Dr R Beynon University Hospital of North Staffordshire

A challenging case early on
Rhys Beynon
Consultant Cardiologist/Electrophysiologist
University Hospital of North Staffordshire

• 19 year old male
Background
• Long history of palpitations
• No other PMH
• Fit and well

12 Lead ECG

1. L posterior
Where is the pathway?
2. L posteroseptal
3. R posteroseptal
4. R posterior
5. Mid septal
20% 20% 20% 20% 20%
1 2 3 4 5

Anterograde curve

Start of antidromic tachycardia

Antidromic tachycardia with CL
230msec

Attempted termination of tachycardia
with V pacing

Shortest RR interval in AF
160 msec

Management
• Attempted to sedate patient to DC cardiovert
– 13 mg midazolam / 100 mcg fentanyl – still awake
• On call anaesthetist fast bleeped
– SHO arrived after 10 mins and stated he was
actually an acute medical trainee on an
anaesthetic attachment, wasn’t happy to put pt
asleep and went to phone consultant

Management
• 3 External DC shocks with 150J biphasic by lab
staff ( I was out of lab trying to get hold of an
anaesthetist )
– Failed to cardiovert to SR
• Rolled patient over – pads changed to AP
– First 150 J shock failed to cardiovert
– Second shock cardioverted to SR

Which investigation has not been shown to be
associated with a risk of sudden death during EP testing
WPW?
1. Inducibility of
tachycardia (AVRT/AF)
2. Shortest RR interval in
AF < 250 msec
3. Anterograde ERP of
pathway < 250 msec
4. Anterograde ERP of
pathway

Clinical course
• Pt spontaneously went into AF again soon
after cardioversion from VF
• 100mg Flecainide given – AF rate slowed
• Phoned a friend …………
– Colleague found to give a hand

Management
• Consultant anaesthetist found unwilling to
commit to supporting the case for prolonged
period due to staffing issues
– options
• 1. Attempt to ablate pathway in AF
• 2. Ask anaesthetist for short GA to cardiovert to
SR accepting he may well go into AF again
• 3. Stop case and admit until full GA case a
possibility

Management
• Initial attempt to ablate in AF – failed
– Unable to map
– Lesson learnt – this is very difficult to do!
• Short GA given – returned to SR

What set up for ablation?
1. Standard RF
catheter
2. Cool tip RF catheter
3. Cryo cath
4. Standard RF
catheter with
Sheath
5. Cool tip cath with
sheath
20% 20% 20% 20% 20%
1 2 3 4 5

Pathway mapped to between 6 and 7
o’clock on TV annulus

Case terminated 5 hours after starting
Unable to ablate pathway
1. Admit and bring
back to lab prior to
discharge
2. Discharge on
antiarrhythmic for
repeat endocardial
ablation
3. Discharge and bring
back for epicardial
ablation
33% 33% 33%
1 2 3

Management
• Pt discharged with regular flecainide
• Readmitted for planned GA case 2 months
later
• 3 consultant procedure, myself, colleague and
visiting consultant with epicardial experience

EPS and attempted ablation
• TV annulus remapped with SRO sheath, F curve cool tip catheter
• AF spontaneously induced with degeneration to VF – cardioverted
to SR
• Prolonged mapping at TV annulus with early signals at 6 o’clock.
• Multiple ablations with occasional suggestion of a change in the
degree of pre-excitation.
• Good signals up to 40 msec ahead of delta over a reasonably wide
area.
• Eventually exchanged SR0 for an Agilis sheath to get better contact
and perform
• Further ablation without success.

Epicardial access gained

Epicardial ablation
• Extensive ablation over TV annulus
• No loss of pre excitation!
• Elected to remap endocardially

Endocardial mapping extended AGAIN
round to CS OS

Termination after 4 secs

Eventual ablation site

Follow up
• Seen in clinic 6 months after ablation – no
recurrence of pre excitation or palpitations -
discharged

Conclusions
• EP studies and ablations are usually straightforward but
not always, pathways are associated with sudden death
• Map extensively and don’t be afraid to remap where you
have been – chipping away at multiple pathways/fans
• AF takes up a lot of training time but pathways can be very
challenging
• GA cases can be a real help, be assertive if necessary.
• Support to a new consultant is crucial – don’t be afraid to
ask for help if necessary during cases, particularly in the
first few years
– Use the contacts you make during your training
– Very grateful to both my colleagues