Cardiovascular Drugs in Pregnancy

Valvular Heart Disease in Pregnancy

Valvular heart disease is a common cause of peripartum cardiovascular morbidity and mortality. The hemodynamic changes of pregnancy and their impact on preexisting valvular lesions are described in this paper. Tools for calculation of maternal and fetal risk during pregnancy are also discussed. The pathophysiology and management of valvular lesions, both obstructive and regurgitant, are then described, followed by discussion of mechanical and bioprosthetic valve complications during pregnancy.

Pregnancy-related acute myocardial infarction: a review of the recent literature

Pregnancy-related acute myocardial infarction is a rare and potentially life-threatening cardiovascular event, the incidence of which is growing due to the heightened prevalence of several risk factors, including increased maternal age. Its main aetiology is spontaneous coronary artery dissection, which particularly occurs in pregnancy and may engender severe clinical scenarios. Therefore, despite frequently atypical and deceptive presentations, early recognition of such a dangerous complication of gestation is paramount. Notwithstanding diagnostic and therapeutic improvements, pregnancy-related acute myocardial infarction often carries unfavourable outcomes, as emergent management is difficult owing to significant limitations in the use of ionising radiation-e.g. during coronary angiography, potentially harmful to the foetus even at low doses. Notably, however, maternal mortality has steadily decreased in recent decades, indicating enhanced awareness and major medical advances in this field. In our paper, we review the recent literature on pregnancy-related acute myocardial infarction and highlight the key points in its management.

Coronary Disease in Pregnancy: Myocardial Infarction and Spontaneous Coronary Artery Dissection

Pregnancy-related maternal mortality and morbidity rates continue to increase in the United States despite global improvements in maternal outcomes. The unique hemodynamic and physiological changes of pregnancy results in a 3- to 4-fold increased risk of acute myocardial infarction (AMI) which causes a substantial proportion of all maternal cardiac deaths. In addition to atherosclerosis, pregnancy-associated AMI is commonly caused by nonatherosclerotic etiologies such as spontaneous coronary artery dissection, embolus to the coronary artery, and coronary vasospasm. Herein, the epidemiology, etiologies, presentation, diagnosis, and management of AMI in pregnancy is discussed along with future directions for multidisciplinary care.

Arrhythmias in Pregnancy

The prevalence of arrhythmias in pregnant women are rising, particularly among women with a history of structural heart disease or prior arrhythmia. The physiological changes of pregnancy increase the risk of both benign and pathologic arrhythmias, with atrial fibrillation representing the most common pathologic arrhythmia. While bradyarrhythmias rarely require treatment during pregnancy, pharmacotherapy is frequently required for tachyarrhythmias. Electrophysiological procedures including cardioversions, ablations, and device placement are occasionally required during pregnancy and can be performed safely with proper precautions. This chapter will discuss the diagnosis and management of a broad array of cardiac arrhythmias that may be encountered in pregnant women.

Pharmacokinetics and Transplacental Transfer of Fluoxetine Enantiomers and Their Metabolites in Pregnant Women

Considering that fluoxetine (FLX) is used to treat depressive states during pregnancy and that it is a cytochrome P450 (CYP)2D6 inhibitor, which is involved in the metabolism of both of its enantiomers, this study aims to describe the enantioselective distribution and metabolism of FLX and of its metabolite norfluoxetine (NorFLX) following a single oral dose. Nine healthy pregnant women received 20 mg FLX at 32 weeks of gestation and later at the day of delivery. The apparent clearance of (S)-(+)-FLX (1.45 vs. 0.66 L/hour/kg) and the area under the plasma concentration vs. time curve (AUC) of the (S)-(+)-NorFLX (AUC_0-∞ 942.7 vs. 498.6 ng hour/mL) were higher (P < 0.05) than those of the respective (R)-(-) enantiomers, indicating that the (S)-(+)-FLX enantiomer is preferentially metabolized to (S)-(+)-NorFLX. The placental transfer (umbilical vein/maternal vein) of FLX and NorFLX is low (30-40%), with the predominant transfer of (S)-(+)-FLX (44 vs. 33%). The distribution of the enantiomers of FLX and NorFLX to amniotic fluid is low (< 10%).

Cardiovascular Emergencies in Pregnancy

Heart disease in pregnancy may manifest as acute coronary syndromes, decompensated valvular disease, and acute heart failure. These disease processes may represent progression of preexisting disease versus newly developed disease resulting from the physiologic changes of pregnancy. Early recognition of clinical presentations, judicious use of diagnostic studies, and multidisciplinary management of patient and fetal considerations can lead to optimal outcomes in this unique patient subset.

Effect of type 2 diabetes mellitus on the pharmacokinetics and transplacental transfer of nifedipine in hypertensive pregnant women

AIMS

Diabetes mellitus can inhibit cytochrome P450 3A4, an enzyme responsible for the metabolism of nifedipine, used for the treatment of hypertension in pregnant women. We aimed to assess the effect of type 2 diabetes mellitus (T2DM) on the pharmacokinetics, placental transfer and distribution of nifedipine in amniotic fluid in hypertensive pregnant women.

METHODS

The study was conducted in 12 hypertensive pregnant women [control group (CG)] and 10 hypertensive pregnant women with T2DM taking slow-release nifedipine (20 mg, 12/12 h). On the 34th week of gestation, serial blood samples were collected (0-12 h) after administration of the medication. At delivery, samples of maternal and fetal blood and amniotic fluid were collected for determination of nifedipine distribution in these compartments.

RESULTS

The median pharmacokinetic parameters of CG were: peak plasma concentration (C_max ) 26.41 ng ml^-1 , time to reach C_max (t_max ) 1.79 h, area under the plasma concentration vs. time curve from 0-12 h (AUC_0-12 ) 235.99 ng.h ml^-1 , half-life (t½) 4.34 h, volume of distribution divided by bioavailability (Vd/F) 560.96 l, and Cl_T /F 84.77 l h^-1 . The parameters for T2DM group were: C_max 23.52 ng ml^-1 , t_max 1.48 h, AUC_0-12 202.23 ng.h ml^-1 , t½ 5.00 h, Vd/F 609.40 l, and apparent total clearance (Cl_T /F) 98.94 l h^-1 . The ratios of plasma concentrations of nifedipine in the umbilical vein, intervillous space and amniotic fluid to those in the maternal vein for CG and T2DM were 0.53 and 0.44, 0.78 and 0.87, respectively, with an amniotic fluid/maternal plasma ratio of 0.05 for both groups. The ratios of plasma concentrations in the umbilical artery to those in the umbilical vein were 0.82 for CG and 0.88 for T2DM.

CONCLUSIONS

There was no influence of T2DM on the pharmacokinetics or placental transfer of nifedipine in hypertensive women with controlled diabetes.

The role of the anesthesiologist in the care of the parturient with cardiac disease

Women with cardiac disease constitute a growing percentage of parturients, and in many series cardiac disease is the leading cause of maternal mortality. Involvement of anesthesiologists in the planning for and management of delivery in these women can improve the experience and potentially the outcome of these patients. Communication with the anesthesiology team about particularly complex cases is essential to avoid both medical complications and inter-disciplinary disagreements. The specific role and contributions of the anesthesiology team will depend significantly on the nature of the institution and the organization of the (obstetric) anesthesiology service.