Download EKGs

Natalia Fernandez, PT, MS, MSc, CCS
University of Michigan Health Care System
Department of Physical Medicine and Rehabilitation.
Premature Atrial Contractions
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 A Premature Atrial Contraction (PAC) occurs when a focus in the atrium other than the SA
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node generates an action potential before the next scheduled SA node action potential.
There are four main characteristics of PACs:
Premature
Ectopic
Narrow complexes (QRS <.12 sec)
Compensatory pause
Premature Atrial Contractions
Defining Criteria and ECG features
 Underlying Rhythm: Usually Regular
 Rate: normal or accelerated (underlying rhythm
dependent)
 P waves: different morphology than sinus P wave,
(premature and abnormal in size, shape and direction as
ectopic pacemaker)
 PR interval: normal vs. not measureable
 QRS: <.12sec
Supra Ventricular Tachycardia (SVT)
Defining Criteria and ECG features
 Rate: seldom <150 per minute, often up to 250 per min
 Rhythm: regular
 P wave: hidden
 PR interval: not measureable
 QRS: normal, narrow (usually <.12sec)
Supra Ventricular Tachycardia (SVT)
Clinical Manifestations:
 Palpitations felt at onset by patients
 Anxious
 Uncomfortable
 Low exercise tolerance at high rates
Common Etiologies:
 Accessory conduction pathways
 In healthy people reentry SVT provoked by caffeine, hypoxia,
cigarettes, stress, anxiety, sleep deprivation, medication
 Frequency of SVT is increased in unhealthy patients with CAD,
chronic obstructive pulmonary disease and CHF.
Heart Block
Second degree Type I -Mobitz I or Wenchebach
Defining Criteria and ECG features:
 Rhythm: Regular atrial rhythm; irregular ventricular rhythm
 Rate: variable
 P waves: Sinus (normal morphology with constant P-P interval)
 PR interval: progressively lengthening of PR interval from cycle to cycle; then
one P wave not followed by QRS complex (“dropped beat”)
 QRS complex: Normal (0.10 second or less) but QRS “drops out” periodically
Heart Block
Second degree Type I -Mobitz I or Wenchebach
Clinical Manifestations:
Rate-related
 Most often asymptomatic
 Symptoms: chest pain, SOB, decreased level of consciousness
 Signs: hypotension, shock, pulmonary congestion, CHF, angina
Common Etiologies:
 AV nodal blocking agents : beta-blockers, non – dihydropyridine
calcium channel blockers, digoxin
 Conditions that stimulate the parasympathetic nervous system
 Acute coronary syndrome that involves the R coronary artery
Heart Block
Second degree Type II -Mobitz II
Defining Criteria and ECG features:
 Rhythm: Regular atrial rhythm; irregular ventricular rhythm
 Rate: Atrial rate: usually 60-100 per minute (underlying sinus rhythm)
Ventricular rate: slower than atrial rate
 P waves: Sinus; some P waves will not be followed by QRS complex
 PR interval: may be normal or prolonged; but is constant.
 QRS complex: Normal or wide
Heart Block
Second degree Type II -Mobitz II
Clinical Manifestations:
 Symptoms: chest pain shortness of breath, decreased level
of consciousness
 Signs: hypotension, shock, pulmonary congestion, CHF,
AMI
Common Etiologies:
 Acute coronary syndrome that involves braches of left
coronary artery
Heart block – Third Degree
Rhythm: Regular atrial and ventricular rhythm
Rate: Atrial: 60-100bpm
Ventricular: 20-40 bpm
P waves: sinus, have no relationship to the QRS complex
PR interval: there is no relationship between P wave and
R wave
QRS complex: Normal or wide
Heart block – Third Degree
Clinical Manifestations:
 Symptoms: chest pain shortness of breath, decreased level of
consciousness
 Signs: hypotension, shock, pulmonary congestion, CHF, AMI
Common Etiologies:
 Acute coronary syndrome that involves braches of left coronary
artery.
Heart Block
Heart Block
Bundle Branch Blocks
Defining Criteria and ECG features:
 Rhythm: regular (regular or irregular depending on underlying
rhythm)
 Rate: that of the underlying rhythm
 P waves: sinus (normal if underlying rhythm is sinus)
 PR interval: normal (0.12-.20 sec)
 QRS complex: wide (0.12 second or greater)