Cardiac 2.1 Flashcards
What criteria must be met to diagnose a myocardial infarction (MI)?
Rise and/or fall of cardiac biomarkers (with at least one value > 99th percentile of upper limit reference range) AND >1 of the following:
- ischemic symptoms
- new ischemic ECG changes,
- image evidence of nonviable myocardium,
- or new regional wall motion abnormalities on imaging.
What are 2 types of MI?
STEMI and nonSTEMI
What are the key features of a ST-elevation MI (STEMI)?
- Easily identified coronary lesion;
- benefits from emergent intervention such as percutaneous coronary intervention or thrombolytics.
What characterizes a Non-ST-elevation MI (NSTEMI)?
- Usually involves multiple coronary lesions
- undergo coronary angiography within days after symptoms begin following initial medical treatment and risk stratification. More common postoperatively.
What defines a Type 1 MI?
- Spontaneous
- due to primary coronary events like plaque erosion, rupture, fissuring, or dissection
- Can lead to STEMI or NSTEMI
What defines a Type 2 MI?
- Results from imbalance between myocardial oxygen supply and demand (e.g., prolonged tachycardia, coronary spasm, anemia, hypertension).
- Leads to NSTEMI only.
Why is it important to distinguish between Type 1 and Type 2 MIs?
- Type 1 MIs are spontaneous and unpredictable, requiring preoperative strategies like plaque stabilization or statin therapy.
- Type 2 MIs typically occur with stable but severe coronary artery disease.
What is systolic heart failure?
Heart failure with reduced ejection fraction.
What is diastolic heart failure?
Heart failure with normal (preserved) ejection fraction.
What is troponin levels in chronic heart failure?
sustained troponin elevation.
How is acute heart failure associated with troponin levels?
Often accompanied by acute troponin release.
How long should elective surgery be postponed after an MI?
Should be postponed 60 days post-MI.
When can elective surgery be performed in CABG patients?
May proceed after 30 days if surgery is deemed “urgent.”
How long should you wait to perform surgery after angioplasty without stents?
Benefits from 2 weeks of dual antiplatelet therapy (DAPT) before surgery.
How long should you wait to perform surgery after angioplasty with bare-metal stents?
Wait at least 4 weeks of DAPT (if no myocardial damage occurred).
How long should you wait to perform surgery after angioplasty with drug-eluting stents?
Requires 6 months of DAPT before elective surgery.
When is it safe to perform noncardiac surgery after bare-metal stent (BMS) placement?
At least 1 month post-revascularization.
When is it safe to perform noncardiac surgery after drug-eluting stent (DES) placement?
At least 12 months post-revascularization (consider 6 months with new-generation DES if risk of postponing outweighs cardiac risk).
When is it safe to perform noncardiac surgery after CABG?
At least 1 month post-CABG.
What is the minimum duration of dual antiplatelet therapy (DAPT) after BMS placement?
≥4–6 weeks.
What is the minimum duration of DAPT after DES placement?
≥6–12 months (≥12 months in high thrombosis risk situations).
What is the DAPT duration for patients with acute coronary syndrome (ACS) and any stent?
≥12 months.
When should you hold antiplatelet therapy for surgery in a high bleeding risk patient with a BMS?
If <4 weeks, bridge; if >4 weeks, hold 7 days.
When can antiplatelet therapy be continued for low/moderate bleeding risk surgery after BMS?
4 weeks: continue SAPT.
What are some key considerations before surgery in patients with revascularization?
- Completeness of revascularization
- stent location in coronary tree
- left ventricular function
- type/length of procedure
What questions help assess a patient’s functional capacity before surgery?
- “Can you climb two flights of stairs without stopping and without chest pain or shortness of breath?”
- “Can you walk two to four blocks without chest pain or shortness of breath?”
What does METs >4 indicate?
Low MACE (major adverse cardiac events) risk during most surgeries.
When is a pre-op ECG indicated?
- History or risk factors of CAD
- abnormal heart rates
- arrhythmias, or conduction defects.
Does a pre-op ECG predict perioperative MACE?
No, it is not predictive.
According to ACC/AHA guidelines, who should get a pre-op ECG?
- Patients with known coronary heart disease
- significant arrhythmia
- peripheral arterial disease
- CVA
- structural heart disease
Is pre-op ECG indicated for low-risk surgeries?
No.
When is a pre-op echocardiogram indicated?
When a clinical question arises based on history, physical, ECG, or chest x-ray (e.g., suspected valvular disease, ventricular dysfunction, pulmonary hypertension, cardiomyopathies).
What patient conditions warrant an echocardiogram preoperatively?
Poor functional capacity, myocardial dysfunction, or valvular disease.
Is routine pre-op echocardiography recommended?
No.
Is echocardiography useful to evaluate CAD or predict perioperative MI?
No, it is not useful for CAD evaluation and not predictive of perioperative MI.
What does an exercise stress test detect?
Myocardial ischemia based on a protocol with gradual physical exertion on a treadmill.
What does an exercise stress test determine?
- Functional capacity in METs
- hemodynamic response to exercise
- ischemia on continuous ECG
What does it mean if a patient reaches 85% predicted heart rate during an exercise stress test without ischemic ECG changes?
Further testing prior to surgery is not indicated.
What is the main disadvantage of an exercise stress test?
Unsuitable for patients with low effort capacity (vascular, orthopedic, neurological issues, or abnormal ECG).
What other cardiac tests might you see besides exercise stress testing?
- Myocardial perfusion imaging
- stress echocardiography
- PET scan
- cardiac MRI
- CT coronary angiography
What medications are considered in preop risk assessment?
- Antiplatelet therapy
- statin therapy
- antihypertensive therapy
What lifestyle factor is also part of risk assessment?
Lifestyle modifications.
How is heart failure defined?
Impaired ventricular filling or limited ejection resulting in insufficient cardiac output to meet metabolic demands.
What are secondary counterregulatory responses in heart failure?
- Sodium and water retention,
- sympathetic nervous system activation
- and activation of the renin-angiotensin-aldosterone system (leading to vasoconstriction, edema, arrhythmia)
How is heart failure categorized?
By left ventricular ejection fraction (LVEF).
What classifies as diastolic heart failure?
Heart failure with preserved ejection fraction (normal LVEF).
What classifies as systolic heart failure?
Heart failure with reduced ejection fraction (<40%).
What LVEF percentage defines reduced ejection fraction (HFrEF)? and what type of HF is that?
≤40%.
Systolic HR
What LVEF percentage defines preserved ejection fraction (HFpEF)? and what type of HF is that?
Diastolic HF, with EF ≥50%, with additional criteria from echocardiography.
* LA volume index >34 ml/m2
* septal e’ velocity <7 cm/s, or lateral e velocity <10 cm/s
* average E/e ratio >14
* TR velocity >2.8 m/s
What are the objectives in preoperative evaluation for heart failure?
- Assess compensation
- determine cause
- identify comorbidities
- exclude new diagnosis
- determine level of activity that elicits HR
- confirm therapy adherence
- plan coordination of care
What is New York Heart Association (NYHA) Class I heart failure?
No limitation of physical activity; ordinary activity does not cause fatigue, palpitations, or dyspnea.
What is NYHA Class II heart failure?
Slight limitation of physical activity; comfortable at rest, but ordinary activity causes fatigue, palpitations, or dyspnea.
What is NYHA Class III heart failure?
Marked limitation of physical activity; comfortable at rest, but less than ordinary activity causes symptoms.
What is NYHA Class IV heart failure?
Unable to perform any physical activity without discomfort; symptoms present even at rest.
What labs are important to check with HF?
- CBC
- Chemistry (CMP)
- PT
- BNP
Why is a CBC important in heart failure patients preoperatively?
Anemia increases postoperative mortality risk twofold.
What do chemistries help assess in heart failure patients?
Electrolyte abnormalities and renal function.
What does a prolonged PT in heart failure indicate?
Possible liver congestion.
What causes BNP to be released? What is BNP level indicates HF?
Myocardial wall stretching.
* 0-100 (pg/mL) = HF unlikely
* 400 (pg/mL) = HF likely
What BNP level indicates heart failure is unlikely?
0–100 pg/mL.
What BNP level suggests heart failure is likely?
≥400 pg/mL.
When might an ECG be useful in heart failure evaluation?
- To confirm arrhythmia causing heart failure.
- Routine EKG not indicated
When is echocardiography indicated in heart failure?
New or worsening symptoms, suspected pulmonary hypertension, or no prior diagnosis.
When is chest radiography recommended in heart failure?
New, suspected, or decompensated heart failure.
What are the differential diagnoses for heart failure?
- MI,
- chronic lung disease,
- pneumonia,
- anemia,
- pulmonary embolus,
- deconditioning,
- depression,
- sleep-disordered breathing.
What are key components of heart failure optimization?
- Treat hypertension
- control heart rate
- manage arrhythmias
- diurese for symptoms
- correct anemia
- treat underlying causes
What medications indicated to treat HF?
- ARB, ACEI, Angiotensin II Inhibitors
1. Continue until 1 day before surgery
1. Resume within 48 hours - Beta Blockers
1. Continue day of surgery
1. Do not initiate just prior to surgery
What is the normal classification of blood pressure?
120/80 mm Hg.
What is the range for prehypertension?
120–139 / 80–89 mm Hg.
What is considered hypertension?
≥140/90 mm Hg.
What is the range for stage 1 hypertension?
140–159 / 90–99 mm Hg.
What is the range for stage 2 hypertension?
≥160/100 mm Hg.
What are secondary causes of hypertension?
- Chronic kidney disease
- coarctation of the aorta
- endocrine disease, primary aldosteronism
- thyroid/parathyroid disease
- pheochromocytoma
- medications
- obstructive sleep apnea
What are some organs affected by end-organ damage due to hypertension?
- Eye (papilledema, retinopathy),
- brain (stroke, TIA),
- heart (LVH, MI, HF),
- kidneys (CKD),
- peripheral vasculature (PAD).
At what BP value might surgery be canceled due to hypertension?
Around 180/100 mm Hg.
Why should aggressive hypertension treatment just before surgery be avoided?
It can lead to poor outcomes.
What should be done for a new murmur before surgery if high risk findings are present?
Obtain formal transthoracic echocardiography.
What findings suggest a murmur is likely innocent and requires no further testing?
Soft systolic murmur ≤II/VI, no concerning findings on exam, CXR, or ECG, and no cardiac/pulmonary symptoms.
What murmur is described as a midsystolic crescendo-decrescendo?
Aortic stenosis.
Heard best at right upper sternal border
midsystolic
Aortic regurgitation
- early diastolic
- heard at the left sternal border,
- increases with handgrip or BP cuff inflation
Where is mitral stenosis best heard and what is the associated finding?
- At the apex;
- associated with an opening snap after S2 and loud S1.
- mid-diastolic
Mitral regurgitation
- is holosystolic
- at the apex
- radiates to the left axilla?
What are types of stenotic valvular disease?
- Aortic stenosis (most common)
- mitral stenosis.
What is the preoperative management step if a patient has symptomatic severe aortic stenosis?
Consider intervention before elective non-cardiac surgery.
What are the types of mitral regurgitation?
Primary and secondary.
What are two key features of aortic regurgitation in the surgical context?
Patients usually present to have it fixed and may require invasive monitoring.
What murmur is midsystolic crescendo–decrescendo at the right upper sternal border and increases with squatting?
Aortic stenosis.
What murmur increases with squatting and decreases with Valsalva and standing?
Aortic stenosis.
What murmur radiates to the carotids and may have an ejection click?
Aortic stenosis.
What murmur is early diastolic at the left sternal border and increases with handgrip?
Aortic regurgitation.
Which murmur may also have a systolic murmur due to increased stroke volume?
Aortic regurgitation.
What murmur is mid-diastolic at the apex and increases with tachycardia?
Mitral stenosis.
What murmur has an opening snap after S2 and radiates to the left axilla?
Mitral stenosis.
What murmur is holosystolic at the apex and increases with handgrip?
Mitral regurgitation.
Which murmur radiates to the left axilla and is high-pitched?
Mitral regurgitation.
What murmur is holosystolic at the lower left sternal border and increases with inspiration?
Tricuspid regurgitation.
What murmur is associated with prominent jugular venous distention and signs of right heart failure?
Tricuspid regurgitation.
What murmur is late systolic at the apex and increases with Valsalva or standing?
Mitral valve prolapse.
What murmur is midsystolic at the lower left sternal border and increases with Valsalva or standing?
Hypertrophic cardiomyopathy.
Which murmur has no associated aortic regurgitation murmur or ejection click?
Hypertrophic cardiomyopathy.
What murmur is midsystolic crescendo–decrescendo at the left sternal border and may increase with exercise?
Functional murmur.
Which murmur has no associated findings?
Functional murmur.
Heard at midsystolic crescendo-decrescendo
