DANNY HAYWOOD FY1 ARRHYTHMIAS. INTRO Conduction system of heart Symptoms/signs Investigations Tachy vs Brady Bradyarrhythmias Different types Management.

D A N N Y H A Y W O O DF Y 1

ARRHYTHMIAS

INTRO

• Conduction system of heart• Symptoms/signs• Investigations• Tachy vs Brady• Bradyarrhythmias• Different types• Management

• Tachyarrhythmias• Broad vs narrow• Types of each• Management of each

• Summary• Some example ECGs

SYMPTOMS/SIGNS

• Syncope• Dizziness• Palpitations• Heart Failure• Chest pain• Sudden death• No symptoms

INVESTIGATIONS

• Bedside• ECG

• Bloods• TFTs, U+E, FBC, Troponins

• Imaging• Echo, CXR

• Special tests• Holter monitor

ARRHYTHMIAS

• Bradyarrhythmias vs Tachyarrhythmias

• Brady • HR < 60bpm

• Tachy • HR > 100bpm

BRADYARRHYTHMIAS

• Type I heart block• 1st degree heart block• Prolonged PR interval > 0.2 seconds

• Type II heart block• Mobitz type 1 – Wenckebach• Gradually increased PR intervals until missed QRS

• Mobitz type 2• Intermittently P wave not followed by QRS• May be pattern eg 2:1, 3:1 ratio of P waves to QRS complexes

– no increase in PR interval

• Type III heart block• Complete heart block• No correlation between P waves and QRS complexes

MANAGEMENT

• Acute (eg. Secondary to MI)• If symptomatic/clinical deterioration• IV atropine• External (transcutaneous) pacing

• Chronic• Mobitz type II or complete AV block• Permanent pacemaker

TACHYARRHYTHMIAS

• Narrow complex (Supraventricular) vs Broad complex (Ventricular)

• Narrow • QRS <0.12 seconds

• Broad • QRS >0.12 seconds

NARROW COMPLEX

• Sinus tachycardia• Atrial Fibrillation (AF)• Atrial Flutter• Atrioventricular nodal re-entry tachycardia

(AVNRT)• Atrioventricular reciprocating tachycardia (AVRT)

AF

• Continuous, rapid activation of atria – due to rapidly depolarising foci within the atria• Often located by pulmonary veins

• No coordinated mechanical action

AF – CAUSES

• ATRIAL PhIB• A – Alcohol• T – Thyroid disease• R – Rheumatic heart disease• I – Ischaemic heart disease• A – Atrial myxoma• L – Lung pathology (pneumonia, PE)

• Ph – Pheochromocytoma• I – Idiopathic• B – Blood pressure (hypertension)

AF - MANAGEMENT

• Conservative• Alcohol cessation• Lifestyle factors (diet/exercise/smoking)

• Medical• Treat underlying cause• Rate control vs rhythm control

• Interventional• Catheter ablation

RATE CONTROL

• Older age, permanent AF• Bisoprolol/verapamil and Warfarin (CHADSVASc)

CHADSVASC C 

Congestive heart failure (or Left ventricular systolic dysfunction)

1

 H Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication)

1

 A2  Age ≥75 years 2

 D  Diabetes Mellitus 1

 S2  Prior Stroke or TIA or thromboembolism 2

 V Vascular disease (e.g. peripheral artery disease, myocardial infarction, aortic plaque)

1

 A  Age 65–74 years 1

 Sc  Sex category (i.e. female gender) 1

Score Risk Anticoagulation Therapy

0 Low

No antithrombotic therapy (or Aspirin)

1 ModerateOral anticoagulant (or Aspirin)

2 or greater High Oral anticoagulant

RHYTHM CONTROL

• Cardioversion• Pharmacological vs DC• younger, symptomatic, physically active patients• Congestive heart failure• Paroxysmal AF• failure of rate control

• < 48 hours• Cardioversion + heparin

• > 48hrs – TOE/anti-coagulation (3 weeks)• risk of failure?• High – 4 weeks sotalol/amiodarone then electrical.• Low - electrical

RHYTHM CONTROL

• Pharmacological• No structural heart disease• 1st - Flecainide• 2nd – Sotalol• 3rd – Amiodarone

• Structural heart disease• Amiodarone

• Interventional• Pulmonary vein isolation - catheter ablation

ATRIAL FLUTTER

• Organised atrial rhythm, coming from ectopic focus in atria (usually left)• Usually 300bpm• Ventricular rate depends on degree of AV block eg

2:1 = 150bpm• Saw tooth pattern

ATRIAL FLUTTER

• Management• Conservative• Vagal manoeuvres

• Medical – similar to AF• Acute

• DC cardioversion or IV adenosine (<48 hours)• > 48 hours - 3 weeks anticoag then cardiovert

• Chronic• Pill in pocket• Regular anti-arrhythmics

• Interventional• Radiofrequency catheter ablation

AVNRT

• 2 pathways within the AV node1) short refractory period + slow conduction2) long refractory period + fast conduction

• Normally conducts through fast pathway• If premature atrial beat, fast pathway still

refractory (long refractory period) therefore travels down slow pathway and back up the fast pathway.

AVNRT

AVRT

• Accessory pathway (Bundle of Kent most common)• Pre-excitation (delta wave) on ECG• Wolff-Parkinson-White syndrome

MANAGEMENT OF SVTS

• Haemodynaically unstable• Electrical cardioversion

• Conservative• Vagal manoeuvres• Valsalva, carotid massage, cold water

• Medical• Adenosine (acute)• Anti-arrhythmics (regular and pill-in-pocket)

• Interventional• Catheter ablation

BROAD COMPLEX TACHYSVT VS VF

• VT• Unstable • electrical cardioversion

• Stable • 1st – Class I Anti-arrhythmics (lidocaine)• 2nd – Amiodarone• 3rd – DC cardioversion

BROAD COMPLEX TACHYSVT VS VF

• VF• Cardiac arrest• Rapid, irregular activity – no cardiac output• Usually provoked by ventricular ectopic beat• Management• Electrical defibrillation

BROAD COMPLEX TACHYS

• Something to be aware of• SVT with concomitant bundle branch block = broad

complex tachy

SUMMARY

• Brady vs tachy• Brady• Sinus Brady• 1st degree heart block• Mobitz I & II• Complete

• Tachy• Narrow

• Sinus tachy, AF, Flutter, AVNRT, AVRT

• Broad• VT, VF,

• Remember causes of AF

ECGS – TEST YOURSELF

A

B

C

D

E

F

G

H

I

J

K

L

ANSWERS

A. Sinus rhythmB. AFC. Atrial FlutterD. VTE. VFF. 1st degree heart blockG. Complete heart blockH. Mobitz type III. AVRTJ. Mobitz type IK. AVNRTL. Right bundle branch block

REFERENCES

• All images and ECGs borrowed gratefully from google images• Kumar & Clarke: Clinical Medicine 7th Ed• NICE guidelines: AF (CG36)