a.  Impulses begin at the ____________ node, generating a P-wave.

b.  The impulse travels through the electrical pathways to the _______________ node.

c.  The ________ node does what to the impulse, so that the atria and ventricles don’t fire at the same time?

a.  Sinoatrial (SA)

b.  Atrio-Ventricular (AV)

c.  AV

a.  What is measured on the horizontal axis of the EKG graph?

b.  What is measured on the vertical axis of the EKG graph?

c.  How much time is measured in one 1mm square of EKG paper?

How much time in one large box (5mm)?

a.  Time

b.  Amplitude, which corresponds to the strength of the electrical impulse

c.  0.04 seconds

d.  0.2 seconds

a.  When the AV node creates a delay in the impulse from the SA node, it is seen on the EKG as the ______ interval.

b.  As the impulse travels down the perkinje fibers in the ventricles, it generates the ________ complex.

c.  This process is known as _______________.

a.  P-R

b.  QRS

c.  Depolarization

Repolarization, T-wave

Step 1: Determine the rhythm of R waves:

a.  How do you determine from the EKG strip if the rate of beats is regular?

b.  If  the distances vary more than ____ seconds (____ boxes), the rhythm is irregular.

a.  Starting at the left side of the strip, place an index card above the first 2 QRS complexes.  Mark the edge of the index card at the top point of two complexes.  Measure from R wave to R wave across the strip

b.  0.12 seconds, 3

1.  Determine the regularity (rhythm) of the R waves

2.  Calculate the HR

3.  Identify and examine P waves

4.  Measure the P-R interval

5.  Measure the QRS complex

Step 2: Calculate the HR.

a.  HR always refers to the __________ rate unless the atrial and ventricular rates differ, and then both will be given.

b.  The rate is the number of _____________ in a 6 second strip multiplied by 10.

c.  You also can multiply a regular rhythm in a 3 second strip by _____ to get a HR.

d.  For irregular rhythms either count a full minute or use the 6 second method (no answer to this)

a.  ventricular

b.  QRS complexes

c.  20

Step 3:  Identify & examine P waves

a.  One P wave should precede every

_____________

b.  How should P waves look, compared with one another?

c.  What do you know is happening if the P waves vary?

a.  QRS complex

b.  All P waves should be identical in size, shape and position.

c.  If the P waves vary, they come from other foci in the atria as well as the SA node.

Step 5:  Measure the QRS complex

a.  What do you measure?

b.  What do you count and multiply?

c.  What is the upper limit of normal?

a.  Measure from the beginning of the QRS complex as it leaves the baseline until the end of the RS when the ST segment begins.

b.  Count the number of small boxes in this distance and multiply by 0.04 seconds. 

c.  Upper limit of normal is 0.12 seconds

Step 4:  Measure the P-R interval

a.  What do you measure?

b.  Multiply this number by _____ seconds.

a.  Measure from the beginning of the P wave as it leaves the baseline to the beginning of the QRS complex.  Move your marked index card so the first mark is on the line of a big box.  Count the number of small obxes to the next mark on the card. 

b.  0.04

a.  What is the real test to determine whether a pt is hemodynamically stable?

b.  Anyone who has an alternation in tissue perfusion is at risk for ______________.

a.  Check blood pressure

b.  dysrhythmias

a.  The blood returns to the heart from what two main vessels?

b.  The blood enters the ________ side of the heart into the ___________.

c.  It passes through the ____________ valve.

d.  With contraction the ______________ forces blood out through the __________valve.

a.  Inferior vena cava and Superior vena cava

b.  right, right atrium

c.  tricuspid

d.  right ventricle, pulmonic

a.  After blood leaves the lungs through the pulmonary veins, it travels to the ______________.

b.  Then it goes through the ___________ valve to the ______________.

c.  A contraction now pushes this blood out through the ______________ into the aorta and on out to the entire body.   The coronary arteries branch off the aorta just as it leaves the heart.

a.  left atrium

b.  mitral valve, left ventricle

c.  aortic valve

a.  After being ejected out through the pulmonic valve, the blood travels through the ____________ to the lung.

b.  It picks up _________ and drops off _______________.

c.  The blood leaves the lung via the _________________.

a.  pulmonary artery

b.  oxygen, carbon dioxide

c.  pulmonary veins

a.  Define cardiac output.

b.  What is the formula for cardiac output?

c.  What “controls” the heart rate?

a.  the amount of blood ejected from the heart in one minute

b.  CO = SV x HR

c.  SNS (Sympathetic nervous system) increases rate;  PNS (Parasympathetic nervous system) slows rate

a.  What affects the stroke volume?

b.  What is preload?

c.  What is afterload?

a.  Contractile strength of myocardial muscle cells (squeezing power), preload, and afterload

b.  Volume of blood in heart at end of diastole

c.  What happens afterward; after the heart – forward into the blood vessels;  what pressure the heart must pump against

What words define:

a.  the ability to transmit an impulse from cell to cell; when one cell is stimulated, the impulse rapidly spreads throughout the heart muscle.

b.  the ability of myocardial fibers to shorten in response to a stimulus

a.  Conductivity

b.  Contractility

What words define:

a.  The ability of pacemaker cells to spontaneously initiate an electrical impulse; Myocardial muscle cells do not possess this ability.

b.  The ability of myocardial cells to respond to stimuli generated by pacemaker cells

a.  Automaticity

b.  Excitability

What words define:

a.  the rapid reversal of charges in and out of the cell (what moves the electrical impulse forward)

b.  the process of the cell getting ready (more ions in and out of cell) to be able to discharge and transmit an impulse again

c.  when no action is possible, right after depolarization

a.  depolarization

b. repolarization

c.  refractory period

a.  On an EKG, if the current is traveling away from the lead placement, the wave will be ____________.

b.  If the current is traveling toward the lead, the wave will be ____________.

c.  Can you be certain that what you see on the graph is what is happening, mechanically?

a.  negative (below the baseline)

b.  positive (above the baseline)

c.  NO – you must always get “hands on,”  assess, palpate, and listen to the pulse for yourself.

P wave:

a.  Indicates ____________________, or contraction of the ____________.

b. Normal duration is not longer than _____ seconds, which is less than ____ small squares

c.  Amplitude (height) is no more than ____mm

d.  No notching or peaking (no answer to this)

a.  atrial depolarization, atrium

b.  0.11 seconds, less than 3 small squares

c.  3

a.  How do you calculate a HR from an EKG strip with a regular heart rate?

b.  How do you calculate with an irregular HR?

a.  The heart rate is 300 divided by the number of large squares between the QRS complexes.

Ex:  There are 4 large squares between regular QRS compleses, so the heart rate is

75 (300/4 = 75)

b.  Count the number of R waves in a 6 second strip and multiply by 10.

Ex:  If there are 7 R waves in a 6 second strip, the HR is 70 (7x10).

QRS complex:

a.  Indicates ___________ ___________, or contraction of the ______________.

b.  Normally not longer than _____ seconds in duration

c.  Amplitude (height) is not less than ____mm in lead II or _____mm in V3 and V4

d.  R waves are deflected _____________ and the Q and S waves are _____________.

T wave:

a.  Indicates _____________ _____________

b.  Not more than ____mm in amplitude in standard leads

c.  Rounded and asymmetrical (no answer to this)

ST segment

a.  Indicates ________ ________ _______

b.  Normally not depressed more than ____mm

c.  May be elevated slightly in some leads

(no more than ____mm

a.  early ventricular repolarization

b  0.5

c.  1

QT interval

a.  Represents ___________ ___________ and _____________ (Na influx and K efflux)

b.  What makes QT vary?  What is normal?

a.  ventricular depolarization and repolarization

b.  QT varies with rate.  Correct for rate by dividing QT by the square root of the RR interval.

PR interval

a.  Indicates _____ __________ time

b.  Duration time is ____ to ____ seconds

a.  AV conduction

b.  0.12 – 0.20

Prolonged QT interval may be inherited or acquired. 

a.  What is wrong when it is inherited?

b.  What is wrong when it is acquired?

a.  Defective sodium or potassium channels

b.  Drugs, electrolyte imbalance, or MI

• At least 50 drugs are known to affect QT , including quinidine, amiodarone and dofetilide.

a.  Because the SA node, also known as the sino-atrial node, is the pacemaker, any rhythm that begins here is called a ________ rhythm.

b.  From the SA node, the internodal pathways carry the impulse across the atria and through the ____ node.

c.  This slows the impulse down a bit so that:

a.  sinus

b.  AV

c.  the atria have time to empty blood into the ventricles

a.  If the SA node fails, where do impulses start?

b.  Rhythms begun here are called what?

c.  Where are the actual pacer cells in this area?

d.  With this system, what would the HR be?

a.  at the level of the AV node

b.  junctional rhythms, because they start at the “junction” between the atria and ventricles

c.  in the Bundle of His, just below the AV node

d.  slows to 40-60 bpm

a.  When the AV node has received an impulse, the impulse travels down the septum in the ____________________.

b.  The electrical impulse then splits to travel where?

c.  Why is the right ventricle smaller than the left?

a.  Bundle of His

b.  to the right and left ventricles

c.  The right ventricle only has to push blood through the lungs, while the left has to push it through the whole body.

.  If the first back-up system, the AV node, cannot function to start an impulse, what happens next?

b.  What are these rhythms called?

c.  What would the HR do?

a.  The heartbeat may start even lower down the conduction pathway in the ventricles –

at the Pukinje fiber level.

b.  ventricular rhythms

c.  15-40 bpm

a.  It is okay for an ST segment to be elevated one small box (1mm).   But what is happening if it is elevated more than 1mm?

b.  What is a “tombstone T?”

c.  What if the ST segment is depressed

a.  a zone of myocardial injury

b.  a term for a zone of myocardial injury

c.  a zone of myocardial ischemia

a. What are ventricular beats?

b.  Why do they occur?

c.  Who is more likely to get them?

a.  Ventricular beats occasionally occur in all  of us.  They start in a Purkinje fiber and depolarize all upside down and backward from usual.  It takes a moment to reset the heart for the next “normal” beat so there is often a pause after this extra ventricular beat.  These complexes are called PVCs.

b.  An area in a ventricle is irritable for some reason, such as hypoxic tissue, low K, etc.

c.  People with heart or lung injury are more likely to have hypoxia so may have PVCs too.

a.  Sinus bradycardia may be too slow to maintain an adequate _____.

b.  What are symptoms of bradycardia?

c.  When do you know you need to treat bradycardia?

d.  What do you give?

a.  cardiac output

b.  falling BP, weakness, dizziness

c.  Treat only if symptomatic

d.  Atropine IV **Never give to a pt who as glaucoma!

a.  From a pacemaker, where does the wire extend within the vein?

b.  Why can a pt not raise his arm any time soon after having a pacemaker placed.

c.  What kind of batteries do pacemakers use, and how long do the batteries last?

a.  the tip is pushed in to the base of the right ventricle, atria, or both

b.  A fibrous growth has to occur to secure the pacemaker before the pt can move around freely.

c.  lithium, 6-10 years

Describe the types of pacemakers:

a.  Transcutaneous (External)

b.  Epicardial

c.  Endocardial

a.   like defibrillator pads; put one on the front and one on the back; temporary

b.  wire on heart surface post heart surgery, in case of need; temporary

c.  Wire from power supply to inner right ventricle, atria or both atria and ventricle

a.  What signs & symptoms should a pt with a new pacemaker be taught to watch for, in getting into an environment that could interfere with pacemaker conduction?

b.  With what s/s should a pt call the physician?

a.  Get away from environment if experience:

• Dizziness
• Faintness
• Fatigue

b.  Call physician:

• s/s of decreased CO
• Hic-ups that last > 15 minutes:  call MD

What pt teaching is needed for a pt with a new pacemaker?

• Wound care
• Family needs to know s/s to watch for at home
• Family member to CPR class
• Medic-alert bracelet
• How to take a pulse
• Avoid powerful magnetic fields
• Activity restrictions:  arm movement
• Clothing restrictions, first few weeks

a.  Describe Failure to Capture.

b.  Describe Failure to Sense.

a.  a pacer spike fires, but elicits no QRS complex; may elicit V fib if it then fires on an ST segment

b.  no pacer spike fires when needed; does not sense or is unaware it is time to function; also danger of throwing a spike during a T wave, causing V fib.

a.  What is a fixed rate in a pacemaker?

b.  What is an “R on T phenomenon?”

c.  What is demand pacing?

a.  the pacemaker keeps firing, despite what the pt’s HR is doing

b.  R on T phenomenon is a danger with fixed rate pacing;  it is a super-normal refractory period that is very sensitive to getting messed-up during the T wave, because the ventricles are not fully repolarized.

c.  Pacemaker set to fire if pt’s HR goes below the set rate, usually 70 bpm

a.  Success of a pacemaker includes the presence of what two components?

b.  What else is a reassuring sign?

c.  What should always follow the spike made by a pacer on a monitor strip?

b.  adequate urine, demonstrating good kidney perfusion

c.  a QRS complex