NUR 405 Exam 2 - 2. impulse goes in both atriums 3. then converg...

NUR 405 Exam 2

• Conduction System

• want impulse to start at SA node (special cells that create that impulse)
• impulse goes in both atriums
• then converges into AV node (junction)
• go down right/left branches simultaneously
• need electrical system to work adequately then need muscular system to contract electricity

can last longer than muscular system

• cardiac cells

Answer

• Automaticity

ability of pacemaker cells to generate electrical impulses

• Excitability

Answer

ability of electrical cell to respond to stimulus

• Conductivity

Answer

ability of cardiac cells to accept and transmit stimulus 1 / 4

• Contractility

Answer

ability of cardiac cells to shorten and cause muscle contraction

• pacemaker cells in SA node very important—> also some in AV junction, ventricles
• cardiac cells can respond, conduct, contract to electricity

• Cardiac Dysrhythmias

Answer

• Any disturbance in origin, rate, rhythm, or conduction

-disorders of impulse formation -disorders of impulse conduction (altered automaticity - inherent ability to depolarize spontaneously to threshold potential without ext. stimuli)

• What are the hemodynamic consequences of arrhythmias? from none to death

-what does the patient look like?-patient in PACU HR of 42—> baseline for pt, not SOB/diaphoretic/pale/chest pain, bp w HR of 42?-if everything is normal w HR of 42 not concerned—> may be a runner -compared to older person w HR of 42 w physical symptoms and not waking up post op call anesthesiologist, give fluids, look at hx, meds to increase HR?

3. 12L EKG/ECG

-any disturbance in origin, rate, rhythm, or conduction

• Determine rate

Answer

30 large boxes = 6sec of ECG - count the #Rwaves, multiply by 10

• Classifications of Dysrhythmias 2 / 4

• Sinus

-impulse starts at SA node

• Atrial

-somewhere in atria

• Junctional

-AV node/junction (uncommon)

• Heart Blocks

-started in SA node and blocked 1/2 way down—> hemodynamic issues (don't need to know either)

• Ventricular

-started in ventricles, lethal dysrhythmias (need to know)

• Depolarization/Repolarization

-electrolytes that are important for heart function

-if too high/low can cause dysrhythmias—> might be able to fix electrolytes

Answer

• Potassium, sodium, calcium, magnesium

• Cardiac muscle contraction caused by electrolyte exchange in cardiac cells
• Depolarization
• Repolarization
• Na-K pump (high K and low Na inside & high Na and low K outside)

• Electrocardiogram

Answer

1. ECG/EKG

• Bedside monitors 3 / 4

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3-5 leads

-seen right next to pt in ER/critical care

• Telemetry

-doesn't show continuous rhythm

• Portable monitors

-for pt who needs to be EKG monitored when going for a test

• 12-lead electrocardiogram

-(12 views of heart) only 10 stickers

• Ambulatory electrocardiogram monitoring (Holter)

-for home use similar to 12 lead EKG monitor then take diary of what they were doing and symptoms to analyze and see what was going on

• lead placement

Answer

• different for each hospital

• white on right, white and black are opposite, snow over trees, smoke over fire, chocolate

close to the heart -between intercostal spaces

• change leads every 24 hrs

• Calculate HR

Answer

• On monitor and on strip

• Quick way

Answer

# of QRS complexes in 6 seconds X 10

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