ArrhythmiasArrhythmias

Dr. Ahmad HersiDr. Ahmad Hersi

Med 441Med 441

6/1/20096/1/2009

Conduction SystemConduction SystemConduction SystemConduction System

Septal Branch

Depolarization SequenceDepolarization Sequence

CatechismCatechismCatechismCatechism

Identification

Quality

Rate

Rhythm

Axis

Waves and intervals

Specifics

Identification

Quality

Rate

Rhythm

Axis

Waves and intervals

Specifics

Frontal (limb lead) axisFrontal (limb lead) axisFrontal (limb lead) axisFrontal (limb lead) axis

II

aVFaVF

IIII

Limb-lead MisplacementLimb-lead MisplacementLimb-lead MisplacementLimb-lead Misplacement

II

aVFaVF

IIII

Precordial LeadsPrecordial LeadsPrecordial LeadsPrecordial Leads

V4: 5th ICS mid-clavicular line

V6: lateral to V4 mid-axillary line

VV11: : Right 4th ICS parasternal

V2: Left 4th ICS parasternal

RateRateRateRate

300 100 60 40

150 75 50

Start if possible on a beat whose QRS (usually R wave) is on the border of a large squareStart if possible on a beat whose QRS (usually R wave) is on the border of a large square

Count Large squares

(0.2 seconds each)

Count Large squares

(0.2 seconds each)

This tracing example shows a rate of 100 bpm

Rate determination for irregular Rate determination for irregular rhythmrhythm

30

8 times 10 = 80 bpm

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.

*

RhythmRhythmRhythmRhythm

““Cherchez la P”Cherchez la P” To be convinced of sinus rhythm, you To be convinced of sinus rhythm, you

should see a P wave in front of every should see a P wave in front of every QRS, and the PR interval should not QRS, and the PR interval should not alter, and be of a plausible length.alter, and be of a plausible length.

Lead II is usually the best lead for Lead II is usually the best lead for

seeing P waves, and is often used for seeing P waves, and is often used for rhythm strips.rhythm strips.

““Cherchez la P”Cherchez la P” To be convinced of sinus rhythm, you To be convinced of sinus rhythm, you

should see a P wave in front of every should see a P wave in front of every QRS, and the PR interval should not QRS, and the PR interval should not alter, and be of a plausible length.alter, and be of a plausible length.

Lead II is usually the best lead for Lead II is usually the best lead for

seeing P waves, and is often used for seeing P waves, and is often used for rhythm strips.rhythm strips.

QRS AxisQRS Axis

Left

Right Normal

I (-)aVF (-)II (-)

I (-)aVF (+)II (+)

I (+)aVF (-)II (-)

I (+)aVF (+)II (+)

Quick Method for QRS AxisQuick Method for QRS Axis

I

aVF

II

The P WaveThe P Wave

•Normally from sinus node

•Upright in I, II, aVF, V4-V6

•Monophasic (except V1)

•Normal ranges: o < 0.12 sec wideo < 2.5 mm tall

The PR IntervalThe PR IntervalThe PR IntervalThe PR Interval

Measure from Measure from beginning of P wave to beginning of P wave to onset of QRS. Usually onset of QRS. Usually measure in Lead II measure in Lead II

Measure the longest Measure the longest PR interval in the limb PR interval in the limb leadsleads

Normal range 0.12-Normal range 0.12-0.20 seconds0.20 seconds

< 0.12 = Accelerated conduction< 0.12 = Accelerated conduction > 0.2 = Heart block> 0.2 = Heart block

Measure from Measure from beginning of P wave to beginning of P wave to onset of QRS. Usually onset of QRS. Usually measure in Lead II measure in Lead II

Measure the longest Measure the longest PR interval in the limb PR interval in the limb leadsleads

Normal range 0.12-Normal range 0.12-0.20 seconds0.20 seconds

< 0.12 = Accelerated conduction< 0.12 = Accelerated conduction > 0.2 = Heart block> 0.2 = Heart block

Right Atrial EnlargementRight Atrial EnlargementRight Atrial EnlargementRight Atrial Enlargement

Left Atrial EnlargementLeft Atrial EnlargementLeft Atrial EnlargementLeft Atrial Enlargement

The QRS ComplexThe QRS ComplexThe QRS ComplexThe QRS Complex

The Q WaveThe Q WaveThe Q WaveThe Q Wave

The J - PointThe J - PointThe J - PointThe J - Point

QRS WaveformsQRS WaveformsQRS WaveformsQRS Waveforms

The ST SegmentThe ST SegmentThe ST SegmentThe ST Segment

The T WaveThe T WaveThe T WaveThe T Wave

T waves may be T waves may be normally inverted in normally inverted in aVR (almost always), aVR (almost always), III (frequently), and V1 III (frequently), and V1 (sometimes).(sometimes).

T waves are “tall” if T waves are “tall” if their height is: their height is: – > 50% QRS height > 50% QRS height – > 5mm in limb lead> 5mm in limb lead– > 10 mm in precordial > 10 mm in precordial

leadlead

T waves may be T waves may be normally inverted in normally inverted in aVR (almost always), aVR (almost always), III (frequently), and V1 III (frequently), and V1 (sometimes).(sometimes).

T waves are “tall” if T waves are “tall” if their height is: their height is: – > 50% QRS height > 50% QRS height – > 5mm in limb lead> 5mm in limb lead– > 10 mm in precordial > 10 mm in precordial

leadlead

The QT IntervalThe QT IntervalThe QT IntervalThe QT Interval

RR

The U WaveThe U WaveThe U WaveThe U Wave

Causes:Causes:– NormalNormal– BradycardiaBradycardia– CADCAD– HypertensionHypertension– HypokalemiaHypokalemia– HypercalcemiaHypercalcemia

Causes:Causes:– NormalNormal– BradycardiaBradycardia– CADCAD– HypertensionHypertension– HypokalemiaHypokalemia– HypercalcemiaHypercalcemia

Left Ventricular HypertrophyLeft Ventricular HypertrophyLeft Ventricular HypertrophyLeft Ventricular Hypertrophy

*

* *

*

Right Ventricular Right Ventricular HypertrophyHypertrophyRight Ventricular Right Ventricular HypertrophyHypertrophy

LBBBLBBBLBBBLBBB

RBBBRBBBRBBBRBBB

Case 1Case 1

65 yr woman, presents to ER with 65 yr woman, presents to ER with Dizziness for 2hrs.Dizziness for 2hrs.

In the past, a doctor told her that In the past, a doctor told her that her heart rate is slow.her heart rate is slow.

Healthy otherwise, and is not on Healthy otherwise, and is not on med’s.med’s.

O/E : Bp=170/100 O/E : Bp=170/100

Another dizzy ladyAnother dizzy lady

Had syncope Had syncope

What is the appropriate What is the appropriate therapy?therapy?

Management Management

ABCABC V/SV/S If serious symptoms or signs:If serious symptoms or signs: - Atropine 1 mg- Atropine 1 mg - TCP- TCP - Dopamine - Dopamine - Epinephrine- Epinephrine - Isoproterenol - Isoproterenol

ManagementManagement

If clinically stable:If clinically stable:

- Prepare for TVP as a bridge device- Prepare for TVP as a bridge device

Case 2Case 2

25yr old woman 25yr old woman 1 hr h/o palpitation1 hr h/o palpitation No other cardiac symptomsNo other cardiac symptoms Intermittent palpitation in the last Intermittent palpitation in the last

3 months , this episode is long3 months , this episode is long BP= 120/70BP= 120/70

What is your What is your management?management?

Management Management

Serious signs and symptoms

Narrow Complex tachycardia

Immediate Cardioversion

Stable clinically

Vagal maneuvers

Adenosine or Verapamil

Consider BB, Diltiazem , or Digoxin

Case 3 Case 3

60 yrs C/O sudden onset dyspnea for 60 yrs C/O sudden onset dyspnea for last 1/2hr last 1/2hr

Past MI 1 yr ago, received Past MI 1 yr ago, received thrombolytics.thrombolytics.

His ECHO at the time revealed impaired His ECHO at the time revealed impaired LV systolic functionLV systolic function

Med’s: ASA, Bisoprolol, Lisinopril, and Med’s: ASA, Bisoprolol, Lisinopril, and LasixLasix

On exam , BP=80/50On exam , BP=80/50

Bouts of palpitations Bouts of palpitations

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.

WPW

Case 4Case 4

75 yrs woman75 yrs woman Presents to ER with fever and Presents to ER with fever and

productive coughproductive cough PMH= HTNPMH= HTN BP=150/90BP=150/90

How would you How would you manage ?manage ?

Management Management

If patient is hypoxemic If patient is hypoxemic O2 O2 Control BP ( may chose a BB or CCB Control BP ( may chose a BB or CCB

for rate control and BP control)for rate control and BP control) Rate control the ventricular Rate control the ventricular

response if tachycardia .response if tachycardia . Consider Long term anticoagulation Consider Long term anticoagulation

if no contraindications if no contraindications

Normal ECGNormal ECG

A 63 year old woman with 10 hours of chest pain and A 63 year old woman with 10 hours of chest pain and sweating.sweating.

An 83 year old man with aortic stenosis.An 83 year old man with aortic stenosis.

A 75 year old woman with loud first heart A 75 year old woman with loud first heart sound and mid-diastolic murmur.sound and mid-diastolic murmur.

A 59 year old woman with chronic bronchitis.A 59 year old woman with chronic bronchitis.

An 84 year old woman with hypertensionAn 84 year old woman with hypertension

A 73 year old woman with dizziness.A 73 year old woman with dizziness.

A 70 year old man with exercise A 70 year old man with exercise

intoleranceintolerance..

A 90 year old lady with syncope.A 90 year old lady with syncope.

A 76 year old man with SOBA 76 year old man with SOB

A woman with Romano-Ward SyndromeA woman with Romano-Ward Syndrome

A 45 year old women with palpitation A 45 year old women with palpitation and a history of CRFand a history of CRF

A 47 year old man with a long history of A 47 year old man with a long history of palpitations and blackouts.palpitations and blackouts.

A 58 year old man on hemodialysis A 58 year old man on hemodialysis presents with weaknesspresents with weakness

A 28 year old A 28 year old woman with woman with prolonged vomitingprolonged vomiting