Cardiac Disease in Pregnancy

Overview

• Eisenmenger syndrome in pregnancy
  • Reduced systemic vascular resistance → reduced afterload → reduced pressure in left ventricle → increased right to left shunting
• Symptoms of heart disease in pregnancy
  • Clubbing
  • Cyanosis
  • Jugular venous distension
  • Dyspnoea
  • Paroxysmal nocturnal dyspnoea
  • Orthopnea
  • Palpitations
  • Diastolic murmur
  • Systolic murmur with a thrill
• General Treatment
  • Pre-conception evaluation by cardiologists
  • Assessment: 12-lead EKG, Echocardiography, Assess functional class
  • Perform all interventions before conception
  • Patient Education
  • Close follow up with cardiologist during pregnancy (frequency depending on functional class)

NYHA functional classification of heart failure (Symptoms = fatigue, palpitations, dyspnea)

Maternal mortality risk

Acquired heart disease in pregnancy

Rheumatic disease is a common cause of acquired heart disease. Mitral stenosis is the most common defect, and CHF may present or worsen in pregnancy due to increased HR and CO. Aortic stenosis is most commonly due to a bicuspid aortic valve. It has an increased risk of aortic dissection due to increased plasma volume. Aortic regurgitation, Tricuspid atresia, and mitral regurgitation are well-tolerated in pregnancy.

• Causes
  • Structural heart defects
    • Mitral stenosis (CHF presents or worsens due to increased HR and CO)
    • **Aortic stenosis (**Increased risk of aortic dissection. Commonly d/t bicuspid aortic valve)
    • Aortic regurgitation (well tolerated)
    • Tricuspid stenosis (well tolerated)
    • Mitral regurgitation (well tolerated)
  • Infective endocarditis (rare, routine antibiotic prophylaxis is given for vaginal and C-section delivery)
  • **Cardiomyopathy (**HCM is well tolerated)
  • Coronary artery disease (many drugs in CAD have to be discontinued)
• Investigations
  • EKG: look for A-fib in mitral stenosis
• Treatment of mitral stenosis
  • LMWH
  • Bed rest
  • Avoid anemia
  • Discontinue ACEi/ARBs/Diuretics
  • Antibiotic prophylaxis

Congenital heart disease in pregnancy

Pregnancy is contraindicated in Class IV congenital heart disease. Get an echocardiography to classify patients. Patients with Eisenmenger syndrome should not get pregnant. The majority of deaths in Eisenmenger occur during delivery or in first week postpartum. The ZAHARA score or CARPREG score can be used for risk stratification.

• Risk factors
  • Pulmonary hypertension (especially with Eisenmenger syndrome)
  • Cyanosis
  • Poor maternal function class (NYHA III or IV)
  • Aortic disease (Marfan’s, bicuspid aortic valve)
  • Elevated BNP at 20 weeks.

Modified WHO classification of CHD in pregnancy

Peripartum cardiomyopathy

Peripartum cardiomyopathy carries a high risk for maternal mortality. It is an idiopathic cardiomyopathy that develops towards the end of pregnancy or in the first few months postpartum. It is associated with left ventricular systolic dysfunction (LVEF < 45%) in the absence of any other possible causes of heart failure. The goal of management is to improve the cardiac output (same as other types of heart failure)

It has a wide geographic variation. It is more common in individuals of African descent.

• Risk factors
  • Age > 30 years
  • Black race (probably genetic)
  • Multiple gestation
  • History of hypertensive disorders of pregnancy
  • History of postpartum hemorrhage
  • Tocolytic use
  • Smoking during pregnancy
  • Cocaine abuse
• Patient History
  • Between 36 weeks gestation and 1 month postpartum
• Signs and symptoms
  • Fatigue
  • Shortness of breath
  • Cough
  • Dyspnea
  • Orthopnea
  • Paroxysmal nocturnal dyspnea
  • Pedal oedema
  • Hemoptysis
• Physical examination
  • Elevated jugular venous pressure
  • Displaced apical impulse
  • S3 heart sound
  • Holosystolic murmur
• Differentials
  • Pre-existing heart disease unmasked by pregnancy e.g. cardiomyopathy, valvular heart disease, congenital heart defect
  • Diastolic heart failure due to hypertensive heart disease: history of hypertension, preserved LVEF
  • Pulmonary embolism: more acute, no signs of heart disease on echo
  • Pre-eclampsia: no signs of heart disease on echo, positive urine protein
• Investigations
  • Electocardiography: sinus tachicardia, rarely A-fib (due to left ventricular strain and regurgitation causing dilatation of the left atriam)
  • Echocardiography: global reduction in left ventricular systolic function (LVEF < 45%) +/- LV dilation or enlargment
  • Chest X-ray: enlarged cardiac silhouette with evidence of congestion
  • Urinalysis: may be nromal
  • BNP: may be elevated
• Diagnostic criteria for peripartum cardiomyopathy
  • Development of heart failure in the last month of pregnancy or 5 months postpartum
  • Absence of preexisting heart disease
  • Indeterminant cause
  • Echocardiographic findings
    • Left ventricular end-diastolic dimension of > 2.7 cm/m2 (must be present)
    • M-mode fractional shortening < 30%
    • Left ventricular ejection fraction < 0.45
• Treatment
  • Preload reduction: diuretics, sodium restriction, fluid restriction
  • Afterload reduction: beta blockers, ACEis (given after delivery) , vasodilators, digoxin
  • Anticoagulation for patient with thrombus formation or A-fib
  • Oxygenation as needed
  • Delivery by high-risk obstetrician: prompt delivery, vaginal delivery is ok. Urgent delivery if hemodynamically unstable
  • Postpartum cardiology follow up, continue medications and close monitoring with echocardiography
  • Non-estrogen based contraception postpartum e.g. IUD
• Prognosis
  • Partial to complete recovery of LVEF is common
  • Patients with persistent left ventricular dysfunction carry a high risk of mortality in subsequent pregnancies
• Poor prognostic factors (10% mortality at 2 years
  • Poor functional class
  • Very low LVEF (< 25%)
  • Low SES
  • Multiparity
  • Age > 30 – 35 years