Aortic Stenosis Flashcards
What are causes of aortic stenosis?
- Idiopathic hypertrophic subaortic stenosis
- Bicuspid aortic valve
- Rheumatic valve disease
- Lupus
Category of aortic stenosis:
Mild: >1.5cm valve area, peak gradient <50 mmHg. Well tolerated in pregnancy
Severe: <1cm valve area, peak gradient >75mmHg or EF less than 55%. Leads to fixed cardiac output
What are maternal risks with aortic stenosis?
Underperfusion (worse outcome than pulm edema)-> angina, syncope
Arrhythmia (leads to sudden death)
Pulmonary edema caused by hypervolemia
What are fetal risks in patient with aortic stenosis?
Hypoxia
Preterm delivery
Fetal growth restriction
Fetal death
What are goals of therapy for pregnant patient with aortic stenosis?
- Avoid hypotension (BP necessary to maintain coronary perfusion)
- Avoid decrease venous blood return and preload (valsalva, excessive blood loss)
- Avoid bradycardia (it will decrease the cardiac output given fixed stroke volume)
- Avoid hypervolemia (leads to pulmonary edema)
How do you follow a patient in pregnancy with aortic stenosis?
- Baseline echocardiogram to evaluate size of aortic valve opening and gradient flow across the valve and ejection fraction
- Baseline EKG which can show left heart hypertrophy
Considerations for labor and delivery in patients with aortic stenosis:
- c section for usual obstetric indications
- shortened second stage and avoid excessive exertion with operative delivery
- be aware of pulmonary edema due to auto transfusion postpartum
- epidural should be used with great caution to avoid hypotension (narcotic epidural acceptable)
What complications may develop in a patient with aortic stenosis and increasing preload?
Pulmonary Edema
What complications may develop in a patient with aortic stenosis and decreasing preload?
Under perfusion leading to angina from coronary artery hypo perfusion and syncope from Cerebral hypo perfusion
