120 ml/m2, respectively; these also did not change significantly from initial to final studies. buy kamagra tablets
Comparing the change in survivors from initial to final with that of the nonsurvivors, the changes in both right and left ventricular ejection fraction were statistically significant. The changes in the end-diastolic volume index were not statistically significant comparing the two groups; the nonsurvivors had small decreases in both the right and left ventricular end- diastolic volume index while the survivors had statistically significant decreases in these parameters.
An examination of serial studies showed that changes in right ventricular ejection fraction followed the same direction as changes in left ventricular ejection fraction in 31 of38 (82 percent) patients. Changes in right ventricular end-diastolic volume index followed the same direction as changes in left ventricular end- diastolic volume index in 28 of37 (76 percent) patients. Pulmonary artery pressure did not consistently change in direction with either the ejection fraction or the end-diastolic volume index, nor did the pulmonary artery pressures consistently change in direction with right ventricular, as opposed to left ventricular, size or function. By Spearman rank correlation the change in right ventricular ejection fraction correlated strongly with the change in left ventricular ejection fraction (r = 0.5, p<0.001). Thus, myocardial dysfunction in septic shock is usually a biventricular phenomenon. Characteristically, the left and right ventricle demonstrate similar qualitative as well as temporal relationships in a variety of ventricular performance measurements.
Pulmonary Vascular Changes and Right Ventricular Dysfunction
To evaluate a possible relationship between right ventricular performance and pulmonary vascular abnormalities, pulmonary artery mean pressure and pulmonary vascular resistance index were correlated with right ventricular performance or size. The Spear¬man rank correlation was used to evaluate the initial values in each individual patient. Pulmonary artery mean pressure did not correlate with either right ventricular ejection fraction or right ventricular end- diastolic volume index. Pulmonary vascular resistance index did not correlate with right ventricular ejection fraction. However, pulmonary vascular resistance index did correlate negatively with right ventricular end-diastolic volume index ill the survivors (r = 0.50, p = 0.02), but it did not correlate in the nonsurvivors (r = 0.30, p = 0.21). Viagra Professional