2- ischemic heart disease + cardiac arrhythmias

definition of atheroscleoris

inflammatory disorder affecting lining of arteries + development of plaque in the walls of arteries → narrowing of the vessel lumen → decreases capacity for blood flow + oxygen delivery

8 modifiable risk factors of atherosclerosis

1. HTN

2. smoking

3. physical inactivity

4. high sugar + starch diet

5. obesity, insulin resistance, diabetes

6. hyperlipidemia

7. stress + depression

8. infections + systemic inflammation

4 non-modifiable risk factors of atheroscleoris

1. age

2. gender

3. family hx

4. genetics

how atherosclerotic plaque forms

endothelial damage → monocytes adhere to injury site → become macrophages that engulf lipids → become foam cells → fatty streak formation → inflammatory response to foam cells → proliferation of smooth muscle + collagen → fibrous cap formation

what happens if this fibrous cap ruptures

allows Tissue Factor (TF) to come into contact w/ circulating blood → thrombus formation on top of plaque

limitation in oxygen supply may occur when the coronary artery reached __% stenosis due to plaque growth

75%

most symptomatic ischemia is due to

disruption/fracture of plaque

4 structures most commonly affected by atherosclerotic plaques

1. brain → vascular dementia

2. aorta

3. peripheral arteries

4. heart: most commonly proximal L anterior descending artery

what’s angina pectoris

sensation of aching, heavy, squeezing pressure, or tightness in the midchest region that may radiate into the shoulder, L/R arm, neck, or lower jaw aka “crushing substernal chest pain” that lasts 5-15 min

T/F: angina can occur w/o chest pain

true, but very rare

how is angina relieved

nitroglycerin administration

what differentiates stable vs. unstable angina

• stable: intact plaque, reproducible + consistent, good prognosis

• unstable: ruptured plaque → clot/thrombus formation w/ rapid expansion of lesion → blockage of blood flow to heart

how does nitroglycerin relieve angina

direct vasodilator:

1. decreases cardiac load → decreasing cardiac oxygen demand

2. coronary artery vasodilation

nitroglycerin should absolutely not be taken w/ this med

viagra (sildenafil) → fatal hypotension

to take nitroglycerin, BP must be

minimum 90/60

3 other drug classes for medical management of angina

1. beta blockers: decreases HR + contractility

2. Ca channel blockers: decreases intracellular Ca → vasodilates, decreases contractility + HR

3. ACE inhibitors + ARBs

after an MI, pts usually take which meds

antiplatelets

T/F: myocardial infarction is the same thing as cardiac arrest

false, myocardial infarction can → ventricular fibrillation → cardiac arrest

unstable angina + myocardial infarction are a part of

acute coronary syndrome

ischemia vs. infarction

• ischemia: reduced blood flow → oxygen deprivation

• infarction: necrosis due to prolonged blockage of blood flow

presentation of myocardial infarction

lasting >15 min w/ increasing severity:

1. crushing substernal chest pain radiating to shoulder, L/R arm, neck, mandible, teeth

2. does not respond to nitroglycerin or rest

3. cough

4. shortness of breath

5. diaphoresis (profuse sweating)

6. dizziness

7. syncope

8. fatigue

9. palpitations

T/F: some women do not present w/ chest pain during myocardial infarctions

true, present w/ fatigue, dyspnea, GERD

myocardial infarction diagnosis requires what 2 things

1. EKG

2. serum cardiac enzymes: troponins, creatinine kinase, myoglobin

tx of myocardial infarctions depends on what

extent of infarct:

1. ST elevation MI (STEMI): complete blockage + profound ischemia

2. non STEMI: partial blockage

management of STEMIs

early fibrinolytic therapy or revascularization via:

1. percutaneous coronary angioplasty

2. stents

2 types of stents

1. bare metal: physical scaffold

2. drug eluting: coated w/ antiplatelet meds

pts w/ drug eluting stents require 1 year of what medication

antiplatelet

T/F: pts w/ drug eluting stents are advised to pause routine/elective dental care

true

T/F: pts w/ ischemic heart disease, coronary artery stents, CABG surgery require antibiotic prophylaxis

false

what should you avoid when anesthetizing pts w/ hx of heart disease

limit to 2 carp of 1:100k epi at a time

definition of cardiac arrhythmia

any variation of normal heartbeat

3 types of cardiac arrhythmias

1. supraventricular: arises above bundle of his

2. ventricular: originates in ventricles

3. repolarization disorders

most common sustained cardiac arrhythmia

atrial fibrillation (A-fib)

define what’s going on during A-fib

rapid disorganized + ineffective atrial contractions w/ irregular ventricular response

A-fib results in blood pooling where

in L atrium → thrombus formation → embolism, therefore A-fib is a major risk factor for strokes

what’s Virchow’s Triad

3 events that will highly likely result in a blood clot:

1. endothelial damage

2. stasis of flow (ex: A-fib)

3. hypercoagulable state

4 risk factors of A-fib

1. cardiovascular factors: HTN, CAD, valvular disorders, CHD

2. excessive alcohol

3. tobacco use

4. advanced age

signs/symptoms of A-fib

1. tachycardia: “irregularly irregular”

2. palpitations

3. exercise intolerance

4. angina possible

5. CHF symptoms (Shortness of breath, peripheral edema)

6. TIA or stroke may be first sign

2 goals of A-fib medical management

1. prevent systemic complications due to uncontrolled tachycardia

   1. rhythm control via cardioversion (electric shocks)

   2. rate control via beta blockers

2. prevent thrombus formation via anticoagulants

5 common anticoagulants

1. Warfarin (coumadin)

2. Dabigatran

3. Rivaroxaban

4. Apixaban

5. Edoxaban

3 types of ventricular arrythmias

1. premature ventricular complexes (PVCs): abnormal QRS complex (not concerning w/ no underlying heart problems)

2. ventricular tachycardia (v-tach): can result in hemodynamic instability + seen after an MI

3. ventricular fibrillation (v-fib): lethal, commonly follows an MI + requires immediately defibrillation

recurrent ventricular tachycardia (v-tach) may require implantation of what device

implantable cardioverter-defibrillator (ICD)

considerations for pts taking warfarin (coumadin)

pts taking warfarin must present an INR lab test that was taken max within last 48 hrs before receiving any dental tx

for pts w/ pacemakers + ICDs, you should avoid which procedures

electrosurgery

avoid prescribing ____ to pts taking anticoagulants

NSAIDs