Aortic stenosis

Keyword

Aortic stenosis

Character

• Bicuspid valve stenosis (congenital-younger age) /

Nonbicuspid valves stenosis (aortic sclerosis-over 60age)

• 25% of 65 to 74 years old, 50% of 84 years old or older
• Risk for sudden death, arrhythmias, heart failure, ischemia, and MI; ischemia
• No hemodynamic compromise
• LV Preload (↑), HR (↓), Contractility (Maintain constant),
• systemic vascular resistance (↑), pulmonary vascular resistance (Maintain constant)

Cf.) Aortic insufficiency : occurs with true valvular disease affecting the leaflets, aortic root dilation, or both.

• Valvular disease from rheumatic heart disease, bicuspid valves, collagen vascular diseases, endocarditis
• Aortic root dilation complicate ankylosing spondylitis, osteogenesis imperfecta, syphilis, hypertension, age-related degeneration, Marfan syndrome, collagen vascular diseases
• Acute aortic insufficiency from trauma,infections,aortic dissection

Preoperative evaluation

• The cardinal symptoms :

angina, heart failure, and syncope, decrease in exercise tolerance and exertional dyspnea

• Clinical evaluation : a systolic ejection murmur (right upper sternal border, radiating to the neck) paradoxically split S2
• ECG : LVH, often with a strain pattern, LAD, LBBB
• ECG 상관없이 Echocardiogram evaluation useful!
• Severity : valve area and mean transvalvular pressure gradient로 결정

(Severe : Echo 1년마다, moderate : 2년마다, mild : 5년마다 f/u)

• Bleeding risk 증가 (von Willebrand multimers가 narrow valve 통과하면서 파괴됨)

- aPTT indicated

• Not indicated antibiotic prophylaxis for endocarditis

Grading severity of aortic stenosis

** Severe or critical stenosis should preclude noncardiac surgery**

(unless it is an emergency and lifesaving procedure)

cardiology evaluation, careful consideration of risks, or valve replacement 하고 수술진행

**Regional anesthesia : systemic vascular resistance 의 급격한 변화에 대처 안됨

more control over hemodynamic changes, and may be a logical alternative choice

Maintenence

• Sensitive to even moderate increase HR
• Avoiding fluctuations in the patient’s hemodynamics
• Induction 시 negative inotropic or vasodilatory effects 가지는 약은 다 피할 것
• Tachycardia should also be avoided
• Stays in sinus rhythm
• Atrial kick may contribute as much as 40% of the total CO

-> 마취 전 any possible arrhythmia 교정 필요, external cardioversion pads 미리 준비

• Maintaining CO sufficient가 CPR을 줄이는데 필수

Reference

Miller’s anesthesia, 8th edition, Chapter 38: Preoperative Evaluation, p.1101-1102

Miller’s anesthesia, 8th edition, Chapter 56: Spinal, Epidural, and Caudal Anesthesia, p.1692

Miller’s anesthesia, 8th edition, Chapter 67: Anesthesia for Cardiac Surgical Procedures, p. 2058-2061