ARRHYTHMIA

DR MANSOUR ALQURASHI

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Objectives

At the end of this session students should be able to:

• Distinguish the normal from abnormal rhythms.
• Understand the pathophysiologic basis of arrhythmia.
• Differentiate ventricular from supraventricular arrhythmias.
• Recognize different types of supraventricular arrhythmias.
• Recognize the different types of heart block.
• Be familiar with strategies of arrhythmia management.

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Basics

Conduction System Hierarchy

Basic ECG Elements

Basic elements	Joining Segments	Duration Interval
P wave	PR segment	PR interval
QRS	ST segment	QT interval
T wave	TP segment	ST interval

2 Dimensions

QRS

• 2 ss in adult
• 2.5 ss in children

PR interval

• 3 ss in children
• 5 ss in adult

Classification of Arrhythmia

Variable	Classes	Classes	Classesx
Rate (Regular: 300 / No. of big bow between)	Tachycardia B.R.		Bradycardia
Morphology	Narrow complex (Coming from above the ventricle)		Wide complex (Coming from ventricle)
Origin	Supra-ventricular (Above AV node)	Junctional (at right AV side)	Ventricular (below AV node)
Mechanism	Reentrant	Automatic	Triggered
P-QRS relationship	1st degree AV block	2nd degree AV block	3rd degree AV block

Mechanisms of Arrhythmia

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Rhythm Analysis

(P-QRS)

Rhythm (P waves & QRS)
Present	Sinus / non sinus	abnormal P wave means it’s not from sw node cualt come from AV node or from ventricular
Absent	Real / technical

Rate (P waves & QRS)
Calculation	QRS x 10 irregular 1500 no small scar between low QRS
Slow	Appropriate/inappropriate
Fast	Narrow/wide complex

Regularity (P waves & QRS)
Regular R - R	equal
Irregular	Group beating or haphazard

P wave morphology & QRS morphology
Axis	up/down P waves, extreme axis
Duration & Axis	Normal or wide (RBBB, LBBB), sup. axis

P-QRS relationship
Normal	1:1, normal PR interval
Abnormal	Ratio, duration (fixed, variable, unrelated)

Others (PR & QT intervals)
Normal
Abnormal	Long or short

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Sinus Rhythms

Normal Sinus Rhythm

• sinus
• 300 divided by each block for HR
• no. big spin

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Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
60-100 bpm	Regular	Before each QRS, identical	.12 to .20	<.12

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Sinus Tachycardia

• Sinus , Requireur

Features:

• P wave normal shape
• HR
• Varibality: “the sinus coming from SA nodes”
• HR > 300 in fetus > 250 in neonate > 180 in pediatric
• Regular: “the sinus coming from ectopic focus”
• R - R wave are fixed
• terminate immediately after valsova maneuver or carotid massage

Clinical Scenario:

• if some one with shock and has tachycardia
• How to know which is first.
• conect the ECG
  • if sinus tachy → shock causes tachy (also if there cause for the shock: Diarrhea, vomiting…)
  • if SUT → SUT complicated by shock or V tach

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Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
> 100 bpm	Regular	Before each QRS, identical	.12 to .20	<.12

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Sinus Bradycardia

$$7\times 10=20\text{ HR}\frac{300}{6}=50\text{ HR}$$

• p^2 degree usually
• ⇐ Tachyon
• rarely cause Brady

Differential Diagnosis (child with Dec HR before doing ECG):

• Sinus Bradycardia
• 2nd, 3rd degree Heart block
• junctional rhythm

Causes:

• Sepsis - Dithaura
• B Blocker

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
< 60 bpm	Regular	Before each QRS, identical	.12 to .20	<.12

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Sinus Arrhythmia

• Cuz SA notes under the effect of sympathetic and parasympathetic so HR may change due to different causes.
• (normal or abnormal?)
• (normal variation

• Sinus, irregular

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
Usually 60-100 bpm	Irregular	Before each QRS, identical (Sinus)	.12 to .20	<.12

Notes:

• normal
• anything stimulate the heart
  • Smoking
  • Anti-histamine
  • coffee
• abnormal P wave shape
• Coming earlier so P wave will be close to the previous QRS
• Compansatory Phase “R-R become pralong”
• It’s no treatment will heal by itself only advice the family to avoid rigers

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Supraventricular Arrhythmias

Premature Atrial Contraction (PAC)

Lead II

• short pralanges
• ectopic focus from Atrium
• 25 mm/sec 10 mm/mV

Atrial Flutter

• Saw tooth appearance

Causes:

• myocarditis
• IHD
• Cardiomyopathy
• caffiene?
• energy drinks?

Treatment:

• tft: Cardioversion or medications
• Close 1 out: Artylbric

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
A: 220-430 bpm	Regular or variable	Sawtoothed appearance	N/A	<.12
V: <300 bpm

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Atrial Fibrillation

Causes:

• myocarditis
• IHD
• Myopathy
• (in adult associate with mixed stenosis & chronic) / in children usually acute

Treatment:

• Att: Anti-Hepatotic - BB / CCB to show down HR - Class 1 anti-amythmic
• work on ectopic focus
• (att: Cardioresistance of medications class 1 anti-amythmic)

I	aVR	V1	V4
II	aVL	V2	V5
III	aVF	V3	V6
II	only shaking no contraction

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
A: 350-650 bpm	Irregular	Fibrillatory (fine to course)	N/A	<.12
V: Slow to rapid

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Paroxysmal Supraventricular Tachycardia (SVT)

(AV nodal reentrant tachycardia)

Causes:

• WBW Syndrom
• ectopic focus
• IHD - Cardiomyopathy
• myocarditis
• sepsis

(Paroxismal SVT / AVNRT):

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
140-250 bpm	Regular	Abnormal P before each QRS (difficult to see)	<.20	<.12

TABLE 2. Clinical Signs and Symptoms Associated With Sinus Tachycardia and SVT

	Sinus Tachycardia	SVT
Heart rate (bpm)	Infants, below 220 Children, below 180	Infants, above 220 Children, above 180
Beat-to-beat interval	Variable	Fixed
P waves	Visible; normal axis	Not visible or abnormal axis Usually hidden in QRS or ST segment
Onset	Gradual	Abrupt
Termination	Gradual	Abrupt
Response to vagal maneuvers	Rate slows gradually, then returns	Tachycardia terminates abruptly (if successful)
Response to cardioversion	No conversion	Conversion
Fever	Strongly suspected when fever is present	2%-3% of patients have fever on presentation
Presentation with shock	Possible	Possible

treatment

• Tet:
  • Valsava manuver
  • Cold shower
  • Carotid massage
  • Blocker
• more frequent you can use BB
• at hospital:
  • Adenosin is pit not in shock
  • & in shock: shock / Cardioverison “sponsorized” need sedation
• The only 2 cases that we can use Debiritalium

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AV Blocks

First Degree AV Block

• Regular
• Prolong QR interview

Causes:

• could be normal in children
• Rheumatic fever
• hypokalemia, hypocalcemia
• IHD

Second Degree AV Block (Type I / Wenckebach)

• same causes ↑
• Progressive Prolongation PR interval
• VA: B agnisf
• Atropin
• Dopamin

P Wave	PR Interval (in seconds)	QRS (in seconds)	Characteristics
Conduction intermittent	Increasingly Prolonged	<.12	QRS dropped in a repeating pattern

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Second Degree AV Block (Type II)

• 197: B agent
• Atropin
• Dopamin
• Block 2:1
• Person aR

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Third Degree AV Block (Complete Heart Block)

• could be with other causes but it’s one of the features of complete heart block
• “Atrioventricular dissociation” no relation between P wave and QRS
• Bradycardia
• Atrial rate more than ventricular rate
• QRS could be wide or narrow (from ventricle itself, just below AV nodes)

Causes:

• SLE in the mother antibodies will skip the placenta
• Rheumatic Carbitis
• IHD
• Digitalis

Treatment:

• ett: Race maker

P Wave	PR Interval (in seconds)	QRS (in seconds)	Characteristics
Normal but not related to QRS	None	N/A	No relationship between P&RS

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Ventricular Arrhythmias

Premature Ventricular Contractions (PVCs) Y

Bigeminal Pattern

• 1:1
• no P wave
• wide QRS coming from ventricle
• “Regularly Irregular” Rhythm
• How to pick PVC clinically: Drop Pests

Causes:

• IHD, coffee, tea
• we don’t treat

Ventricular Tachycardia (VT)

What do you notice?

• no Pwowe
• wide QRS → v Tach
• monomorphic

• Rates range from 100-250 beats/min
• Non-sustained or sustained
• P waves often dissociated (as seen here)

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Monomorphic VT

What is the mechanism?

Treatment:

• ekt: Amidoron → IV line in lcu pn
• still more: Puls → cardioversion
• no Puls → defib

Polymorphic VT

What is the mechanism?

• no P wave
• wide QRS

25mm/s 10mm/mV 40Hz 005C 12SL 231 CID: 10 EID:40 EDT: 08:41 03-NOV-2004 ORDER:

True side Point

• xtt: Mg Sulfate
• aller trail of
• Carbination
• Polymorphic V each

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Ventricular Fibrillation

Treatment:

• ett:
• ICU for any resone - Amidaron → IV Line in ICU PIR
• ER
  • still there’s Puls → Carbioversion
  • no Puls → Defibrillation

Heart Rate	Rhythm	P Wave	PR interval (in seconds)	QRS (in seconds)
300-600	Extremely irregular	Absent	N/A	Fibrillatory baseline

Asystole

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Syndromes

Brugada Syndrome

• 12-lead electrocardiogram (ECG) from a patient with the Brugada syndrome shows downsloping ST elevation
• V tachycardia

• ST segment elevation and T wave inversion in the right precordial leads V1 and V2 (arrows); the QRS is normal. The widened S wave in the left lateral leads (V5 and V6) that is characteristic of right bundle branch block is absent.
• Courtesy of Dr Rory Childers, University of Chicago.
• UpToDate

Loc 55545-5000 25 mm/sec 10.0 mm/mV - W 0.50-40

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Long QT Syndrome (Jervell-Nielson-Lange)

Causes:

• hypothyroidism
• ↓ mg⁺ ↓ Ca⁺ ↓ Na⁺
• macrolides “Erythromycin”
• Glucosamine “sokimalarina”

Congenital:

• ↓ subba Death
• ↓ Definess

**QT

$$QTc=\frac{QT(\text{msec})}{\sqrt{R-R}}$$

(sec)

$$=640/1.05$$ $$=610\text{msec}$$

• significant

• 450 m sec is

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Wolff-Parkinson-White (WPW) Syndrome

• WBW
• • wide QRS
• -delta wave
• short P-R interval

Complications:

• SVT
• V each in adult

Treatment:

• Lift: if SVT treat it as SVT
• if recurrent * electrophysiotherapest * if persistent (burn the exercise electrical focus

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Tores de pointes

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Management

Arrhythmia Management

Aim:

• Hemodynamic stability
• Prevent complications
• Symptomatic relief

Strategies:

• Restoration of normal rhythm
• Slowing of tachyarrhythmia
• Augmenting the slow rhythm

Options:

• Pharmacological agents
• Electrical cardioversion
• Transcatheter ablation
• Device implantation

Logistics:

• Emergency versus elective management
• Electrophysiology lab

Emergency Cardioversion

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