Coronary Artery Disease and Valvular Disorders

atherosclerosis

abnormal accumulation of lipid deposits and fibrous tissue within arterial walls and lumen

what is the leading cause of MI?

CAD

CAD prevention

Control cholesterol

Dietary measures

Physical activity

Medications

Cessation of tobacco use

Manage HTN

Control diabetes

medications for CAD control

▪Statins

▪Fibrates

▪CAIs

▪PCSK9 inhibitors

statins

lower cholesterol in the blood and reduce its production in the liver by blocking the enzyme that produces it (LDL)

'-statin'

statins side effects

GI upset: nausea, abdominal pain, diarrhea

Headache

Rash

Myopathy / rhabdomyolysis

Hepatotoxicity

Fibrates

activate PPAR-α → ↑ LPL → ↓ triglycerides and ↑ HDL

gemfibrozil

fenofibrate

cholesterol absorption inhibitors

Ezetimibe

Lowers cholesterol by inhibiting absorption in small intestine

Side effects: hepatotoxicity and muscle pain

Monitor liver function and CK levels

PCSK9 inhibitors moa

Inactivation of LDL-receptor degradation, increasing amount of LDL removed from bloodstream

Alirocumab (Praluent)

Evolocumab (Repatha)

acute coronary syndrome

umbrella term characterized by an acute onset of myocardial ischemia that results in myocardial death (i.e., MI) if definitive interventions do not occur promptly

can turn into infarction

myocardial infarction

the occlusion of one or more coronary arteries caused by plaque buildup (heart attack)

STEMI

ST-segment elevation myocardial infarction

NSTEMI

Non ST segment elevation MI; a heart attack that is not diagnosed on the EKG but is diagnosed by an elevated troponin on blood test

lateral leads

I, aVL, V5, V6

left circumflex or diagonal of LAD

inferior leads

II, III, aVF

Right coronary and/or left circumflex artery

anterior/septal leads

V1, V2, V3, V4

Left anterior descending artery

s/s of ACS

radiating chest pain

dyspnea

dizziness

nausea/vomiting

diaphoresis

dizziness

extreme fatigue (more common in women)

diagnostics for ACS

ECG

Cardiac biomarkers: CK-MB, troponin, high-sensitivity troponin

normal CK-MB

0-3 ng/mL

normal troponin

<0.5 for Troponin 1 and <0.1 for Troponin T

acute interventions for ACS

ASA: reduces platelet aggregation; 160-325mg

Morphine: pain reducer and reduces vasospasms

O2: non-rebreather

Nitroglycerin: vasodilator

Heparin: blood thinner; reduces oxygen demand of the heart (high dose IV drip protocol)

invasive interventions for ACS

▪PCI / Heart Catheterization (door to balloon time of 90 minutes is optimal)

▪PTCA

▪PTCA With Stenting

▪Thrombolytic (Firbinolytic) Therapy (Activase, TPA)

▪CABG

thrombolytic therapy for ACS

high risk for bleeding

can be used if pt has multiple areas of infarction

chest pain assessment

P-precipitating events

Q-quality

R-radiation

S-severity (0-10)

T-timing

PTCA

percutaneous transluminal coronary angioplasty

can be done with or without stenting

commonly inserted through femoral artery or vein

right PCTA

right side of the heart; venous access from vena cava; mostly used for assessment using contrast agents

left PTCA

left side of the heart; interventional; through aorta and into the left side

fem stop

puts pressure on femoral artery to help clot to form

TR band

Compression device to assist hemostasis of the radial artery after transradial procedure

Patient can get up right after procedure

Left on patient for 24 hours without air

PCI considerations

▪Allergies: shellfish/iodine (pre medication with solucortef/solumedrol; corticosteroid and diphenhydramine antihistamine)

▪Medications

▪Comorbidities: renal conditions (contrast is hard on kidneys)

▪Post-Care: watching site for bleeding, bedrest, checking pulses on extremities, draw blood for activated clotting time

CABG

Coronary Artery Bypass Graft, "Open heart surgery"

used only when PCTA cannot be used: significant occlusions in multiple areas

can be a single or multiple bypass

off pump CABG

chest is opened

mechanical device used to steady heart

aka beating heart bypass grafting

slightly lower risk of complications

On-pump CABG

uses extracorporeal circulation

▪Allows artificial pumping/oxygenation in order to MD to perform operation

CABG post op care

Airway: intubated and sedated

Central line: for medications and CVP (right atrial pressure)

Medications: epi/norepi, fluids, insulin, antibiotics, blood

Swan-ganz catheter: right ventricular and pulmonary artery pressure

Art line: for ABGs and vital signs

Continuous ekg: common to use 12 leads

Pacing wires: may have to increase HR

Chest tubes: check often

SCDs: even if lower extremety graft was taken

Urinary catheter: strict Is/Os

nursing care of chest tubes

-mark level of drainage

-observe integrity

-check air vent

-coil tubing

-secure system upright position

avoid lifting system above pts chest

-encourage ambulation and position change

-cough and deep breathing

-sit up right

-assess dressing

-assess drainage system

common graft sites for CABG

internal mammary artery: best due to proximity to the heart

greater saphenous vein: in lower leg

CVP monitoring

∙ Measures the pressure in the vena cava and right atrium

∙ Normal CVP (post open heart) = wide variations, but somewhere between 2 - 10 mmHg

•This # varies based on fluid volume status.

∙ Elevated CVP indicates increased right ventricular preload; most often secondary to hypervolemia

∙ Decreased CVP indicates reduced right ventricular preload; most often secondary to hypovolemia

pulmonary artery pressure monitoring

∙ Measures right ventricular function

∙ Normal Pulmonary Artery Pressure

  Systolic =  18 – 25 mmHg (MAP around 15)

  Diastolic = around 10 mmHg

∙ Elevated PAP indicates Pulmonary HTN, sometimes pulmonary embolism

∙ Catheter (Swan Ganz) is inserted through sterile procedure by a trained provider and covered with sterile dressing

CABG complications

▪Bleeding

▪Arrhythmias

▪Clots

▪Hypotension

▪Dehydration

▪Pain

valve regurgitation

back up of blood flow due to valves not closing completely

valvular stenosis

reduction of blood flow through valves due to narrowing causing incomplete opening of the valve

valve prolapse

one or more cusps will protrude in the wrong direction resulting in backflow

Semilunar and tricuspid: have three leaflets

Mitral: only bicuspid

mitral valve prolapse

Part of one or both mitral valve leaflets slide back into the atrium during systole causing blood to regurgitate from the left ventricle into the left atrium; usually both leaflets

Can be hereditary; increases risk for infective endocarditis

treatment of mitral valve prolapse

none for mild cases, medication to treat symptoms, surgery to repair

mitral valve regurgitation

During systole, blood "backflows" from left ventricle to left atrium during systole

Leads to increased systolic pressure in the left atrium; can lead to left atrial enlargement due to the atria working harder to pump into the ventricle

s/s of mitral valve regurgitation

Asymptomatic for years. Fatigue, dyspnea, orthopnea, murmurs (grade 3 or higher) and occasional palpitations

treatment of mitral valve regurgitation

Ace/ARB: vasodilation

BB: lower heart contractility

Surgery (valvuloplasty or valve replacement if severe enough)

aortic regurgitation

flow of blood backward from the aorta into the heart; caused by a weak heart valve

usually secondary to to endocarditis, congenital defect, syphilis, aortic abnormalities

complications of aortic regurgitation

hypertrophy of the left ventricle, systolic HF

ACE inhibitors

"PRIL" Captopril, Enalapril, Afosiopril

Antihypertensive. Blocks ACE in lungs from converting angiotensin I to angiotensin II (powerful vasoconstrictor). Decreases BP, Decreased Aldosterone secretions, Sodium and fluid loss.

Check BP before giving (hypotension)

*Orthostatic Hypotension

ARBs

Angiotensin II Receptor Blockers

'-sartan'

Treatment of aortic regurgitation

valve replacement once LV dysfunction develops

ACE inhibitors, BB, lifestyle modification, and stress reduction

aortic stenosis

- Narrowing/hardening of aortic valve (calcification); does not close or open properly

causes of aortic stenosis

-congenital defect

-degenerative changes (CAD, HTN, cardiomyophathy)

-rheumatic endocarditis

treatment of aortic stenosis

valve replacement after onset of complications

BB, ARBs, ACE

valvuloplasty

surgical repair of a valve

* Commissurotomy - repair of the commissure (area where the leaflets connect)

* Annuloplasty - repair of the annulus

* Leaflet Repair - repair of the leaflets

* Chordoplasty - repair of the chordae tendineae

types of valve replacements

* Open (sternotomy)

  * Secondary Approach: more common

      - TAVI (Transcatheter Aortic Valve Implantation)

      - TAVR (Transcatheter Aortic Valve Replacement)

types of artificial valves

  * Mechanical: more prone to blood clotting

  * Tissue:

       - Bioprostheses: pig or cow    

   - Homograft: from a cadaver       

   - Autograft: a leaflet from another valve of the same person

post valve replacement care

* Anticoagulation therapy

* Warfarin - lab maintenance and dietary restrictions

* Prevention of infective endocarditis

* Antibiotic prophylaxis prior to dental procedures or surgery

* Follow up

* Cardiologist

* CT surgeon

* Cardiac rehab

* Repeat echocardiograms