Mitral Stenosis

Question 1

What is mitral stenosis?

Answer 1

Most common valve lesion in pregnancy. Occurs when there is narrowing of the mitral valve which decreases inflow into the left ventricle. This condition can be caused by rheumatic heart disease (from Group A strep. pyogenis).

Question 2

What are the categories of mitral stenosis?

Answer 2

Moderate stenosis: 1-1.5cm

Severe stenosis: less than 1cm

Question 3

What are the maternal risks in pregnancy complicated with mitral stenosis?

Answer 3

Severe pulmonary edema 
Severe pulmonary congestion 
Pulmonary hypertension
Right sided heart failure 
Atrial fibrillation 
Left atrial enlargement 
Thromboembolism 
Embolic stroke 
Maternal death

Question 4

What are the fetal risk with maternal mitral stenosis?

Answer 4

Hypoxia
Preterm delivery
Fetal death

Question 5

What are therapy goals for pregnant patients with mitral stenosis?

Answer 5

• Avoid fluid overload (it can lead to right heart failure)
• Avoid hypotension (it can lead to decrease cardiac output)
• Avoid tachycardia (it can lead to decreased diastolic filling time and decrease left atrial pressure)

Question 6

List complications of mitral stenosis in pregnancy:

Answer 6

Pulmonary edema (avoid with diuretics)
Atrial fibrillation (avoid with beta blocker, calcium channel blocker or digoxin)
Left atrial enlargement (avoid with diuretics)
Thromboembolism and embolic stroke (avoid with anticoagulation) 
Worsening mitral stenosis (treat with balloon valvulotomy)

Question 7

How do you follow a patient with mitral stenosis in pregnancy?

Answer 7

• Baseline EKG (to assess for atrial fibrillation or left atrial enlargement)
• Baseline echocardiogram (assess for size of the stenosis)

Question 8

What are indications for cesarean delivery in a patient with mitral stenosis?

Answer 8

Usual obstetric indications

Question 9

Can epidural be used for pain management in patients with mitral stenosis?

Answer 9

Yes, epidural can help to prevent tachycardia that arises from pain.

Question 10

What is the target heart rate for patient with mitral stenosis?

Answer 10

Heart rate less than 100 beats per min

Question 11

What are the potential complications of tachycardia in patients with mitral stenosis?

Answer 11

Tachycardia decreases the diastolic filling time and can lead to decrease cardiac output and tissue hypoxemia

Question 12

At what mean gestational age does 60% of patients have their initial episode of pulmonary edema

Answer 12

30 weeks