Alexia Rossi MD, Presenter: Nothing to Disclose

Jerome Cornette, Abstract Co-Author: Nothing to Disclose

Tirza Springeling, Abstract Co-Author: Nothing to Disclose

E. A. Steegers, Abstract Co-Author: Nothing to Disclose

Jolien Roos - Hesselink, Abstract Co-Author: Nothing to Disclose

Robert Jan Van Geuns MD, Abstract Co-Author: Nothing to Disclose

There are physiological reasons for the effects of positioning on hemodynamic variables and cardiac dimensions, related to altered intra-abdominal and intra-thoracic pressures. This problem is especially evident in pregnant women due to the additional aorto-caval compression by the enlarged uterus. The purpose of this study was to investigate the effect of postural changes on cardiac dimensions and function during the second and third trimester of pregnancy using MRI.

Fourteen healthy pregnant women at mid (20th week of gestation; n=6) and late pregnancy (32th week of gestation; n=8) and ten no pregnant women with no history of cardiac disease underwent cardiac MRI in supine and left lateral positions. Heart rate (HR), ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and cardiac output (CO) were compared in both positions. Lateral and supero-inferior left atrial diameters were measured at the end of ventricular systole on a 4-chamber view.

Heart rate was 81±13 bpm in the supine position and it decreased to 74±9 in the left lateral position (p-value=0.09). EDV, EF, SV and CO increased significantly from supine position to left lateral position: 10%, 19%, 31% and 14%, respectively. Cardiac left atrium dimensions increased significantly from supine position to left lateral position (p-value<0.05). ESV did not change significantly between the two recumbent positions. During late pregnancy left ventricle CO significantly increased between supine and left lateral position; the percentage of increment at 32 weeks was 24.3%. No changes between the two recumbent positions were present at 20 gestational weeks. In no pregnant women no significant differences were found between supine and left lateral position.

Positional changes affect cardiovascular performance especially at longer duration of gestation. To correctly investigate the cardiac workload in pregnant women with congenital heart disease cardiovascular MRI should be performed in the lateral position.

Magnetic resonance imaging is the gold standard for the evaluation of cardiac dimensions and function outside pregnancy but no normal values are available during pregnancy.

Rossi, A, Cornette, J, Springeling, T, Steegers, E, Roos - Hesselink, J, Van Geuns, R, Quantitative Cardiac Magnetic Resonance in Pregnant Women: Supine or Left Lateral Position?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9011307.html