The effect of maternal hypothermic cardiopulmonary bypass on fetal lamb temperature, hemodynamics, oxygenation, and acid-base balance

Management of Complex Cardiac Issues in the Pregnant Patient

Management of peripartum heart disease in the intensive care unit requires optimization of maternal hemodynamics and maintenance of fetal perfusion. This requires fetal monitoring and should address the parturient's oxygen saturation, hemoglobin, and cardiac output as it relates to uterine blood flow. Pharmacologic strategies have limited evidence pertaining to hemodynamic stabilization and fetal perfusion. There is some evidence that surgical management of critical mitral stenosis should be percutaneous when possible because cardiac bypass is associated with increased fetal mortality. Fetal monitoring strategies should address central organ perfusion because peripheral scalp pH has not been associated with improved fetal outcomes.

Foetal aortic flow velocity waveforms in healthy and hypertensive pregnant women

Background

The foetal aortic Doppler frequency spectrum is influenced by cardiac output and contractility of the foetal heart as well as vascular compliance, blood viscosity and impedance of the arterial vascular system. The present study aimed at comparing Doppler flow pulsatility (PI) and resistance (RI) indexes of foetal proximal descending aorta (AoF) in the first, second and third trimesters of pregnancy, in low risk women and in those with chronic arterial hypertension, who had normal pregnancy outcomes.

Methods

A longitudinal and prospective study was carried out in 101 singleton pregnancies (71 low-risk pregnancies and 30 with essential hypertension). Multivariate regression had to be considered due to the experiment’s nature: two different indexes were read on the same set of individuals, once at each trimester of the pregnancy [1^st (11–14 weeks), 2^nd (19–22 weeks) and 3^rd (28–32 weeks) trimesters]. The response variable was denoted as index d, in a subject with hypertensive status h (hypertensive or normotensive), at continuous time t.

Results

In both groups, AoF-PI and AoF-RI showed a small, but significant increase from the first to the second (1.850 ± 0.339 vs 2.110 ± 0.242 for PI, and 0.829 ± 0.068 vs 0.857 ± 0.038 for RI; p < 0.001) and the first to the third (1.850 ± 0.339 vs 2.163 ± 0.282 for PI, and 0.829 ± 0.068 vs 0.864 ± 0.037 for RI; p < 0.001) trimesters of pregnancy. The global model showed that while AoF-RI trends were converging as time progressed, the AoF-PI values exhibited a divergent trend (p < 0.05).

Conclusions

Chronic stable hypertension in pregnancies with normal outcome, evidences an upward regular trend of foetal descending aorta pulsatility index that is similar to the normotensive condition.

Emergency aortic valve replacement and Caesarian section in a primigravida with severe aortic stenosis: a case report

INTRODUCTION

Congenital bicuspid aortic valve with severe aortic stenosis (AS) is a rare condition (3-6% of patients with congenital heart disease). Pregnancy in these patients carries a high risk of maternal and fetal mortality. With advancing gestational age, these women may develop cardiac failure due to increased cardiorespiratory requirements. When medical therapy proves insufficient, cardiac surgery becomes mandatory to save the patient's life. Balloon valvuloplasty is only palliative treatment, the duration of benefit being only 6 months. Valve replacement is thus recommended. Cardiopulmonary bypass (CPB) surgery with valve replacement has been reported to carry a lower risk of maternal mortality (1.5-13%) but a very high fetal risk (16-40%). This paper reports the case of a 30-year-old primigravida with severe AS with bicuspid aortic valve and pulmonary congestion clinically uncontrolled, in whom CPB surgery and aortic valve replacement was performed as an emergency procedure, along with a lower segment Caesarian section.

CONCLUSION

The outcome of unrelieved severe symptomatic AS in pregnancy is poor. Multidisciplinary management is important to avoid deterioration in cardiac performance in parturients with severe AS. CPB during pregnancy carries a high risk to the fetus. Therefore, open heart surgery during pregnancy should be advised only in extreme emergencies (ie, heart failure refractory to conventional therapy).

Emergency redo mitral valve replacement in a pregnant woman at third trimester: case report and literature review

Pregnancy carries significant physiological changes that demand more cardiac output, so structural cardiac disease can cause life-threatening complications. A woman had rheumatic mitral stenosis and underwent mitral valve replacement (MVR) with bioprosthesis 8 years prior to admission. She presented with dyspnea and leg edema at 30 weeks of gestation. Severe mitral stenosis caused by xenograft failure was noted on echocardiography. Management was conservative until a sudden onset of hemodynamic compromise requiring emergency redo MVR under normothermic cardiopulmonary bypass with intra-aortic balloon pump. Monitoring of fetal heartbeat and uterine contractions showed no significant abnormalities and the woman gave birth to a full-term baby by Cesarean section with postoperative warfarin therapy.