Approach to Cardiac Disease in Pregnancy

1. Approach to Cardiac Disease in Pregnancy Mehul Bhatt, MD Athens Heart Center March 13, 2009

2. Physiological changes in pregnancy Systematic approach to cardiac lesions Principal of monitoring and treatment Individualizing treatment to each patient Approach to Cardiac Disease in Pregnancy

3. Normal Physiological Changes in Pregnancy • Framework to understand effects of cardiac pathology • Tremendous cardiocirculatory changes in normal pregnancy: • SV (increase 40-50%) • CO (increase 30-50%) • Examine changes at various points of pregnancy • Normal changes in physical exam, EKG, CXR, Echo, PA catheter

4. Normal Physiological Changes in Pregnancy Braunwald E et al. Heart Disease. 2001. pg. 2173.

5. Normal Physiological Changes in Pregnancy Braunwald E et al. Heart Disease. 2001. pg. 2173.

6. Normal Physiological Changes in Pregnancy • Changes in blood volume start by 6 weeks • Most hemodynamic changes completed by 22-25 weeks (major underlying cardiac disease should present by this point) • Mechanisms of cardiovascular hyperactivity: • Estrogen levels • Elevated renin-aldosterone levels • Elevated chorionic somatomammotropin • Elevated prolactin • Fetus not necessary for changes to occur (as evidenced from hydatidiform moles)

7. Normal Physiological Changes in Pregnancy Braunwald E et al. Heart Disease. 2001. pg. 2172.

8. Normal Physiological Changes in Pregnancy • Symptoms: • Decreased exercise tolerance / Tiredness – increased body weight and physiological anemia • Orthopnea – pressure of uterus on diaphragm • Palpitations – usually sinus tachycardia • Lightheadness / Syncope – compression IVC, decrease CO • Dyspnea – 76% of women at 34th week • Physical Exam: Hyperventilation, peripheral edema, capillary pulsations, brisk PMI, palpable RV + PA impulse, bibasilar rales (from atelectasis), distended neck veins (promient a,v waves, brisk x,y descents) • May be similar changes from cardiac pathology in pregnancy

9. Normal Physiological Changes in Pregnancy • 3rd heart sound in upto 90% • Systolic ejection murmur – from hyperkinetic flow • Most auscultatory changes resolved 1-2 weeks postpartum Cutforth R et al. Heart sounds and mumurs in pregnancy. Am Heart J. 1966;71:741-747.

10. Normal Physiological Changes in Pregnancy • EKG changes • QRS axis deviation • Small Q wave and inverted P wave in lead III • Sinus tachycardia • Increase R/S ratio in V1 and V2 • CXR changes • Straightening of left upper cardiac border • Horizontal positioning of heart • Increased lung marking • Small pleural effusion at early postpartum • Echocardiogram • Slightly increased EDdV and ESdV • Slightly improved LV function • Enlargment of ventricular dimensions • Slight enlargement of left atrial size • Small pericardial effusion • Increased tricuspid annulus diameter • Functional tricuspid regurgiation Elkayam U et al. Cardiac Problems in Pregnancy. 1990.34-7.

11. Normal Physiological Changes in Pregnancy • Effect of position on IVC return • Positioning in cardiac pathology may be beneficial or detrimental Braunwald E et al. Heart Disease. 2001. pg. 2172.

12. Normal Physiological Changes in Pregnancy • Labor and Delivery: • Pain / Anxiety – can increase CO by 50-61% • Uterine contraction – 300-500 mL infusion into central venous system • Cardiocirculatory effects of uterine contraction: Elkayam U et al. Cardiac Problems in Pregnancy. 1990. 16.

13. Normal Physiological Changes in Pregnancy • Labor and Delivery: • Hemodynamic changes of pregnancy less dramatic in lateral position • Maneuvers in delivery position depending on cardiac pathology

14. Normal Physiological Changes in Pregnancy • Labor and Delivery • Epidural anesthesia – systemic vasodilation that can reduce SV • Poorly tolerated in patient who cannot increase SV, fixed CO • Cesarean section – with GETA • Reduced maternal metabolic needs and stabilization of blood volumes

15. Normal Physiological Changes in Pregnancy Hemodynamic Changes Postpartum

16. Cardiac Diseases in Pregnancy:Basics • Cardiac disease hinders physiological reserves • Increasing incidence congenital heart disease • Decreasing incidence of rheumatic heart disease

17. Cardiac Disease in Pregnancy:Basics • Non-cyanotic cardiac disease • NYHA Functional Class • Maternal mortality • Class I and II: 0.4% • Class III and IV: 6.8% • Fetal mortality • Class I: negligible • Class IV: 30% • Cyanotic cardiac disease • 45% rate of fetal death • Low birth weight and immaturity

18. Cardiac Disease in Pregnancy:Congenital Heart Disease • Increased CO and blood volume on already stressed hemodynamic system

19. Cardiac Disease in Pregnancy:Cardiac Lesions

20. Cardiac Disease in Pregnancy:Cardiac Lesions • Factors that increase risk of CHF with pregnancy: • Age > 30 YO • Gestational age > 20 weeks • Cardiac enlargement > 55% lung space on CXR • Atrial tachycardia • Physical effort • Toxemia • Infection • Emboli

21. Cardiac Disease in Pregnancy:Monitoring and Treatment • In perfect world: • Diagnosis of cardiac disease prior to pregnancy • Pre-pregnancy counseling of patient and partner with obstetrics, cardiology, and anesthesia involved • Pre-pregnancy treatment • Medical therapy • CHF treatment • Arrhythmia management • Surgical therapy • Valve replacement • Congenital heart disease repair

22. Cardiac Disease in Pregnancy:Monitoring and Treatment • General objectives of treatment • Shunts: avoid favoring R to L shunting, lower PA pressures, avoid hypoxemia, avoid prolonged Valsalva • Obstructive Lesions: β-blockers, avoid volume depletion, maintain preload • CHF: diuretics (only with pulmonary edema), reduce afterload • Arrhythmias: rate and rhythm control, anticoagulation as necessary, higher dose digoxin • Tenuous aorta (Marfan’s, aortic dissection): β-blockers (reduce dp/dt)

23. Cardiac Disease in Pregnancy:Monitoring and Treatment • Indications for considering PA catheter: • NYHA Functional Class II, III, IV • Mitral stenosis • Aortic stenosis • Pulmonary hypertension • Pulmonary edema • Hypoxemia • Ischemic heart disease • Intractable hypertension • Oliguria unresponsive to fluids • Risk of PA catheter: • Increased procedural fear and pain leading to increased CO

25. Cardiac Disease in Pregnancy:Monitoring and Treatment • Labor and Delivery: • Epidural anesthesia: • Systemic vasodilation • Decrease CO 25-45% even in normal patients • Well tolerated (often beneficial): • AR, MR, L to R shunts • Poorly tolerated: • Limited ability to increase SV • R to L shunts • AS, MS • Hypertrophic CM • Pulmonary hypertension without ASD

26. Cardiac Disease in Pregnancy:Monitoring and Treatment • Labor and Delivery • Caesarian section recommended: • Obstetrical reasons • Anticoagulation with coumadin • Avoid forceps, use vacuum/suction devices • Severe fixed obstructive cardiac lesions • Avoid vasodilation (reduced preload) with epidural anesthesia • Severe pulmonary HTN • Marfan’s with dilated aorta or aortic dissection • Avoid increased blood volume, aortic stress with contractions

27. Cardiac Disease in Pregnancy:Monitoring and Treatment • Labor and Delivery • Shorten stage II labor • Prolonged valsalva • Increase PA pressures, Increases R to L shunting • Shunts: ASD, VSD, Tetralogy of Fallot, Eisenmenger’s • Maternal Position: • Supine versus lateral decubitus • Consider lateral decubitus with obstructive lesions • Consider supine with CHF • Post-delivery: • Continue monitoring • Increased CO (returns to normal after several weeks) • Increased SVR (with loss of placenta) • Hemorrhage risk

28. Cardiac Disease in Pregnancy:Highest-Risk Cardiac Lesions • Suprasystemic pulmonary vascular resistance (Eisenmenger’s syndrome) • Marfan’s syndrome with dilation of the aortic root • Peripartum cardiomyopathy with persistent cardiac enlargement

29. Cardiac Disease in Pregnancy:Peripartum Cardiomyopathy • Incidence: 1 in 4000 pregnancies • More common after age 30 • Can result in severe CHF • Clinically present by 3rd trimester • Close hemodynamic monitoring and early delivery maybe necessary • Cardiomyopathy may persist even after delivery • High rate of recurrence so birth control recommended

30. Cardiac Disease in Pregnancy:Acute Myocardial Infarction • Rare in pregnancy • 1 in 10,000 to 30,000 pregnancies • Coronary dissections • Thrombolytic therapy relatively contraindicated • Primary angioplasty safe after 1st trimester with lead shielding over fetus

31. Cardiac Disease in Pregnancy:Anticoagulation • Increased thrombogenicity in pregnancy • Increased fibrinogen • Increased factors II, VII-X • Increased von Willebrand factor • Increased endothelial cell inhibitor of tPA • Increased placental inhibitor of tPA • Decreased protein S • Same indication as in non-pregnant • Mechanical valves still particularly challenging

32. Cardiac Disease in Pregnancy:Anticoagulation • Anticoagulants: • Warfarin • 1st trimester teratogenicity – due to low levels of Vit. K clotting factors in early fetus • “Coumadin embryopathy”: Facial abnormalities, optic atrophy, mental impairment (5-25% risk) • Possibly dose related effects (one study) • Higher rates of spontaneous abortion • Unfractionated Heparin • Used during 1st trimester to avoid coumadin embryopathy • Subcutaneous unfractionated heparin still see fatal valve thrombosis

33. Cardiac Disease in Pregnancy:Anticoagulation • Anticoagulants • Low molecular weight heparin (LMWH) • Seemed easy, cost-effective, non-teratogenic • Effective in DVT, antiphospholipid syndrome in pregnancy • Safe in peri-procedural bridging in non-pregnant patient with mechanical valve replacements • Randomized trial of LMWH in prosthetic heart valves terminated after 12 patients enrolled secondary due to 2 deaths from prosthetic valve thrombosis

34. Cardiac Disease in Pregnancy:Prosthetic Valves • Treatment dilemma: • Warfarin best for prevention of thromboembolic events, but fetal safety issues • Heparin reduces fetal complications, but dosing issues increase risk of thromboembolic events • Consider bioprosthetic valves in women of childbearing age or planning pregnancy • Anticoagulation with mechanical valves • Very high risk patients • Limited data • ACC / AHA Guidelines

35. Cardiac Disease in Pregnancy:Prosthetic Valves Braunwald E et al. Heart Disease. 2001. pg. 2186.

36. Cardiac Disease in Pregnancy • Framework for evaluation and treatment • Individualized management • Anticoagulation with mechanical valves remains challenge