Arrhythmias. A/Prof Drew Richardson. The Canberra Hospital May MB BS (Hons) FACEM Grad CertHE MD

Transcription

1 Arrhythmias A/Prof Drew Richardson MB BS (Hons) FACEM Grad CertHE MD The Canberra Hospital May 2013

2 Objectives Recognise the features of the common nonlethal arrhythmias Describe the emergency treatment of broad complex and narrow complex tachyarrhythmias Describe the causes and effects of atrial fibrillation in emergency practice Outline an approach to the different emergency presentations of atrial fibrillation Understand the concept of risk stratification in the long term management of atrial fibrillation with anticoagulants

3 Anxious 65yoF, 1st hospital episode

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5 61yo F, 10th episode, drugs fail

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7 ACLS is a separate topic This is not a talk on lethal arrhythmias Patients without meaningful output go into resuscitation algorithm Simple ways to think about nonlethal arrhythmias One reasonable way to treat them More on atrial fibrillation

8 Emergency Management of Arrhythmias Classification 1 Ventricular arrhythmias VT AVJ arrhythmias Heart Block (1/2/3) Junctional Rhythms Atrial Arrhythmias SVT, Wolffe-Parkinson-White AF

9 Emergency Management of Arrhythmias Classification 2 Tachyarrhythmias by conduction/rhythm Broad complex Narrow complex Irregular Bradyarrhythmias by level Sinus AV block Junctional Ventricular

10 Emergency Management of Arrhythmias Classification 3 With significant compromise Hypotension (for this patient) Chest pain Pulmonary Oedema Without significant compromise Palpitations only General Malaise Not SOB at rest

11 Ventricular Tachycardia

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13 7 years ago

14 SVT with aberrancy

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16 Broad Complex Emergency Physicians are simple people Any Arrhythmia with compromise needs immediate reversion Synchronised DCV under procedural sedation Broad complex arrhythmias are 80% VT but the electrical rhythm does not matter DCV or Amiodarone (2-3mg/kg IV) DO NOT GIVE CA CHANNEL BLOCKERS

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20 Narrow Complex Tachycardia Common: Atrial flutter, 2-3:1 block, WPW Regular without compromise Vagal manoeuvres: Supine Valsalva Adenosine 6/12/18mg IV with flush Warn about side effects Likely to at least slow conduction to see rhythm Second line: Verapamil long half life but do not mix with Bblockers, irregular rhythm Can use flecainide

21 AF

22 Atrial Fibrillation Commonly seen in ED as a rapid rate with new symptoms Need to distinguish acute from chronic AF which has just come to light Management depends on underlying cause Most causes get worse with time (pre-excitation excluded) but often very slowly Acute causes like sepsis need to be addressed

23 The final common rhythm of many cardiac and other diseases Inefficient, reduced end diastolic volume Danger of thrombi (10-15% of all strokes) Risks actually low, but over time significant

24 Warfarin Emergency Departments see the bad side Starting chronic therapy not ED decision But EM is a generalist specialty Weigh the risks and benefits Incidence of alcoholism in barmen? Incidence of falls in alcoholics? External validity of relevant controlled trials?

25 In 1000 people with AF In clinical trial setting, about 50 will have stroke in 1 year Real but modest reductions with treatment Risks (?benefits) higher in elderly Aspirin (v placebo) Warfarin (v placebo) Warfarin (v aspirin) Stroke ARR 17 NNT 59 ARR 31 NNT 32 ARR 8 NNT 125 Major bleeds ARI 1 NNH 1000 ARI 3 NNH 333 ARI 2 NNH 500 MJA 2004; 180 (11): Obviously treatment needs to be targeted

26 Cardiac Causes of AF Ischaemic heart disease Pericarditis Hypertension Rheumatic Heart disease Pre-excitation Cardiomyopathy Atrial septal defect Atrial Myxoma Postoperative (esp thoracotomy)

27 Non-cardiac causes of AF Electrolyte disturbance Sepsis Pulmonary Embolism Drugs and alcohol COAD Thyrotoxicosis Lung Carcinoma Other intrathoracic pathology

28 Course of AF Patients with an apparently normal heart and paroxysmal AF (common presentation) Most have IHD to some extent 90%+ will revert in 48 hours Abnormal heart Depends on treatment of underlying disease Particularly acute ischaemia Other cause depends on that

29 Rate vs Rhythm Control Long term rhythm control not better than rate control Anticoagulation needed in both groups NOT an ED population

30 Ottawa Aggressive Protocol Procainamide 58% reverted DCV if needed Another 35% 660 patients 97% discharged Safe, effective Recurrence 30%

31 The ED Approach History: particularly duration, symptoms Examination: Signs of compromise, cause Investigations: Screen for causes & effects FBE UEC LFT TFT (if not done recently) ECG CXR Troponin if ischaemic symptoms or IHD risk

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34 PLAN 0: Compromised Patient Myocardial Ischaemia Hypotension Pulmonary Oedema Synchronised DC Cardioversion with sedation High Risk, requires admission (Cardiology)

35 Paroxysmal AF - Options Do Nothing most will revert Control Rate most will revert Digoxin, BBlockers Control Rate and Revert Amiodarone or Sotolol Just plain Revert DC shock Any combination of above

36 Paroxysmal AF - Reversion Indications Compromise already dealt with Symptom Control Just because aiming for sinus rhythm Contraindications More than 48 hours in AF & not anticoagulated Interactions of negative ionotropes

37 PLAN A well, paroxysmal AF Attempt chemical reversion with amiodarone or sotolol (not both) [flecainide option, procainamide in literature] If fail, fast patient (conveniently overnight) Can often be discharged if no evidence ischaemia If not reverted next morning, DC Version Screen for Thyrotoxicosis, electrolytes, etc Cardiologist followup

38 PLAN B Well, >48 hours AF Check for Ischaemia Control rate if needed Digoxin or metoprolol Decide: Rate control only + Warfarin if needed on risk score and no contraindication Warfarin with view to DC Version in 6 weeks Followup +/- decision by cardiologist ED does not do chronic care

39 CHADS2 Congestive Heart Failure Hypertension (any history) Age >75 Diabetes Mellitus Secondary Prevention (CVA/embolis) Gage BF, Waterman AD, Shannon W. JAMA 2001; 285:2864

40 CHADS2 Events per 100 person-years CHADS2 Warf NoWarf NNT or Go AS, Hylek EM, Chang Y, et al. JAMA 2003; 290:2685

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43 PLAN C - unwell Not acutely compromised but underlying cause leading to illness Treat the underlying cause Consider reversion but do not expect it to work well if precipitant persists Rate control with care

44 When to give up This approach will see some paroxysmal cases come back again and again Evidence suggests that they have many more asymptomatic episodes Need to be anticoagulated Little guidance on how much is too much Suggest 3 times in a year But some patients keep requesting reversion

45 AF - Summary Increasingly frequent issue ED population different to chronic studies Compromise = DC version & admission Paroxysmal = Amiodarone or Sotalol with DC version for failure proven safe Unwell = seek causes, consider rate control Anticoagulation will be an issue use a score

46 QUESTIONS?