Medicine (Cardiovascular) Flashcards
What is hypertension?
-Persistently elevated arterial blood pressure of 130/80 in adults.
-Diagnosed by 2 elevated readings of at least 130/80 on 2 or more visits
What are the stages/classification of HTN?
-Normotension: <120/80
-Elevated: 120-129/<80
-Stage I: 130-139/80-90
-Stage II: >140/90
What are the types of hypertention?
-Essential hypertension: No identifiable cause (most common). Assoc
-Secondary hypertension: From an identifiable cause (pheochromocytoma, renal artery stenosis, cushing syndrome, pregnancy)
What are the sequelae of HTN?
-Left ventricular hypertrophy
-Ischemic heart disease
-CVA
-CHF
-Renal insufficiency
How is HTN treated?
-Secondary HTN: Treat underlying cause.
-Lifestyle modification: Weight loss, smoking cessation, decreased sodium intake, exercise
-Pharmacologic: Ca channel blocker, Ace inhibitor, ARBs, beta blockers, thiazide diuretics, alpha 2 agonists
How do ACE inhibitors and ARBs work?
-ACE inhibitor: Block conversion of angiotensin I to angiotensin II. Angiotensin II responsible for vasoconstriction
-ARBs: Block angiotensin II receptors. Leads to decreased vasoconstriction and aldosterone secretion
How do beta blockers work?
What are examples of selective vs non-selective beta blockers?
-Block b-adrenergic receptors. Results in decrease in myocardial contractility and decrease in renin productino. Relaxes smooth muscles
-Selective beta 1 blockers: Atenolol, esmolol, metoprolol (A-M)
-Non selective beta blockers (b1, b2): L-P and carvedilol (propranolol, timolol, sotalol)
How does clonidine work?
-A2 agonist
-Central adrenergic receptors leading to decreased norepinephrine release (sedation, decreased BP, ADHD and other applications)
What are anesthetic considerations for HTN patients?
-Pre-op ECG, CBC, BMP
-Intraop monitoring of EKG and BP
-Limit epi in local to 0.4 mg
-Avoid ketamine
-Watch for intra-op hypotension due to meds pt is taking
What is atherosclerosis?
-Hardening of arteries due to lipid accumulation within arterial wall
What are risk factors for atherosclerosis?
-Genetics, dyslipidemia, tobacco, HTN, DM, metabolic syndrome
What are complications of atherosclerosis?
-Embolization of atherosclerotic plaque to distant site causing infarction (CVA)
-Weakening of vessel wall leading to aneurysm
-Peripheral artery disease
-Renal artery stenosis
-MI
What is ischemic heart disease?
-Disease process secondary to stenotic coronary arteries that leads to ischemic sequelae from a myocardial oxygen supply and demand imbalance
What is stable angina?
-Transient chest discomfort due to a fixed atheromatous plaque secondary to a myocardial oxygen supply and demand imbalance
What are symptoms of stable angina and how is it worked up?
-Dyspnea on exertion, chest pain. Symptoms occur at 70% stenosis
-EKG may show ST depression or wave inversion, stress test to assess cardiac reserve, echocardiogram to assess wall function, coronary angiography to assess stenotic coronary arteries
What is acute coronary syndrome?
-Disease process along a continuum secondary to a ruptured atherosclerotic plaque with subsequent formation of a thrombus within the coronary vessel
What is unstable angina?
-Chest pain not relieved by rest.
-Occurs secondary to a coronary thrombus that is partially occlusive
-May see ischemic changes on EKG
What is a STEMI and NSTEMI?
-NSTEMI: Partially occlusive thrombus results in a subendocardial infarction. Elevated biomarkers are seen
-STEMI: Occlusive thrombus resulting in a trasnmural infarct. Will see ST elevations and biomarkers
What are complications of an MI?
-Can lead to fatal arrhythmias, conduction blocks, cardiogenic shock, wall rupture, heart failure
How is ischemic heart disease treated?
-Nitrates: Cause venodilation and decrease preload, dilates coronary arteries
-beta blockers/calcium channel blockers: Decrease oxygen demand by decreasing heart rate and contractility
-Percutaneous coronary intervention (Cath lab): Stent placed at stenotic coronary vessel
What are drug eluding stents and bare metal stents?
-Used to increase patency of the coronary vessel
-Bare metal stents decrease rate of epithelialization but are thrombogenic (need longer anticoagulation)
When is a CABG completed?
-Coronary artery bypass grafting
-Graft done to bypass obstructive coronary vessels
-Preferred for multivessel disease
What is the acute treatment for an MI?
-Morphine: Analgesia/anxiolysis
-Oxygen: Increase oxygen supply to myocardium
-Nitrates: Improve coronary flow
-Aspirin: Decrease platelet aggregation
-Beta blocker: Decrease myocardial oxygen demand
-Transfer to hospital for PCI and stent deployment vs fibrinolytic therapy
Why are clopidogrel, prasurgrel and ticagrelor used s/p MI?
-ADP receptor inhibitors (prevent platelet aggregation).
-Used to prevent coronary thrombosis
What are METS and why are they important in pre-op work-up?
-Metabolic equivalents
-Helps with risk stratification of functional capacity.
-METS less than 4 concerning for treatment
What are anesthetic considerations for IHD patients?
-Pre-op optimization, EKG, etc
-Non-cardiac surgery can be carried out 6 weeks after an episode of ACS
-Maintain HR and BP within 20% of pre-op
-Anxiolysis
-Limit epi 0.04 mg
-Avoid ketamine
How much epi is in each mL of 1:100k anesthetic?
-0.01 mg/mL
What is CHF?
-Condition characterized by the inability of the heart to pump enough blood to meet the metabolic demands of the body
-Compensatory: Body increases sympathetic tone to decrease pulmonary congestion and fluid retntion
-Decompensated: Pulmonary and systemic congestion
What is the difference between systolic and diastolic heart failure?
-Systolic: Impaired contractility of the heart, high afterload. EF <40%
-Diastolic: Impaired diastolic relaxation or ventricular filling (left ventricular hypertrophy). EF >50%
What are classifications of CHF?
-New York Heart Association
-Class I: Heart disease, no limitations on physical activity
-Class II: No symptoms at rest, slight limitation of activity
-Class III: Marked limitation of activity with minimal exertcion
-Class IV: Symptoms at rest. Severe limitation of activities
What is the work-up of a CHF patient?
-EKG
-Echo
-CXR
-Clinical exam
-BNP, BMP, LFT, lipid pannel, glucose, CBC, TSH
How is CHF treated?
-Diuretics: Decrease systemic and pulmonary congestion
-Beta blockers: Decrease myocardial oxygen consumption
-Digoxin: Increase cardiac contractility
-ACE inhibitor: Decrease afterload
-Nitrates: Decrease preload
-Ventricular assist devices
What are anesthetic considerations of a CHF patient?
-Supplemental oxygen
-Pre-op labs
-Avoid NSAIDs (renal failure)
-Avoid fluid overload
-Avoid drugs that depress myocardial activity or increase myocardial oxygen consumption
What is mitral stenosis?
-Decrease in the size of the mitral valve orfice resulting in decreased blood flow across the valve during diastole and increased arterial pressures and volume
What is the treatment of mitral stenosis?
-Diuretics to decrease left atrial pressure
-Control heart rate
What is mitral regurgitation?
-Backflow of blood across mitral valve during systole.
-Leads to increased atrial pressure and decreased stroke volume/cardiac output
What is treatment for mitral regurgitation?
-ACE inhibitor, beta blockers, biventricular pacing
-Decrease afterload (with vasodilators)
-May need mitral valve surgery (repair vs replacement)
What is mitral valve prolapse?
-Prolapse of one or more mitral leaflets into the atrium during systole.
-Can occur with or without regurgitation
What is the treatment for MVP?
-Beta blockers and SSRIs
-Mitral valve repair
What is aortic stenosis?
-Decrease in aortic valve resulting in obstruction of blood flow into the aorta and increased left ventricular pressures
How is aortic stenosis managed/treated?
-Medical management
-Valve replacement if symptomatic or severe aortic stenosis (bioprosthetic or mechanical valves)
What is aortic regurgitation?
-Disease of the aortic leaflets or root resulting in backflow of blood across the aortic valve into the left ventricle during diastole
What is the treatment for aortic regurgitation?
-Reduce afterload
-Surgical replacement before permanent left ventricular dysfunction
What is tricuspid regurgitation?
-Backflow into the right atrium during systole
How is tricuspid regurgitation treated?
-Diuretics
-Medical management
-Rarely surgical
What is tricuspid stenosis?
-Decreased blood flow across valve, increased right atrial pressure
How is tricuspid stenosis treated?
-Relieve fluid congestion with diuretics
-Bioprosthetic valves preferred for surgical correction
What is pulmonic regurgitation?
-Backflow across valve into right ventricle during diastole
How is pulmonic regurgitation treated?
-Rarely needs treatment
-Sometimes valve replacement
What is pulmonic stenosis?
-Obstruction of flow into pulmonary arteries, causes increased right ventricular pressures
How is pulmonic stenosis treated?
-Balloon valvotomy
What are general recommendations for patient management of valvulopathies?
-Consultation with cardiologist or PCP to understand underlying pathology and severity
-Fragile patient, decreased cardiac reserve
-Avoid tachycardia and anxiety
What are anesthetic considerations for mitral valve stenosis?
-Avoid excessive fluid administration
-Avoid trendelenburg
-Avoid and manage tachycardia
-Avoid ketamine
-Control blood pressure to decrease afterload
Maintain fluid, HR, BP
What are anesthetic considerations for mitral valve regurgitatino?
-Normal or slightly increased HR
-Bradycardia bad. Avoid increase in systemic vascular resistance.
Slightly increased HR, BP low to normal. Keep things moving forward
What are anesthetic considerations for aortic stenosis?
-Avoid hypotension
-Preserve cardiac output
-Avoid ketamine and propofol
Need to be extremely careful with these patients
What are anesthetic considerations for aortic regurgitation?
-HR above 80 bpm
-Avoid increase in systemic vascular resistance
-Keep things moving forward with HR and decreased BP
What happens with a transplanted heart?
-Denervation
-Can’t use atropine, digoxin, glycopyrolate
-Ephedrine has decreased effect
-Need to use epinephrine, dopamine, norepinephrine or beta blockers
