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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 4, July/August 2016
AFRICA
259
Cardiopulmonary bypass was established and following
cardioplegic arrrest, 32°C blood–body temperature was
provided. Following right atriotomy, the defect was evaluated
in the presence of pre-operative echocardiographic findings.
In group 1, the defect was closed with a primary continuous
suture technique with 4/0 prolene. In group 2, the defect was
closed by means of a fresh autologous pericardial patch using a
continuous suture technique with 4/0 prolene.
Pre-operative, fifth- and seventh-day postoperative and three-
month 12-lead surface electrocardiograms were provided from
patients’ records, which were obtained at a paper speed of 50
mm/s with 1-mV/cm standardisation. Electrocardiograms were
scanned for evaluation of the P waves. Electrocardiograms
exhibiting P waves at least nine in 12 derivations were analysed
for the existing P waves.
4
Measuring the length of the P waves using Photoshop
®
(Adobe), the longest P wave was denoted as P
max
whereas the
shortest P wave was P
min
. The difference between P
max
and P
min
was
the P-wave dispersion (P
d
) (P
d
= P
max
– P
min
).
Statistical analysis
The 5.0 version of the GraphPad Prism program was used
for statistical analysis. Data are shown as mean
±
standard
deviation. Postoperative P-wave changes of the patients in
group 1 and 2 were compared with pre-operative values and the
differences were evaluated. Continuous variables were compared
using Mann–Whitney
U-
and Student’s
t
-tests. A
p-
value
≤
0.05
was considered statistically significant.
Results
Pre-operative demographic characteristics of the two groups
were similar. Demographic characteristics and transthoracic
echocardiographic data of our patients are shown in Table 1. All
of the patients were in sinus rhythm in the pre-operative period.
Arrhythmia was not observed in the postoperative follow up and
there was no need for pace implementation. The patients were
discharged 6.2
±
1.4 days postoperatively.
In group 1, compared to the pre-operative period, P
max
was
significantly increased in the five to seven days postoperatively,
and P
max
was still significantly longer three months after the
procedure (Table 3). P
max
was also increased in the postoperative
period in group 2 but this change gained statistical significance
at three months following the procedure (Table 4). In the
evaluation of P
min
, compared to the pre-operative period, P
min
was
significantly increased in the five to seven days postoperatively
and three months after the procedure in both groups (Tables 3,
4).
Evaluation of the P-wave dispersion revealed that in group 1,
compared to the pre-operative period, no significant difference
was found in the five to seven days postoperatively and three
months after the procedure. Similarly, in group 2, compared to
the pre-operative period, no significant difference was found in
any postoperative follow-up periods. No statistically significant
difference was found in a comparison of group 1 and 2, both
pre-operatively and at the postoperative follow up in terms of
P-wave analysis (P
max
, P
min
and P
d
) (Table 5).
Discussion
The presence of ASD causes volume overload and increased
stretch induces right heart dilatation and dysfunction. In these
patients, P
max
and P
d
extension develops as a result of prolongation
of the atrial depolarisation time.
2,4,7
The prolongation of P
d
and P
max
reflect non-homogeneous and discontinuous sinus
stimulation and may be predictors of atrial fibrillation.
2
In the literature, P-wave changes have been compared in
repaired and unrepaired ASDs, or in repaired ASDs by surgical
or percutaneous means. There is no study comparing the effects
of two different surgical techniques on the P wave. In our study,
two different surgical ASD closure techniques were compared in
terms of P-wave analyses using primary repair and pericardial
patch plasty techniques.
The incidence of dysrhythmia increases with increasing
age in patients with unrepaired ASD.
8
Additionally, the risk
Table 1. Comparison of pre-operative patients’ characteristics
Demographics
Group 1 (
n
= 72) Group 2 (
n
= 29)
Age (years)
21.8
±
2.4
22.3
±
3.7
BMI (kg/m
2
)
25.2
±
1.2
24.7
±
1.3
Diameter of defect (mm)
20.6
±
8.5
23.9
±
10.3
Qp/Qs
2.0
±
0.7
2.3
±
0.9
EF (%)
60.9
±
6.2
64.3
±
5.2
PASB (mmHg)
30
±
10.7
32.3
±
11.8
≤ Mild tricuspid regurgitation (
n
)
5
1
≤ Mild pulmonary regurgitation (
n
)
1
0
Anomalous pulmonary venous return (
n
)
0
1
≤ Mild pulmonary stenosis (
n
)
2
1
≤ Mild aortic regurgitation (
n
)
1
0
BMI: body mass index, EF: ejection fraction, PASB: pulmonary artery systolic
pressure.
Table 2. Comparison of surgical data
Surgery
Group 1 (
n
= 72) Group 2 (
n
= 29)
Median sternotomy (
n
)
44
25
Mini-sternotomy (
n
)
17
1
Mini-thoracotomy (
n
)
11
3
CPB time (min)
38.5
±
12.2
42.4
±
16.6
Cross-clamp time (min)
20.3
±
7.6
23.3
±
10.6
Revision (
n
)
1
0
Hospital stay (days)
6.2
±
1.4
6.4
±
1.4
CPB: cardiopulmonary bypass.
Table 3. P-wave changes in primary repair procedure for ASD closure
Pre-operative
Postoperative
5th day
Postoperative
3rd month
P
1
P
2
P
max
205.9
±
29.4 220.6
±
31.5 231.1
±
39.4 0.0033 0.0001
P
min
108.1
±
29.4 121.2
±
32.7 129.5
±
36.9 0.0162 0.0003
P
d
97.2
±
33.1
98.8
±
35.9 101.7
±
42.2 0.7011 0.4432
p
1
: comparison of the pre-operative period and the fifth day postoperatively
;
p
2
:
comparison of the pre-operative period and the third month postoperatively.
Table 4. P-wave changes in pericardial patch
plasty procedure for ASD closure
Pre-operative
Postoperative
5th day
Postoperative
3rd month
P
1
P
2
P
max
219.4
±
37.7 236.1
±
39.4 254.3
±
51.1 0.1092 0.0089
P
min
107.1
±
28.7 120.3
±
27.7 132.8
±
35.6 0.06
0.043
P
d
110.6
±
43.6 115.9
±
39.9 121.7
±
47.9 0.5659 0.2796
p
1
:
comparison of the pre-operative period and the fifth day postoperatively; p
2
:
comparison of the pre-operative period and the third month postoperatively.