TỔNG QUAN Bradyarrhythmias brady

– First Degree AV block– Complete AV Block – Bifascicular and trifascicular block... Sinus Node Dysfunction –Sinus Bradycardia from this waveform include: – Rate = 55 bpm – PR interval =

Bradyarrhythmias

SA node

• Abnormally slow heart

rhythms

• Can be caused by failure of

the SA node to start the

normal pacemaker impulse or

defects in the conduction

system that prevent the

electrical impulses from

reaching the ventricles

• A very common disorder,

affecting millions of people

worldwide

AV node

What is bardyarrhythmia?

Patient Assessment

Basic indication for pacing: Symptomatic bradycardia

How Are Bradyarrhythmias Diagnosed?

• History and Physical

Examination

• EkG/ECG (Electrocardiogram)

• Continuous ECG Recording

( Holter)

• Graded Treadmill Test

• External loop recorder

• Insertable loop recorder (Reveal Plus)

• Cardiac Electrophysiology Study (EP study)

– First Degree AV block

– Complete AV Block

– Bifascicular and trifascicular block

Sick Sinus Syndrome (Sinus Node Dysfunction )

Sinus Node Dysfunction –

Sinus Bradycardia

from this waveform include:

– Rate = 55 bpm

– PR interval = 180 ms (.18 seconds)

Sinus Node Dysfunction –

Sinus Node Dysfunction –

Bradycardia-Tachycardia (Brady-Tachy) Syndrome

node or atria

– Rate during bradycardia = 43 bpm

– Rate during tachycardia = 130 bpm

Slow

Second-Degree AV

Block – Mobitz II

• Regularly dropped ventricular beats

– 2:1 block (2 P waves to 1 QRS complex)– Ventricular rate = 60 bpm

– Atrial rate = 110 bpm

P P QRS

Bifascicular Block

Right bundle branch block and left posterior hemiblock

Bifascicular Block

Right bundle branch block and left anterior hemiblock

Bifascicular Block

Complete left bundle branch block

Trifascicular Block

right bundle branch and complete or incomplete block in both divisions of the left bundle branch

Therapies

Drug therapy Pacemaker

Considerations: Drug Therapy

or temporary uses.

long-term therapy.

Considerations: Drug Therapy vs Pacing

Therapy Options for Bardycardia

•Medications are not effective in treating slow heartbeats

•Treated by implanting a pacemaker

Considerations: Paced vs Nonpaced

50-60% mortality without pacing

at the end of the first year.

Considerations: Paced vs Nonpaced

Shaw DB, Kekwick CA, Veale D, et al Survival in second degree AV block Br Heart J 1985;53:587-593.

Pacing Indications

Sick Sinus Syndrome

• Sinus node dysfunction with documented symptomatic sinus bradycardia

In some patients , bradycardia is iatrogenic and will occur as a consequence of essential long-term drug therapy of a type and dose for which there are no acceptable alternatives

• Symptomatic chronotropic incompetence

• Chronic heart rate < 30 bpm in minimally symptomatic patients while awake

JACC Vol 31, no 5 April 1998, 1175-1209

Heart Block

• Third-degree AV block at any anatomic level associated with any one of the following conditions:

– Bradycardia with symptoms presumed to be due to AV block

– Arrhythmias and other medical conditions that require drugs that result in symptomatic bradycardia

– Documented periods of asystole greater than or equal to 3 seconds or any escape rate less than 40 beats per minute (bpm) in awake, symptom-free patients

– After catheter ablation of AV Junction

– Postoperative AV block that is not expected to resolve.

– Neuromuscular diseases with AV block such as myotonic muscular dystrophy, Sayre syndrome, Erb’s dystrophy (limb-girdle), and personal muscular atrophy.

Kearns-Pacing Indications

JACC Vol 31, no 5 April 1998, 1175-1209

Heart Block

Pacing Indications

JACC Vol 31, no 5 April 1998, 1175-1209

of block, with associated symptomatic bradycardia.

Chronic Bifascicular and Trifascicular

Pacing Indications

JACC Vol 31, no 5 April 1998, 1175-1209

Case Study: Sinus Pause

:43 :42

:41 :40

:39 :38

:37

:37 :36

:35 :34

:33 :32

:31 :30

:29

:29 :28

:27 :26

:25 :24

:23 :22

6 second pause and PVCs

• Discontinued seizure medication

• A dual chamber pacemaker was implanted

Case Study: Heart Block

Background:

• 56 Year-old Female

• 7 syncopal episodes over nine months

• Bruising and cuts from falling

• 2 minute asystole with burst of P wave activity

• no subjunctional escape beats

• 4 idio-ventricular beats and gradually resumes normal conduction

• Diagnosed with infra-Hisian AV block

• Dual-chamber pacemaker implanted

Case Study: Sinus Arrest

Background:

• 83 year-old female

• Presented at emergency room after syncopal episode

• Suffered burns and tendon damage from falling against radiator

Ten-second slowing in heart rate followed by an eight-second sinus arrest

Pacemaker implanted

Patient has experienced no further syncope