this presentation in the form of slide share that describe explaining about ECG and rhythm associated with cardiac disease

1. Basic Cardiac Dysrhythmias
Introduction and Sinus Rhythms

2. Basic Electrophysiology
*Electrocardiography cannot detect mechanical
performance of the heart*
Beware of Pulseless Electrical Activity
Expert Level Dysrhythmia Interpretation does
not replace expert level patient assessment.

3. The Hierarchy of Pacemakers
SA Node (60-100)
AV Node (40-60)
Purkinje Fibers (20-
40)

4. Organized Depolarization

5. PQRST Complex
P wave
PR Interval
QRS Complex
QRS Duration
QT Interval
ST Segment
T Wave

6. Basic Electrophysiology
Absolute Refractory
Period – Cells Unable to
receive impulse
Relative Refractory Period
Vulnerable period
Prone to internal and
external stimuli.

7. Electrocardiographic Monitoring
A “lead” is an interface
between the electrical
current of the heart and
one or more electrode.
Standard Leads
Unipolar (Limb) Leads
Modified Leads
Frontal Plane

8. Precordial Leads
V1 is placed in the 4th ICS at the
Right Sternal Border
V2 is placed in the 4th ICS at the
Left Sternal Border
V4 is then placed in the 5th ICS at
the Midclavicular Line
V3 is placed between V2 and V4
V6 is placed in the 5th ICS at the
Midaxillary Line
V5 is then placed between V4 and
V6

9. Electrocardiographic Monitoring
3 seconds 200 ms 40 ms

10. Rhythm Analysis Procedure
1) Determine Heart Rate (Atrial and Ventricular)

11. Rhythm Analysis Procedure
2) Determine Regularity (Pattern of Irregularity)

12. Rhythm Analysis Procedure
3) Identify Morphology of P waves and A:V
Ratio

13. Rhythm Analysis Procedure
4) Determine PR Interval (Normally between
120 and 200ms and consistent)

14. Rhythm Analysis Procedure
5) Determine QRS Morphology and Duration
(Normally less than 120 ms and consistent)

15. Rhythm Analysis Procedure
6) Determine the QT Interval (Normally less
than ½ the preceding R-R interval)
R - R Interval

16. Questions?
What is Automaticity?
What is the inherent rate of the AV node?
What does the T wave represent?
When is the Relative Refractory Period?
What is the normal duration of the QRS Interval?
What is a normal QT interval?

17. Sinus Rhythm
Rate: 60 to 100 bpm Regularity: Regular
Early/Late Beats: None
P Wave Morphology and AV Ratio: Uniform Upright P waves.
Ratio 1:1
PR Interval: Between: 120-200ms (0.12-0.20seconds)
QRS Duration and Morphology: Less than 120ms
(0.12seconds). Identical Morphology
QT Interval: Less than ½ the preceding R-R Interval

18. Sinus Bradycardia
Rate: Below 60 bpm Regularity: Regular
Early/Late Beats: None
P Wave Morphology and AV Ratio: Uniform Upright P waves.
A-V Ratio 1:1PR Interval: 120-200ms (0.12-0.20seconds)
QRS Duration and Morphology: Less than 120ms
(0.12seconds). Identical Morphology
QT Interval: Less than ½ the preceding R-R Interval

19. Sinus Bradycardia
Causes: Desired effect of β-adrenergic blockers or other
medications with negative chronotropic effects (decrease heart
rate) such as Calcium Channel Blockers and digitalis
preparations. Increased Vagal tone from vomiting, straining, or
carotid sinus massage. Sinus Brady may be a normal variant,
especially in athletes. Hypothyroidism, hyperkalemia.
Concerns: Sudden onset Sinus Bradycardia can severely decrease
cardiac output and lead to dizziness, lightheadedness, syncope
etc. It is also a common early rhythm in acute inferior
myocardial infarction. It can also be the presenting rhythm
with increased intracranial pressure. Determine the
hemodynamic consequence of this rhythm for this patient.

20. Treatment of Bradycardias
Only symptomatic Bradycardia is Treated!
What Symptoms would a patient with
bradycardia experience?
Atropine 0.5 – 1.0 mg q3-5min (total of 0.03-
0.04 mg/kg)
Transcutaneous Pacing
Dopamine Infusion (Not Push) 2-10µg/kg/min
Epinephrine Infusion (Not Push) 1-4µg/min

21. Sinus Tachycardia
Rate: 100bpm to 160bpm Regularity: Regular
Early/Late Beats: None
P Wave Morphology and AV Ratio: Uniform Upright P waves.
A-V Ratio 1:1
PR Interval: 120-200ms (0.12-0.20seconds)
QRS Duration and Morphology: Less than 120ms
(0.12seconds).
Identical Morphology
QT Interval: Less than ½ the preceding R-R Interval

22. Sinus Tachycardia
Causes: Exertion, Exercise, Fever, Pain, Anxiety,
Stimulants (caffeine, nicotine, cocaine),
Medications that decrease parasympathetic tone
(atropine), Medications that increase sympathetic
tone, Hypoxia, Hypo/Hypervolemia, CHF,
Hyperthyroidism, Pulmonary Embolism
An increased heart-rate improves cardiac output (to a
certain point), but also increases the work of the
heart. Above approx. 120bpm, the coronary arteries
suffer impaired filling. Patients with preexisting heart
disease may have trouble maintaining cardiac output.

23. Sinus Tachycardia
Treatment: Treat the underlying cause: fever, pain,
dehydration, volume overload
In rare instances, a patient with compromised heart
function may not tolerate sinus tachycardia. If the
underlying cause cannot be corrected before the
patient develops signs and symptoms of diminished
cardiac output; administration of medications may be
required. Two examples of medications with negative
chronotropic properties are β-adrenergic blockers and
Calcium Channel Blockers.

24. Sinus Arrhythmia
Rate: Varies, Between 60-100bpm termed Sinus Arrhythmia, below 60bpm
termed S. Bradyarrhythmia, above 100bpm termed S.
Tachyarrhythmia
Regularity: Irregular, may be Irregularly or Regularly Irregular
Early/Late Beats: Beats occur at variable intervals.
P Wave Morphology and AV Ratio: Uniform Upright P waves. A-V Ratio
1:1PR Interval: 120-200ms (0.12-0.20seconds)
QRS Duration and Morphology: Less than 120ms (0.12seconds). Identical
Morphology
QT Interval: Less than ½ the preceding R-R Interval

25. Sinus Arrest
Sinus Arrest is caused by failure in the Autorhythmicity of the SA
node
Causes include increased Vagal tone, Sinus Node calcification or
Ischemia, Myocarditis Hypoxia, or medications with negative
chronotropic properties (digitalis, β-blockers, Ca++ Channel
Blockers).