What is coronary artery disease?
Atherosclerosis of the coronary Arteries
What is atherosclerosis?
- the accumulation of lipids and fibrous tissue causing progressive narrowing of the lumen (stenosis), increasing resistance to blood flow, decreasing the ability to adapt to myocardial oxygen demand.
- --also causes stiffening of the coronary artery walls causing loss of dilatory response which decreases ability to adapt to myocardial oxygen demand.
What three conditions make up Acute Coronary Syndrome?
STEMI, Unstable Angina, NSTEMI
What is unstable angina?
- ischemia of the heart without cardiac damage. Characterized by chest pain.
- S/S of ischemia are present at rest and can occur with or w/o ST depression. Pain is NOT relieved by SL NTG.
What is an NSTEMI?
Non-ST segment elevation MI. Heart damage is present. Presents like unstable angina however cardiac enzymes are released to indicate damage to the myocardial tissue. CK, CK-mb, Triponin 1
What is a STEMI?
ST segment elevation MI. ST Segment is elevated >1 mm and chemical markers are released. Characterized by severe chest discomfort with pain and heaviness that is unrelieved by SL NTG . Pt has a sense of impending doom, diaphoretic, N&V. CAN BE ASYMPTOMATIC.
Pt reports to ER with chest pain and nausea. What are you going to do in the first 10 minutes?
Vitals with O2 sat, 12 lead EKG, Targeted H&P, labs (CK, troponin, CBC, electrolytes, coags, Portable Chest Xray, O2 @ 4L, Aspirin 160-325, Nitro SL x 3 q 5 min--hold if SBP is <100, morphine 2-4 mg IV q 5 min, IV access, continuous EKG.
Left Anterior Descending Infarction
Septal--V1-V2 conduction problems, Septal defects
Anterior wall--V3-V4 Tachy, heart failure, aneurysms
Lateral wall--V5-V6, I, aVL
Left circumflex artery infarctino
Lateral wall I, aVL, V5-V6
Right Coronary Artery infarction
- inferior wall
- II, III, aVF
- Bradycardia, 1st and 2nd degree type 1 HB, GI symptoms
What does a targeted H&P include?
- 1. Time of sx onset
- 2. History of CAD, MI, CABG, Cath, PCI, HTN, DM
- 3. Eligibility for thrombolytics
- 4. Heart lungs, pulses
- 5. Skin--color, temp, diaphoretic?
What will the results of the EKG show?
- --ST elevation or new BBB
- --ST depression or T wave inversion
What does it mean if they have an ST elevation or a new BBB?
- REquires IMMEDIATE treatment:
- Heparin IV, NTG IV, Morphine, Beta Blockers (decr the risk of sudden cardiac death, decr O2 demand and HR)
- Choose reperfusion strategy (percutaneous coronary intervention, thrombolytics)
Thrombolytics--What do they do and interventions
- Clot fibrinolysis--Door to injections <30 minutes.
- Drugs: Alteplase (TPA), Retaplase (RPA), Tenecteplase (TNK)
Interventions: Separate IV site, don't infuse other meds in this site until TPA admin, cont. EKG, monitor PTT and overt S/S of bleeding, avoid injections and blood draws, no auto BP cuff.
Contraindications for Thrombolytics
- Absolute CI:
- Prior intracranial hemorrhage, CVA, Aortic dissection, active bleeding, head/facial trauma
- Relative CI:
- recent surgery, uncontrolled HTN, pregnancy, current coumadin with INR >1.7, peptic ulcer
Nursing Care for STEMI
- Admit to ICU w/continuous EKG looking for ectopy, reperfusion, vtach, st segment changes.
- Pain mgmt--Nitro IV 10-200 mcg/min, morphine 2-4 mg IVP PRN
- Frequent BP's, consider Art line,
Cardiac Cath post procedure care
q15 min assess insertion site, bleeding, hematoma, bruising, distal pulses, color, temp. VS q15 for 1 hour, q 30 min for 2 hours, then q1h for 2 hour. Bedrest. Don't bend leg for 6-12 hours post removal of sheath. HOB <30 degrees, log roll. Monitor for S?S of decr CO, heart sounds, lung sounds, perfusion, pulses, urine output, cognition.
- Heparin--IV infusion to maintain PTT @50-70
- Aspirin 160 mg qday
- Calcium channel blockers--Verapamil, Diltiazem
- Ace Inhibitors--Enalapril, Lisinopril
- Specific to PCI & Stents:
- Plavix 300 mg PO before PCI or on admit to CCU then 75 mg qd
- GPIIb/IIIa receptor inhibitors--Peopro, aggrastat, integrillin
Low Cardiac Output Syndrome
- Etiology: Abnormal heart rate, bradycardia, tachy, hypovolemia, Poor LV function.
- Clinical Manifestations: Hypotension, oliguria, cool extremities
- What monitor will show: Hypovolemia--low CVP, PAP, PCWP
- Poor LV function--high CVP, PAP, PAWP
Treatments for Low Cardiac Output Syndrome
- Bradycardia--Epicardial pacing
- Tachy--Esmolol (500 mcg/kg/min X 1 min loading and 50-200 mcg/kg/min maintenance), Diltiazem 5-15 mg/hr
- A fib--diltiazem, cardioversion
- Hypovolemia--volume replacement
- crystalloid solutions (LR, NaCl)
- Colloid solutions (Normosol, Plasmanate, Hetastarch)
- Packed RBC's
- Poor LV function--Positive inotropic (ctx) agents: Dobutamine, milrinone
S/S Decr chest tube output, muffled heart sounds, decreased EKG amplitude, Incr CVP, PAP, PCWP, Pulsus paradoxus (10 mm/gh fall in SBP w inspiration)
Treatment: Remove Chest tube obstruction, pericardiocentesis, REturn to surgery.
Hypertensive Crisis "Emergency"
- Sudden severe elevation of BP >180 systolic and/or 120 diastolic. increased risk for end organ damage
- Caused by Acute renal failure, neurovascular, illicit drugs, elcampsia, pheochromocytoma
- CM: Depends on end organ affected:
- CNS--headache seizure, LOC
- Renal--Acute intrinsic Renal failure
- CVS--chest pain, MI, Heart failure, Abdominal pain=aortic dissection
- Treatment: 1 or more of the following
- Sodium nitroprusside, NTG, Hydralazine (eclampsia), Short acting Beta Blockers (aortic dissection), Enalapril (heart failure) consider lasix.