Transcript Arrythmias
ARRHYTHMIAS DANNY HAYWOOD FY1 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) C Congestive heart failure (or Left ventricular systolic dysfunction) 1 CHADSVASC 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 Score Sc Risk Sex category (i.e. female gender) Anticoagulation Therapy Low No antithrombotic therapy (or Aspirin) 1 Moderate Oral anticoagulant (or Aspirin) 2 or greater High Oral anticoagulant 0 1 1 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 node 1) short refractory period + slow conduction 2) 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 TACHYS VT VS VF • VT • Unstable • electrical cardioversion • Stable • 1st – Class I Anti-arrhythmics (lidocaine) • 2nd – Amiodarone • 3rd – DC cardioversion BROAD COMPLEX TACHYS VT 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. B. C. D. E. F. G. H. I. J. K. L. Sinus rhythm AF Atrial Flutter VT VF 1st degree heart block Complete heart block Mobitz type II AVRT Mobitz type I AVNRT Right bundle branch block REFERENCES • All images and ECGs borrowed gratefully from google images • Kumar & Clarke: Clinical Medicine 7th Ed • NICE guidelines: AF (CG36)