CV Flashcards

Question 1

Q

What is the goal of cardiac assessment What is the cardiac evaluation alogrithm?

Answer

A

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.

Step 1: urgency of surgery
Step 2: determine if active cardiac condition nStep 3: determine surgical risk
Step 4: assess functional capacity
Step 5: assess clinical predictors/markers
We use American college of cardiology and American heart association

Question 2

Q

What determine urgency of surgery (step 1)?

Answer

A

one where life or limb would be threatened if surgery did not proceed:
- emergent- within < 6 hours
- urgent- within 6-24 hours
  - Emergency sx → focus on:
    - Risk reduction- ex: BB, statins, pain management
    - perioperative surveillance – ex: serial EKG, cardiac enzymes

Question 3

Q

What is Step 2 in Cardiac eval algorithm?

Answer

A

Active cardiac conditions should be ruled out in pt not requiring emergent sx
example: TREAT or DELAY/CANCEL if active conditions (unless emergency sx)
- Acute coronary syndrome
- decompensated heart failure
- severe valvular disease
- pulm HTN
- significant arrhythmias
  - Should be ruled out in patients not requiring emergency surgery.
  - If any conditions present → TREAT
Recent MI— Attempt to find DATE of infarction
- Nonurgent surgery – delay for 60 days.<< american heart guidlines

Question 4

Q

What is the risks of perioperative MI?

Answer

A

Risk of perioperative MI in the patient with previous MI
- General population= 0.3%
- MI > 6 months =6%
- MI if 3-6 months = 15%
- MI< 3months =30%

Question 5

Q

What is Step 3 in cardiac algorithm?

Answer

A

perioperative cardiac risks for non cardiac surgical procedures
- CV risk under what type of sx undergoing
Highest risk involving aorta/vascular sx
Low risk- cataract, breast, ambulatory sx
- LOW RISK→ proceed directly to sx
- KNOW TABLE

Question 6

Q

What is step 4 in cardiac algorithm?

Answer

A

Determine METS

METs (Metabolic equivalent of Task)= Exercise equivalent
1 MET= amount of O2 consumed while sitting at rest
- O2 consumption of 3.5 ml/min/kg body wt
Preop- fx capacity should be found
- AHA:
  - > 4 METs = proceed directly to sx
    - “Are you able to walk a flight of stairs?” → YES = immediately know they are MET=5
  - < 4 METs = undergo CV stress testing prior to going to elective sx

Question 7

Q

What is the Duke Activity Specific Index (DASI)?

Answer

A

Estimated METS = (0.43 X DASI score) + 9.6

3.5

Asking pt not necessarly estimate exercise capacity
Not seen used… but more reliable estimate of exercise capacity
Don’t need to know formula for test…

Question 8

Q

What can you use in lieu of assessing functional capacity?

Answer

A

Canadian Cardiac Guidelines recommend utilization of Cardiac biomarkers (BNP, Pro-BNP) to assess periop risk
- Low risk:
  - BNP: < 100
  - Pro-BNP: < 300
- High risk:
  - BNP: > 300
  - Pro-BNP: > 900

Question 9

Q

What are some general risk factors for periop cardiac morbidity/mortality for non cardiac sx

Answer

A

General risk factors: INCREASED periop cardiac m/m (know!!!)

High risk surgeries
- ex: Aortic and other vascular sx
- Peripheral vascular sx
Ischemic heart ds hx
- unstable angina – GREATEST risk of periop MI
CHF hx
Cerebrovascular ds hx
Diabetes
Serum creatinine > 2 mg/dL

Question 10

Q

What is Step 5 in cardiac evaluation algorithm? What are minor risk factors for CAD?

Answer

A

Clinical risk factors for CAD
# of CV clinical predictors (ex: IHD, HF, CVA, DM, Renal insufficiency) → determine the likely benefit of further cardiac testing who reach step 5
- Pts with no clinical predictors → proceed to sx
- With risk predictors → benefit from further testing, only if results will alter management

MINOR : clinical markers for CAD

HTN
abnormal ECG
smoking
increased age/ male sex –hypercholesterolemia
rhythm other than sinus rhythm –family history
obesity
- COLLECTIVELY: Recognized markers for Heart Disease
- INDEPENDENTLY: do NOT show increase periop CV risk

Question 11

Q

Intermediate clniical predictors for periop CV M/M?

Answer

A

known CAD
Prior MI > 1 month and Q waves on ECG
history of mild, stable angina
compensated or previous LV failure / CHF
Diabetes
chronic renal insufficiency (Cr > 2.0 mg/dL)
cerebrovascular disease (stroke, TIA)

Question 12

Q

Major clinical predictors of increased CV risk?

Answer

A

Major (ACTIVE cardiac conditions- from step 2) – of periop CV M/M risk

unstable coronary syndromes
acute or recent MI < 1 month
unstable or severe angina
decompensated CHF
significant arrhythmias 3rd degree, SVT, uncontr AF
severe valvular disease

Question 13

Q

What is the Cardiac Risk Index?

Answer

A

High-risk sx
Ischemic Heart dx
CHF hx
CV dx hx
Cerebral vascular dx
DM requiring insulin
Creatinine > 2.0 mg/dl
- Summation provide score to estimate risk of major CV events
  - Ex: Score 0 = 0.4% risk of major CV event periop
  - >3= 5.4% risk of major CV event periop

Question 14

Q

Basic components of cardiac exam?

Answer

A

History taking
- –including medications
Physical exam
Resting 12-Lead ECG
- if indicated → within 30 days of surgery

Question 15

Q

What is important to assess for on EKGs preop?

Answer

A

EKGs →
- assessment of rhythm
- L ventricular hypertrophy
- Prior MI (abnormal Q-waves).
  - Ex: Abnormal Q-waves in high risk patients = highly suggestive of previous MI
  - Absent Q-wave does not rule out MI in past
It has been estimated that ~30% of MIs occur without symptoms
- “silent infarct”→ can only be detected on screening EKG
  - Silent infarcts occurrence most:
    - Diabetic patients
    - Hypertensive patients
However, the 2014 ACC/AHA guidelines recommend a preop 12- lead EKG only for patients w known CAD or other structural heart ds.

Question 16

Q

What are the recommendations for preop 12- lead EKG?

Class IIA? IIB? III?

Answer

A

CLASS IIA RECOMMENDATION:
- It is Reasonable to Perform the Procedure (12-lead) for patients with:
  - IHD
  - significant arrhythmia
  - PAD
  - CVD
  - significant structural heart disease
    - EXCEPT: if undergoing low-risk surgical procedures (ex: breast, cateract, ambulatory, superficial, endoscopic sx)
Class IIB:
- The Procedure may be Considered for asymptomatic pts w/o known coronary heart ds, except for those undergoing low-risk surgical procedures
Class III:
- The Procedure Should Not Be Performed Because it is Not Helpful for asymptomatic patients undergoing low-risk surgical procedures

Question 17

Q

What are some adjunct tests done to patient with CV risk factors or pt undergoing high risk sx?

Answer

A

Chest X-Ray
Labs
Stress testing
Echocardiography
MRI
CAT scan
Coronary angiography
- (Gold Standard-for coronary anatomy)
  - Rule of thumb: Will results of test change management of pt?
    - YES → proceed with test collection

Question 18

Q

What is goal of history?

Answer

A

Goal of history is to elicit:
- Severity
- Progression
- functional limitations
  - Interviewing: Identify RISK factors (not symptoms)
    - Symptoms vary person to person
      - Ex: Elderly, females, DM – present with atypical features
      - Women MI s/s: N/V, SOB, back pain (atypical features)

Question 19

Q

What are some questions that can be asked during cardiac evaluation?

Answer

A

Short of breath lying flat (orthopnea)?
Paroxysmal nocturnal dyspnea?
Congestive heart failure?
Heart attack? (diagnosed by EKG or elevated enzymes)
Angina (with activity/ @ rest), or chest pain/ pressure/ tightness related to your heart?
- What are precipitating factors?
- Associated symptoms?
- What is frequency?
- Duration of pain?
- Methods of relief?
Irregular heartbeat or palpitations?
Pacemaker? ICD?
Heart murmur?
Diagnostic tests, therapies, names of treating physician?
Problems with blood pressure or HTN?
- Untreated HTN pts→ greatest ¯in BP during induction
  - risk of myocardial ischemia/arrythmias
PVD?
TIA/CVA?

Question 20

Q

What is paroxysmal nocturanl dyspnea?

Answer

A

Sudden difficulty breathing and orthopnea that awakens pts from sleep
- Prompts pts to sit up, stand up, go to window for air
- +/- wheezing
- ~1-2 hrs after bed- occurs around same time on subsequent nights
  - → Indicative: LV HF, Mitral Stenosis, or Obstructive Lung Dx

Question 21

Q

Even more questions to ask….

Answer

A

Diabetes?
Renal insufficiency?
High cholesterol?
Estrogen status?
- Research: Estrogen offers CV protection
Age and weight?
Fatigued?
Syncope?
Anemia?
Smoke or drink alcohol?
Illicit drug use?
- Marijuana→ tachycardia
- Opioids → hypotension & bradycardia
- Cocaine → tachycardia & HTN

Question 22

Q

What is angina?

Answer

A

Angina – sign of imbalance between myocardial oxygen supply vs. demand.
- GERD and Esophageal spasm MIMIC angina
  - heartburn can result in angina-like pain
  - Can be relieved by Nitroglycerin
Stable vs unstable angina

Question 23

Q

What is stable angina?

Answer

A

Stable—substernal discomfort à exertion.
- Relieved by: rest, NTG, or both in < 15 min.
- Typical pattern à radiation to jaw, shoulder, neck, inner aspect of arm.
  - Poses no greater threat to periop MI than the absence of anginal symptoms

Question 24

Q

What is unstable angina?

Answer

A

Unstable—occurs at rest
- newly developed (w/in past 2 mo) or angina that last > 30 min.
- Angina that has worsened w/ inc freq, intensity, or duration.
- Less responsive to meds.
- A/w highest risk for perioperative MI
- Present in EKG, not labs:
  - Produces transient ST or T wave changes WITHOUT development of Q waves
  - No elevation of cardiac enzymes
Unstable angina–> cancel elective sx until evaluated
- WORKUP: coronary angiography, exercise EKG stress testing

Question 25

Q

What is Prinzmetal’s Angina?

Answer

A

aka variant angina
Produced by Coronary vasospasm (rather than occlusion)
Vasospastic angina that occurs at rest.
- Triggered by stress, cold weather, smoking, medications, etc
Presentation:
- ST elevation during episode on 12-lead
- patients have a higher incidence of migraine HA and Raynaud’s (perhaps due to a basic vaso-spastic disease)
Treatment: Nitrates, CCBs

Question 26

Q

What are some things we want to know about patient with pacemake and ICD?

Answer

A

Things to know:

The indication for insertion of the pacemaker or ICD
- Ask why?
The underlying rhythm and rate
- Do you know what number
The type of pacemaker (demand, fixed), the chamber paced, and the chamber sensed
- Does your heart ever beat on its own? Or are you completely dependent on it?
Have the pacemaker or defibrillator interrogated by a qualified member of CIED
- Note current settings and battery life
Evaluate effect of magnet
Inactivate ICD tachyarrhythmia detection and put defibrillator pads on

Question 27

Q

When should pacemaker/ICD be evaluated before sx?

Answer

A

Device should be evaluated before surgery
- Pacemakers: Assess w/in 12 mo of elective sx
- ICD: assess w/in 6 mo of elective sx
  - Ex: Pacemaker evaluation → card that has date of insertion, manufacturer, contact rep
  - Hospital contacts major company reps in area. Always available and can answer questions. Assist with pre/intra/post op

Question 28

Q

Periop consideration of pacemakers and ICDs? What should be done to ICDs intraop? Pacemakers? Special considerations?

Answer

A

Electromagnetic interference can occur with electrocautery, which can inhibit pacemaker firing
- Ex: Demand pacemakers sense electrocautery→ inhibit pacemaker firing → ASYSTOLE
ICD devices →** **should have tachyarrythmia treatment algorithms program turned off before sx and on after sx
- Prevent unwanted shocks that signals might interpret as V tach or V fib
- ICD always have pacemaker fx → place in asynchronous mode
Ensure monitor enabled to displace pacer spikes **
Have a magnet immediately available.
- Most pacemakers can be converted to a fixed rate (asynchronous mode) by placing a magnet over the pacemaker box
- Demand pacemakers Intraop:
  - Program Asynchronous mode
  - Place magnet over device – converts to fixed rate (90-100 bpm)
    - Ensure when magnet removal → automatically resets when removed (pacemaker rep helps)
Grounding pads should be as far from the pulse generator and leads as possible
Bipolar electrocautery is preferred; avoid monopolar
Monitor some form of blood flow (pulse oximetry, intra-arterial BP measurement)
Have external pacing and crash cart available

Question 29

Q

What can we observe on inspection during cardiac assessment?

Answer

A

stature (obese?)
sternal incision (scars), pacemaker box
PMI-5^{<strong>t</strong>h<strong> </strong>}ICS @ or just medial to left MCL (supine about hte size of quarter)
JVD→ Jugular venous pressure- CRNAs do not perform
- Jugular venous pressure provides an estimate of central venous pressure (CVP).
  - Jugular vein distention is a sign of increased CVP.
  - Increased CVP:
    - right-sided heart failure
    - pulmonary hypertension
    - tricuspid stenosis
    - superior vena cava obstruction.
Edema

Question 30

Q

What can we assess on palpation of chest?

Answer

A

PMI (< 2.5cm) – point of maximal impulse (~size of quarter)
- Cardiac Apex: The tapered inferior tip of the left ventricle → **produces the apical impulse
- Children/Young adults: PMI easy to visualize/palpate
  - As chest deepens the AP diameter → impulse harder to find
- Normal Location:
  - Located 5^th intercostal space, midclavicular line
  - Supine= the normal PMI about the size of a quarter (~1-2.5 cm).
Thrills- vibratory/buzzing sensations caused by underlying turbulent flow
- Thrills can be palpated by pressing the ball of the hand firmly on the chest.
- The presence of thrill changes the grading of murmurs

Question 31

Q

Where are some location/corresponding dx with abnormal PMI?

Answer

A

Abnormal PMI locations:

Right ventricular Hypertrophy- shifted to xiphoid or epigastric area
Ventricular dilation (HF, cardiomyopathy, IHD)- displaced laterally toward axilla
Pregnancy- shift apical impulse upward and left

Question 32

Q

Cardiac auscultation process?

Answer

A

Aortic valve
1. Right sternal, 2^nd intercostal space
Pulmonic valve
1. Left sternal border, 2^nd intercostal space
Erb’s point- Left sternal border, 3rd intercostal
- hear S1 + S2 sounds equally (S2 is best auscultated here)
Tricuspid valve- fourth (or fifth) intercostal space, left sternal border
Mitral valve- 5^th left intercostal mid-clavicular

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Question 33

Q

What does S1 signify? S2? S3? S4?

Answer

A

S1
- Closure of mitral and tricuspid valves Marks onset of systole
S2
- Closure of aortic and pulmonic valves
- Onset of diastole
S3 (ventricular gallop)
- Physiologic in children, young adults, and pregnancy (last trimester). Pathologic in adults > 40 → heart failure. “Kentucky”
S4 (atrial gallop)
- Occ is normal in trained athletes.
- Usually suggest ventricular hypertrophy (esp in older adults)- from increased resistance in ventricular filling “Tennessee”

Question 34

Q

What is a physiologic mumur? pathologic?

Answer

A

Physiologic- abnormal sound/murmur result from physiologic changes in body

Pathologic- abnormal sounds arise from structural abnormalities in heart or great vessels

Question 35

Q

What is the grading scale of murmurs?

Answer

A

Grade 1
- Very faint, heard only after the listener has “tuned in”
Grade 2
- Quiet, but heard immediately after placing the stethoscope on the chest
Grade 3
- Moderately loud
Grade 4
- Loud with palpable thrill
Grade 5
- Very loud, with thrill. May be heard when the stethoscope is partly off the chest
Grade 6
- Very loud, with thrill. May be heard with stethoscope entirely off chest

Grade 4-6: added presence of palpable thrill

Ex: Moderately loud murmur in R, 2^nd intercostal space that radiates to the neck→ descriptive of Grade 3 murmur
- DOCUMENT: “moderately loud, grade 3/6 murmur in the right 2^nd intercoastal space radiating to the neck”

Question 36

Q

Description of valvular murmurs?

Aortic stenosis, regurg? Mitral stenosis, regur? mitral prolapse?

Answer

A

aortic stenosis
- timing: midsystolic
- radiation: often to the carotids (neck)
aortic regurgitation
- timing: holodiastolic
- radiation: often to the carotids, if loud àto the apex
mitral stenosis
- timint: middiastolic
- radiation: little or none
mitral regurgitation
- timing: holosystolic
- radiation: to the left axilla
mitral valve prolapse
- timing: midsystolic click
- radiation: no radiation, but a ballooning of the mitral valve into left atrium

Question 37

Q

What does timing of murmur tell us?

Answer

A

Timing allows us to differentiate between systolic and diastolic murmurs.
- Systolic murmur: between S1 and S2
- Diastolic murmurs: between S2 and S1

Question 38

Q

Way to remember murmur timing?

Answer

A

MRS.ASS

MSD -ARD

MRS= Mitral regurgitation/systolic

ASS= Aortic stenosis/systolic

MSD= Mitral stenosis/ diastolic

ARD= Aortic regurge/diastolic

Question 39

Q

HTN preop evaluation goals?

Answer

A

HTN = > 130/80 mmHg (2017 ACC/AHA)
- HTN= inc risk for LVH, heart failure, IHD, CKD, CVA, & PAD
preoperative goals:
- identify secondary causes of HTN: coarctation of the aorta, pheo, hyperthyroidism, OSA, illicit drug use, etc
- identify cardiac risk factors (smoking, diabetes, obesity)
- assess for end target organ damage (cardiomegaly, bruits, etc)
  - If target organ end dame exist→ additional testing needed
SBP > 180 mmHg, DBP >110 mmHgà delay?
- Might be considered
- Without END ORGAN DAMAGE: Little association w/ elevated BP > 180/110 with adverse outcomes
  - Risks vs benefits: if no EOD
    - Benefit: delaying sx to optimize HTN
    - Risk: delay procedure
    - >220/120 → Lovern Delays

Question 40

Q

What do you need to obtain preop when pt has HTN? Med continuation around surgery?

Answer

A

If patient has long-standing severe HTN or uncontrolled HTN
- NEED:
  - 12-lead ECG
  - Serum Cr/BUN
If on diuretics –> BMP/CMP
Continue meds morning of sx (except ACEIs and ARBs)
Anti-anxiety medications → for anxiety pt w/ HTN

Question 41

Q

Beta blocker therpay periop?

Answer

A

2014 ACC/AHA recommendations:
- Continue beta blocker therapy on pts who have been on chronic beta blocker therapy
  - Discontinuation: may increase perioperative CV morbidity
- Start beta blockers on high risk patients
  - > 1day prior to surgery; preferably 2-7 days
  - Harm if started day of surgery

Rule: AntiHTN (minus ACEI and ARBS) → CONTINUE

MEDS TO D/C or CONTINUE → HANDOUT FROM 1^st LECTURE

Question 42

Q

What is heart failure? When should elective surgery be postponed?

Answer

A

Abnormal contractility or abnormal relaxation of the heart muscle
Can be caused by HTN, IHD
Suspected in the presence of orthopnea, nocturnal coughing, fatigue, peripheral edema, 3^rd/4^th heart sound, paroxysmal nocturnal dys, rales, JVD, ascites
LVH on ECG should raise suspicion
Decompensated HF/ LV function is high-risk and elective surgery should be postponed.
- NYHA (NY Heart association) Class 3 or 4
- Medical condition optimized prior to sx

Question 43

Q

What are diagnostics often performed on heart failure patients?

What is the New York Heart Assocation functional status assessment?

Answer

A

ECG
CMP, BUN/ CR
BNP (brain naturetic peptide)
- < 100 is normal
CXR, if suspected pulmonary edema
Echo, as objective measure of LV function
Functional status assessment: New York Heart Association
- NYHA Class 1: no limitation on physical activity
- NYHA Class II: slight limitation on physical activity
- NYHA Class III: marked limitation on physical activity
- NYHA Class IV: inability to do physical activity w/o discomfort-symptoms at rest
  - HF pts typically based on this scale
  - Severe- Decompensated HF/ LV function= Class 3 or 4

Question 44

Q

What to consider with valvular abnormalities?

Answer

A

Identify type of valvular lesion
- Presenting w/ Murmurs → Listen to Heart tones
- Presenting w/ Valvular abnormalities- attempt to gather old records (can show severity, fx status, recent Echo results)
Evaluate clinical symptoms and testing data
Greatest risk if Severe aortic stenosis → valve area is < 1 cm²
- Symptoms of Aortic stenosis:
  - Angina
  - HF
  - Syncope
  - Decreased exercise tolerance
- Symptoms present → POSTPONE
Diastolic murmurs always pathologic and require further evaluation
- MSD= Mitral stenosis/ diastolic
- ARD= Aortic regurge/diastolic
If prosthetic heart valve in place:
- May need to bridge anticoagulant therapy
- May need SBE (subacute bacterial endocarditis) prophylaxis

Question 45

Q

What valvular abnormality poses the greatest risk? symptoms?

Answer

A

Greatest risk if Severe aortic stenosis → valve area is < 1 cm²
- Symptoms of Aortic stenosis:
  - Angina
  - HF
  - Syncope
  - Decreased exercise tolerance
- Symptoms present → POSTPONE

Question 46

Q

Arrhythmia considerations? When to postpone surgery?

Answer

A

Arrythmias present:
- Obtain:
  - 12-Lead EKG
  - Labs levels: Electrolytes and Antiarrhythmic drug levels
SVT and ventricular tachyarrhythmias associated with perioperative risk
LBBB is strongly associated w/ CAD
- If new, stress testing or consultation needed
Postpone surgery if,
- uncontrolled atrial fibrillation
- ventricular tachycardia
- new-onset atrial fibrillation
- symptomatic bradycardia
- high-grade or third degree HB

Question 47

Q

Rule for antiplatelet, anticoag and fibrinolytic therapy around sx?

Answer

A

Need to ask about anticoagulants and antiplatelet medications
Decision to D/C meds based on interdisciplinary team
Most common guidelines:
- Antiplatelet (ASA, Plavix, Brilinta, Effient)
  - Discontinue 7-10 days prior surgery
- Anticoagulants (Coumadin, LMWH)
  - Discontinue 3-5 days (Coumadin)
  - INR <1.5
  - Discontinue 12 hours prior (LMWH)
- Fibrinolytic drugs (TPA,Streptokinase, Urokinase)
  - Usually cannot discontinue

Question 48

Q

When do we get CXR for cardiac assessment?

Answer

A

Not specific for Ischemic Heart Disease
Useful for:
- cardiomegaly
- pulmonary vascular congestion/ pulmonary edema (CHF)
- pleural effusions
- tumors
- suspected mediastinal masses
  - REVIEW CXR SLIDES FOR ORAL EXAM

Question 49

Q

What are 5 principle indicators of ischemia?

Answer

A

ST segment elevation , ≥1mm
T wave inversion
Development of Q waves → myocardial necrosis
ST segment depression, flat or downslope of ≥1mm
T wave “pseudonormalization”
- Patients with chronically inverted T waves (resulting from previous MI) → manifest a return of the T waves to the normal upright position during myocardial ischemia (pseudonormalization of the T wave).

EKG displays ischemia by means of changes in the rate of repolarization of ischemic myocardial tissue.
- “Thus, the ST segment and the T wave portions of the ECG signal are primarily affected.

Generally, the T wave is affected initially, followed by ST segment changes as ischemia worsens

Know these indicators

Question 50

Q

Which labs should be obtained to evaluate patients general medicatl condition r/t comorbidities and meds?

Answer

A

To ascertain general medical condition related to comorbidities and medications

K+
BUN/ Cr
ABG’s
Hbg/ Hct
- all CAD pts: CBC → evaluate for anemia.
  - Calculating ABL w/ CAD → use a higher Hbg/Hct.
  - (Hct < 28 % –> inc periop ischemia)
INR/ PT
C-reactive protein- serum inflammation marker
- Atherlosclerosis – Inflammatory process (inflam cells)
- Inflammation important in cascade of events → lead to plaque rupture
  - Ex: Serum inflammation markers (CRP): INCREASED in susceptible CAD pts

Question 51

Q

What is a treadmill excercise stress test? Interpreted based on?

Answer

A

EKG Stress Test → traditional method of evaluating pts w/ suspected CAD
- Cost effective and least invasive method to detect ischemia
Simulates sympathetic nervous system stimulation by increasing BP and HR and therefore increasing myocardial O2 demand and consumption w/ exercise
Look for ischemia by ECG changes
- Positive test: indicated pt at risk for ischemia associated with increased HR
  - Greatest risk: positive test (ischemia) with MILD exercise.

Interpreted based on:

a) Duration of exercise the patient can perform—desire >3-5 minutes
b) Max. HR achieved—desire HR > 120bpm
c) Time of onset of ST depression
d) Degree of ST depression
e) Time until resolution of the ST segment

Question 52

Q

What shows a positive test/predictive of CAD during treadmill exercise stress test?

Answer

A

ECG criteria

ST-segment depression > 0.2mm (w/in 1^st 3 min)
- The greater the degree depression → likelihood significant CAD
  - ST seg abnormal w/ Angina in early stages of exercise and persists for several minutes → SEVERE CAD
ST-elevation >1.0 mm
Serious ventricular arrhythmias
Development unusual S/S: angina, breathlessness, cold sweats, pallor, cyanosis

Non-ECG responses

Failure of SBP to rise
Progressive fall in SBP
Elevation of DBP

Question 53

Q

What is pharmacologic stress testing? What is injected in order to visualize coronaries? What meds are given to induce stress?

Answer

A

Useful in patients unable to exercise or have contraindications to exercise
- CI for exercise ex: PVD with claudication, SC injury, morbid obesity
Myocardial Perfusion Scans:
- Attempt to dx IHD and allow differentiation of ischemia and infarction
- Myocardium imaged at rest and during stress
- These tests reveal myocardial wall defects and heart pump performance during increased O₂demand
Nuclear Tracers (Thallium- IV injection of gamma-emitting radiopharmaceutical)
- Detected over myocardium by specialized scanners → permits the imaging of blood within the heart and lungs.
- The area of decreased perfusion (cold spot) during stress indicates ischemia
  - Ex: A significant coronary obstruction causes less blood flow and thus less tracer activity (cold spot).
Medications used to induce stress: adenosine, dipyridamole (Persantine), dobutamine, atropine
- Produces rapid HR to create cardiac stress
- Normal Arteries: dilate normal coronary arteries,
- Sclerosed Arteries: evoke minimal or no change to dilation
Look for ischemia by perfusion imaging, not ECG changes
After cardiac stress induced by med→ nuclear scanning performed to asses myocardial perfusion

Question 54

Q

When do we request stress testing?

Answer

A

Active cardiac condition → (ANY ACTIVE CONDITION= STRESS TESTING)
- unstable coronary syndromes
- unstable or severe angina
- recent MI
- decompensated HF
- significant arrhythmias
- severe valvular disease
3 or more clinical risk factors and poor functional capacity having vascular surgery
Maybe if:
- at least 1-2 clinical risk factors and poor functional capacity having intermediate risk surgery if it will change management
- at least 1-2 clinical risk factors and good functional capacity having vascular surgery

Question 55

Q

What is echocardiography? What is its diagnostic usefulness?

Answer

A

Echocardiography is a noninvasive technique for examining the heart and can provide information about its position and size,movements of the valves and chamber, and velocity of blood flow.
Echoes from pulsed high-frequency sound waves are used to locate and study the movements and dimensions of cardiac structures.
Diagnostic usefulness of ECHO:
- Measurement of the dimensions of cardiac chambers and vessels and the thickness of the myocardium
- Global ventricular systolic function: EF
- Regional wall motion abnormalities
- Valve structure and motion
- Can detect blood flow and measure gradients
- Chamber enlargement
- Detection of pericardial fluid
2014 AHA/ACC guidelines: preop ECHO for MODERATE or SERVE valvular abnormalities with no ECHO w/in 1 yr

Question 56

Q

When to order a preop echo?

Answer

A

When to Order a Preop Echo (when not followed by specialist and don’t know)

Current or prior heart failure
- with worsening dyspnea or other change in clinical status
- Reassessment of LV function with documented previous LV dysfunction, if not assessed in last year
Dyspnea of unknown origin
Valvular disease clinically suspected
- Significant change in symptoms

Question 57

Q

What iare some indications for coronary angiography? usefulness? cons?

Answer

A

Provides the BEST information about the condition of coronary arteries/anatomy
Gold standard test for pts undergoing cardiac surgery
Indications:
- pt surviving sudden cardiac death
- those considered for CABG
- those needing definitive diagnosis for CAD (airline pilots)
Usefulness:
- diagnose nonatherosclerotic CAD
  - CA spasm
  - Kawasaki’s ds
  - radiation-induced vasculopathy
Cons:
- Cannot predict which areas of plaque are most likely to rupture and produce acute coronary syndrome
- expensive
2014 ACC/AHA guidelines: do NOT recommend routine preop coronary angiography prior to noncardiac sugery without specific clinical indications

Question 58

Q

What is electron beam CT?

Answer

A

Detects atherosclerotic calcifications in CA (vessels that contain calcium)
- electron beam CT detects calcifications
- “calcium score” = degree of CAD
Test:
- Highly sensitive
- Low specificity → (many false positives)
  - use is not recommended- results are minimum value

Question 59

Q

What are guidlelines for elective noncardiac surgeyr after balloon angioplasty? bare metal stent? drug eluting stent?

Answer

A

Delay of elective noncardiac Surgery: (after _____ sx = wait ____ days to get elective sx)

BALLOON ANGIOPLASTY – wait 14 days
BARE-METAL STENT – wait 30 days
DRUG-ELUTING STENT – wait 12 months (might be considered after 6 mo)

Question 60

Q

What are recommendations for dual antiplatleet therapy after ballon angioplasty, BMS, and DES?

Answer

A

Current recommendations for dual antiplatelet (ticlopidine or clopidogrel + ASA) therapy:

Continue for @ least 2 weeks after balloon angioplasty,
for at least 6 weeks after bare metal stent placement, and
for at least 1 year after drug-eluting stent placement

Question 61

Q

Who should receive subacute bacterial endocarditis prophylaxis?

Answer

A

Guidelines updated in 2017
Prophylaxis for patients with high risk cardiac conditions associated with high risk of adverse outcomes for infective endocarditis:
- Prosthetic heart valves
- History of infective endocarditis
- Congenital heart disease
  - Unrepaired cyanotic congenital heart disease
  - Repaired congenital heart defect with prosthetic material or device, during the 1^st 6 months after the procedure
  - Repaired congenital heart disease with residual defects
- Damaged heart valves
- Cardiac transplantation recipients with cardiac valvular disease
- Hypertrophic cardiomyopathy

Question 62

Q

For patients who need to receive SBE (subacute bacterial endocarditis) prophylaxis, when should they receive them?

Answer

A

For patients with high cardiac risk, antibiotic prophylaxis is recommended for these procedures/surgeries:

All dental/oral procedures that involve manipulation for gingival tissue, perforation of oral mucosa, or the periapical region of teeth
Invasive respiratory tract procedures with perforation of respiratory mucosa (tonsillectomy, adenoids, abscess drainage, lung biopsy)
Procedures involving infection of GI/GU tract, skin/ musculoskeletal tissue
- NOT recommended in routine genitourinary or gastrointestinal tract surgery or bronchoscopy*
Hepatobiliary procedures w/ high risk of bacteremia
For Cardiac Surgery

Question 63

Q

What meds are used for SBE prophylaxis?

Answer

A

All antimicrobial prophylaxis are administered as a single dose, given 30-60 min. before procedure (up to 2 hrs after if missed pre-procedure dose)

Standard prophylaxis
- Ampicillin 2 gm IV
  - (50mg/kg pediatrics)
- Cefazolin 1 gm IV
  - (50 mg/kg pediatrics)
- Ceftriaxone 1 gm IV
  - (50 mg/kg pediatrics)
- PCN allergic: Clindamycin 600 mg IV
  - (20 mg/kg pediatrics)