ACQUIRED HEART DISEASE IN PREGNANCY


I. General issues

  1. Us from RHD or IVDU (r-sided)
  2. Cause probs from CHF, arrhythmias, thromboemboli
  3. Highest risk of CHF with older mom and later in gest
  4. Risk of CHF and thromboemboli higher with AFib start in preg than if previously present

II. Mitral stenosis

  1. Most common rheumatic valvular lesion in pregnant women; ass'd c aortic & r-sided lesions
  2. Causes problems because of fixed cardiac output (from obstr to diastolic filling)
  1. Greater PCWP required for adequate vent filling than in nl people
  2. Inadequate vent filling will give lower CO
  3. So, preload reduction to be avoided--keep on the wet side if nec.
  1. Can get pulm edema particularly during l & d and even more right after
  2. Tachycardia, from exertion, pain, etc. can precipitate CHF from lower diastolic filling time
  3. Management of l & d:
  1. Monitor with S-G; keep on wet side (up to 16mm Hg--PE at 28-30)
  2. May need to diurese cautiously if very high PCWP, espec. in anticipation of postpartum autotransfusion
  3. Minimize exertion, pain, anxiety--B-blockers if indicated
  4. Epidural anesthesia for least fluctuation in CO
  5. Delivery--some say use forceps liberally to shorten stage II; Clark says forceps rarely nec.
  6. If really severe may need c/s but vag is us. safe

II. Mitral regurgitation

  1. Us. from RHD; often ass'd with other lesions
  2. Us. no prob in preg, l & d
  3. Must give SBE prophylaxis
  4. Risk factors
  1. Atrial enlargement
  2. AFib (some give DIG prophyactically)

III. Mitral valve prolapse

  1. 17% of young healthy women!--us. no prob
  2. If have click/murmur then SBE prophyl in l & d

IV. Aortic stenosis

  1. Us. from RHD, with other lesions too (higher mort); some congenital (lower mort)
  2. Us. well tolerated unless AS is severe and limits CO
  3. If severe AS and exert, sudden drop in perf press to brain/coronaries can cause angina, MI, sudden death (many of these women have IHD)
  4. So, must limit physical activity (if preg or not)
  5. Overall matmort 17%--worse with worse stenosis
  1. Most during delivery; TOP carries 40% matmort
  1. Management:
  1. Maintain CO by maintaining venous return
  2. S-G and keep on wet side (16mm)
  3. Avoid hemorrhage, IVC occlusion by uterus

V. Aortic regurgication

  1. Us. from RHD and almost always ass'd with mitral valve disease
  2. Us. no prob in preg--tachycardia of preg limits regurgitant flow
  3. SBE prophyl during l & d

VI. Right-sided valvular lesions

  1. More common from IVDU-endocarditis than from RHD
  2. Us. no prob in preg, l & d--just avoid fluid overload, esp in l & d

VII. Peripartum idiopathic cardiomyopathy

  1. Peripartum CHF of obscure cause--a dx of exclusion
  2. Developing between last mo of preg and 6mo pp (pk in 2nd mo pp)
  3. Us. no cardiac hx, no other cause of CHF (valv., met, toxic, inf)
  4. Diff. dx: amnio embolism, severe pre-ecl, chronic HTN, steroid-or sympathomimetic- induced pulm edema
  5. Incidence 1:1500-4000 preg's in U.S.; mortality 25-50%
  6. Represents 80% of idiopathic cardiomyopathy in women of childbearing age
  7. Risk factors: older, multip, black, mult. gest, chronic HTN, h/o eclampsia-preeclampsia, poss. familial component
  8. Clinical pres:fatigue, dyspnea, chest pain, periph and pulm edema, JVD, rales, S3, cardiomegaly, holosys murm, pulm edema on CXR; LV, LA dil on EKG
  9. Pulmonary or emboli in 50% of pts (why?)
  10. Histology: nonespecific hypertrophy, degeneration, fibrosis, fat deposition
  11. Etiology--ideas: nutritional, hormonal, autoimmune
  12. Management:dig, diuretics, Na restriction, bedrest (latter speeds recovery)
  13. If refractory, afterload reduction (hydralaxine, nitrates)
  14. Some people have used steroids after endocardial bx showing inflammation
  15. Usually recovers after preg & recurs with subsequent pregs
  1. Recurrence risk rel'd to whether cmegaly resolves--40-80% if don't

VIII. CAD

  1. Rare in preg
  2. Associated with aortic stenosis
  3. Preg contraindicated, esp. if HTN (high risk of fetal wastage)
  1. However, successful vag deliv has been done
  1. Tx of AMI no diff in preg. pt
  2. 35% matmort
  3. 87% had no CAD dx before preg (unmasked by burdens of preg)
  4. Try not to deliver <2wk post-MI
  5. Nitrates, radionuclide imaging safe
  6. Management of l & d: lat. recumb, O2, epidural, S-G if bad

IX. Valvular prostheses

  1. Role of anticoagulation is controversial
  2. Coumadin derivatives are teratogenic & thus contraindicatd
  3. Heparin recommended for mechanical prostheses (adjusted subq 1.5-2xnl PTT)
  4. With bioprostheses, no need unless AFib or h/o thromboemboli
  5. In a meta-analysis of 28 published studies involving 976 women with mechanical heart valves, mostly mitral prostheses(6 cohort studies and 22 case series), comparing several tx options (warfarin with heparin near term; warfarin with heparin between 6-12wks gestation and near term; heparin throughout pregnancy, no anticoagulation, with or without antiplatelet therapy); rates of fetal anomalies were 6.4%, 3.4%, 0%, and 3.3% respectively; maternal thromboembolic complications occurred in 3.9%, 9.2%, 33.3%, and 24.3%, respectively; all-cuase maternal death occurred in 1.8%, 4.2%, 15%, and 4.7%, respectively. (Arch. Int. Med. 160:191, 2000--JW)

X. Arrhythmias

  1. Safe treatments include:
  1. Digoxin
  2. Quinidine, procainamide
  3. B-blockers (for some tachyarrhythmias, hyperthyroid, IHSS)
  4. Verapamil for SVT (maternal and fetal)
  5. Subq-adjusted-dose hep for AFib antithrombotic prophylaxis
  6. Electrocardioversion
  1. Unsafe treatments:
  1. Disopyramide (1 case preterm labor)
  2. Warfarin