CV

Question 1

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

Answer 1

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

What determine urgency of surgery (step 1)?

Answer 2

• 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

What is Step 2 in Cardiac eval algorithm?

Answer 3

• 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

What is the risks of perioperative MI?

Answer 4

• 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

What is Step 3 in cardiac algorithm?

Answer 5

• 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

What is step 4 in cardiac algorithm?

Answer 6

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

What is the Duke Activity Specific Index (DASI)?

Answer 7

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

What can you use in lieu of assessing functional capacity?

Answer 8

• 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

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

Answer 9

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

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

Answer 10

• 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

Intermediate clniical predictors for periop CV M/M?

Answer 11

• 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

Major clinical predictors of increased CV risk?

Answer 12

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

What is the Cardiac Risk Index?

Answer 13

• 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

Basic components of cardiac exam?

Answer 14

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

Question 15

What is important to assess for on EKGs preop?

Answer 15

• 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

What are the recommendations for preop 12- lead EKG?

Class IIA? IIB? III?

Answer 16

• 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

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

Answer 17

• 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

What is goal of history?

Answer 18

• 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

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

Answer 19

• 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

What is paroxysmal nocturanl dyspnea?

Answer 20

• 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

Even more questions to ask….

Answer 21

• 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

What is angina?

Answer 22

• 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

What is stable angina?

Answer 23

• 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

What is unstable angina?

Answer 24

• 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

What is Prinzmetal’s Angina?

Answer 25

• 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

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

Answer 26

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

When should pacemaker/ICD be evaluated before sx?

Answer 27

• 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

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

Answer 28

• 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

What can we observe on inspection during cardiac assessment?

Answer 29

• 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

What can we assess on palpation of chest?

Answer 30

• 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

Where are some location/corresponding dx with abnormal PMI?

Answer 31

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

Cardiac auscultation process?

Answer 32

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

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Question 33

What does S1 signify? S2? S3? S4?

Answer 33

• 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

What is a physiologic mumur? pathologic?

Answer 34

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

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

Question 35

What is the grading scale of murmurs?

Answer 35

• 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

Description of valvular murmurs?

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

Answer 36

• 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

What does timing of murmur tell us?

Answer 37

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

Question 38

Way to remember murmur timing?

Answer 38

MRS.ASS

MSD -ARD

MRS= Mitral regurgitation/systolic

ASS= Aortic stenosis/systolic

MSD= Mitral stenosis/ diastolic

ARD= Aortic regurge/diastolic

Question 39

HTN preop evaluation goals?

Answer 39

• 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

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

Answer 40

• 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

Beta blocker therpay periop?

Answer 41

• 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

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

Answer 42

• 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

What are diagnostics often performed on heart failure patients?

What is the New York Heart Assocation functional status assessment?

Answer 43

• 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

What to consider with valvular abnormalities?

Answer 44

• 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

What valvular abnormality poses the greatest risk? symptoms?

Answer 45

• 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

Arrhythmia considerations? When to postpone surgery?

Answer 46

• 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

Rule for antiplatelet, anticoag and fibrinolytic therapy around sx?

Answer 47

• 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

When do we get CXR for cardiac assessment?

Answer 48

• 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

What are 5 principle indicators of ischemia?

Answer 49

1. ST segment elevation , ≥1mm
2. T wave inversion
3. Development of Q waves → myocardial necrosis
4. ST segment depression, flat or downslope of ≥1mm
5. 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

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

Answer 50

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

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

Answer 51

• 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

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

Answer 52

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

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

Answer 53

• 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 O₂ demand
• 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

When do we request stress testing?

Answer 54

• 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

What is echocardiography? What is its diagnostic usefulness?

Answer 55

• 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

When to order a preop echo?

Answer 56

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

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

Answer 57

• 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

What is electron beam CT?

Answer 58

• 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

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

Answer 59

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

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

Answer 60

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

Who should receive subacute bacterial endocarditis prophylaxis?

Answer 61

• 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

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

Answer 62

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

What meds are used for SBE prophylaxis?

Answer 63

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)