Term
| What are the 4 ways to characterize dysrhythmias? |
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Definition
1. too slow
2. too fast
3. inappropriate extra beats
4. complete disorganization or dissociation |
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Term
| What happens when the heart beats too slow (bradycardia)? |
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Definition
*Sinus bradycardia
*Blockade of conduction (AV blocks) = slows conduction from atria to ventricles
*First, second, third degree blocks = 3rd is medical emergency (tx c Atropine) |
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Term
| What happens when the heart beats too fast (tachycardia)? |
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Definition
*Sinus tachycardia
*Impulse originates above ventricles |
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Term
| What is Atrial fibrillation (A-fib)? |
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Definition
*Disorganized electrical activity in the atria
*Poor ventricular filling
*Risk of thrombus
*Ventricular response variable |
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Term
| What happens with inappropriate extra beats? |
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Definition
| *Abnormal cardiac impulses which arise superimposed on an underlying rhythm |
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Term
| What is ventricular fibrillation (V-fib)? |
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Definition
*Complete disorganization or dissociation
*No effective CO = no pulse
*Cardiovascular collapse
*Most "treatable" form of CA
*Tx = electricity |
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Term
| What does enhancing or blocking ion flow do? |
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Definition
| *Changes conduction and muscle cell function in the heart |
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Term
| What are the 4 classes of Rxs used to treat dysrhythmias? |
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Definition
Class I: Sodium Channel Blockers= dec conduction velocity (Qinidine, Lidocaine)
Class II: Beta Blockers (metoprolol)
Class III: Potassium Channel Blockers = delay depolarization (Amiodarone)
Class IV: Calcium Channel Blockers (diltazem) |
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Term
| What are some other drugs used to treat dysrhythmias? |
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Definition
*Adenosine for SVT = dec automaticity; slows AV conduc; extremely short 1/2life
*Digoxin = esp. for A-fib = dec AV conduc
*For bradycardia: Artopine, Isoproterenol |
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Term
| What is special about Quinidine? |
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Definition
*Dec conduction velocity
*Potent effect on Dig levels
*More powerful ppb & bumps Dig off |
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Term
| What is a major ADR of all anti-dysrhythmics? |
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Definition
| *All can worsen existing dysrhythmias or create new ones |
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Term
| How is Cardiac Output calculated? |
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Definition
| Heart rate x stroke volume = CO |
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Term
| What is stroke volume? What is it effected by? |
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Definition
*Quantity of blood pumped out with each cardiac contraction = ejection fraction
*Effected by: blood entering heart (preload), force of contraction, force against which heart must pump (afterload) |
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Term
| How can the body maintain adequate CO? |
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Definition
*Increase heart rate = inc preload & retain Na & H2O in kidneys
*Increase stroke volume = fluid retention, preload, or hypertrophy |
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Term
| What is Angina? What causes myocardial ischemia? |
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Definition
*Chest pain cause by myocardial ischemia
*Workload exceeds oxygen supply |
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Term
| When are the coronary arteries perfused? |
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Definition
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Term
| What are the three types of Angina? |
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Definition
1. Stable angina = exertional d/t CAD & partial occlusion
2. Prinzmental's angina = spasm of coronary arteries; may occur @ rest
3. Unstable angina = CAD complicated by vasospasm, aggregation, trombi or emboli |
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Term
| What is acute myocardial infarction? |
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Definition
| *Cardiac tissue death = loss of blood supply or oxygen = not functional in conduction elect |
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Term
| What is acute coronary syndrome? |
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Definition
*A continuum or spectrum of conditions jeopardizing myocardial oxygen supply
*Progresses from UA to AMI |
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Term
| What three drugs are used to treat angina? |
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Definition
1. Beta-blockers = stable angina, not vaiant
2. Ca-Channel blockers = Stable, variant or unstable angina
3. Organic nitrates |
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Term
| What do beta-blockers do for angina? |
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Definition
*Dec O2 demand by dec contractility, HR, CO
*Longer diastole = improved coronary O2 supply |
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Term
| What do Ca-Channel Blockers do for angina? |
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Definition
*Peripheral vasodilation lowers preload/afterload
*Dec HR, slows AV conduc, dec O2 demand |
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Term
| What do organic nitrates do for angina? |
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Definition
*Promote vasodilation in VEINS
*Reduces preload & O2 demand |
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Term
| How can Organic Nitrates be administered? What is a common side effect? What must be monitored? |
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Definition
*PO sublingual or spray = terminate acute angina = usually dosed 3x
*Long acting PO = Isosorbide = not for acute attack = first pass
*Patch = slow onset
*Ointment = faster acting than patch
*IV
*Headache common c PO
*MONITOR BP |
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Term
| What are the ADRs of organic nitrates? |
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Definition
*HypoTN = intesifies other HypoTN drugs
*Reflex tachycardia
*Pounding headache; facial flushing
*N/V
*Life-threatening hypoTN c Viagra
*Rapid tolerance development |
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Term
| What surgical interventions can be done for ACS? |
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Definition
*Coronary artery bypass graft (CABG)
*Percutaneous Coronary Intervention (PCI) = stent placement |
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Term
| What is heart failure? What causes it? |
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Definition
*Heart is unable to pump sufficient blood to meet metabolic needs of tissues
*Chronic HTN, MI, Valvular dysfunction, congenital abnormality, aging tissue |
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Term
| What are compensatory mechanisms for chronic increased cardiac demands? |
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Definition
*Starlings law = inc stretch of myocradium = inc FOC
*Hypertrophy of myocardium = inc FOC
*Fluid retention = inc preload
*Symp NS = inc rate & FOC & vasoconstric
*Cardiac remodeling |
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Term
| What does left ventricular failure cause? |
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Definition
*Pulmonary congestion
*Dyspnea
*Cough |
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Term
| What does right ventricular failure cause? |
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Definition
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Term
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Definition
*Cardiac enlargement
*Elevated BNP = proteins released by myocard r/t stress
*Inadequate tissue perfusion = fatigue, dyspnia, end organ damage
*Volume overload = edema, crackles, JVD |
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Term
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Definition
*Valve repair
*Cardiac repair/re-vascularizaiton (exercise)
*Control HTN
*Limit Na intake
*Lifestyle modification
*Rx |
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Term
| What drugs are used to treat HF? |
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Definition
*Diuretics
*Selected Beta-blockers
*ACE Inhibs/ARBS
*Inotropic agents = gympathomimetic, cardiac glycosides |
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Term
| How do diuretics work for HF? |
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Definition
*Reduce fluid overload
*Risks: HypoTN, hypokalemia |
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Term
| How do Beta-blockers work for HF? |
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Definition
*diminishes cardiac contractility
*contraindicated c asthma |
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Term
| How do ACE Inhibitors/ARBS work for HF? |
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Definition
*ACE Inhib: decreased cardiac remodeling. ADR = cough
*ARBs: same as above
*Aldosterone inhibitors = prevents fluid retention |
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Term
| How does Digoxin work for HF (Cardiac Glycoside)? |
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Definition
*Increases contractility
*Lowers HR s elevating O2 requirements
*Positive inotrope (inc force)
*Negative chronotrope (dec rate)
*High doses: dec AV conduc = helps c atrial flutter/fib |
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Term
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Definition
*Dysrhythmias (brady or heart block)
*N/V/D, anorexia
*Fatigue, HA
*Hypokalemia |
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Term
| What drugs does Digoxin interact with? |
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Definition
*MANY
*Diuretics
*Other anti-arrhythmics
*ACE inhib & ARBs |
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Term
| What precautions must be taken with Digoxin? |
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Definition
*Loading dose then daily maintenance
*Very narrow therapeutic range
*Dig levels drawn as indicated
*S/S toxicity = abd pain, N/V, bradycardia
*Know elyts
*Apical pulse one minute prior to admin if less than 60 don't give |
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