CV Assessment Flashcards
The goal of preop cardiac assessment
is to identify patients with heart disease who are at high risk for perioperative cardiac morbidity or mortality or those with modifiable conditions or risk.
5 steps of CV assessment
Step 1: urgency of surgery
Step 2: determine if active cardiac condition
Step 3: determine surgical risk
Step 4: assess functional capacity
Step 5: assess clinical predictors/ markers
Minor Clinical Predictors of Increased Cardiovascular Risk (6)
1- Uncontrolled HTN 2- Advanced age >75 yrs old 3- Abnormal ECG 4- Low functional capacity 5- Hx CVA 6- Rhythm other than sinus rhythm
Intermediate Clinical Predictors of Increased Cardiovascular Risk (6)
1- Known CAD
2- Prior MI > 1 month and Q waves on ECG
3- History of mild, stable angina
4- Compensated or previous LV failure / CHF
5- Diabetes
6- Chronic renal insufficiency (CR > 2.0 mg/dL)
Major Clnical Predictors of Increased Cardiovascular Risk (6)
(Active Cardiac Conditions)
1- Unstable coronary syndromes
2- Acute or recent MI < 1 month
3- Unstable or severe angina
4- Decompensated CHF
5- Significant arrhythmias (SVT, Sympt Brady, Vent, complete AV)
6- Severe valvular disease (aortic stenosis)
The overall mortality risk of acute MI after GA is
Risk post intra ab/thor or long surg
about 0.3%
incidence is increased in the patient undergoing intra-thoracic or intra-abdominal surgery or surgery lasting longer than 3 hours
If history of prior MI, periop risk of reinfarction
> 6 months
3-6 months
< 3 months
mortality if reinfarction occurs
greater than 6 months ago, the incidence of
perioperative myocardial reinfarction is about 6%
3-6 months ago, the incidence is 15%
within 3 months, 30%
If reinfarction occurs, the mortality rate is @ 50%
Highest risk period of MI
< 30 days
ACC/AHA guidelines recommend wait for surg post MI
wait 4-6 weeks
High risk surgery (4)
1- Aortic surgery and other major vascular surgery
2- peripheral vascular surgery
3- emergent major operations (esp. elderly),
4-prolonged procedures with large fluid shifts/blood loss.
> 5% additional risk
Intermediate risk surgery (7)
1- Intraperitoneal, 2- intrathoracic, 3- transplant, 4- carotid endarterectomy, 5- head and neck, 6- major neurologic/orthopedic, and 7- endovascular aneurysm repair.
Low risk surgery (6)
1- Endoscopic procedures, 2- superficial, 3- biopsies, 4- cataract, 5- breast surgery, 6- GYN. < 1%
Basic Components of CV assessment
1- History taking 2- Medications 3- Physical exam 4- Resting 12-Lead ECG, if indicated within 30 days of surgery (EKG indicated if ID cardiac risk)
Adjunct Testing
Chest X-Ray Labs Stress testing Echocardiography MRI CAT scan Coronary angiography (Gold Standard-for coronary anatomy)
Goal of history is to elicit
if there are clinical predictors of cardiac dx
severity
progression
functional limitations
Cardiac Specific Questions To Ask?
Short of breath lying flat (orthopnea)? With exertion? Congestive heart failure? Heart attack? Angina (with activity/ @ rest), or chest pain/ pressure/ tightness related to your heart? Irregular heartbeat or palpitations? Pacemaker? ICD? Heart murmur? Diagnostic tests, therapies, names of treating physician? Problems with blood pressure or HTN? PVD? TIA/CVA?
ROS questions
Diabetes? Renal insufficiency? High cholesterol? Estrogen status?- post menopausal need supplements dues to cardio protectiom Age and weight? Fatigued? Syncope? Anemia? Smoke or drink alcohol? Illicit drug use?
Most significant evidence of cardiac dx evident by
Exercise tolerance - in the absence of significant lung disease, is the most “striking” evidence of decreased cardiac reserve.
How is exercise tolerance / functional capacity evaluated
Duke Activity Status Index
1-4 METS (eating, dressing, walking around house, dishwashing)
4-10 METS (climbing stairs, walk in neighborhood, heavy housework, golf, bowl, dance)
> 10 METS (strenuous sports ie:swimming, tennis, running, football, basketball)
Those patients unable to meet a 4-MET demand are considered to be at higher risk.
Angina sign of…
Angina in AS…
Angina with esophageal spasm…
Angina – sign of imbalance between myocardial oxygen supply vs. demand
Aortic Stenosis pts may experience angina despite normal coronaries.
Esophageal spasm caused by heartburn can result in angina-like pain and can be relieved by NTG.
% of ischemic episodes in cad wo angina
% of MI wo angina
80%
10-15%
Prinzmetal’s Angina def..
% of lesion % with spasm
associated co disease
Vasospastic angina that occurs at rest.
In 85%, there is a fixed proximal lesion in a major artery. 15% have just spasm.
Patients have a higher incidence of migraine HA and Raynaud’s perhaps due to a basic vaso-spastic disease.
Things to know about AICD pacer (6)
What to do during surgery
When should it be evaluated
1- The indication for insertion of the pacemaker or ICD
2- The underlying rhythm and rate
3- The type of pacemaker ( demand, fixed, or radiofrequency), the chamber paced, and the chamber sensed
4- Have the pacemaker or defibrillator interrogated by a qualified member of CIED
5- Note current settings and battery life
6- Evaluate effect of magnet
- Inactivate ICD tachyarrhythmia detection and put defibrillator pads on
- Device should be evaluated within 3-6 months before surgery
Electromagnetic interference occurs w and inhibits
can occur with electrocautery, which can inhibit pacemaker firing
Have a magnet immediately available for
convert to a fixed rate (asynchronous mode)
Grounding pads should be placed
as far from the pulse generator and leads as possible
Bi vs monopolar
Bipolar electrocautery is preferred; avoid monopolar
Additional monitoring with pacer aicd (2)
1- Monitor some form of blood flow (pulse oximetry, intra-arterial BP measurement)
2- Have external pacing available
Components of physical exam (6)
1- overall appearance 2- Heart 3- neck 4- lungs 5- vs 6- extremities
Overall appearance
Obesity
SOB
Sternal incision, pacemaker box
Heart
Heart sounds
Murmurs
AV
2nd IC rt sternal border
PV
2nd IC LT sternal border
TV
4 or 5th IC lt sternal border
MV
5th IC let mid clavicular
Neck
JVD
Carotid Bruit
Lungs
Lung sounds (rales) SOB, effort
Vital signs
(BP in both arms)
Extremities
Peripheral edema
Pulses
Clubbing
Skin color
Major risk for cv mortality
HTN
HTN increases the incidence of (4)
1-stroke,
2- CHF,
3- MI
4- progression to renal insufficiency and malignant hypertension
Treat HTN if
SBP > 160 mmHg and diastolic BP >90 mmHg
Beta-blockers may have a protective benefit
If patient has long-standing severe HTN or uncontrolled HTN
Consideration: surgery, labs, meds
1- may need to delay surgery to control BP
2- need ECG and serum CR/BUN
3- If on diuretics, CHEM 7
4- Continue meds
5- Antianxiolytics
ACC/AHA Beta Blocker Therapy
recommendations
ACC/AHA recommendations:
1- Continue beta blocker therapy bc
Discontinuation may increase perioperative CV morbidity
2- Give beta blockers to high risk patients having vascular surgery
Heart Failure def..
Caused by.. (2)
Abnormal contractility or abnormal relaxation of the heart muscle
Can be caused by HTN, IHD
HF suspected Symptoms (10)
1- orthopnea, 2- docturnal coughing, 3- fatigue, 4- peripheral edema, 5- 3rd/4th heart sound, 6- resting tachycardia, 7- rales, 8- JVD, 9- ascites 10- LVH on ECG should raise suspicion
Decompensated HF/ LV function level of risk and plan
is high-risk and elective surgery should be postponed.
When a Patient has Heart Failure.. tests plan (5)
labs, meds, tests
1- ECG 2- Chem 7, BUN/ CR BNP (Brain naturetic peptide) < 100pg/mL 3- CXR, if suspected pulmonary edema 4- Echo, as objective measure of LVEF 5- Continue all medications, including beta blockers, hydralazine, nitrates, digoxin, ACEIs, ARBs, diuretics, anticoagulants (if possible)
Valvular Abnormalities
Identify and evaluate..
greatest risk..
If symptoms..
Identify type of valvular lesion
Evaluate clinical symptoms and testing data
Severe aortic stenosis poses the greatest risk, if valve area is < 1cm2
If symptoms, postpone surgery
If prosthetic heart valve in place 2 medication considerations
1- May need to bridge anticoagulant therapy
2- May need SBE (subacute bacterial endocarditis) prophylaxis
Diastolic murmurs
Diastolic murmurs always pathologic and require further evaluation
Arrhythmias of greatest risk (2)
SVT and ventricular arrhythmias associated with perioperative risk
LBBB is strongly associated with…
if new, order…
associated w/ CAD
If new, stress testing or consultation needed
Postpone surgery if having these arrhythmia.. (5)
1- Uncontrolled atrial fibrillation 2- Ventricular tachycardia 3- New-onset atrial fibrillation 4- Symptomatic bradycardia 5- High-grade or third degree HB
Meds to look for
Beta blockers Statins ACE inhibitors/ ARBs Calcium channel blockers Nitro for angina Diuretics Antiarrhythmics
In medication hx, Must ask about these 2..
Need to ask about anticoagulants and antiplatelet medications
Anti platelet discontinuation
Antiplatelet (ASA, Plavix)
Discontinue 7-10 days prior surgery
Anticoagulants (Coumadin, LMWH) discontinuation
Anticoagulants (Coumadin, LMWH)
Discontinue 3-5 days (Coumadin)
INR <1.5
Discontinue 12 hours prior (LMWH)
Fibrinolytic drugs discontinuation
Fibrinolytic drugs (TPA,Streptokinase, Urokinase) Usually cannot discontinue
Order CXR preop if: (3)
1- Over 75 years old
2- History of CHF
3- Symptomatic cardiovascular disease
CXR is specific for (4)
not specific for..
1- Cardiomegaly
2- Pulmonary vascular congestion/ pulmonary
3- edema (CHF)
4- Pleural effusions
Not specific for Ischemic Heart Disease
12-Lead ECG reviewed for (6)
1) Acute Myocardial ischemia
2) Prior myocardial infarction
3) Rhythm or conduction disturbances
4) Cardiomegaly or ventricular hypertrophy
5) Other ECG abnormalities,
6) Electrolyte imbalances
ECG Indicators of Acute Ischemia (5)
5 Principle Indicators:
1- ST segment elevation , ≥1mm 2- T wave inversion 3- Development of Q waves 4- ST segment depression, flat or downslope of ≥1mm 5- Peaked T waves
Inferior II, III, AVF
RCA
Lateral I, AVL, V5, V6
LCA circumflex
Antero-Septal
V1,V2, V3,V4
LAD
Posterior V1, V2, V3
RCA
When to do an 12-Lead ECG? (2)
When to maybe do an EKG (2)
Not needed in
1- At least 1 clinical risk factor having vascular surgery
2- Known CAD, PVD, CVD having intermediate or high risk surgery
Maybe, if—
1- No clinical risk but vascular surgery
2- At least 1 clinical risk factor having intermediate or high risk surgery
Not needed in asymptomatic patients having low risk surgery
ACC/AHA recommends ECG
within 30 days of surgery
Lab DataTo ascertain general medical condition related to comorbidities
K+ BUN/ Cr ABG’s Hbg/ Hct INR/ PT
Treadmill Exercise Stress Testing
Looks for..
Procedure..
Simulates sympathetic nervous system stimulation by increasing BP and HR and therefore increasing myocardial O2 demand and consumption w/ exercise
Looks for ischemic changes
Treadmill st interpreted based on: (5)
a) Duration of exercise the patient can perform
b) Max. HR achieved
c) Time of onset of ST depression
d) Degree of ST depression
e) Time until resolution of the ST segment
Positive test
Predicts..
Determined by (2)..
predictive of CAD
1- ECG criteria
ST-segment depression > 2.5mm
ST-depression occurs early in test (first 3 minutes)
Serious ventricular arrhythmias
Prolonged duration of ST depression in post recovery period
2- Non-ECG responses
If increase in BP or HR occurs at time of ST-depression
If hypotension occurs
Hypotension an ominous sign
Pharmacologic Stress Testing useful for…
Looks for ischemia by…
Useful in patients unable to exercise
Look for ischemia by perfusion imaging, not ECG changes
Pharm ST components
IV injection of gamma-emitting radiopharmaceutical (thallium) that permits the imaging of blood within the heart and lungs.
Dipyridamole or adenosine administered as a vasodilator to increase coronary blood flow
The area of decreased perfusion (cold spot) only during stress shows ischemia, whereas a constant perfusion defect suggests old MI.
Areas of redistribution defects are at higher risk of ischemia and infarction
When to Request Stress Testing? (2)
1-Active cardiac condition Unstable coronary syndromes Unstable or severe angina Recent MI Decompensated HF Significant arrhythmias Severe valvular disease
2-
3 or more clinical risk factors and poor functional capacity having vascular surgery
When Maybe to Request Stress Testing?
Maybe if:
1- At least 1-2 clinical risk factors and poor functional capacity having intermediate risk surgery if it will change management
2- At least 1-2 clinical risk factors and good functional capacity having vascular surgery
Echocardiography 7 measurements
1-Measurement of the dimensions of cardiac chambers and vessels and the thickness of the myocardium
2-Global ventricular systolic function: EF
3-Regional wall motion abnormalities
4-Valve structure and motion
5-Can detect blood flow and measure gradients
6-Chamber enlargement
7- Detection of pericardial fluid
Stress Echocardiography looks for
abnormal results consist of..
1- Look for regional wall motion abnormalities under stress.
An abnormal result consists of new regional wall motion abnormalities or worsening of existing regional wall motion abnormalities during an infusion of dobutamine (exercise/stress)
Highly predictive of adverse cardiac events
Abnormal stress echo
When to Order a Preop Echo
3
1-Current or prior heart failure
with worsening dyspnea or other change in clinical status
2-Dyspnea of unknown origin
3-?Aortic stenosis
Coronary Angiography Information obtained (7)
1- Diffuseness of obstructive disease
2-Adequacy of any previous angioplasties or bypass grafts
3-CA spasms
4- LV pressures, volumes, and EF
LV dysfunction: akinesis, dyskinesis, low EF, high LVEDP
5-Valvular lumen area and valve gradients
Pressure gradients across valves and shunts, as well as degree of regurgitation
6-PA pressures
7- CO and SVR
Provides best method defining coronary anatomy
Coronary Angiography
Gold standard test for undergoing cardiac surgery
Coronary Angiography
When to Have a Preop Catheterization? 5
1- Stable angina with Left main CAD
2- Stable angina with 3-vessel disease
3- Stable angina 2-vessel disease with significant proximal LAD lesion and EF <50% or demonstrable ischemia on noninvasive stress testing
4- High-risk unstable angina or non-ST elevation MI
5- Acute ST-elevation MI
MRI used for (3)
1- Used to assess function and viability of myocardium
2- Highly sensitive in detecting infarctions using gadolinium
3- Also good at determining intracardiac tissue characterization
BALLOON ANGIOPLASTY and surgery time
wait >14 days
BARE-METAL STENT and surgery time
wait > 30-45 days
DRUG-ELUTING STENT and surgery time
wait > 365 days
Subacute Bacterial Endocarditis (SBE) Prophylaxis recommended for
Patients..
Procedures..
not recommended for..
For patients with
1- high cardiac risk, antibiotic prophylaxis is recommended for:
2- All dental procedures that involve manipulation for gingival tissue, perforation of oral mucosa, or the periapical region of teeth
3- Invasive respiratory tract procedures with incision or biopsy of respiratory mucosa
NOT recommended in genitourinary or gastrointestinal tract surgery
High-Risk Cardiac Conditions requiring SBE prophylaxis (6)
High-Risk Cardiac Conditions
1- Prosthetic heart valves
2- History of infective endocarditis
3- Unrepaired cyanotic congenital heart disease
4- Repaired congenital heart defect with prosthetic material or device, during the 1st 6 months after the procedure
5- Repaired congenital heart disease with residual defects
6- Cardiac transplantation recipients with cardiac valvular disease
Subacute Bacterial Endocarditis (SBE) Prophylaxis
TX
single dose
given 30-60 min. before procedure
Ampicillin 2 gm IV
Or Cefazolin 1 gm IV
Or Ceftriaxone 1 gm IV
If PCN allergic, Clindamycin 600 mg IV
