Download Congenital third-degree AV block in the infant with a ventricular rate

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Pacemaker
Therapy in
Congenital
AV Block
Alpay Celiker M.D.
Acıbadem University
Istanbul, Turkey
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Pacing in Pediatric Patients
 Advances
in lead and device technology allow
pacemaker system implantation in children and
even in neonates
 Specific
problems in children such as small
vessel size, cardiovascular abnormalities often
lead to implant problems.
 Physical
activity and somatic growth may affect
lead longevity in young patients
Class I-IIa Indications
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Advanced second- or third-degree AV block associated with
symptomatic bradycardia,ventricular dysfunction, or low
cardiac output. (Level of Evidence:C)
Congenital third-degree AV block with a wide QRS escape
rhythm, complex ventricular ectopy, or ventricular dysfunction.
(Level of Evidence:B)
Congenital third-degree AV block in the infant with a
ventricular rate less than 55 bpm or with congenital heart
disease and a ventricular rate less than 70 bpm. (Level of
Evidence: C)
Congenital third-degree AV block beyond the first year of life
with an average heart rate less than 50 bpm,abrupt pauses in
ventricular rate that are 2 or 3 times the basic cycle length, or
associated with symptoms due to chronotropic incompetence.
(Level of Evidence:B)
Points of
Interest
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Leads: Route
Endocardial
Classical
Lumenless (4F)
Epicardial
Leads: Implant Place
Right ventricle vs Left ventricle
Apex vs septum
Chamber Paced
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VVIR, DDD, or VDD
Leads: Fixation
Mechanism
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Pros and Cons of
Transvenous Leads
 Leads
generally more
reliable than
epicardial implants
 Procedure
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more easy
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Less thresholds
Fast adaptation to new
pacemaker systems
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Venous obstructions
Pace related impaired
ventricular function.
Lead infections
Lead extraction
necessity
Interaction with
cardiac valves
Impossible in some
patients
Venous Occlusion: 11 out of 85
(13%) total venous obstruction;
10 (12%) partial obstruction. Age,
body size and lead type not
associated with occlusion > 3
years . Bar Cohen 2006
Tricuspid valve issue: 27
out of 123 TR increased.
No severe TR. No change
(63%) or improved (12%).
Berul 2008.
15 year old boy with
postoperative AV block.
VDD pacemaker . Needs
biventricular pacing.
What to do???
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Pediatric Pacemaker Infections*
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Perioperative Infections (before discharge):
Superficial 1,2 %
Deep 0,2 %
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Early Pacemaker Infections (< 60 days)
Superficial 3,1 %
Deep 1,2 %

Late Pacemaker Infections
Superficial 0,5 %
* Cohen et al J Thorac Cardiovasc
Deep 0,7 %
Surg 2002; 124.
LEAD EXTRACTION WITH SEVERAL METHODS
Cecchin et al. Circ Arrhythm Electrophysiol. 2010.
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Excimer-laser extraction in
children
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25 patients, 43 leads (36 pacing/7 ICD leads)
Median age at extraction 13,9 years (8,4-29,2)
Mean duration of lead 49,4 months (3-128)
Lead fracture 37/43 leads (86,6%)
Lead position: Ventricular 58%, atrial 42%
Complete removal 39/43 (91%), partial in four
Major complication 2/25
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Cardiac perforation and tamponade
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Thrombosis of left subclavian and innominate vein
Moak J et al. PACE 2006.
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Epicardial Pacing
Pros:
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Venous access not required
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Usable patients with
compromised venous
access
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Allows left ventricular
pacing, even in small
patients
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Dual chamber pacing in
small patients
Cons
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Implantation procedure
more invasive than
endocardial

Surgery required
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Leads are weaker
Papadopulos et al. Long-term followup after steroid-eluting epicardial
pacemaker implantation in young
children: a single centre experience.
45 patients,
45 patients, mean age at
implant 3,2 yrs, 5.7 years + 15
months (range of 6 months to
7.3 year) follow-up
Retrocostal approach is neither superior
nor inferior to the subrectus or subxiphoid
approach in terms of lead longevity and
from failure.
Lichtenstein BJ, et al. Does Pocket Location
Affect Lead Survival? Pediatr Cardiol 2010.
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Epicardial versus Endocardial
Pacing: Conclusion
Epicardial:
<15 kg
Compromised venous access or a univentricular
heart
Pace the left ventricle
Endocardial
Possible implant >15kg
Venous occlusion
Risks of future lead extraction
Beware of pacing induced heart failure
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VVIR vs DDD Pacing
VVIR
Pros:
DDD
One lead
required, Smaller
 Pros: Physiological heart
generator, gives
rate response, AV synchrony
satisfactory exercise
maintained, reduced risk of
tolerance, slower heart
atrial fibrillation
rates than DDD
Cons: Heart rate
 Cons: Two leads required,
response is not
physiological, loss of
larger generator, faster heart
AVsynchrony,
rates than VVIR, pacemaker
mediated tachycardia
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VDD Pacing
 Disadvantages
 Advantages
 Single
lead dual
chamber sensing
 Avoid of many
electrodes
 Provide AV
Synchrony
 Avoid of venous
thrombosis??
Atrial sensing
problems in postop.
cases
 Relative change of
atrial dipole with the
growth
 Decrease of AV
synchrony with time
 Lack of active fixation
 Large electrodes
 No indication in SSS
 Lack of epicardial use
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An inhomogeneous and dyssynchronous electrical activation of
ventricles, leading to changes in myocardial architecture and left
ventricular mechanical contractions. This problem is secondary to
right ventricle apical pacing via transvenous pacing.
Karpawich P. Pace 2008
+ Site Selective
Pacing
• Pioneereed by Karpawich.
• Implant possible to desired
place
• Less material at venous
system and heart
• Similar results compared
to conventional systems
• Lead extraction issue?
•Long-term results?
Select Secure system: steroid
eluting, bipolar, lumenless, nonretractable screw-in 4,1 F lead
(model 3830, Medtronic, Inc.),
delivered through a 8F steerable
catheter (Select Site)
Karpawich et al. Altered cardiac histology following
apical right ventricular pacing in patients with
congenital atrioventricular block. Pacing Clin
Electrophysiol 1999
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Gabbarini and Agnoletti. Selective-site pacing in
paediatric patients: use of the Select Secure System and
risk of vein occlusion. Europace 2010
20 patients 40 leads. No sign of venous occlusion at the ultrasound exam
at a median follow-up of 19 mos (range 6-44 mos)
Khan a, Zelin K and Karpawich P. Performance of the Lumenless 4.1Fr Diameter Pacing Lead Implanted at Alternative Pacing Sites in
Congenital Heart: A Chronic 5-Year Comparison. PACE 2010.
Group I
Group 2
n= 80
n=91
P-wave (mV)
3.3 ± 1.9
3,7 ± 2.2
R-wave (mV)
10 ± 4.2
12 ± 5,6
Impedance (Ω)
747 ± 251
881 ± 224
Threshold (msec at 2,5 V)
1,02 ± 0,5
0,056 ± 0,2
Follow-up (4-5 year)
n=80
n=11
P-wave (mV)
3.9 ± 2.4
6,2± 4,8
R-wave (mV)
11,2 ± 6.9
10 ± 4,3
Impedance (Ω)
677 ± 267
562 ± 75
Threshold (msec at 2,5 V)
0,05±0,02
0,08 ± 0,07
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Implant
Preserved cardiac synchrony and
function
with
single-site
left
ventricular epicardial pacing during
mid-term follow-up in paediatric
patients. Tomaske M, Breithardt OA,
and Bauersfeld U. Europace 2009.
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RV PACE (N=10
LV PACE (N=15)
Interventricular mechanical delay (ms)
62±15
17±10
Septal-to-posterior wall motion delay
(ms)
294±84
59±23
Septal-to-lateral wall delay, by TDI (ms)
59+12
40±19
LV mechanical delay, 2D strain (ms)
Mitral valve level
159±44
72±31
LV mechanical delay, 2D strain (ms)
Papillary muscle level
127+25
64±23
RV mechanical delay, 2D strain (ms)
62±33
57±23
RV (ms)
197±42
210±43
LV ejection fraction (%)
45±6
60±6
LV end-systolic volume index (mL)
33±11
22±5
Aortic velocity – time integral (cm)
21±2
26±4
LV Tei index
0,63±0,11
0,38±0,07
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Conclusion
 Long
term complications of pacing in childhood
include venous occlusion, impaired ventricular
function, lead failure, and risks of multiple implants
and explants.
 Right
ventricular apical pacing should be minimised
where possible.
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In small infants epicardial pacing should be
encouraged.
 Long
term complications largely related to problems
with the leads.