Self-Study Perfusion

Cardiac Output

Total volume of blood pumped by the heart in 1 minute

Formula for Cardiac Output

Heart Rate X Stroke volume = cardiac output

Name 3 categories of arrhythmia that can interfere with cardiac output.

Ventricular irritability

List 8 symptoms of reduced cardiac output.

o Anxiety
o Chest pain
o Shortness of breath
o Diaphoresis
o Hypotension
o Cool, clammy skin
o Cyanosis
o Decreased consciousness

Name additional measures that may be needed to support perfusion.

o Ventilation
o Chest compression
o Medication to stabilize blood pressure

Give an overview of the American Heart Advanced Cardiac Life Support recommendations for treating arrhythmias.

o All patients with arrhythmias or the potential for them should be monitored and receive oxygen and an IV line.
o When arrhythmias cause symptoms, treatment should be initiated immediately.
o In addition to treatment of the specific presenting arrhythmia

Normal P wave

atrial depolarization

Normal QRS

ventricular depolarization

Normal T wave

ventricular repolarization

Define a normal PR interval (PRI)

From beginning of P wave to beginning of the QRS complex
Between .12 and .20 seconds

Define a normal QRS interval.

From beginning of Q wave to end of S wave
Less than .12 seconds

List some external factors capable of producing artifact on an EKG tracing.

Muscle tremors
Patient movement
Loose electrodes
60-cycle interference

Normal Sinus Rhythm

Regular rate and rhythm- 60-100 beats per minute - P wave normal and upright - always in front of the QRS - one P wave for every QRS complex

Sinus Bradycardia

Regular rhythm - less than 60 in the adult

Sinus Bradycardia Treatment

-Admin O2
-Atropine Sulfate
-IV fluids

Sinus Tachycardia

Regular rhythm greater than 100 in the adult - P wave is normal but may be buried in the preceding T wave

Sinus Arrhythmia

irregular rhythm and irregular rate- 60-100 in adult
HR decrease during expiration
HR increase during inpiration

Premature Atrial Contractions

A single premature ectopic beat
P wave of the premature beat will have a different shape than the P waves of the rest of the rhythm strip.
The ectopic beat will have a P wave, but it can be flattened, notched, or otherwise unusual. It may be hidden within

Wandering Pacemaker

Shape of P wave changes from beat to beat
Rhythm slightly irregular

Atrial Tachycardia

Regular rhythm - 150-250 - atrial P wave (looks different than sinus P wave)

Atrial Flutter

Atrial rate between 250 and 400 - ventricular rate between 75 and 150 - P wave is saw-toothed shape

Atrial Fibrillation (A-fib)

Atrial rate is 300-600 - ventricular rate is 120-200 - highly irregular ventricular and atrial rhythm - no P waves seen - cannot measure PR interval

Atrial Fibrillation Treatment

-anticoagulants (formation of thrombi that can dislodge due to quivering atrium)
-antidysrhythmic drugs
-cardio-version drugs

Premature Junctional Contractions (PJC)

P waves are inverted - P waves can fall before, during or after the QRS complex

Junctional Escape Rhythm

Rate of 40-60
P waves are inverted

Accelerated Junctional Rhythm

Rate of 60-100 - P waves are inverted

Junctional Tachycardia

Rate of 100-180 - P waves are inverted

First-Degree Heart Block

PR interval greater than 0.20 seconds

Second-Degree Heart Block, Type 1, Wenckebach

PR interval becomes longer with each succeeding complex until there is a P not followed by a QRS ("marching off")

Second-Degree Heart Block, Type II

P to QRS ratio is 2:1, 3:1, 4:1, 5:1 and so forth

Third-Degree Heart Block

- Very irregular PR interval
- more P waves than QRS complexes
(most serious degree of heart block-- the pt will code if we don't do something)

Premature Ventricular (PVC)

Irregular rhythm
- shape of QRS is bizarre and abnormal
- P-wave will be absent

Ventricular Tachycardia (V-Tach)

Ventricular rate is 100-200
QRS is 0.12 seconds or more with a bizarre and abnormal shape
Very irregular PR intervals
Usually more QRS complexes than P waves
(if the rhythm is regular with no visible P waves it is supraventricular tachycardia)

Treatment of V-Tach w/ pulse and no signs of decreased cardiac output

- O2
- Antidysrhythmic

Treatment of V-Tach w/ pulse and signs of decreased cardiac output

- O2
- antidysrhythmic
- Vagal maneuver
- synchronized cardioversion

Treatment of pulse-less V-Tach

(fatal if not terminated in 3-5 mins)
- O2 and antidysrhythmic

Ventricular Fibrillation (V-Fib)

Ventricular rate greater than 300
Extremely irregular rhythm

Idioventricular Rhythm

Rate between 20-40
QRS has a bizarre abnormal shape


Absent QRS complexes

Explain the advantage of a 12-lead EKG tracing over a single lead strip.

12 lead EKG shows the heart from 12 different directions providing a more complete picture of cardiac function
� can locate issue damage
� identify abnormally large chambers
� provide more details about conduction
� point out metabolic and chemical abnorm

V1 (EKG Placement)

right side chest - 4th intercostal space - next to sternum

V2 (EKG Placement)

left side chest - 4th intercostal space - next to sternum

V3 (EKG Placement)

left side chest - draw imaginary line between V2 and V4 - halfway in between

v4 (EKG Placement)

left side chest - 5th intercostal space - straight down from nipple

V5 (EKG Placement)

left side chest - 5th intercostal space - draw
imaginary line between V4 and V6 - halfway in between

V6 (EKG Placement)

left side chest - 5th intercostal space - draw imaginary line down from axilla

Define ischemia

Tissue damage caused by a lack of oxygen in a portion of myocardial wall

Define myocardial infarction.

Results of ischemia causing myocardial wall tissues to die completely

Describe EKG changes associated with myocardial damage.

ST segment - depression, elevation
T wave - peaking, flattening, inversion
Q wave - deepening and widening of Q waves

Describe the evolution of ischemic changes (age of infarction.)

As ischemic damage evolves from the first hours through days, weeks and months, the EKG picture will continue to change in a more or less predictable sequence, thus suggesting age of infarction

Define bundle branch block

Conduction defect within the bundle branches, causing a prolonged QRS measurement (>.12 seconds)

State which leads identify damage on specific surfaces of the heart.
Anterior -
Lateral -
Inferior -

Anterior - V1-V2-V3-V4
Lateral - I, AVL, V5, V6
Inferior - II, III, AVF

Describe the appearance of pericarditis on an EKG.

ST changes similar to those of ischemia/infarction. (ST elevation)

Describe the appearance of digitalis on an EKG.

Digitalis toxicity produces scooped ST segments and a shortened QT interval

Describe the appearance of hyperkalemia on an EKG.

peaked T waves and merging of the QRS and T waves

Describe the appearance of hypokalemia on an EKG.

flat T waves, widening of QRS complexes and appearance of "U" waves

Describe the appearance of hypercalcemia on an EKG.

QT intervals that are unexpectedly short for the rate

Describe the appearance of hypocalcemia on an EKG.

QT intervals are longer than expected

Explain the purpose of an artificial pacemaker.

Pacemakers apply an artificial stimulus to the heart muscle and stimulate the ventricles, the atria or both.

Explain the two basic ways pacemakers can initiate pulses.

Triggered pacemakers fire at a predetermined rate.
Inhibit pacemakers fire only when needed.

Describe the appearance of pacemakers on an EKG.

Unnaturally sharp spikes superimposed on the patient's underlying rhythm