CEP Exam 2

CVD includes

• coronary heart disease 

• heart failure

• hypertension 

• stroke

Approximately 50% of all CVD deaths are from

CHD

• most common

Leading cause of death in the US

Cardiovascular disease (CVD)

Every ____ someone in US suffers a heart attack

42 secs

Average age of first MI

MI caused by plaque buildup caused by free radicals

• Men: 65 (younger)

• Women: 72

  • Estrogen is cardioprotective 

    • Directly targets free radicals (limits number) that cause damage to blood vessels

  • Added protection until menopause 

Acute Coronary Syndromes fall under

Coronary Heart Disease

Acute Coronary Syndromes include

• Unstable angina pectoris (chest pain)

• Acute myocardial infarction (heart attack)

• Potentially sudden cardiac death

• Potentially sudden cardiac death 

• Abrupt loss of heart function caused by electrical disturbance to heart 

  • Time is of the essence! 

    • Restore normal sinus rhythm (AED, defibrillator) 

  • Arrhythmias → fatal 

• Electrical disturbance may be triggered by MI

  • SA node cells die → no heart beat generated

• Acute myocardial infarction (heart attack)

• Death of cardiac muscle cells due to prolonged ischemia 

  • Cardiac cells without oxygen for a long period of time → heart tissue becomes necrotic

• Unstable angina pectoris (chest pain)

• Result of ischemia (decreased blood flow / oxygen to heart) 

  • Ischemic cells → heart / chest pain (Greater amount → more severe)

• opening where blood flows through (innermost)

Lumen

• innermost layer

• Protects against atherothrombosis (plaque break off)

  • Cardioprotective: Prevents plaque buildup in arteries (NO plaque formation here)

  • Very thin: gets injured → exposes intima 

Endothelium

• thin layer of connective tissue on top of endothelium 

• Initial formation site of atherosclerotic lesions 

  • Plaque buildup starts here

Intima

• located on top of intima 

• Contains mainly smooth muscle cells along with some connective tissue 

  • Allow vasodilation / constriction of vessel 

media

• outermost layer

•  Contains connective tissue, fibroblasts, and a few smooth muscle cells 

  • Plaque buildup can reach deepest layers of vessel 

Adventitia

Atherogenesis

• creation/new formation/generation of plaque → CV issue

• disease process that may result in blood flow-limiting lesions in the

  • Epicardial coronary 

  • Carotid

  • Iliac 

  • Femoral arteries 

  • Aorta 

Pathophysiology of Atherogenesis

• (Chronic or excessive) Endothelial injury

• Inflammatory response

• Endothelial dysfunction

• Plaque formation

Progression of Atherogenesis

• rogression varies 

  • Size & volume of lesions 

  • Stability of plaque 

• Risk for embolus 

  • Due to plaque rupture or fissuring of fibrous cap 

  • Greater risk at initial stages of plaque buildup 

How are ACS diagnosed?

• History of symptoms (ex chest pain)

• Silent MI

• dyspnea (labored breathing)

• atypical symptoms (flu, shoulder pain down arm, fatigue)

Physical examination for ACS

assess for presence of multiple things (not 1 specific) - MI look dif in everyone

• BP

• Diaphoresis

• Sinus tachycardia

• Tachypnea

• New murmur of mitral regurgitation

• Pulmonary rales (crackling)

Clinical Testing for ACS

• EKG (electrocardiogram)

• Echocardiogram

• Chest x-ray

• Lab results

cardiac triad

• Chest pain persisting for >30 mins (prolonged)

• ECG showing ST-segment elevation (cell death prevents repolarization) or T-wave changes

• Presence of biomarkers of myocyte necrosis (Cardiac troponin (cTn) - heart tissue dies)

Diagnosis of Acute Myocardial Infarction

• At LEAST 2 of the cardiac triad (3 variables)

ST-segment elevation (STEMI)

• more severe 

  • Occluded coronary artery 

  • Extensive damage (more cell death)

  • Worse prognosis 

Non-ST-segment elevation (NSTEMI)

• T wave abnormalities 

• Less damage (clot dissolution) 

• Better prognosis 

Statin

• lower cholesterol 

  • Prescribed daily for rest of life

• Improves survival

Antiplatelet

• lower platelets available and limit plaque buildup (blocks aggregation, improves survival)

  • Aspirin: thin blood to minimize plaque 

  • Clopidogrel: prescribed 

Nitroglycerin

• coronary vasodilation (lumen blocked)

  • increases chance of surviving MI (does NOT stop MI)

    • Squeeze blood through plaques in BVs in body 

  • Only taken as needed (when they feel like they have MI)

  • Bad to take if not actually having MI

    • BV dilation, BP drop → pass out 

  • Take pill and call for help 

• Lower workload on heart 

  • Lower HR & BP

  • Minimize stress on heart

• Beta blocker (metoprolol)

• ACE inhibitor (lisinopril) 

• ARB (losartan)

• Aldosterone antagonist (spironolactone)

• Reperfusion therapy

• Percutaneous coronary intervention (PCI)

  • Coronary catheterization 

  • Remove / distribute plaque to outside vessel walls, open lumen, restore blood flow

    • Stent - permanent way to keep vessel open 

• Coronary artery bypass graft surgery (CABG) 

  • Most invasive - open chest cavity to open heart 

  • Bypass with healthy vessels from other body parts

Factors Associated with Poor ACS Prognosis 

• LVEF (left ventricle ejection fraction) <= 35% or congestive heart failure (CHF)

• Poor exercise capacity < 5 METs

• Evidence of extensive myocardial ischemia during exercise or pharmacologic stress testing (chest pain?)

• Complications such as renal failure, stroke

  • Kidneys involved → prognosis drops (drastically worse)

• Benefits of exercise testing after MI

• Evaluate symptoms (chest pain) & possible ischemia 

  • Ischemic threshold

• Determine need for angiography

  • Picture of vessels to see where plaque is forming 

  • Continue with surgical interventions or just meds?

• Determine effectiveness of medication therapy 

  • Correct concoction of meds

• Assess future risk & prognosis

  • inability to exercise

  • capacity < 5 METs

  • Exercise-induced ischemia 

  • Failure of SBP to increase => 10 mmHg 

• Determine exercise capacity 

Absolute Contraindications to stress testing after acute MI

• MI within prior 2 days or other acute cardiac event 

• Change in ECG suggesting MI or other acute event 

• Unstable angina 

Exercise Prescription after Acute MI

• OLD prescription

• bed rest up to 6 months 

• After heart attack / open heart surgery 

Exercise Prescription after Acute MI

• Phase 1: Inpatient (cardiac) rehabilitation 

• When hospitalized - Quick turnaround (2-3 days) to discharge 

• mobilization ASAP!

• Secondary coronary prevention (modifiable health behaviors to decrease risk of future MI)

  • Medication adherence 

  • Diet 

  • Exercise 

    • Lifestyle activity

    • Educate on cardiopreventative 

  • Tobacco cessation 

Exercise Prescription after Acute MI

• Initial home prescription (segway to phase 2) 

• Very basic, low intensity 

• Keep from doing nothing (ex 5 chair stands 3x/day) 

Exercise Prescription after Acute MI

• Phase 2: Outpatient cardiac rehabilitation

• CEP involved (supervised) 

• Minimize cardiovascular event 

exercise prescription at a minimum

• cardiorespiratory (aerobic)

  • 10 mins per bout of exercise

  • 2-3 days/week

• resistance training

  • 2-3 days/week

• flexibility & balance

  • as often as possible

• Exercise Prescription Special Considerations 

• Intensity below ischemic threshold (can use RPE vs HRR) 

  • Tolerable exercise, withstand longer duration 

• Stretching: maximize proper posture

  • Chest stretches for open heart patients 

    • incision on front, tight chest muscles, hunched over back

• Take medications on schedule for performance of exercise training sessions 

• Educate patient on importance of lifestyle physical activity

#1 Goal of clinical procedures (heart revascularization)

restore myocardial blood flow

Angiography

• “road map” to know where to intervene 

• Prior to revascularization procedures 

• Take picture of vessel (no intervening) 

• Catheter in leg & guided up aorta 

  • Tip stops at left coronary artery 

  • Contrast injected into arteries 

  • X-ray imaging shows stenosis (plaque buildup/blockage)

    • Dye unable to fill portion of vessel bc plaque present

Atherectomy

• plaque removal using blade catheter 

  • Risks - if vacuum doesn’t catch it all → pulmonary embolism 

    •  Blade can damage vessel 

Laser angioplasty

• beam vaporizes plaque into water and gas 

  • Degree of healthy tissue will die 

  • Small, narrow area

• Indications (optimal candidates for PTCA)

• 1-2 vessel involvement 

  • Minor plaque buildup

• Ejection Fraction approx > 55% 

PTCA success

• 85-90%

  • Very high!

stent therapy

• pair with coronary cath PTCA

• permanent open 

• elude drugs 

CABG Reserved for these patients

• Unsuccessful PTCA (no other choice)

• Patients are no longer candidates for angioplasty (max. At 3-4x stented)

• Multivessel disease not amenable to angioplasty or stenting 

  • > 1-2 vessels 

• Technically difficult vessel lesions (ex on curve or in distal location)

  • Not readily amenable to angioplasty or stenting 

Open-chest / FULL Sternotomy

• Most common

• Use stabilizer to hold chest cavity open 

• Dissect full sternum (cut in half) 

• Open up like a textbook 

• Give surgeon full assess & vision to heart  

  • Best interest of surgeon & patient 

  • Plaque buildup may be more involved than you think since opened 

• Right Anterior Thoracotomy

• Fastest 

• Incision between ribs 

• Access only small portion

• Mini-sternotomy 

• ONLY upper or lower half of heart 

Hypovolemia

• blood volume loss post-surgery (decreases cardiac output)

  • Seated exercises for first 1-2 weeks 

    • Recumbent bike (aerobic) 

    • Seated resistance 

most common symptom of ACS

angina (chest pain)

most common symptom of PAD

intermittient claudication

preferred PAD scale

Rutherford (subjective AND objective criteria)

most common first-line PAD diagnostic imaging test 

CT angiography 

• needs iodine contrast in IV 

can be done with or without contrast if iodine allergy

MRI angiography

• radio frequency waves give image

most common hemodynamic test

ankle-brachial index (ABI)

PRIMARY GOAL of exercise training (PAD)

increase walking distance

Goal of exercise testing PAD

define functional limitations 

• Can they walk?

• claudication threshold (stay below when exercising - time & intensity)

natural pacemaker

SA Node

stimulating contraction

atria

delays signal

AV node

AV delay

• allows ventricles to fill with blood from atrium 

ferries signal thru fibrous skeleton to interventricular septum

Bundle of His

• convey signal to apex 

R & L branches

• carry signal up thru ventricles

Purkinje fibers

• stimulating contraction from bottom upward

more life-threatening Cardiac Electrical Pathophysiology

AV conduction block (heart block)

1st pacemaker code letter

• chamber paced 

  • Receiving signal, acted on

• A, V, D, o

2nd pacemaker code letter 

•  chamber sensed

  • Sending info back to PM 

  • PM sense what’s happening in heart/body to know when to pace

• A, V, D, o

3rd pacemaker code letter

• how pacemaker responds (T, I, D, o)

  • Trigger: increase HR

  • Inhibit: decrease HR

  • Dual: can both inc AND dec 

    • Rate responsive PM 

    • R for 4th letter 

  • Off

Chrontropic assessment exercise protocol

• Very small increases in stages compared to other protocols 

• Low intensity 

• To safely determine if PM works 

  • If it is adequately responding to smaller increases in intensity

AICD: Exercise Consideration

Avoid reaching maximal shock rate