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Explain the conduction of the heart
- Begins with the SinoAtrial node in the right atrium, the hearts primary pacemaker at 60-100 bpm creates (creats depolarization.
- Then continues to the atrioVentricular node, next the Bundle of His, then the right and left bundle branches, lastly the perkinje fibers.
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Describe Normal Sinus Rhythm?
- begins in the SA; rate is 60-100bpm,
- rhythm: atrial and ventricular rhythms are regular
- P waves: consistent
- PR interval: regular and constant
- QRS duration: constant
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Describe tachycardia. What does it cause?
- more than 100 bpm
- increases workload of the heart
- increases oxygen demand
- palpitations
- chest pain
- restlessness/anxiety
- pale, cool skin
- syncopial episodes
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What is bradycardia and what does it cause?
- HR less than 60 bpm
- O2 demand is low
- Can lead to MI and heart failure
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What is the most common dysrhythmia? What are the risk factors? What can it lead to? What are symptoms?
- Atrial fibrillation
- Risk factors: HTN, TIAs, Stroke, CAD, DM, age, obesity, being Caucasian, and increased alcohol intake
- multiple atrial goci fire, no P wave, rapid irregular rate
- Atria and ventricles are not coordinated. Reduced CO.
- Can lead to thrombus formation
- Symptoms: fatigue, weakness, SOB, SOBOE, dizziness, anxiety, syncope, CP,
- Some patients may be symptomatic
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What is the treatment for atrial fibrillation?
- Long term AF without S&S= no treatment
- Uncontrolled ( greater than or = to 100bpm)= diltiazem(cardiazem), miodarone (cordarone), metoprolol (Toprol), digoxin (lanoxin), heperain, enoxaparin (lovenox), warfarin (Coumadin for pts at risk for emboli
- Cardioversion used when drugs are ineffective
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Describe diltiazem (cardizem), what are the side effects? nursing care?
- inhibits calcium influx into myocardium
- improves myocardial perfusion (dilation)
- Reduces left ventricular workload
- slows SA and AV node conduction
- Used for A fib, A flutter, Supraventricular trachycardia and angina
- side effects: CNS (HA, fatigue, dizziness, drowsiness, nervousness, insomnia, confusion, tremor); CV (edema, arrhythmias, angina, bradycardia, hypotension, CHF); GI (N/V/D, constipation), Derm: rash
- Nursing care: check BP and ECG before therapy, monitor and report S&S of chf, supervise ambulation, *metabolized in lever
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What is the class, action, indication Side effects and nursing implications of amiodarone (Cordarone)
- Class: antiarrhythmic
- action: slows conduction time through the AV node
- Indication: tx for A fib
- Side effects: CNS (peripheral neuropathy, fatigue, dizziness) CV ( bradycardiaa, ypotension, sinus arrest, cardiogenic shock) Senses (blurred vision, photosensitivity), GI (anorexia, N/V, constipation, hepatotoxicity
- Nursing implications: monitor BP, HR, Rhythm, monitor AST, ALT, thyroid and GI, diminished breath sounds, rales, pleuritic friction rub, check pulse daily, DC if <60
- Avoid grapefruit juice, dark glasses, regular eyes exams
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What is atrial flutter? S&S? causes? treatment?
- Not life-threatening but can be if continuos or left untreated, blood moves slowly, which causes a High risk of emboli, Atria are not in sync with the ventricles, but in a regular pattern
- S&S: may be asymptomatic, palpitations, increased HR, SOB, Activity intolerance, Chest pain, dizziness/fainting; Sawtooth pattern ECG
- Causes: heart failure, Abnormal valves, congenital anomalies, HTN, thyroid dysfunction, binge drinking, DM
- Treatment: diltiazem can be used to slow AV conduction, digoxin, cardioversion
- *can lead to a-fib
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What are premature ventricular contractions?
- Something other tha the SA node fires initiating the rythm complex (PORST); followed by a pause, can lead to decreased CO and dizziness.
- Common dysrhythmia that increases with age
- may be asymptomatic
- Eliminate contributing cause (stress, caffeine)
- Sometimes occur in repetition: Bigeminy(2 in a row) trigeminy (3 in a row) Quarigeminy (4 in row)
- PVCs not palpable- noticed as skipped beat
- Tx is corderone, and oxygen
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What is ventricular tachycardia "V Tach"
- Life threatening emergency
- repetitve firing of ectopi foci
- Rate is 140-180 BPM
- intermittent or sustained
- Associated with MI, cardiomyopathy, hypokalemia, hypomagnesemia, valvular disease, HF, drug Toxicity or hypotension
- Elective cardioversion is the treatment for stable VT
- VT can lead to ventricular fibrillation (lethal rhythm) then cardiac arrest
- TX. VT with cardioversion and PO antidysrhyhmics, IV bolus amiodarone, Lidocaine, procainamide
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Ventricular Fibrillation
- Life threatening: multifocal firing, disorganized, no contraction occurs, NO CO, no pulse, no perfusion, no LOC, no breathing, no BP lethal within 3-5 minutes
- Defibrillate immediately
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Ventricular asystole
- No ventricular rhythm so no QRS complex
- No contraction or CO
- Full cardiac arrest
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What is a pace maker?
- pulse generator and pacing electrodes
- stimulate depolarization as a spike on EKG
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What should you assess for and notify the HCP when assessing a pacemaker site?
- infection or hematoma at site
- PVCs
- Spike but no QRS complex
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What medications are used to treat arrythmias?
- Procainamide hydrochloride
- Action: decreases myocardial excitability
- slows conduction
- prolongs repolarization and the QT interval
- treatment of arrythmias, excreted by liver,
- given IV or IM
- SE: confusion, dizziness, NVD
- AE: seizures, asystole, heart block, arrythmias
- NI: monitor EKG, Pulse, BP continuously
- Patient teaching: SE, AE and when to notify the MD
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What is the cause of Left sided heart failure? S&S?
- Causes: HTN, CAD, mitral or aoritc valve disease (stenosis or regurg)
- S&S: impaired tissue perfusion, SOBDOE, DOE, Fatigue, orthopnea, chest discomfort, palpitations, skipped beats, tachycardia, pulmonary congestion, dry to wet cough
- DX: elevated NA and K+, elevated BUN, elevated H&H, CXR shows cardiomegaly, pulmonary congestion
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Angiotension converting enzyme inhibitors
- Enalapril (vasotec)
- Action: systemic vasodilation
- metabolized through kidneys
- given PO and IV
- lower dose in pt with diuretic
- SE: dizziness, drowsiness, fatigue, HA, hypotension, cough, dyspnea, CP, tachy, angioedema (facial swelling)
- NI: monitor BP, assess for dyspnea, angioedema, daily wt, crackles, BUN, electrolytes,
- *used for left sided heart failure
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What is the cause of right sided heart failure?
- results when the right ventricle fails
- fluid retention in lower legs, nausea and anorexia, ascites in advance heart failure, frequent diuresis, awakening at night to urinate, excessive thirst due to sodium retention
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Digoxin (lanoxin)
- Action: increases the force of myocardial contraction and decreases conduction (slows HR), increases cardiac output and decreases HR
- SE: fatigue, HA, weakness, blurred vision, yellow.green halos around lights, diarrhea
- AE: fatigue, brady < 60, NV, anorexia
- Half life is 36-48 r
- given PO, IM, IV, (Admin PO QOD)
- NI: monitor apical pule for 1 minute, < 60 omit drug and notify HCP, monitor I&O and serum digoxin level (narrow tx range) monior K+, BUN, LFT
- Monitor for Signs and symptoms of toxicity: abdominal pain, anorexia, NV, visual disturbances, bradycardia
- Administer Digibind: binds to digoxin and excreted by the kidneys
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What is the diet therapy for heart failure?
- Low sodium diet: 2000 mg/day or less
- low in fat
- No caffeine
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What is cardioversion?
- synchronized countershock administered to patient with dysrhythmias resistant to medications
- Dig is DC X2 days
- Anticoagulants given for 4-6 weeks after to prevent clots
- NI: pg 737
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What is Coronary artery bypass graft?
- (CABG)
- Elective or emergent
- Under general anesthesia
- A heparinized, oxygenated bypass machine circulates blood during the surgery
- Potassium stops the heart during surgery
- Heart is defibrillated back into NSR
- Saphenous veins or mammary artery grafts are used to bypass damaged coronary arteries
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What is the post op care for CABG?
- Ventilated for 3-6 hours
- Pacemaker and chest tubes
- Central lines, 2 lg bore IVs
- Cardiac monitor, FC
- Multiple meds
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Furosemide (Lasix)
- Class: diuretic
- Action: increasess renal excretion of water and electrolytes
- Half life: 30-60minutes
- PO, Im, IV
- PO Onset: 30-60 minutes, IV onset is 5 minutes
- SE:
- AE:
- NI:
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