6.2 MTB Step 3 - Valvular Heart Disease (Aortic Stenosis) Flashcards
AORTIC STENOSIS (AS)
What are (5) Common Clinical Presentations of AS?
- Older Patient w/ hx of HTN
- CHEST PAIN (most common)
- CAD (in upto 50% of patients)
- Syncope
- CHF
AORTIC STENOSIS (AS)
What is the Prognosis in the following (3) types of patients with AS?
- AS + CAD
- AS + Syncope
- AS + CHF
- AS + CAD = 3 - 5 year average survival
- AS + Syncope = 2 - 3 year average survival
- AS + CHF = 1.5 - 2 year average survival
AORTIC STENOSIS (AS)
What is the Mechanism of Syncope/Angina in AS?
A stiff valve just proximal to the entry point of coronaries blocks blood flow into the vertebral and basilar arteries and carotids:
- No Flow to Brain = Passing out.
- Thus, AS causes LV Hypertrophy.
- LV Hypertrophy = Increased Demand
- AS = Blocked Flow with Increased Demand = Chest Pain
AORTIC STENOSIS (AS)
What Type of Murmur does AS give?
Crescendo-Decrescendo Systolic Murmur
AORTIC STENOSIS (AS)
What is the Mechanism of Crescendo/Decrescendo Murmur of AS?
The first part of the Cardiac Cycle is Isovolumetric contraction:
- With Isovolumetric contraction, no blood moves.
- No blood moving = No murmur.
- Peak flow occurs in Mid-Systole.
- Peak Flow = Peak Noise.
- Hence, AS yields a Diamond-shaped Crescendo-Decrescendo murmur.
AORTIC STENOSIS (AS)
- What is the Best INITIAL Test for AS?
- What is a MORE Accurate Test for AS?
- What is the Most ACCURATE Test for AS?
- TTE
- TEE
- Left Heart Catheterization - also allows the most accurate method of assessing the Pressure Gradient across the Aortic Valve (normal aortic valve gradient = 0).
AORTIC STENOSIS (AS)
- What is considered Mild AS?
- What is considered Moderate AS?
- What is considered Severe AS?
Left Heart Catheterization:
- Mild AS = gradient < 30 mmHg
- Moderate AS = gradient 30 - 70 mmHg
- Severe AS = gradient > 70 mmHg
AORTIC STENOSIS (AS)
What is the Best INITIAL Therapy for AS?
Diuretics
- However, they will NOT alter Long-term prognosis
- Further, overdiuresis is Dangerous, and use of diuretics needs to be VERY judicious.
AORTIC STENOSIS (AS)
What is the Most Common definitive Treatment for AS?
Valve Replacement Surgery:
- Bioprosthetic Valves (porcine, bovine) last 10 years on average, but do NOT require anticoagulation with Warfarin.
- Mechanical Valves last 15 - 20 years on average, but MUST be treated with Warfarin to an INR = 2 - 3.
Valve replacement is well tolerated, even in the elderly.
Answer for “Which procedure has a Higher Risk of AKI and A-Fib?” = SURGERY
AORTIC STENOSIS (AS)
What is considered an Acceptable Alternative to the Most Common definitive Treatment for AS?
Transcatheter Aortic Valve Replacement (TAVR)
- Valve Replacement deployed through a catheter.
- Slightly lower risk of death compared with surgery.
- NOT an option for Regurgitant Lesions (i.e., AR, MR)
- Answer* *for “Which procedure has a Higher Risk of Residual Aortic Regurgitation and Need for Pacemaker Placement?” = TAVR