Cardiac surgery during pregnancy: Continuous fetal monitoring using umbilical artery Doppler flow velocity indices.

The fetal death rate associated with cardiac surgery with cardiopulmonary bypass (CPB) is as high as 9.5‑29%. We report continuous monitoring of fetal heart rate and umbilical artery flow‑velocity waveforms by transvaginal ultrasonography and their analyses in relation to events of the CPB in two cases in second trimester of pregnancy undergoing mitral valve replacement. Our findings suggest that the transition of circulation from corporeal to extracorporeal is the most important event during surgery; the associated decrease in mean arterial pressure (MAP) at this stage potentially has deleterious effects on the fetus, which get aggravated with the use of vasopressors. We suggest careful management of CPB at this stage, which include partial controlled CPB at initiation and gradual transition to full CPB; this strategy maintains high MAP and avoids the use of vasopressors. Maternal and fetal monitoring can timely recognize the potential problems and provide window for the required treatment.

Trans-esophageal echocardiography for tricuspid and pulmonary valves.

Transesophageal echocardiography has been shown to provide unique information about cardiac anatomy, function, hemodynamics and blood flow and is relatively easy to perform with a low risk of complications. Echocardiographic evaluation of the tricuspid and pulmonary valves can be achieved with two-dimensional and Doppler imaging. Transesophageal echocardiography of these valves is more challenging because of their complex structure and their relative distance from the esophagus. Two-dimensional echocardiography allows an accurate visualization of the cardiac chambers and valves and their motion during the cardiac cycle. Doppler echocardiography is the most commonly used diagnostic technique for detecting and evaluating valvular regurgitation. The lack of good quality evidence makes it difficult to recommend a validated quantitative approach but expert consensus recommends a clinically useful qualitative approach. This review ennumerates probe placement, recommended cross-sectional views, flow patterns, quantitative equations including the clinical approach to the noninvasive quantification of both stenotic and regurgitant lesions.