Septic Patients: Two-dimensional real-time echocardiographic studies were performed with a wide-angle phased-array digital sector scanner (SONOS 500 K; Hewlett-Packard; Palo Alto, CA). A transthoracic approach via an apical or a left subcostal window was used to obtain a long-axis four-chamber view of the heart. In each patient, the same view was used during serial echocardio-graphic studies. Echocardiographic images were recorded on videotape for further quantitative analysis. Analysis was performed within a few hours by the same senior investigator (F. J.) who was, at this time, unaware of the final outcome. 2D-ECHO images were reviewed for single-frame stop-motion analysis. The end-diastolic frame was selected at the peak of the R wave on the simultaneous ECG recording, and the end-systolic frame was defined as the smallest ventricular dimension during the last half of the T wave. Using a microcomputer interfaced with the videotape player, stop-motion frames at end-diastole and end-systole were displayed on the microcomputer screen to digitize the endocardial outlines of the left ventricle. The LV end-diastolic and LV end-systolic areas were automatically processed. LV end-diastolic and LV end-systolic long axes were measured as the distance from the apex to the midpoint of the mitral valve ring, and LV volumes were calculated using the single-plane, area-length formula. Left ventricular stroke volume (LVSV) was calculated as LVEDV—LVESV. LVEF was calculated as LVSV/ LVEDV.
Control Group: During the same period, 44 medical students, residents, or practitioners taking part in medical care in the ICU underwent 2D-ECHO studies by the same investigator and constituted the control group (30 men and 14 women; mean age, 33 ± 10 years). birth control pills online
Statistical calculations were performed using a software package (SAS Version 5; SAS Institute; Cary, NC). Data are expressed as mean ± 1 SD. Echocardiographic measurements at day 1, day 2, day n, and recovery (group I) and at day 1, day 2, day n (group II) were compared by an analysis of variance for repeated measurements, followed by Fisher’s protected least significant difference test when significant changes were individualized. Unpaired t tests were used for comparisons between groups concerning initial echocardiographic measurements, changes in echocardiographic measurements between day 1 and day n, and the duration of the monitoring period. A Fisher’s Exact Test was performed to compare bacteriologic data and the distribution of severe LV hypokinesia. A p value < 0.05 was required to reject the null hypothesis.