Week 3: Anesthetic Management for Patients with Cardiovascular Disease
Coronary Artery Disease
Answers:
Myocardial O2 Balance with CAD
Answers:
Remember Laplace’s Law
Study the illustaration on GoogleDoc
LV Wall Stress = (LV Pressure) x (Radius) / 2(LV Wall Thickness)
HFrEF: Expected increased Radius and Decreased wall thickness
HFpEF: Increased Wall thickness BUT decreased Radius
Answers:
1. intracavitary pressure
2. wall thickness
3. intraventricular pressure
4. distention
Preload and Afterload
Preload
- Volume of blood in ventricles at end of diastole (end diastolic pressure)
- Increased in: _______(1), _______(2) of cardiac valves, _______(3)
Afterload
- Resistance left ventricle must overcome to circulate blood
- Increased in: _______(4), _______(5)
Athlete: Increased Thickness of Myocardium but body accommodates accordingly
Stucy the Myocardial Oxygen Supply Graphic Chart
Answers:
1. Hypervolemia
2. Regurgitation
3. Heart Failure
4. Hypertension
5. Vasoconstriction
Coronary Blood Flow
Myocardial O2 balance with CAD: Compensatory Mechanisms
Answers:
Hemodynamic Goals for Coronary Artery Disease
Parameter | Goal
— | —
Preload | Keep the heart small: decrease wall tension (diameter) and LVEDP; increase perfusion pressure gradient
Afterload | Maintain: Hypertension is better than hypotension
Contractility | Depress (if LV function is normal)
Rate | Slow
Rhythm | Sinus
MVO2 | Monitor for and treat “supply” —related issues
CPB | Elevated filling pressures are usually not needed after CABG
Small, Steady, Slow, and Sinus
CPB=Cardiopulmonary Bypass
Preoperative Evaluation
What are the risks of a perioperative event? ______(2)
Answers:
1. beta blockers
2. Arrhythmias, MI, heart failure, death
Goldman Cardiac Risk Index
Table 1. Revised Cardiac Risk Index
Lee Variables
1. _______(2)
2. Ischemic heart disease (includes any of the following: history of myocardial infarction; history of positive exercise test; current complaint of chest pain that is considered to be secondary to myocardial ischemia; use of nitrate therapy; electrocardiography with pathologic Q waves)
3. _______(3)
4. History of cerebrovascular disease
5. Preoperative treatment with _______(4)
6. Preoperative serum creatinine > 2.0 mg/dL
No. of Variables | Risk of Major Postoperative Cardiac Complication
— | —
0 | 0.4%
1 | 0.9%
2 | 7.0%
≥3 | 11.0% High risk
Adapted from reference 19.
Goldman created RICHES
Risky Surgery
Ischemic Heart Dse
Congestive Heart Failure
History of CVD
Endocrine (insulin use)
Serum Creatinine > 2.0
RCRI = REVISED CARDIAC RISK INDEX
Pathological Q waves usually indicate current or prior myocardial infarction. SEE BELOW
Answers:
1. independent predictors
2. High-risk type of surgery
3. Congestive heart failure
4. insulin
Patients with Symptomatic CAD
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1. silent
2. Elderly
3. Women
4. Diabetics
5. hypercoagulable state
6. increase
7. 20%
Preoperative Evaluation: HISTORY
Answers:
1. higher incidence
2. silent MI
3. ischemia
PHYSICAL EXAM
Answers:
1. S4 GALLOP
2. stiff
3. resistance
a. late diastole
b. hypertension or aortic stenosis
4. thickened heart muscle walls
5. reduced ventricular compliance
LUNG SOUNDS
BLOOD PRESSURE MEASUREMENT (SUPINE AND STANDING)
- ORTHOSTATIC CHANGES (VOLUME DEPLETION, HEMORRHAGE, EXCESSIVE VASODILATION)
- One study showed: Admission ______(b) was the best predictor of response to laryngoscopy (_______(4)?)
Answers:
1. S3 GALLOP
2. dilated
a. children or young adults
3. congestive heart failure
b. BP and HR
4. anxiety
Electrocardiogram
ECG Changes during Myocardial Infarction (MI)
Location of MI | Leads Affected | Vessel Involved | ECG Changes
— | — | — | —
Anterior wall | V2 to V4 | Left anterior descending artery (LAD) - Diagonal branch | Poor R-wave progression ST-segment elevation T-wave inversion
Septal wall | V1 and V2 | Left anterior descending artery (LAD) - Septal branch | R wave disappears ST-segment rises T-wave inverts
Lateral wall | I, aVL, V5, V6 | Left coronary artery (LCA) - Circumflex branch | ST-segment elevation
Inferior wall | II, III, aVF | Right coronary artery (RCA) - Posterior descending branch | T-wave inversion ST-segment elevation
Posterior wall | V1 to V4 | Left coronary artery (LCA) - Circumflex branch Right coronary artery (RCA) - Posterior descending branch | Tall R waves ST-segment depression Upright T waves
Posterior wall only one with _______(1)
Lateral wall is the only one without _______(2), whilst Posterior wall has _______(3) T Waves
The LAD causes loss of _______(4), whilst poster wall inc _______(5)
Posterior wall as a _______(6) MI of Anterior wall MI — _______(7) of LAD infarct
Answers:
1. ST-depression
2. T-wave inversion
3. Upright
4. R-wave progression
5. R waves
6. reciprocal
7. mirror image
Abnormal “Q” waves
Preoperative Evaluation might include:
Answers:
1. past MI
2. diabetics
3. hypertensives
4. Q wave
5. BUN LEVELS
Surgical Procedure Risk
TABLE 21–3 Cardiac risk1 stratification for noncardiac surgical procedures.
Risk Stratification | Procedure Examples
— | —
Vascular (reported cardiac risk often more than 5%) | Aortic and other major vascular surgery Peripheral vascular surgery
Intermediate (reported cardiac risk generally 1% to 5%) | Intraabdominal and intrathoracic surgery Carotid endarterectomy Head and neck surgery Orthopedic surgery Prostate surgery
Low2 (reported cardiac risk generally less than 1%) | Endoscopic procedures Superficial procedure Cataract surgery Breast surgery Ambulatory surgery
Which of the following is the higher stratification surgery? A carotid endarterectomy, intrathoracic surgery, or peripheral vascular surgery?
Ans: _______(2)
PLEASE STUDY
2014 ACC/AHA guidelines
Answers:
1. highest incidence of complications
2. PVS
Importance of Exercise Tolerance
Answers:
1. Exercise tolerance
2. 4 METS Equivalent
3. does not necessarily
TABLE 21-2
TABLE 21–2 Estimated energy requirements for various activities.
Can you …
1 MET
- Take care of yourself?
- Eat, dress, or use the toilet?
- Walk indoors around the house?
- Walk a block or 2 on level ground at 2 to 3 mph (3.2 to 4.8 kph)?
4 METs
- Do light work around the house like dusting or washing dishes?
Can you …
4 METs
- Climb a flight of stairs or walk up a hill?
- Walk on level ground at 4 mph (6.4 kph)?
- Run a short distance?
Greater than 10 METs
- Participate in strenuous sports like swimming, singles tennis, football, basketball, or skiing?
TABLE 21-13
TABLE 21–13 Modified New York Association functional classification of heart disease.
Class | Description
— | —
I | Asymptomatic except during severe exertion
II | Symptomatic with moderate activity
III | Symptomatic with minimal activity
IV | Symptomatic at rest
Choice of Anesthetic - Regional
Answers:
1. catecholamine release is suppressed
a. Increase
2. Alpha-agonist
3. Phenylephrine
4. Large volume loads
Choice of Anesthetic: General
Selection of Anesthetic
Answers:
1. patients with CAD
2. severe myocardial dysfunction
3. Protect
Treatment of Intraoperative Problems
Answers:
1. Restrict fluids
2. Volatile anesthetic
Treatment of Intraoperative Problems
Answers:
a. Alpha
1. phenylephrine
2. Good for ischemic changes
Valvular Heart Disease
Valve Review Sheet
Pathophysiology of Valvular Heart Disease
2 types of hemodynamic overload → HF
Answers:
1. handy
2. pressure
3. increase in ventricular wall thickness
4. normal wall thickness
History and Physical
Tests to evaluate valvular heart disease:
Answers:
1. Marfans
2. hepatic
3. left ventricle
4. enlargement
5. CAD
Transesophageal Echocardiography (TEE)
Pressure-Volume Loops
(Know these, compare these, know what they’re describing, how do they change due to pathology)
Answers:
1. bypass
2. basura
Pressure-Volume Loops
Match the event/description with the valve action (answer below the next img)
A. Aortic Valve Closes
B. Aortic Valve Opens
C. Mitral Valve Opens
D. Mitral Valve Closes
Preload is represented by the point just before the mitral valve closes, indicating the ventricle is at its maximum volume in diastole.
Please study the Pressure Volume Loop graph
P-V Loops: Valve disease
Aortic Stenosis (AS) “______(a)”
Pathology of Aortic Stenosis
Answers:
A -> 1. End Systolic Volume
B -> 2. Beginning of Systole
C -> 3. End Diastolic Volume
D -> 5. Beginning of Ventricular Filling
a. FULL, SLOW, AND CONSTRICTED
Pathophysiology of Aortic Stenosis
Presentation of Aortic Stenosis
Answers:
a. elevated
b. late
c. Older, male, smoker, HTN, Hyperlipidemia
d. Rheumatic fever
1. bicuspid
2. dyspnea
e. 5
f. 3-4
g. 1-2