Cardiovascular Management in Pregnancy

Introduction to Cardiovascular Management

• The American Heart Association and ACC/AHA/ESC guidelines indicate propranolol is generally considered safe but should be avoided in the first trimester when possible, while the European Society of Cardiology recommends prioritizing maternal safety and minimizing fetal risk in medication management for pregnant women with pre-existing cardiac conditions 1, 2
• Pregnant women with cardiac disease require multidisciplinary care involving cardiology and maternal-fetal medicine specialists, with regular echocardiographic monitoring essential, particularly in the third trimester when most complications occur 3

Adverse Effects and Complications

• Intrauterine growth restriction (IUGR) is the most consistently reported adverse effect of propranolol use during pregnancy 1
• Beta-blockers with selective β1 properties (like metoprolol) are theoretically preferable to propranolol (non-selective) because they may interfere less with peripheral vasodilatation and uterine relaxation 1
• ACE inhibitors, angiotensin receptor blockers (ARBs), direct renin inhibitors, and atenolol are absolutely contraindicated in pregnant women with cardiac conditions due to potential fetal toxicity or other adverse effects 2
• Myosin inhibitors are also contraindicated due to potential fetal toxicity 3

Management and Monitoring

• More recent guidelines suggest propranolol can be used with appropriate monitoring, especially after the first trimester, and regular ultrasound monitoring of fetal growth is essential to minimize risks such as intrauterine growth restriction (IUGR) 1, 4, 2
• Blood pressure should be closely monitored as pregnancy may alter drug effect even without changing pharmacokinetics, with non-pharmacological management recommended for blood pressure (BP) 140-150/90-99 mmHg, and drug treatment initiated at BP ≥140/90 mmHg in women with gestational hypertension with proteinuria, pre-existing hypertension with superimposed gestational hypertension, or hypertension with subclinical organ damage or symptoms 2
• Treatment should be initiated at BP ≥150/95 mmHg for all other pregnant women, and BP ≥170/110 mmHg is considered an emergency requiring hospitalization 2

Treatment Considerations

• The European Society of Cardiology recommends labetalol (α/β-blocker) as the preferred medication for severe hypertension, which can be given IV, methyldopa as safe with adequate infant follow-up, metoprolol as a recommended β1-selective blocker, and nifedipine as an effective calcium channel blocker 2
• For supraventricular tachycardia (SVT), vagal maneuvers should be attempted first, followed by IV adenosine if vagal maneuvers fail, and then IV metoprolol if adenosine fails 2
• Prophylactic antiarrhythmic therapy options include digoxin or selective β-blockers (metoprolol) as first-line, and sotalol, flecainide, or propafenone as second-line, with atenolol avoided completely and amiodarone used only when other agents fail and at the lowest effective dose 2
• For ventricular tachycardia (VT), immediate electrical cardioversion is recommended for sustained VT, with long-term management options including metoprolol, propranolol, or verapamil 2
• For pulmonary edema, IV nitroglycerine starting at 5 mg/min and gradually increased is recommended, with diuretics recommended when congestive symptoms persist despite β-blockers 2
• For mitral stenosis with symptoms or pulmonary hypertension, restricted activities and β1-selective blockers are recommended, with percutaneous mitral commissurotomy considered for severe symptoms or pulmonary artery pressure >50 mmHg 2
• For mechanical heart valves, oral anticoagulants (OACs) are recommended during the second and third trimesters until the 36th week, with a switch to dose-adjusted unfractionated heparin (UFH) or low molecular weight heparin (LMWH) at 36 weeks, and weekly monitoring of anti-Xa levels for patients on LMWH 2

Delivery and Postpartum Care

• A delivery plan should be established by the end of the second trimester, with vaginal delivery preferred for most cardiac conditions, and cesarean delivery indicated only for obstetric reasons, severely decompensated heart failure, or emergency delivery while on OACs 2
• For women with hypertrophic cardiomyopathy (HCM), delivery should be performed with β-blocker protection 2
• Methyldopa should be avoided postpartum due to the risk of postnatal depression, and close monitoring should be continued postpartum as blood pressure often rises in the first 5 days after delivery 2
• Women with gestational hypertension or pre-eclampsia have an increased risk of hypertension, stroke, and ischemic heart disease in later life, with the risk of ischemic heart disease more than doubled 2
• For women with peripartum cardiomyopathy (PPCM), subsequent pregnancy is not recommended if left ventricular ejection fraction (LVEF) does not normalize 2
• Facilities for monitoring neonates at birth should be available due to potential complications such as bradycardia, hypoglycemia, and respiratory depression 4, 2