Bradycardia and Syncope

P Boon Lim, MB BChir PhD

Imperial College Healthcare

London, UK

Disclosures

Medtronic: Research Grant

Boston Scientific: Consulting Fee, Research Grant

Biosense Webster: Consulting Fee

St Jude Medical: Consulting fee

Sanofi – Speaker fee for BJCA meeting

Bayer – Speaker fee for BJCA meeting

Bradycardia

Lead II

Q: A 75 yo man had a PPM implant on the ward for 2:1 HB, and has palpitations

the day after implant . What is the diagnosis?

1) Atrial flutter with PPM tracking

2) Atrial tachycardia with PPM tracking

3) Pacemaker mediated tachycardia

4) Ventricular tachycardia

Lead II

Q: Why does this initiate?

1) VA conduction

2) Atrial non-capture

3) PVARP too short

4) All of the above

UR Interval

Vpace

VACT

Asense

Retro P

Vpace

Pacemaker mediated tachycardia

Rate PMT < Upper rateVACT = VA conduction time, AVI = AV interval

AVI

UR Interval

Vpace

VACT

Retro P

AVI

Asense

DDD pacemaker atrial non capture induced

1 5 10 16

Q: Why does this terminate?

1) VA conduction block occurs spontaneously

2) VA conduction for one beat is rapid falling within PVARP

3) PVARP is extended

4) Pacemaker switches to non-atrial sensing mode (VVI)

DDD pacemaker atrial non capture induced

1 5 10 16

Extension PVARPFor 1 cycle

Tachycardia termination algorithm

UR IntervalUR Interval

Vpace

VACT

Asense

Retro P

Vpace

Tachycardia terminating algorithm

VACT = VA conduction time, AVI = AV intervalPVARP + AVI = Total atrial refractory period

AVI

Prolonged AVI

PVARP

VACT

Extended PVARP AVI

Vpace

ApaceP Ingnored

Retro P

Bradycardia

Anatomy of the conducting system - bradycardia

Sinus bradycardia

Sinus arrest

Sick sinus syndrome

Carotid sinus

hypersensitivity1st degree heart block

2nd degree heart block

- Wenkebach

- Mobitz II

3rd degree heart block

Trifascicular block

Sinus bradycardia

Sinus arrest

Sick sinus syndrome

Carotid sinus

hypersensitivity

1st degree heart block

2nd degree heart block

- Wenkebach

-Mobitz II

3rd degree heart block

Trifascicular block

Below AV node:

Fibrosis/disease

LOW THRESHOLD

FOR PACING

Above AV node: Vagal

tone

HIGH THRESHOLD

FOR PACING

Anatomy of the conducting system - bradycardia

Questions: What are these rhythms?

Reversible causes Do not pace

ESC pacing guideline 2013, EHJ

Reversible causes Do not pace

Reversible causes Do not pace

65 yo man received a VVI (single chamber) pacemaker last month but

remains very short of breath. What needs to be done now ?

1. Echocardiogram

2. Upgrade pacemaker to DDD

3. Urgent pacemaker check

4. Upgrade pacemaker to CRTP

65 yo man received a VVI (single chamber) pacemaker last month but

remains very short of breath. What was likely previous underlying rhythm?

1. AF with CHB

2. Atrial flutter with pauses

3. AF with offset pauses

4. Trifascicular block

Q: A 56 yo man with sinus arrest only, with 10 second pauses and

unheralded syncope, with PR interval of 140ms, and otherwise normal 12

lead ECG is recommended for PPM . What device should he receive?

1. AAI pacemaker

2. DDD pacemaker

3. DDD Pacemaker with AV delay management

4. DDDR pacemaker

5. DDDR pacemaker with AV delay management

ESC pacing guideline 2013, EHJ

Q: A 36 yo man with reflex syncope, with 12 second pauses on Holter, with PR interval

of 140ms, and otherwise normal 12 lead ECG is recommended for PPM. Normal and

echo ETT. He is recommended for pacing. What device should he receive?

1. DDD pacemaker

2. DDD pacemaker with AV delay management

3. DDDR pacemaker

4. DDDR pacemaker with AV delay management

5. Do not put in a pacemaker – refer to specialist syncope unit

Q: A 36 yo man with reflex syncope, with 12 second pauses on Holter, with PR

interval of 140ms, and otherwise normal 12 lead ECG is recommended for PPM.

Normal and echo ETT.

What other questions would you ask to determine pace or not?

Q: A 36 yo man with reflex syncope, with a 12 second pause on Holter, with PR

interval of 140ms, and otherwise normal 12 lead ECG is recommended for PPM.

Normal and echo ETT. He is recommended for pacing. What device should he

receive?

What other questions would you ask to determine pace or not?

1. Frequency of symptoms

2. Trigger

3. Warning / prodromal symptoms

4. What was he doing at the time of 12s pause

5. What is hydration / salt state

Shades of grey

Brignole et al, EHJ 2018 Syncope Guidelines

82 yo man presents to GP with unexplained syncope without prodrome with

negative Holter, normal echo and normal tilt. What is next management step?

1. ILR implant

2. PPM insertion

3. EP study

4. 7 day Holter

ESC pacing guideline 2013, EHJ

Old patients with BBB and unexplained syncope after a reasonable work-up might benefit from empirical PM, especially if syncope is unpredictable (with no- or short prodrome) or has occurred in supine positionor during effort.

ESC pacing guideline 2013, EHJ

EP MDT meetings can be useful in grey cases

65yo man with previous MI, EF 34%, with NYHA 3 on best medical

Rx with no syncope – what is next appropriate step ? 1. CRT

2. CRT-D

3. VT stim ? VT to guide therapy

4. Prolonged holter monitoring to look for NSVT

EF <35%

LBBB + QRS >120 CRT

NON-LBBB QRS >150 CRT

NON-LBBB QRS >120 ? CRT

EF <35%

QRS < 120 NO CRT

ESC task force guidance 2013 – CRTP vs CRTD

The evidence from RCTs is insufficient to show the superiority of combined CRT and ICD over CRT

alone. Owing to the potential incremental survival benefit of CRT-D over CRT-P, the prevailing opinion

among the members of this Task Force is in favour of a superiority of CRT-D in terms of total mortality

and sudden death. Nevertheless trial evidence is usually required before a new treatment is used

routinely. In the absence of proven superiority by trials and the small survival benefit, this Task Force is of

the opinion that no strict recommendations can be made, and prefers to merely offer guidance regarding

the selection of patients for CRT-D or CRT-P, based on overall clinical condition, device-related

complications and cost (Tables 17 and 18).

What about patients with EF<35% and permanent AF?

What about patients with EF<35% and permanent AF?

More “greyness” …

Q: A 64yo man has just undergone TAVI, and after d4, remains epicardially-pacing

dependent with an escape junctional rhythm of 37bpm, with good BP with this

escape rhythm with no dizziness. What is next appropriate management?

1. Depends on the day of week

2. Depends on the surgeon

3. DDD Pacemaker insertion

4. Wait until day 7, then reassess, so long as epicardial wires are

checked daily

5. All of the above are reasonable

A 46 yo man with HCM with LVOTO is paced following “unsuccessful septal

alcohol ablation” for post-operative AV block which is now recovering . How

should the pacemaker be set?

1. Minimise Ventricular pacing mode (ie AAI with MVP)

2. DDD-R

3. DDD with long AV delay

4. DDD with short AV delay

Syncope

Syncope and Transient Loss of Consciousness

Brignole et al, EHJ 2018 Syncope Guidelines

Syncope

Syncope = transient loss of consciousness due to global cerebral hypoperfusion

This is usually caused by a combination of:-

• reduced Cardiac output (i.e. Asystole > 6s pause, or BP<60mm Hg)

AND/OR

• reduced peripheral vascular resistance

Brignole et al, EHJ 2018 Syncope Guidelines

Tachycardia (VT)

Bradycardia (CHB)

Structural (AS/HCM)

Channelopathies

(Brugada, Long QT)

ECG

Echo

24h tape

“Other Ix” – cardiac

MRI, ILR, ajmaline

or adrenaline

challenge, EPS

Blood loss

Dehydration

Orthostatic

intolerance(OI) =

inability to

maintain BP on

standing

a) Early OI, initial

BP drop, then

recovery

b) Delayed OI,

common in

elderly due to

inability to

maintain

compensatory

reflexes

c) POTS

Primary and

secondary

autonomic failure

syndromes

Multiple syst atrophy

Parkinson’s

Diabetes, Amyloid

Alcohol, diuretics,

vasodilators

Situational (cough,

sneeze, micturition,

post-prandial /

exercise, laugh)

Carotid sinus syncope

Vasovagal (mediated

by emotional stress,

fear, pain, blood

phobia, orthostatic

stress)

How to diagnose syncope ?

1. History

2. History

3. History(unrushed, with an open trusting patient-physician relationship)

Key points:

Posture immediately before event

Provoking factors (dehydration, warm environment, stress)

Warning symptoms, appearance, colour

Abnormal movements / behaviour

Injury

Confusion after recovery

A 24 yo woman presents with syncope whilst on a flight back from USA. She has

history of childhood syncope. What is the next appropriate management step?

1. History, Echo, ECG, Holter and Tilt test

2. History, Holter, ECG

3. History, BP measurements, physical exam

4. History, active stand, ECG, physical exam

5. History, BP measurements, ECG, physical exam, tilt test

A positive active stand for orthostatic hypotension is:

1. sBP drops >30mm Hg, without symptoms

2. dBP drops >20mm Hg, without symptoms

3. sBP drops >20mm Hg, without symptoms

4. dBP drops >10mm Hg, with symptoms

5. sBP drops <100mm Hg, with symptoms

ESC Recommends active stand during initial evaluation

Risk Stratification

Brignole et al, EHJ 2018 Syncope Guidelines

18 yo man attends clinic, with single episode of syncope after having a shower at the gym, whilst

changing. Felt nauseous, dizzy and lightheaded, and tried to get out of locker to get “fresh air”, but

LOC on way out. Rapid recovery, and not confused after. Had a tendency to postural head rushes

when standing.

Question: “Can I continue driving ?”A) Yes B) No C) No, until assessed and given all clear by syncope specialist.

18 yo man attends clinic, with single episode of syncope 6 weeks ago after having a shower at the

gym, whilst changing. Felt nauseous, dizzy and lightheaded, and tried to get out of locker room to get

“fresh air”, but LOC on way out. Rapid recovery, and not confused after. Had a tendency to postural

head rushes when standing.

Features suggesting uncomplicated faint: 3 P’s

Posture: symptoms related to standing

Provoking factors: phlebotomy, micturition, cough

Prodromal symptoms: sweating, warmth, nausea

Driving in syncope

Reflex syncope = benign, 3P’s

But beware new guidelines : re:

sitting syncope (notify DVLA)

Investigations for syncope

History + clinical examination

Active standing – BP up to 3 minutes standing positive if

symptomatic fall in sBP>20mm Hg

ECG

Investigations for syncope

History + clinical examination

Active standing – BP up to 3 minutes standing positive if

symptomatic fall in sBP>20mm Hg

ECG

THIS MAKES A DIAGNOSIS in >80% CASES, IF DONE

CORRECTLY

Investigations for syncope

History + clinical examination

Active standing – BP up to 3 minutes standing positive if

symptomatic fall in sBP>20mm Hg

ECG

24h tape, echo

Implantable loop recorder

Tilt table test

Tilt testing

Therapy for syncope (largely evidence-free)

Lifestyle measures (6-10g salt, 2-3L fluid, avoid caffeine)

Physical counter-pressure manoeuvres

• Leg crossing, buttock and teeth clenching, tensing of all large muscles in body

• 2 short-term trials, 1 long f/u trial 220pts with long term reduction in syncope

Drugs.

• Beta-blockers, SSRI, disopyramide, scopolamine, ineffective in long term randomised placebo-controlled trials

• Fludrocortisone widely prescribed but no randomised long-term trial, (1 paediatric trial, n=33, which failed to show benefit)

• Midodrine is only drug with evidence base but only v small no pts

Question: “Can I continue driving ?”A) Yes B) No C) No, until assessed and given all clear by syncope specialist.

18 yo man attends clinic, with single episode of syncope 6 weeks ago after having a shower at the gym,

whilst changing. Felt nauseous, dizzy and lightheaded, and tried to get out of locker room to get “fresh

air”, but LOC on way out. Rapid recovery, and not confused after. Had a tendency to postural head

rushes when standing.

But what do you advise?

Therapy for syncope (personal experience)Syncope is not fully “cured” – but patients can cope well with it

Reassurance

Acknowledgement of severity of illness

Understand will have “on” and “off” days

Understanding of pathophysiology

• “Blood pools in legs, heart is empty”

• Important to keep vessels “full”

POTS:

• Physical reconditioning

• Grinch heart – “small” for size

• Low circulating volume – keep working at increasing this over time (salt and water, exercise)

1. A diagnosis of vasovagal syncope can usually be made clearly from the

history, examination and 12 lead ECG

2. Reassurance of a clear diagnosis and simple conservative advice is an

important first-line treatment for patients

3. Pacing is the last resort in syncope, and data only exists for >40yo with

ECG-documented syncopal episodes attributable to bradycardia

Summary

Bradycardia and Syncope

P Boon Lim, MB BChir PhD

Imperial College Healthcare

London, UK