سشنات الدكتور احمد مؤيد

Cardiac Arrhythmia

Arrhythmias
Disturbance of heart rhythm and/or conduction. Arrhythmia : Tachyarrhythmia bradyaahythmia

Conductive system of the heart

SA Node - Dominant pacemaker with an intrinsic rate of 60 - 100 beats/minute. AV Node - Back-up pacemaker with an intrinsic rate of 40 - 60 beats/minute. Ventricular cells - Back-up pacemaker with an intrinsic rate of 20 - 45 bpm.

Mechanism of tachyarrhythmia

Increased automaticity. Re-entry. triggered activity
For more presentations www.medicalppt.blogspot.com

Antiarrhythmic drugs

Digoxin Adenosine Atropine

pot.com

Arrhythmias
Sinus Rhythms Premature Beats Supraventricular Arrhythmias Ventricular Arrhythmias AV Junctional Blocks

spot.com

Sinus Rhythms
Sinus Bradycardia Sinus Tachycardia

Sinus Bradycardia

Deviation from NSR A sinus rate of less than 60/min

Causes of Sinus Bradycardia

• MI • Sinus node disease (sick sinus syndrome) • Hypothermia • Hypothyroidism • Cholestatic jaundice • Raised intracranial pressure • Drugs, e.g. β-blockers, digoxin, verap

Rhythm

30 bpm
Rate?
Regularity?
regular
normal
0.10 s
P waves?
PR interval?
0.12 s
QRS duration?
Interpretation?
Sinus Bradycardia

Sinus Tachycardia

Deviation from NSR -a sinus rate of more than 100/min

Causes of Sinus Tachycardia

* Anxiety • Fever • Anaemia • Heart failure • Thyrotoxicosis • Phaeochromocytoma• Drugs, e.g. β-agonists (bronchodilators)

Rhythm

130 bpm
Rate?
Regularity?
regular
normal
0.08 s
P waves?
PR interval?
0.16 s
QRS duration?
Interpretation?
Sinus Tachycardia

Sinus arrhythmia

Phasic alteration of the heart rate during respiration (the sinus rate increases during inspiration and slows during expiration

For more presentations www.medicalppt.blogspot.com

Sick Sinus Syndrome(SSS)

Supraventricular Arrhythmias

Atrial Fibrillation Atrial Flutter Paroxysmal Supraventricular Tachycardia

Premature Beats

Premature Atrial Contractions (PACs) Premature Ventricular Contractions (PVCs)

Premature Atrial Contractions

Deviation from NSR These ectopic beats originate in the atria (but not in the SA node), therefore the contour of the P wave, the PR interval, and the timing are different than a normally generated pulse from the SA node.


Atrial Fibrillation
The most common sustained cardiac arrhythmia. AF can cause palpitation, breathlessness and fatigue. In patients with poor ventricular function or valve disease, it may precipitate or aggravate cardiac failure. AF is associated with significant morbidity ( Thromboembolic )and a twofold increase in mortality . AF can be classified as paroxysmal (intermittent episodes which self-terminate within 7 days), persistent (prolonged episodes that can be terminated by electrical or chemical cardioversion) or permanent.

Common causes of atrial fibrillation

Coronary artery disease (including acute MI)Valvular heart disease, especially rheumatic mitral valve diseaseHypertension Sinoatrial disease Hyperthyroidism Alcohol • CardiomyopathyCongenital heart disease Chest infection Pulmonary embolismPericardial disease Idiopathic (lone atrial fibrillation)

Atrial Fibrillation

Deviation from NSR No organized atrial depolarization, so no normal P waves (impulses are not originating from the sinus node). Atrial activity is chaotic (resulting in an irregularly irregular rate). Common, affects 2-4%, up to 5-10% if > 80 years old

AF


Rhythm control Pharmacologic cardioversion Flecainide ,Propafenon,AmiodaronElectrical cardioversion- Less than 48 hours direct cardioversion. - More than 48 hours +Anticoagulates for 4 weeks prior and 3 months after. Rate control Using Digoxin, β-blockers and calcium antagonists, such as verapamil or diltiazemCatheter ablation in refractory cases Management

Prevention of thromboembolism

Risk stratification is based on clinical factors using the CHA2DS2-VASc scoring system. Warfarin INR 2-3 Aspirin

Atrial Flutter

Etiology: a large (macro) re-entry circuit, usually within the right atrium encircling the tricuspid annulus with every 2nd, 3rd or 4th impulse generating a QRS (others are blocked in the AV node as the node repolarizes).


Atrial Flutter
Deviation from NSRNo P waves. Instead flutter waves (note “sawtooth” pattern) are formed at a rate of 250 - 350 bpm.Only some impulses conduct through the AV node (usually every other impulse)

Atrial F

70 bpm
Rate?
Regularity?
regular
flutter waves
0.06 s
P waves?
PR interval?
none
QRS duration?
Interpretation?
Atrial Flutter

Atrial Flutter 4:1 block

Causes and Symptoms
Similar to atrial fibrillation Management Treat the cause Rate control -Digoxine B blocker,verapamil.Rhythm control –Amiodaron ,DCMaintanance B- Blocker or amiodaroneAnticoagulantCatheter ablation offers a 90% chance of complete cure and is the treatment of choice for patients with persistent symptoms

Paroxysmal Supraventricular Tachycardia (PSVT)

Deviation from NSR The heart rate suddenly speeds up, often triggered by a PAC (not seen here) and the P waves are lost. Tends to occur in normal heart.

PSVT

Etiology: There are several types of PSVT but all originate above the ventricles (therefore the QRS is narrow). Most common: abnormal conduction in the AV node (reentrant circuit looping in the AV node). Rate 150-250

PSVT

For more presentations www.medicalppt.blogspot.com

Managment

Episode may be terminated by carotid sinus pressure or by the Valsalva manœuvre. Adenosine (3–12 mg rapidly IV in incremental doses until tachycardia stops) or verapamil (5 mg IV)Recurrent SVT, catheter ablation is the most effective therapy and will permanently prevent SVT in more than 90% of cases

Effect of Adenosine

Effect of Adenosine

Ventricular Arrhythmias

Premature Ventricular Contractions Ventricular Tachycardia Ventricular Fibrillation

Rhythm

60 bpm
Rate?
Regularity?
occasionally irreg.
none for 7th QRS
0.08 s (7th wide)
P waves?
PR interval?
0.14 s
QRS duration?
Interpretation?
Sinus Rhythm with 1 PVC

* Ventricular Bigeminy

Normal
VPC
VPC
Normal

Ventricular Tachycardia

Dangerous. Nearly in abnormal heart. 3 or more successive PVC at rate of more than 120. Can occur in normal heart.

Ventricular Tachycardia

Deviation from NSR Impulse is originating in the ventricles (no P waves, wide QRS).

Ventricular Tachycardia

Etiology: There is a re-entrant pathway looping in a ventricle (most common cause). Ventricular tachycardia (VT) occurs most commonly in the settings of acute MI, chronic coronary artery disease, and cardiomyopathy.

Rhythm

160 bpm
Rate?
Regularity?
regular
none
wide (> 0.12 sec)
P waves?
PR interval?
none
QRS duration?
Interpretation?
Ventricular Tachycardia



VT

Management

Treat cause. Hemodynamically unstable DC Stable IV amiodarone or lidocaine. With poor LV function indication for ICD

Ventricular Fibrillation

Deviation from NSR Completely abnormal.

Ventricular Fibrillation

Etiology: The ventricular cells are excitable and depolarizing randomly. Rapid drop in cardiac output and death occurs if not quickly reversed

Rhythm

none
Rate?
Regularity?
irregularly irreg.
none
wide, if recognizable
P waves?
PR interval?
none
QRS duration?
Interpretation?
Ventricular Fibrillation

Management

Asystole

Management of Asystole

AV Nodal Blocks
1st Degree AV Block 2nd Degree AV Block, Type I 2nd Degree AV Block, Type II 3rd Degree AV Block

1st Degree AV Block

Etiology: Prolonged conduction delay in the AV node or Bundle of His.

Rhythm

60 bpm
Rate?
Regularity?
regular
normal
0.08 s
P waves?
PR interval?
0.36 s
QRS duration?
Interpretation?
1st Degree AV Block

Rhythm

50 bpm
Rate?
Regularity?
regularly irregular
nl, but 4th no QRS
0.08 s
P waves?
PR interval?
lengthens
QRS duration?
Interpretation?
2nd Degree AV Block, Type I

2nd Degree AV Block, Type II

Deviation from NSR Occasional P waves are completely blocked (P wave not followed by QRS).

Rhythm

40 bpm
Rate?
Regularity?
regular
nl, 2 of 3 no QRS
0.08 s
P waves?
PR interval?
0.14 s
QRS duration?
Interpretation?
2nd Degree AV Block, Type II

3rd Degree AV Block

Deviation from NSR The P waves are completely blocked in the AV junction; QRS complexes originate independently from below the junction.

Rhythm

40 bpm
Rate?
Regularity?
regular
no relation to QRS
wide (> 0.12 s)
P waves?
PR interval?
none
QRS duration?
Interpretation?
3rd Degree AV Block

Management of symptomatic heart block

Bundle branch block and hemiblock

Left bundle branch block LBBB Right bundle branch block RBBB
For more presentations www.medicalppt.blogspot.com

Complete RBBB

Complete LBBB
*

Questions