Download Arrhythmias

Arrhythmias
Dr. Ahmad Hersi
Med 441
6/1/2009
Conduction System
Septal Branch
Depolarization Sequence
Catechism
Identification
Quality
Rate
Rhythm
Axis
Waves and
intervals
Specifics
Frontal (limb lead) axis
I
II
aVF
Limb-lead Misplacement
I
II
aVF
Precordial Leads
V1: Right 4th ICS parasternal
V4: 5th ICS mid-clavicular line
V2: Left 4th ICS parasternal
V6: lateral to V4 mid-axillary line
Rate
Start if possible on a beat whose QRS (usually R wave) is on the
border of a large square
300 100 60
40
150 75 50
Count Large squares
(0.2 seconds each)
This tracing example shows a rate of 100 bpm
Rate determination for irregular
rhythm
*
8 times 10 = 80 bpm
30
For irregular rhythm (such as atrial fibrillation), the method shown on the last slide
may be inaccurate. Use this alternate method.
Start as before by finding a QRS that lands on the border of a large square (*).
Then count 30 large squares (= 0.2 X 30 = 6 seconds). Add up all beats (QRSs)
that land within the interval (not counting that first beat (*) and multiple by 10.
This equals the number of beats per minute.
Rhythm
“Cherchez la P”
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To be convinced of sinus rhythm, you
should see a P wave in front of every QRS,
and the PR interval should not alter, and be
of a plausible length.
Lead II is usually the best lead for seeing
P waves, and is often used for rhythm
strips.
QRS Axis
Left
I (-)
aVF (-)
II (-)
I (+)
aVF (-)
II (-)
Right
I (-)
aVF (+)
II (+)
Normal
I (+)
aVF (+)
II (+)
Quick Method for QRS Axis
I
aVF
II
The P Wave
•Normally from sinus node
•Upright in I, II, aVF, V4-V6
•Monophasic (except V1)
•Normal ranges:
o < 0.12 sec wide
o < 2.5 mm tall
The PR Interval
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Measure from
beginning of P wave to
onset of QRS. Usually
measure in Lead II
Measure the longest
PR interval in the limb
leads
Normal range 0.120.20 seconds
< 0.12 = Accelerated conduction
> 0.2 = Heart block
Right Atrial Enlargement
Left Atrial Enlargement
The QRS Complex
The Q Wave
The J - Point
QRS Waveforms
The ST Segment
The T Wave
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
T waves may be
normally inverted in
aVR (almost always),
III (frequently), and V1
(sometimes).
T waves are “tall” if
their height is:
– > 50% QRS height
– > 5mm in limb lead
– > 10 mm in precordial
lead
The QT Interval
RR
The U Wave

Causes:
–
–
–
–
–
–
Normal
Bradycardia
CAD
Hypertension
Hypokalemia
Hypercalcemia
Left Ventricular Hypertrophy
*
*
*
*
Right Ventricular
Hypertrophy
LBBB
RBBB
Case 1
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65 yr woman, presents to ER with
Dizziness for 2hrs.
In the past, a doctor told her that her
heart rate is slow.
Healthy otherwise, and is not on
med’s.
O/E : Bp=170/100
Another dizzy lady
Had syncope
What is the appropriate
therapy?
Management

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ABC
V/S
If serious symptoms or signs:
- Atropine 1 mg
- TCP
- Dopamine
- Epinephrine
- Isoproterenol
Management

If clinically stable:
- Prepare for TVP as a bridge device
Case 2
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25yr old woman
1 hr h/o palpitation
No other cardiac symptoms
Intermittent palpitation in the last 3
months , this episode is long
BP= 120/70
What is your management?
Management
Narrow Complex tachycardia
Serious signs and symptoms
Immediate Cardioversion
Stable clinically
Vagal maneuvers
Adenosine or Verapamil
Consider BB, Diltiazem , or Digoxin
Case 3
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60 yrs C/O sudden onset dyspnea for last
1/2hr
Past MI 1 yr ago, received thrombolytics.
His ECHO at the time revealed impaired LV
systolic function
Med’s: ASA, Bisoprolol, Lisinopril, and Lasix
On exam , BP=80/50
Bouts of palpitations
WPW
 Short PR interval, less than 3 small squares (120 ms)
 Slurred upstroke to the QRS indicating pre-excitation
(delta wave)
 Broad QRS
 Secondary ST and T wave changes
• An accessory pathway, bundle of Kent, exists between
atria and ventricles and causes early depolarisation of
the ventricle.
Case 4
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75 yrs woman
Presents to ER with fever and
productive cough
PMH= HTN
BP=150/90
How would you manage ?
Management
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If patient is hypoxemic  O2
Control BP ( may chose a BB or CCB
for rate control and BP control)
Rate control the ventricular response if
tachycardia .
Consider Long term anticoagulation if
no contraindications
Normal ECG
A 63 year old woman with 10 hours of chest pain and
sweating.
An 83 year old man with aortic stenosis.
A 75 year old woman with loud first heart sound and
mid-diastolic murmur.
A 59 year old woman with chronic bronchitis.
An 84 year old woman with hypertension
A 73 year old woman with dizziness.
A 70 year old man with exercise intolerance.
A 90 year old lady with syncope.
A 76 year old man with SOB
A woman with Romano-Ward Syndrome
A 45 year old women with palpitation and a
history of CRF
A 47 year old man with a long history of
palpitations and blackouts.
A 58 year old man on hemodialysis presents
with weakness
A 28 year old woman
with prolonged
vomiting