1. Heart Rhythm Disorders
Dr Husain Shabeeh
Consultant Cardiologist & Cardiac Electrophysiologist
Croydon University Hospital and King’s College Hospital

2. My interests Diagnosis and management of heart rhythm disorders
Electrophysiology studies and ablation for AF, SVT, VT
Cardiac devices including PPM, ICD, CRT, ILR
Syncope

3. Agenda Atrial fibrillation SVT Atrial flutter Syncope
Anything else you would like to discuss…

4. Atrial Fibrillation

5. William Harvey Circulation of the Blood (1628)
“It is...evident that the auricles pulsate, contract...and eject the blood into the ventricles. [The auricle] has to help infuse blood into the ventricle so that [the ventricle] may send it on with greater vigour”
First physician to describe completely the systemic circulation

6. Loss of P waves
Atrial activity (‘f’ waves) ‘rate’ bpm
Irregular ventricular response (unless heart block or VT)

7. AF – who, when and why? Affects 1-2% of population (over 10% in 80+)
2/3 of patients with AF are aged 65-85
Lifetime risk 25% for individuals over 40y (or 1 in 4!)
Causes/associations
Male gender, age
Hypertension, heart failure, valvular heart disease, ischaemic heart disease, thyroid dysfunction, diabetes, alcohol excess
Obesity, OSA
Acutely: sepsis, surgery, stress, electrolyte loss, binge drinking
Other arrhythmias (e.g. WPW) especially in young

8. AF is harmful because… Thromboembolism Haemodynamics
Anti-coagulants can reduce this risk by 50-70%
Haemodynamics
Loss of atrial component of filling
Irregular ventricular rhythm
High ventricular rates (AV nodal drugs can help with this one only)

9. AF leads to… Relative mortality risk 1.5-2.0
5-fold increase in ischaemic stroke
20-30% of all strokes are due to AF
cognitive decline / vascular dementia
Increased hospitalisation / healthcare costs
1% of total healthcare spending in UK (currently)
Symptoms / QoL:
palpitations, breathlessness, exercise incapacity, chest pain, syncope…
Heart failure (cause and/or exacerbator)

10. AF detection / screening
Pulse check
ECG
ECG monitoring (e.g. Holter)
Prolonged ECG monitoring (e.g. patches, implantable recorders)
Personal ECG recorders (e.g. AliveCor)
Some patients have these!

11. Anticoagulation
ESC guidelines 2016

12. Net clinical benefit NOACs vs. warfarin
Net clinical benefit and 95% CI of all treatment arms of non-vitamin K antagonist oral anticoagulants versus warfarin tested in phase III clinical trials for the weighed composite outcome of ischemic stroke + systemic embolism + myocardial infarction + hemorrhagic stroke + adjusted major bleeding (major bleeding minus hemorrhagic stroke). Net clinical benefit is expressed as ischemic stroke equivalents prevented per 100 person-years using ischemic stroke as the reference event (weight = 1). CI = confidence interval; IS = ischemic stroke; NNT = number needed to treat (to prevent all grouped events included in the net clinical benefit evaluation, per year of treatment); NOAC = non-vitamin K antagonist oral anticoagulant.
Renda et al Am J Med. 2015

13. Case 1 74 female Asymptomatic Hypertensive
Routine visit to GP found to have irregularly irregular pulse
ECG confirms AF with ventricular rate 110
What would you do?

14. Case 1 Rate control OAC Bloods? Echo? Holter? Refer to Cardiology?
Aim initial resting HR < 110
OAC
CHADSVASc = 3
Bloods? Echo? Holter? Refer to Cardiology?

15. ESC guidelines 2016

16. Case 2 58 male Breathless for 4 months No PMHx Alcohol 30 units / week
Examination
Pulse irregular
Nil else
ECG confirms AF, ventricular rate 120
What would you do?

17. Case 2 GP started Bisoprolol 2.5mg
Patient felt a little better with better heart rate control but still lethargic and breathless
Asked patient to reduce alcohol intake (which he did!)
Referred to cardiology
Seen in cardiology clinic
Echo: Mild LV dysfunction in AF, mild LA dilatation
CHADSVASC = 0
Referred for DCCV, started on apixaban and amiodarone
When came for DCCV found to be in SR.
Switched to Flecainide, Bisoprolol and Apixaban
lethargic and still has 1 hour episodes of PAF every week
Referred to electrophysiologist for ablation.

18. Beyond electric shocks and poisons… can we cure AF?
ESC guidelines 2016

19. AF ablation AF ablation in symptomatic AF patients
instead of (or after failed/intolerable) drug therapy (note risk of medium-long term AAD)
especially in patients with heart failure (ARC-HF, CASTLE-AF trials, etc.)
emerging evidence of prognostic benefit of ablation-based rhythm control compared with rate control
Particularly effective in paroxysmal and early persistent AF

20. AF ablation
Pulmonary vein isolation (+/- other substrate modification for persistent AF)
Success rates
PAF: 70% SR at 1y off AAD
after 2-3 procedures 80%-90%
persistent AF: 40-50% at 1y,
70-80% with 2-3 ablations
(reduced success LA size, duration of AF, structural heart disease e.g. HCM)
Complication rates
<1 in 1000 death
<1 in 200 stroke
<1 in 100 major bleeding
Kuck K et al. N Engl J Med 2016;374:

21. Isolation of right pulmonary veins

24. Case 2 3 month follow-up OPA 12 months follow-up OPA
Well with no further episodes after the first few weeks post ablation.
All meds stopped at this OPA (flecainide, bisoprolol, apixaban)
12 months follow-up OPA
Remains well
Discharged

25. Case 3 67 female Palpitations last 2 hours with SOB PMHx: Hypertensive
irregularly irregular pulse at 160
Feels clammy
BP 90/60
What would you do?

26. Case 3 Unwell patient – refer to A&E Adverse features are for DCCV:
shock, syncope, ischaemia, heart failure

27. Current Croydon pathway – any comments?

28. Other arrhythmias

29. What are SVTs? AVNRT AVRT Atrial flutter Atrial tachycardia
Rare SVT syndromes
Rare Accessory pathway Syndromes
Permanent Junctional Reciprocating tachycardia (PJRT)
Junctional ectopic tachycardia (JET)
Narrow complex VT!

30. Case 3
34 female
Fast regular palpitations every few weeks lasting 10 to 30 mins
No PMHx
Normal physical examination
Normal ECG
What would you do?

31. Case 3 Medications? Await symptom-ECG correlation?
Had longer episodes and presented to A&E on 2 occasions

32. SVT (AVNRT) ECG

33. AVNRT explanation

34. Treatment
Medication -Used when attacks infrequent -Aim is to change the properties of the pathways so SVT can’t happen -Drugs that act on the AVN BB, Ca Channel blockers, digoxin -Drugs that change the speed of conduction – Flecainide -Don’t need OAC - ACUTE – vagal manoeuvres adenosine or BB
Ablation
For pts who are intolerant of medications or who have break through symptoms
Success / cure rate >95%
Main complication we worry about is PPM

35. Case 3 Slow pathway ablation for AVNRT
All medications stopped the same day as ablation
OPC 3/12 – no symptoms, discharged

36. AVRT
Due to an extra fibre of electrically conducting tissue in the heart / accessory pathway
Pre-excitation / delta wave
WPW
Concealed accessory pathway

37. WPW / accessory pathway

38. Treatment WPW small risk of pre-excited AF and sudden death Medical Mx
Ablation
Only curative strategy
Aim is to find the accessory pathway and ablate it
APs can be on the right side or the left side of the heart (TV or MV)
Success (cure) rates >90-95%

39. Atrial Flutter Arrhythmia from the right atrium
Like AF in that it is fast and patients usually need to be on oral anticoagulation
Has a characteristic ECG
Heart rate in atrial flutter is usually 150bpm (2:1 AV conduction) pre rate control

40. Flutter (‘F’) waves at bpm Slow downstroke/rapid upstroke II/III/aVF (typical flutter) Often regular ventricular response (classically 150bpm 2:1 pre-rate control)

41. Treatment Ablation Only curative strategy Success rate >90%
Medical
Anticoagulation (CHADSVASC score)
Ventricular rate control
Robust circuit so often doesn’t work. AV nodal blockers (BB, CaB) and conduction slowers (Flecainide)
DCCV – successful but may not last.
Ablation
Only curative strategy
Success rate >90%
Comps 1%
Painful so usually done with sedation
Target is the Cavotricuspid annulus

42. Atrial flutter

43. Case 4 What would you do? 23 female
Episodes of light-headedness for last couple of years, but increasing frequency.
Often in warm places (e.g. train), always standing.
Has had a 6 episodes of LOC last 1 year, including injury to hand, and shorter warning.
Quick recovery from LOC
No tongue biting / incontinence / shaking
No PMHx
Normal physical examination
Normal ECG
Fairly active with work and young child
What would you do?

44. Case 4 History consistent with vaso-vagal syncope
Current fluid intake:
2 glasses water
3 cups coffee
Cola with lunch
Advised:
litres non-caffeinated, non-carbonated fluid
Added salt to diet (6-9g / day)
Counter-pressure maneuvers
Lie down to avoid LOC!
Improvement in symptoms but still having symptoms at next OPC as new job requires longer train journey

45. Case 4
Tilt table test
Symptoms reproduced with documented hypotension consistent with vaso-vagal syncope
Continued symptoms including LOC despite adhering to good fluid status
Midodrine started with good effect
Likely to improve over time (natural progression) and can reduce Midodrine once stable

46. Current CUH referral system:
Syncope
Current CUH referral system:
Refer to A&E
Syncope associated with angina or known structural heart disease
Syncope with abnormal ECG
Refer to community clinic
Recurrent dizziness or syncope
Manage in primary care
Suspected vaso-vagal syndrome responding to conservative measures AND no evidence of structural heart disease

47. Other…? Is there anything else you would like to discuss?
Any cases you would like to discuss?
Any questions?

48. Summary AF Screening is vital to reduce risk esp. of stroke OAC
Rate +/- rhythm control
Atrial flutter
Treat similar to AF
Catheter ablation very successful
SVT
Usually non-malignant and manage symptoms
Pre-excitation on ECG means potentially dangerous especially if has symptoms
Thank you!