Review lead placement
What is an ECG
12 lead ECG provides information about rate, rhythm, conduction, areas of ischemia and infarct, hypertrophy, electrolyte imbalance, and systemic pathologies
P wave
arterial depolarization
Always the same
P-R interval time
required for impulse to travel from atria through conduction system to Purkinje fibers
0.12 - 0.2 sec
QRS Wave
Ventricle depolarization
0.04 - 0.1 sec
ST segment
beginning of ventricular depolarization
T wave
ventricular repolarization
QT interval
time for electric systole
Counting heart rate by ECG
-count intervals between QRS complexes in 6 second strip and multiply by 10
Possible etiology of arrthymias
- ischemic conditions of myocardium, electrolyte imbalance, acidosis or alkalosis, hypoxia, hypotension, emotional stress, drugs, alcohol, caffeine
ventricular arrhythmia
- originate from an ectopic focus in the ventricles (outside the normal conduction system)
- significant in adversely affecting cardiac output
what is a premature ventricular contraction
- a premature beat arising from the ventricle
- occurs occasionally in the majority of normal population
How does PVC look on ECG
- no P wave
- A bizarre and wide QRS that is pre-mature followed by a compensatory pause
Serious PVCs
- > 6 per minute
- paired or in sequential runs
- multifocal
- very early PVC (R on T phenomena)
Ventricular tachycardia
- A run of four or more PVC’s occurring sequentially
- very rapid rate (150-200 bpm)
-may occur paroxysmally (abrupt onset) - usually the result of an ischemic ventricle
What does ventricular tachycardia look like on ECG
- wide, bizarre QRS waves, no P wave
- very compromised cardiac output
Non-sustained ventricular tachycardia (NSVT)
a run of four or more consecutive beats in duration, terminating spontaneously in less than 30 seconds
Sustained ventricular tachycardia (VT)
VT > 30 seconds in duration and/or requiring termination due to hemodynamic compromise in less than 30 seconds
Ventricular fibrillation
- a pulseless, emergency situation requiring emergency medial treatment (CPR, defibrillation), and medication
- characterized by chaotic activity of ventricle originating from multiple foci
- unable to determine rate
how does V-Fib look on ECG
Bizarre, erratic cardiac output without QRS complexes
- no effective cardiac output
- clinical death within 4-6 mins
Atrial Arrhythmia (supraventricular)
- rapid and repetitive firing of one or more ectopic foci in the atria (outside the sinus note)
- cardiac output usually maintained if rate is controlled; may precipitate ventricular failure in an abnormal heart
how does atrial arrhythmia look on ECG
- P waves are abnormal (variable in shape) or not identifiable (a-fib)
- rhythm may be irregular: chronic or occurring paroxysmally
- Rate: rapid w/ arterial tachycardia (140-250 bpm), atrial flutter (250-350 bpm), fibrillation (>300 bpm)
AV Blocks
abnormal delays or failure to conduct through normal conducting system
- First, second, or third (complete) degree blocks; bundle branch blocks
- if ventricular rate is slowed, CO is decreased
Third degree heart block
- complete heart block
- life threatening
- requires medication (atropine), surgical implantation of pacemaker
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The Heart and Circulation34
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Peripheral Circulation20
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Neurohumeral Influences of the Heart31
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Cardiovascular System Physical Examination70
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EKG36
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Peripheral Vascular Examination40
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Cardiovascular Diagnostic Tests11
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Cardiac Laboratory Tests and Values19
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Coronary Artery Disease/ Acute Coronary Syndrome20
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Myocardial Infarction14
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Heart Failure16
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Medical and Surgical Management of CVD22
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Peripheral Vascular Disease: Evaluation, Differential Diagnosis, Prognosis28
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Intervention 140
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Intervention 2- Exercise Prescription32
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Cardiac Rehab35
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Heart Failure Exercise Prescription18
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Cardiac Transplant Exercise Prescription4
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Pacemakers and Automatic Implantable Cardioverter Defibrillators Exercise Prescription8
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Rehab Guidelines for Arterial Disease13
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Rehab Guidelines for Venous Disease3
