MI’s
Describe the pathophysiology of myocardial infarctions.
What is:
-Myocardial tissue is abruptly and severely deprived of oxygen
-occurs when blood flow is reduced by 80-90%
-usually begins in the subendocardial layer of the cardiac muscle
Describe what is meant by coronary artery disease.
What is:
-includes chronic stable angina and acute coronary syndrome
-can lead to ischemia and infarction
Describe the necessary interventions for the Killip system heart failure classifications.
-Class I: nitrates, diuretics, monitor urine output, vitals, s/s of HF, and serum K+
-Class II and III: Nitroprusside or Nitroglycerin, positive inotropes, ARBs, ACEIs
-Class IV (cardiogenic shock): diuretics, Nitro, O2, intubation, mechanical ventilation
Explain the pharmacology of fibrinolytics.
What is:
-given prior to PICI, only for a STEMI
-given within 30 mins of arrival
-tissue plasminogen activator
-ex) reteplase, enecteplase
-most effective within 6hrs of MI
-contraindications: hx of head bleed, active bleeding, significant trauma within 3mths
Explain the process of a coronary artery bypass graft (CABG).
-most common surgery for older adults
-an occluded artery is bypassed with the patient’s own venous or arterial blood vessel, or a synthetic graft. Most commonly used is the mammary artery.
-Cardiac arrest is induced so that the bypass provides oxygenation and circulation.
-The patient experiences hypothermia, with a core temp of 95F, to decrease metabolic rate and O2 demand.
List the clinical manifestations of an MI.
What is:
-diaphoresis
-chest pain (unless diabetic)
-weakness, SOB
-stress, denial, anxiety, fear
-depression, anger
-tachycardia, increased temperature
-BP that is initially high then declines
List the modifiable and nonmodifiable risk factors for CAD.
What is:
-nonmodifiable: genetics, gender, age
-modifiable: smoking, poor diet, high cholesterol, obesity, lack of exercise, alcohol, stress, diabetes
List the clinical manifestations of HF.
What is:
-decreased cardiac output
-edema, JVD
-crackles, wheezing
-S3 heart murmur
-tachypnea, frothy sputum
List and describe the medications used to increase tissue perfusion.
What is:
-aspirin: inhibits platelet aggregation
-GP inhibitors: prevent platelet aggregations and thrombus formation
-antiplatelets: Plavis, Eloquis
-statins: decrease hyperlipidemia
-ACEI/ARBS- prevent ventricular remodeling and development of HF, must have <40% ejection fraction
-beta blockers: decrease size of infarct, decrease risk of ventricular dysrhythmias, started 1-2hrs after MI
Describe the postoperative care needed for a CABG procedure.
What is:
-management of potential complications: F/E imbalances, hyperthermia, bleeding, low/high BP, anginal pain, cardiac tampanod, A-fib and SVT
-monitor blood glucose levels
-patient education: lifestyle modifications, healing process, complimentary health, sexual advice, drug therapy regimen, when to seek medical attention
Name the risk factors and populations at risk for having an MI.
What is:
-atherosclerosis
-African American, Mexican American, Alaskan Native
-metabolic syndrome (3 or more: HTN, hyperlipidemia, increased HDL or decreased LDL, increased waist central obesity, increased triglycerides, increased fasting glucose)
-family hx
-diet, smoking, alcohol
Describe the characteristics of unstable angina.
-not familiar to patient
-causes limitation
-does not respond to Nitro
-lasts >15 mins
-50% or more blockage of vessel causes decreased perfusion
-3 types: new onset, variant (vasospasm), and pre-infarction
Describe what an intra-aortic balloon pump is and its function.
What is:
-a temporary invasive percutaneous intervention during an acute MI
-decreased preload and afterload and facilitate left ventricle ejection
-heart doesn’t have to work as hard because balloon inflating helps pump blood
What is considered the “gold standard” medication regimen after an MI?
What is:
-dual antiplatelet (aspirin + antiplatelet)
-ACEI
-ARB
-statin
What is the purpose of hemodynamic monitoring?
What is:
-measures BP, heart function, volume status, cardiac output, right atrial pressure and pulmonary artery pressure (PAOP), using a Swann gans catheter
-most invasive, inserted internal jugular or subclavian
-normal PAOP= 5-12mmHg
Describe what is meant by a STEMI.
What is:
-ST elevation in at least 2 of 12 EKG leads
-caused by: rupture of fibrous plaque leading to thrombus formation, leading to complete occlusion
Explain the term chronic stable angina pectoris.
What is:
-chest discomfort caused by moderate to prolonged exertion, relieved by rest
-familiar to patient
-frequency, duration, and intensity stay the same
-fixed atherosclerotic plaque
-risks: HTN, DM, smoking, hyperlipidemia
-treated by: Nitro 0.4mg q 5mins (x3)
What is the pathophysiology of cardiogenic shock?
What is:
-necrosis of more than 40% of the left ventricle
- high mortality rate
Explain the acronym MONA.
What is:
•Morphine: -used for pain not relieved by aspirin
-decreases O2 demand and circulating catacholamines, relaxes smooth muscles
•Oxygen
•Nitroglycerin- decreased preload and afterload, increases collateral blood flow
-gives extra O2 to subendocardium
-monitor orthostatic BP and have pt lay down when taking
•Aspirin- thins blood, inhibits platelet aggregation
-324mg, usually taken at home prior to admission after an MI
Describe the nursing interventions necessary for an MI.
What is:
-do not give false hope
-monitor O2, EKG, pain, lung sounds, pulses, presence of murmur S3 or dysrhythmias, orthostatic BP
-position Semi-Fowler’s
-promote a calm environment
-cardiac rehab: diet, exercise, ADLs (Acute stage ends at discharge, then discharge and home care, then long term conditioning)
-assess support system, give resources
Describe what is meant by an NSTEMI.
-ST depression and T wave inversion
-caused by: coronary vasospasm, spontaneous dissection, sluggish blood flow due to vessel narrowing
-troponin: normal initially then elevated within 3-12 hrs
List the known manifestations of reperfusion.
-pain and discomfort goes away or decreases in intensity
-ST elevation or T wave inversion resolves
-reperfusion beats: vessels get excited and may cause temporary V-fib or V-tach
-markers of cardiac damage will peak within 12 hrs
List the clinical manifestations of cardiogenic shock.
What is:
-tachycardia
-hypotension (SBP <90mmHg or 30mmHg less than baseline)
-urine output 0.5-1mL/kg/hr
-cold, clammy skin
-pulmonary congestion, continuing chest discomfort
-tachypnea
Describe the dynamic process of MIs and the catacholamines released during an MI.
What is:
-a gradual process that results in an MI as vessels are narrowed and eventually obstructed
-the hear develops scar tissue and ventricles stiffen, leading to ventricular remodeling
-norepinephrine: increases O2 demand
-epinephrine: increases contractility, making heart beat harder
List the necessary diagnostic testing for a suspected MI.
What is:
-troponin: every 6hrs x3
-echocardiogram: shows structure of heart and ejection fraction, needed within 10mins of arrival, again after stent placement and 3mths later
-chest x-ray: rules out dissection
-exercise test (stress test)- for NSTEMI, assessed for ischemia
-12 lead EKG: done within 10mins of arrival, distinguishes NSTEMI vs STEMI
-CT scan: diagnoses CAD
-cardiac catherization: shows plumbing of heart