Cardiac Assessment

Question 1

What can be used to identify the patients at risk for perioperative cardiac morbidity and mortality?

Answer 1

CARDIAC EVALUATION ALGORITHM

1. Urgency: “life or limb”
   
   1. emergent ( <6 hrs)
   2. Urgent (6-24 hrs )
2. Active cardiac conditions
   
   1. Unstable Coronary Syndromes
   2. Valvular disease
   3. Significant arrhythmias
   4. Decompensated HF
   5. Recent MI < 1 mo
   6. Pulmonary HTN
3. Risk- surgical risk
   
   1. Low risk: cataracts, endoscopic, breast, superficial, ambulatory
   2. Intermediate (ICHOP): intrathoracic, intraabdominal, head & neck, ortho, prostate
   3. High risk: aortic and peripheral vascular sx
4. Functional limitation = METS
   
   1. Use METs to determine their functional capacity
      
      1. > 4 METs → proceed
      2. < 4 METs → additional testing (stress testing)
         
         1. EXERCISE TOLERANCE → automatically MET 5
5. Predictors/markers
   
   1. General risk factors for INCREASED periop cardiac m/m
   2. IHD
   3. Prior CHF
   4. CVA
   5. Renal insufficiency (> 2 creatinine)
   6. DM

Question 2

What are some cardiac conditions that would require you to delay or cancel surgery?

Answer 2

• Active cardiac conditions
  
  • Unstable Coronary Syndromes → Acute/unstable Angina (greatest risk)
  • Valvular disease- AS or MS
  • Significant arrhythmias- Mobitz II, CHB, SVT, AF with RVR, bradycardia, new VT
  • Decompensated HF - new onset; NYHA class IV
  • Recent MI < 1 mo
  • Pulmonary HTN

Question 3

RECOMMENDATIONS FOR PREOP 12 LEAD:

Answer 3

• — IIa: reasonable to perform 12-lead → IHD, Significant arrhythmia, PAD, CVD. Significant structural HD (unless low risk procedure)
• IIb: Considered 12-lead → asymptomatic pts w/o known coronary heart disease, (except low risk sx)
• III: NOT BE PERFORMED → not helpful for asymptomatic pts undergoing low risk procedure

Question 4

Describe the differences between stable and unstable angina.

Answer 4

• Stable Angina: substernal discomfort on EXERTION
  
  • Relieved by NTG and rest in < 15 min
  • Symptoms:
    
    • radiation to jaw
    • shoulder, neck
    • inner aspect of arm
  • Poses no greater threat to perioperative MI than absence of anginal symptoms
• Unstable angina
  
  • Newly developed w/in past 2 months and angina that last >30 min
  • Worsened in intensity, frequency, duration
  • Less responsive to meds
  • a/w highest risk for periop MI
  • Present in EKG: NOT labs
    
    • ST or T wave changes without increase in cardiac enzymes
  • Unstable angina→ cancel elective sx until evaluated
    
    • Workup- coronary angio, exercise EKG stress test

Question 5

Things to inquire the patient about if they have a pacemaker or ICD.

Answer 5

• Indication for pacemaker/ICD
• Underlying rhythm and rate
• Type of pacemaker (demand/fixed), chamber placed, and chamber sensed
  
  • Does your heart ever beat on its own? Are you completely dependent on it?
• Has it been interrogated by a qualified member of CIED
  
  • Note battery life and settings
    
    • Pacemakers: needs to be evaluated w/in 12 mo before sx
    • ICD: evaluated win 6 mo of elective sx
• Evaluate effect of magnet
• Inactivate ICD tachyarrhythmia detection and put defibrillator pads on

Question 6

Perioperative considerations for pacemaker and ICD?

Answer 6

• Pacemakers need to be placed in asynchronous mode, or a magnet placed over the device
  
  • Demand pacemakers can sense the electrocautery which will inhibit pacemaker firing and cause asystole
  • If magnet used, make sure it automatically reset to preop settings once magnet removed
• ICD devices need to have tachyarrhythmias turned off and pacemaker function set to asynchronous mode (ensure defib pads on)
  
  • Prevent unwanted shocks that signals might interpret as VT/VF
• Ensure monitor enabled to displace pacer spikes
• Have magnet available
• Place grounding pads as far away from pulse generator and leads as possible
• Bipolar electrocautery preferred; avoid monopolar
• Monitor blood flow (pulse ox, intra-arterial BP)
• Have external pacing and crash cart available.

Question 7

What are some potential palpation findings on a cardiac assessment?

Answer 7

Palpation

• 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 5th intercostal space, midclavicular line
      • Supine= the normal PMI about the size of a quarter (~1-2.5 cm).
    • 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
• Thrills- vibratory/buzzing sensations caused by underlying turbulent flow

Question 8

Describe the auscultation assessment of the heart

Answer 8

• Aortic valve - 2nd ICS, RSB
• Pulmonary valve: 2nd ICS, LSB
• Erb’s point: 3rd ICS, LSB
• Tricuspid Valve: 4th ICS, LSB
• Mitral valve: 5th ICS, MCL
• S1- mitral and tricuspid closure → ventricular systole
• S2- aortic and pulmonary valve closure → ventricular diastole

Question 9

Describe some common heart murmurs.

Answer 9

• Aortic stenosis
  
  • Timing- midsystolic
  • Radiation- often to the carotids (neck)
• Aortic regurg
  
  • Timing- holodiastolic
  • Radiation- often to carotids, if loud→ apex
• Mitral stenosis
  
  • Timing- middiastolic
  • Radiation- little to none
• Mitral regurg
  
  • Timing- holosystolic
  • Radiaiton- to the left axilla
• Mitral valve prolapse
  
  • Timing- midsystolic click
  • Radiation- no radiation, but ballooning of the mitral valve into the left atrium

Question 10

Your patient has hypertension. What preoperative tests do you anticipate ordering? What medications should be continued/held?

Answer 10

• EKG
• BUN/Creatinine
• If on diuretics → BMP/CMP
• Meds:
  
  • CONTINUE: BB, CCB
  • D/C: ACEI, ARBS

Question 11

Your patient has the results for a stress test. What are the indicators for a positive stress test?

Answer 11

• EKG criteria
  
  • ST elevation > 1 mm
  • ST depression > 0.2 mm (w/in 1st 3 min)
  • Serious ventricular arrhythmias
  • Unusual S/S:
    
    • angina
    • breathlessness
    • cold sweats
    • pallor
    • cynosis
• Non-EKG responses
  
  • No increase in SBP
  • Progressive fall in SBP
  • Elevated DBP

Question 12

When is ordering a stress-test appropriate?

Answer 12

• unstable coronary syndromes
• unstable or severe angina
• recent MI
• decompensated HF
• significant arrhythmias (SVT, a fib, 3rd deg HB)
• severe valvular disease

Question 13

What can an echocardiography show?

Answer 13

1. Measure dimensions of cardiac chambers, vessels, and thickness of myocardium
2. Global ventricular systolic function: EF
3. Wall motion abnormalities
4. Valve structure/motion
5. Blood flow/measure gradients
6. Chamber enlargement
7. Pericardial fluid detection

Question 14

What patients require subacute bacterial endocarditis prophylaxis?

Answer 14

• Prophylaxis patients with high risk cardiac conditions associated with high risk of adverse outcomes for infective endocarditis:
  
  • Prosthetic valves
  • History of infective endocarditis
  • Congenital heart disease
    
    • Unrepaired cyanotic heart disease
    • Repaired congenital heart defects with prosthetic material/device < 6mo
    • Repaired with residual defects
  • Damaged heart valves
  • CV transplantation with cardiac valvular disease
  • Hypertrophic cardiomyopathy

Question 15

For which procedures is Subacute Bacterial Endocarditis Prophylaxis recommended?

Answer 15

• All dental/oral procedures involving manipulation/perforation of gingival tissue or oral mucosa
• Invasive respiratory tract procedures with perforation of respiratory mucosa
• Procedures involving infection of GI/GU tract, skin/musculoskeletal tissue
  
  • NOT recommended in routine GU/GI tract sx or bronch
• Hepatobiliary procedures with high risk bacteremia
• Cardiac sx

Question 16

What are the perioperative MI risks in a patient with a previous MI?

Answer 16

• General population= 0.3%
• MI > 6 months =6%
• MI if 3-6 months = 15%
• MI < 3months =30%

Question 17

Your patient has heart failure. At what point would surgery be delayed? What preoperative testing would you order for the patient?

Answer 17

• Decompensated HF/LV function is high-risk and elective sx should be postponed
  
  • NYHA Class ¾
• Diagnostics
  
  • EKG
  • CMP
  • BUN/Cr
  • BNP
    
    • < 100 normal
  • CXR- if pulmonary edema suspected
  • ECHO
  • Stress testing

Question 18

What are some reasons why you would want to obtain coronary angiography? What are some benefits and shortfalls of this diagnostic test?

Answer 18

• Coronary angiography provides the best information about the condition of coronary arteries/anatomy
  
  • gold standard for cardiac sx patient
• Indications
  
  • pt surviving sudden cardiac death
  • those considered for CABG
  • Those needing definitive dx for CAD (airline pilots)
• Usefullness
  
  • dx nonatherosclertoic CAD
    
    • Coronary sapsm
    • akwasaki’s dx
    • radiation inudced vasculopathy
• Cons
  
  • cannot predict which area of plaque are most likely to rupture and produce ACS
  • expensive
• 2014 AHA guidliens do NOT recommend routine preop coronary angiography prior to noncardiac sx without speicfic clinical indicators