6.4 MTB Step 3 - Valvular Heart Disease (Mitral Stenosis)

Question 1

MITRAL STENOSIS

What is the Most Common Cause of Mitral Stenosis?

Answer 1

Rheumatic Fever

Question 2

MITRAL STENOSIS

What are the Most Common Demographics for a patient Mitral Stenosis, and why?

Answer 2

1. Immigrant: because of Low Rates of RF in the US
2. Pregnant: because of Large Increase in Plasma Volume

Question 3

MITRAL STENOSIS

What are (3) Special Clinical Features of Mitral Stenosis?

Answer 3

1. Dysphagia: Large LA pressing on the Esophagus
2. Hoarseness: Pressure on Recurrent Laryngeal Nerve
3. Atrial Fibrillation: leading to Stroke

Question 4

MITRAL STENOSIS

Describe the Murmur of Mitral Stenosis.

Answer 4

• Diastolic Rumble AFTER Opening Snap (extra sound in diastole)
  
  • As Mitral Stenosis worsens, the Opening Snap moves closer to S2 (remember, S1 is louder than S2).
  • Increases in Intensity with Leg Raise, Squatting, and Expiration.

Question 5

MITRAL STENOSIS

What is the Mechanism of the Opening Snap occurring EARLIER in Worsening Mitral Stenosis?

Answer 5

• The Mitral Valve OPENS when LA Pressure > LV Pressure.
• Worse MS = Higher LA Pressure.
• Higher LA Pressure pushes the Mitral Valve Open EARLIER.

Question 6

MITRAL STENOSIS

1. What is the Best INITIAL Diagnostic Test for Mitral Stenosis?
2. What is a MORE Accurate Diagnostic Test for Mitral Stenosis?
3. What is the Most ACCURATE Diagnostic Test for Mitral Stenosis?

Answer 6

1. TTE
2. TEE
3. Left Heart Catheterization

**For CCS, also order an ECG & CXR which shows LAH**

Question 7

MITRAL STENOSIS

What are (3) CXR Findings in a patient with Mitral Stenosis?

Answer 7

1. Straightening of the Left Heart Border
2. Elevation of the Left Mainstem Bronchus
3. +/- Double Density in the Cardiac Silhouette (from left atrial enlargement)

Question 8

MITRAL STENOSIS

What is the Best INITIAL Therapy for Mitral Stenosis?

Answer 8

Diuretics (however, they do NOT alter progression)

Question 9

MITRAL STENOSIS

What is the Most EFFECTIVE Therapy for Mitral Stenosis?

Answer 9

Balloon Valvuloplasty (Pregnancy is NOT a contraindication)

• Balloon Valvuloplasty works in Mitral Stenosis because the Stenosis results from excessive Fibrosis of the Valve.
• Rheumatic Fever causes Cardiac Endomyocardial and Valvular Fibrosis.
• Fibrosis can be Stretched by the Balloon.
• By contrast, Aortic Stenosis is Calcified, and Calcification does NOT stretch or rip easily with a balloon

MS = Balloon Fibrosis

AS = Remove/Replace Calcifications