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112 Cards in this Set

  • Front
  • Back
What generates the regular sinus rhythm that paces the heart?
SA Node
It is the ________of the SA node that generates the regular wave of depolarization.
Normally the SA node discharges regular pacing impulses (60-100 per minute) that depolarize the _____.
The SA node generates pacing impulses at a constant unvarying rate, producing cycles of equal length, so that the rhythm of the heart is said to be _____. This characteristic is typical of SA node pacing.
Sinus arrhythmia is a normal, but extremely minimal ____in HR during inspiration (Why?________)

and extremely minimal ____in HR during expiration. (Why? _______)
Increase on inspiration bc of sympathetic stimulation of SA node

Decrease on expiration due to parasympathetic inhibition of the SA node
The atrial conduction system consists of 3 specialized internodal tracts ( ___, ___, ____) and one conduction tract known as _____ that innervates the _____.
Anterior, middle, posterior

Bachman's bundle depolarizes the left atrium
Depolarization of the atrial myocardium shows up as a ____ on an ECG.
P wave
When the depolarization stimulus passing down from the atria reaches the AV node, what happens?
The impulse SLOWS DOWN in the AV node and creates a pause on the EKG.
The AV node pause is represented as what on the ECG?
the horizontal piece of baseline btw the P and the QRS complex
After passing slowly through the AV node, depolarization proceeds RAPIDLY through the ____ --> ___ --> ____. When the impulse reaches the last part the _______ are finally depolarized, resulting in a ___on the ECG.
bundle of His --> R/L bundle branches --> purkinje fibers

ventricles, QRS complex
Ventricular depolarization initiates contraction of the ventricles, which continues until they are repolarized completely at the end of the ___.
T wave
Ventricular contraction begins and ends during the ____.
QT interval
Although the ventricles are totally repolarized by the end off the T wave the purkinje fibers do not repolarize until later, represented as a small hump, or ___ on the ECG.
U wave
Should the highest level of pacemaking fail, an automaticity focus from the next highest level (no longer overdrive suppressed by the SA node) begins to pace at its own inherent rate. This new pacer overdrive suppresses all automaticity foci below it.

What are the 4 levels of automaticity foci?
1st: SA Node (60-100bpm)

2nd: Atrial foci (60-80bpm)

3rd: Junctional foci (40-60bpm)

4th: Ventricular foci (20-40bpm)
Wandering pacemaker
this occurs when the pacemaking activity wanders from the SA node to atrial foci, causing:
Cycle lengths to vary
P wave shape to keep changing
HR is still under 100.
Multifocal Atrial tachycardia
No single focus achieves pacemaking dominance so they all pace together, making a rapid rhythm over 100bpm.

P wave shape varies
Cycle length varies
HR over 100
What heart rhythm is commonly seen in COPD patients?
multifocal atrial tachycardia
Atrial fibrillation
No P wave, irregular R to R

This is caused by continuous firing of multiple atrial automaticity foci. Only some of these get through to the AV node, causing the irregular rhythm.
When we see a premature beat we recognize that it was fired by ______, so we need to identify it as ___, ___, or ___.
an irritable automaticity focus

atrial, junctional, or ventricular
Which foci are the world's most sensitive O2 sensors? When they sense low O2 they become irritable!
Ventricular automaticity foci
What can cause atrial and junctional foci to become irritable?
Epinephrine or NE release
Adrenergic chemicals
If there is a premature atrial beat what do you see on the ECG?
One P wave that looks different from all the other ones.

The PAB originates in an irritable atrial focus (not the SA node).
If the SA node is depolarized by a premature atrial beat then the SA node pacemaking is ____ in step with the premature stimulus so that the SA node will fire one cycle from that stimulus.
A premature atrial beat may be unable to depolarize the AV node is the AV node is not fully repolarized from the last impulse. On an ECG this shows up as ________.
an early unusual P wave with no QRS behind it
When an irritable atrial focus repeatedly adds a Premature atrial beat to the end of each sinus cycle it is called ________.
Atrial bigeminy
Sometimes an irritable atrial focus may prematurely fire after 2 normal sinus cycles. This is called ________
Atrial trigeminy
If you see a premature QRS that is slightly widened you should consider that it may be due to a ________ with _______conduction.
Premature junctional beat

Aberrant ventricular
A ventricular focus can be made irritable (and thus cause a premature ventricular beat) by what circumstances?
Low oxygen, low potassium, or pathologies
What is a PVC?
Premature ventricular contractions are when an irritable ventricular focus sends an impulse.

You see super wide, super tall wave flipped opposite of the direction the QRS complexes are going.
What is the most likely reason for a ventricular focus to become irritable and cause a PVC?
low oxygen
How many PVCs per minute are considered pathological?
When you see QRS, PVC, QRS, PVC what is it called?
Ventricular bigeminy
When you see QRS, QRS, PVC, QRS, QRS, PVC what is it called?
Ventricular trigeminy
When you see QRS, QRS, QRS, PVC, QRS, QRS, QRS, PVC what is it called?
Ventricular quadrigeminy
Paroxysmal tachycardia is how many bpm?
150-250 bpm
Flutter is how many bpm?
250-350 bpm
Fibrillation as a tachyarhythmia is how many bpm?
350-450 bpm
What does "paroxysmal" mean?
Is sinus tachycardia a paroxysmal tachycardia?
NO! Because it is not sudden and does not originate in an automaticity focus.
Premature atrial tachycardia with AV block has what characteristics?

What should you expect if you patient has this dysrhythmia?
Rapid rate, 2 P-waves before each QRS bc the AV node is blocking the conduction of every other atrial stimulus.

Suspect digoxin toxicity
During Ventricular tachycardia the heart rate is ____bpm.
Sudden runs of Ventricular tachycardia resemble a rapid series of ____, which they really are.
Ventricular tachycardia often indicates coronary _____, causing poor oxygenation of the heart.
Torsades de pointe is a rapid ______ rhythm caused by low _____, which lengthens the ____ of the ECG. The rate is between ___ and ___bpm.
Atrial flutter originates in what type of automaticity focus?

This focus fires at ____-___ times per minute, producing a rapid series of _____depolarizations.


Ventricular flutter is when a ventricular automaticity focus fires at ___-___times per minute. This rhythm looks like what?

A lot of sine waves back to back of similar amplitude
True ventricular flutter almost invariably deteriorates into __________, which requires what 2 actions?
Ventricular fibrillation

CPR and defibrillation
Ventricular fibrillation is easily recognized by what characteristics?
A totally erratic appearance and lack of any identifiable waves on the ECG. It looks different at every moment!
Ventricular fibrillation is a type of __________. There is no effective cardiac output bc the ventricles are only _____.
Cardiac arrest

What is an Automated External Defibrillator? (AED)
A small portable defibrillator.
What is an implantable cardioverter defibrillator (ICD)?
A defibrillator implanted under the chest skin of patients likely to develop VFib. Wire leads from the ICD unit are attached to the heart to detect VFib and deliver a shock.
What problem do AV blocks cause?
They retard or eliminate conduction from the atria to the ventricles.
The heart derives its own blood supply from the ____arteries, so when one of these (or its branches) is occluded an area of the myocardium is without blood supply.
What part of the heart that suffers MI (the majority of the time)?
The thick left Ventricle bc it uses the greatest blood supply from the coronary arteries.
Infarctions usually involve an area of the wall of the _____. An area of infarction cannot be depolarized (_____) bc the cells are ______.
Left ventricle.


The MI triad is ____, ____, and _____. Any of the three can occur alone, however. This triad is the basis for recognizing and diagnosing a MI.
Ischemia, injury, necrosis
The characteristic sign of ischemia is the _______. This can occur without an MI resulting from it.
inverted symmetrical T wave
What on an ECG indicates injury? This is the earliest consistent sign of scute MI.
ST elevation above the baseline
During an angina attack the ST segment may become ______.
depressed below the baseline
When a patient with narrowed coronary arteries excercises the myocardium demands more blood flow than its arteries can deliver. A stress test will record the _________ on an ECG when the patient is exercised.
depression in ST segment.
Digoxin can cause ____of the ST segment, however it looks unique like a curve of Dali's mustache.
The diagnosis of MI is usually based on the presence of significant ____ waves produced by an area of necrosis in the wall of the Left ventricle. A significant Q wave is at least how wide?

1 small box wide (0.04s)
Significant Q waves in V1 through V4 means what type of infarction?
Anterior wall of the Left ventricle
If there are significant Q waves in the LATERAL leads ____ and ___ there is a lateral infarction.
1 and AVL
Inferior infarction is diagnosed by the presence of significant Q waves in the inferior leads ___, ___, and ___.
2, 3, AVF
Always check V1 and V2 for

1. Anterior infarct
2. Posterior infarct
1. Anterior: ST elevation, Q waves

2. Posterior: ST depression and large R waves
The left coronary artery has 2 major branches: ____ and ____.
Circumflex branch, anterior descending branch
Where is the Right coronary artery?
It curves around the right ventricle
The circumflex branch of the left coronary artery distributes blood to where?
The lateral portion of the left ventricle.
The anterior descending branch of the left coronary artery distributed blood to where?
the anterior portion of the left ventricle
The right coronary artery wraps around the right ventricle to supply blood where?
the posterior portion of the left ventricle
Normal BP
120/80 or under
How do you measure orthostatic hypotension?
Move from supine to sitting to standing. A drop of 20/10 or more between any position indicates orthostatic hypotension
What is acute pericarditis?
inflammation of the pericardium, the membranous sac that encloses the heart
What are the assessment findings in someone with pericarditis?
Substernal pain that radiates to the Left side of the neck/shoulder/or back.

Pain aggravated by inspiration, coughing, swallowing, laying flat.

You may hear a pleural friction rub at the L lower sternal border
What is the major complication of pericarditis?
Pericardial effusion (space btw the parietal and visceral layers of the pericardium fills with fluid). This puts the pt at risk for cardiac tamponade, which drops your cardiac output.
Describe cardiac tamponade.

How can you treat this?
Occurs when lots of fluid accumulates in percardium. CARDIAC TAMPONADE IS A MEDICAL EMERGENCY!!!

Treatment: Pericardiocentesis, where a catheter removes the excess fluid.
Troponin levels in MI _____.

Troponin T should be below 0.2 in a healthy individual.
Creatinine Kinase levels ____ in MI.

Females 135 or under is good
Males 170 or under is good
Myoglobin in MI ________.
Increases abt 2 hours after MI occurs and declines rapidly after 7 hours

90 or under is healthy normal
If homocysteine is increased what is this a risk factor for?
Levels of C-reactive protein over _____ put you at high risk for heart disease.
3 mg/dL
What values do you look at if a pt is on coumadin?
pt and inr
What lab value do you look at if a pt is on heparin?
What is the most definitive but most invasive test in the diagnosis of heart disease?
Cardiac catheterization
Tricuspid valve
separates R atrium from R ventricle
Bicuspid (Mitral) valve
separates L atrium from L Ventricle
What are the 2 semilunar valves?
Pulmonic valve and aortic valve
Pulmonic valve
Between R ventricle and pulmonary artery
Aortic valve
Between L ventricle and aorta
To maintain adequate blood flow through the coronary arteries mean arterial pressure (MAP) must be___mmHg.
60+ This is sufficient to perfuse major body organs and tissues.
Relaxation and filling of atria and ventricles
Contraction and emptying of atria and ventricles
How do you calculate cardiac output?
CO = HR x Stroke Volume
Stroke Volume
Amt of blood ejected by L ventricle during each systole
The amount of cardiac muscle fiber stretch at the end of diastole
What happens if stretching is too high during diastole?
cardiac output decreases
The resistance that the ventricles must overcome to eject blood through the semilunar valves.
Hemodynamic monitoring
an invasive system used in critical care areas to directly measure blood pressures in the heart anad great vessels
Pulmonary artery catheter
multilumen catheter that can measure right atrial and indirect left atrial pressures, as well as cardiac output.
How do you hang blood products?
With normal saline. NEVER add meds to the blood. Take vitals 1st (including temp). Begin transfusion. Stay with client for first 15-30mins. Retake vitals 15 mins after transfusion starts and then every hour.
When are packed red blood cells given?
To replace blood lost from trauma or surgery. Client usually has Hgb of less than 6 g/dL.
When are platelets given?
If a client has less than 20,000 platelets. Rigors (severe chills) during the transfusion is normal.
When is fresh frozen plasma given?
To replace blood volume in actively bleeding clients with a PT or PTT greater than 1.5 times the normal value.
Where is lead V1?
4th IC space, R sternal border
Where is lead V2
4th IC space, L sternal border
Where is lead V3?
Diagonally between V2 and V4
Where is lead V4?
5th IC space, midclavicular (Apical pulse)
Where is lead V5?
5th IC space, anterior axillary line
Where is lead V6?
5th IC space, midaxillary line