Cardiac Adaptation of the Maternal Heart During Pregnancy: A Color-Coded Tissue Doppler Imaging Study--Feasibility, Reproducibility and Course during Pregnancy.

PURPOSE: Tissue Doppler imaging (TDI) allows the noninvasive quantification of global and regional myocardial function. Since there are changing loading conditions during pregnancy, this study aimed to determine maternal myocardial adaptation in normal pregnancy with TDI and tracking of the heart cycle. PATIENTS AND METHODS: 106 pregnant women, mean age of 33.4 years at baseline, prospectively underwent a total of 161 color-coded tissue Doppler echocardiography samples throughout pregnancy. In further offline analysis of the global and regional myocardial function of the basal segments, maximum tissue velocities at systole (Sm), in the early filling phase of diastole (Em) and during atrial contraction (Am) were assessed. RESULTS: From those stored samples, S-wave, E-wave and A-wave velocities could be obtained with a feasibility of 94.8 % and with good inter- and intra-observer variability. S-wave velocity first showed an increase during early pregnancy followed by a decline to baseline characteristics at the 3 rd trimester. The E-wave velocity declined throughout pregnancy. The A-wave velocity increased continuously. These alterations result in a continuous decline of Em/Am ratio as pregnancy advances. CONCLUSION: Alterations in tissue velocities during pregnancy reflect maturational changes that mimic "diastolic dysfunction". Based on an understanding of those normal physiological changes, TDI may therefore assist in the monitoring and/or detecting of subclinical myocardial dysfunction during pregnancy.

Sample volume positioning in colour-coded Doppler myocardial imaging: effect of systolic and diastolic tracking.

To date, Doppler myocardial imaging (DMI) is no longer an intriguing new research tool only, but is rather on the verge of becoming a routinely used diagnostic method in adult and pediatric cardiology. Clinical studies have proven its diagnostic relevance for global left and right ventricular function. Concerns about reliability and reproducibility of DMI functional analysis, however, rely on lacking standards for the acquisition and analysis of DMI parameters. This study focuses on the effect of sample volume positioning during the cardiac cycle on the absolute myocardial velocities. Our hypothesis was that systolic sample volume placement leads to altered diastolic measurements, and diastolic placement vice versa to altered systolic measurements, when compared with continuous systolic and diastolic tracking. The effect of tracking on intra- and interobserver variability was a second endpoint of the study. Twenty healthy women underwent color-coded Doppler myocardial imaging. Clips of three heart cycles were stored in digital format for off-line analysis, administering sector angles of approximately 30 degrees and a mean frame rate of 280 frames per second. Using the Echopac software (GE, Germany), the sample volume was positioned immediately below the atrioventricular valvar annulus within the basal segments of the right and left ventricular free wall and the interventricular septum. Three conditions were investigated: conventional end-systolic or end-diastolic placement of the Doppler probe, or continuous tracking to the ideal position during systole or diastole. Descriptive statistics, intra and interobserver variabilities and Bland-Altman analyses were performed. Tracking revealed higher values of early diastolic myocardial velocities compared with measurements during systolic sample volume placement only, and higher systolic myocardial velocities, preejection acceleration and late diastolic myocardial velocities using diastolic sample volume placement. Inter and intraobserver reproducibility improved remarkably with the new procedure with the exception of isovolumic acceleration (IVA), which could not be reproduced satisfactorily at all. In summary, tracking is a promising method that helps to improve reproducibility of DMI-derived myocardial velocities. It helps to minimize the effect of changing myocardial velocities during the natural longitudinal cardiac movement, and should be considered as standard method during DMI.

Prevalence and risk factors of hepatitis C infection after cardiac surgery in childhood before and after blood donor screening.

BACKGROUND: Since 1974, the risk of acquiring non-A non-B hepatitis by blood transfusion is well known. In 1999, children having had polytransfusions (group 1) after cardiac surgery prior to the establishment of routine blood donor screening could be identified as a risk group for hepatitis C (HCV) infection. PATIENTS AND METHODS: In 1991, Germany began screening blood donors for hepatitis C. To describe the risk after the implementation of blood donor screening, we studied 211 children (group 2) having had open heart surgery after 1991 and compared prevalence for anti-HCV antibodies and known risk factors to group 1. RESULTS: None of the 211 patients with cardiac surgery after 1991 had detectable anti-HCV antibodies, compared to 67 of the 458 patients (14.6%) of group 1 (p < 0.001). The mean number of operations in both groups was virtually the same (mean 1.7 +/- 0.9 in group 1, mean 1.6 +/- 0.9 in group 2, p = 0.075), whereas the total number of blood products per patient differed significantly (group 1 mean 8 +/- 17.6, group 2 mean 3.5 +/- 2.8; p < 0.001). Multivariate analysis of risk factors demonstrates affiliation to group 1, transfusion of fresh blood, warm whole blood, heparinized blood (p < 0.001) and plasma (p = 0.004) as significant. CONCLUSION: After the implementation of blood donor screening, the risk for HCV infection after cardiac surgery in childhood dropped significantly from 14.6% to < 0.5%. These data show the necessity of HCV screening for patients at risk (operations before 1991) and do not favor a general screening for all patients.