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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
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AFRICA
(41.2%) for one to five years, and seven (13.7%) for less than a
year.
In the ICD group, there was one device in the re-used device
group that delivered inappropriate shocks (inappropriate delivery
of shocks for supraventricular tachycardia), during the early
stages of implantation but this resolved without any intervention.
This device subsequently needed generator replacement after
14 months from implantation. There were no device infections
identified after a median follow up of 35.9 months (IQR,
17.0–70.9 months) for the cases and 45.7 months (IQR, 37.6–53.7
months) for the controls. There were no procedure-non-related
infections documented for the follow-up period.
For the ICD cases, five (41.7%) patients were followed up
for five years or more, and seven (58.3%) for one to five years.
For the ICD controls, seven (58.3%) were followed up for five
years or more, and five (41.7%) for one to five years. In both
groups (pacemaker and ICD) there were no devices explanted for
infection or malfunctioning during the follow-up period.
In the re-used pacemaker group, 26 (51%) patients attended
follow up at three months, whereas 25 (49%) did not attend. Of
those who did not attend, 11 (44%) had died, nine (36%) were
alive, and five (20%) were lost to follow up (Fig. 2). Of those
who died, eight (72.7%) were documented to have died from
natural causes, one (9.1%) from cancer and two (18.2%) from
non-pacemaker-related sepsis, of whom one died within 24 hours
of implantation and the other after two months of implantation.
The patient who died within 24 hours of device implantation
was admitted with a methicillin-resistant
Staphylococcus aureus
(MRSA) endocarditis prior to pacemaker implantation.
In the new pacemaker group, 43 (84.3%) patients attended
follow up at three months, whereas eight (15.7%) did not attend
follow up. Of those who did not attend, one (12.5%) had died
and seven (87.5) were alive (Fig. 2). The patient who died was
an 87-year-old man who passed away at home two days after
pacemaker implantation from natural causes.
In the re-used pacemaker group, at one-year follow up, 19
(37.3%) patients attended follow up, whereas 32 (62.7%) did
not attend follow up. Of those who did not attend follow up, 15
(46.9%) had died, nine (28.1%) were alive, and eight (25%) were
lost to follow up (Fig. 2). All deaths were due to natural causes
except the two who were septic, mentioned above.
For the new pacemaker group, 38 (74.5%) patients attended
follow up while 13 (25.5%) patients did not attend follow up at
one year. Of those who did not attend follow up, three (23.1%)
had died, seven (53.8%) were alive and three (23.1%) were lost to
follow up (Fig. 2). All deaths were due to natural causes.
Table 2. Pacemaker parameters
Parameters
Patients with
re-used pace-
makers (cases)
Patients with
new pacemak-
ers (controls)
p
-value
DDD,
n
(%)
11 (21.6)
7 (13.7)
0.30
VVI,
n
(%)
39 (76.5)
42 (82.4)
0.463
Other,
n
(%)
1 (2)
2(3.95)
Minimum pacing rate, bpm 63.4
±
6.0
61.6
±
5.1 0.09
Ventricular pacing,
n
(%)
50 (98)
49 (96.1)
0.558
Battery voltage, V
2.78 (2.77–2.79)
Battery current, A
13.86
±
4.9
Battery impedance, K
Ω
0.482
±
0.3
Estimated battery life (years) 6.085
±
1.7
Capture
Amplitude, V
Atrial
0.48
±
0.15 0.57
±
0.23 0.323
Ventricular
0.49
±
0.34 0.48
±
0.18 0.747
Pulse width, ms
Atrial
0.5 (0.5–0.5) 0.5 (0.475–0.5) 0.485
Ventricular
0.5 (0.5–0.5)
0.5 (0.5–0.5) 0.355
Sensitivity, mV
Atrial
4.3 (3.750–5.5) 3.8 (2.875–6.2) 0.255
Ventricular
14.09
±
6.50 15.27
±
7.14 0.406
Electrode impedance,
Ω
Atrial
692
±
178
804
±
275 0.289
Ventricular
748
±
267
808
±
285 0.289
Other = AAI, V = volts; mV = millivolts; ms = millisecond;
Ω
= ohms;
K
Ω
= kilo-ohms; A = amperes; bpm = beats per minute; DDD = dual-
chamber pacemaker; VVI = single-chamber pacemaker.
Table 3. Characteristics of patients who received implantable
cardioverter defibrillators
Characteristics
Patients with
re-used ICDs
(cases)
Patients with
new ICDs
(controls)
n
-value
Sample size,
n
12
12
Age
49.83
±
17.34 50.58
±
17.27 0.916
Gender,
n
(%)
Male
10 (83.3)
10 (83.3)
Female
2 (16.7)
2 (16.7)
Co-morbidities,
n
(%)
Hypertension
4 (33.3)
4 (33)
1.00
Diabetes mellitus
1 (8.3)
2 (16.7)
0.537
Renal impairment
8 (66.7)
6 (50)
0.408
Cancer
0 (0)
0 (0)
Myocardial infarction
7 (58.3)
4 (33.3)
0.49
Cardiomyopathy
3 (25)
2 (1.7)
1.00
CVA
1 (8.3)
1 (8.3)
1.00
COPD
2 (1.7)
0 (0)
0.48
Dementia
0 (0)
0 (0)
Baseline function,
n
(%)
NYHA functional class 1
1 (8.3)
5 (41.7)
0.20
NYHA functional class 2
7 (58.3)
7 (58.3)
1.00
NYHA functional class 3
4 (33.3)
0 (0)
0.11
Wheelchair bound
0 (0)
0 (0)
Bed bound
0 (0)
0 (0)
Ventricular tachycardia,
n
(%)
9 (75)
10 (83.3)
0.615
Other,
n
(%)
3 (25)
2 (16.7)
0.615
First implantation,
n
(%)
12(100)
11(91.7)
0.307
Battery change,
n
(%)
0(0)
1 (8.3)
0.307
Primary implanter,
n
(%)
Cardiologist
11 (91.7)
12 (100)
1.00
Cardiology registrar
1 (8.3)
0 (0)
Follow up at 3 months,
n
(%)
Yes
12 (100)
12 (100)
1.00
No
0 (0)
0 (0)
Follow up at 1 year,
n
(%)
Yes
12 (100)
11 (91.7)
0.307
No
0 (0)
1 (8.3)
CVA = cerebrovascular accident; COPD = chronic obstructive
pulmonary disease; NYHA = New York Heart Association; AV block
= atrioventricular block;
n
= number; (%) = percentage; Other =
ventricular fibrillation and arrhythmogenic right ventricular cardio-
myopathy.