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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 6, November/December 2015
218
AFRICA
group was selected from healthy women who presented with
infertility and the male factor was detected to be the cause of
the infertility. PCOS was diagnosed by ultrasound if there were
polycystic ovaries [enlarged ovaries (2–8 mm in diameter) with
cysts
≥
8], oligo-amenorrhea (intermenstrual interval > 35 days),
hirsutism (Ferriman–Gallwey score
≥
7) and elevated serum
testosterone levels (
≥
2.7 nmol/l, convention factor 0.03467; 80
ng/dl).
8
Patients with hypertension, diabetes mellitus, electrolyte
imbalance, a history of chronic renal failure or a glomerular
filtration rate
<
60 ml/min according to the MDRD formula,
chronic inflammatory disease, chronic lung disease, heart
failure or valve disease, thyroid function disorders, history of
arrhythmia, sleep-apnoea syndrome, smoking and drug use in
the last three months were excluded. The study protocol was
approved by the local ethics committee and written informed
consent was obtained from all patients.
Laboratory, electrocardiographic and echocardiographic
assessments were done on the second or third days of the
menstrual cycle, which is the follicular phase. Fasting levels of
blood glucose and insulin, lipid profiles and hormone levels were
determined by standard laboratory methods. Insulin resistance
was assessed using the homeostasis model assessment (HOMA–
IR) calculation: fasting serum insulin (μIU/ml)
×
fasting plasma
glucose (mg/dl)/405.
9
Analysis of electrocardiography
A 12-lead surface electrocardiogram was used to evaluate P-wave
parameters. The paper speed was 50 mm/s and amplitude was
20 mm/mV. All electrocardiograms were recorded on the second
or third day of the menstrual cycle. P waves were measured
manually on all derivations and at least three cardiac cycles were
recorded.
Pd was defined as the difference between the maximum
(P
max
) and minimum (P
min
) P-wave duration. The onset of the
P wave was defined as the point of first visible upward slope
from baseline for positive waveforms, and as the point of first
downward slope from baseline for negative waveforms. The
return to baseline was considered as the end of the P wave.
Echocardiography
Two-dimensional, M-mode, pulsed and colour-flow Doppler
echocardiographic examinations were performed on all patients
by one cardiologist on the second or third day of the menstrual
cycle (Vivid 7 Pro, GE, Horten, Norway, 2–4 MHz phased-
array transducer). During echocardiography, a single-lead
electrocardiogram was recorded simultaneously. Data were
recorded from the average of three cardiac cycles.
M-mode andDopplermeasurements were performed adhering
to the American Society of Echocardiography guidelines.
10
TDI
was performed with transducer frequencies of 3.5–4 MHz. The
monitor sweep was set at 100 mm/s. A pulsed Doppler sample
volume was placed at the level of the LV septal mitral annulus,
lateral mitral annulus and tricuspid annulus in the apical four-
chamber view. Peak systolic, early diastolic (E) and late diastolic
(A) velocities were obtained at these levels.
Atrial electromechanical coupling, the time interval from the
onset of the P wave to the beginning of the late diastolic wave,
was calculated from the lateral mitral annulus (PAlat), septal
mitral annulus (PAsep) and tricuspid annulus (PAtri). Interatrial
electromechanical delay was defined as the difference between
PAlat and PAtri, and intra-atrial electromechanical delay was
defined as the difference between PAsep and PAtri.
11
LA volumes were measured echocardiographically by the
biplane area–length method from the apical four-chamber view.
LA maximal volume (V
max
) was calculated at the onset of mitral
valve opening, LA minimum volume (V
min
) at the onset of mitral
valve closure, and LA presystolic volume (Vp) at the beginning
of the P wave on a surface ECG. LA passive emptying volume
[(PEV)
=
V
max
– Vp], LA passive emptying fraction [(PEF)
=
(V
max
– Vp)/V
max
], LA active emptying volume [(AEV)
=
Vp – V
min
], LA
active emptying fraction [(AEF)
=
(Vp – V
min
)/Vp], and LA total
emptying volume [(TEV)
=
V
max
– Vmin] were defined as LA
emptying function parameters.
12,13
Statistical analysis
All continuous variables were expressed as mean
±
standard
deviation and median (interquartile range). All measurements
were evaluated with the Kolmogorov–Smirnov and Shapiro–Wilk
tests, and comparisons of parametric and non-parametric values
between two groups were performed by means of the Mann–
Whitney
U
-test or Student’s
t-
test. Univariate linear regression
and stepwise multiple regression analyses were used to identify
the clinical characteristics of interatrial electromechanical delay.
Age, body mass index (BMI) and testosterone levels were entered
into the model. All statistical studies were carried out with the
SPPS program (version 15.0, SPSS, Chicago, Illinois, USA);
p
<
0.05 was accepted as statistically significant.
Results
Clinical and laboratory findings of the subjects are shown
in Table 1. Age and serum FSH levels, respectively, were
significantly lower in patients with PCOS [24
±
4 vs 30
±
7 years,
p
<
0.01; and 5.07 (2.92–10.1) vs 7.68 (2.02–19.10) mIU/ml,
p
<
0.001]. BMI (22.5
±
3.4 vs 25.4
±
5.4 kg/m
2
,
p
=
0.029) and serum
estradiol levels (28.8
±
11.3 vs 43.2
±
17.8 pg/ml,
p
<
0.001) were
significantly higher in PCOS patients than in the control subjects.
Serum testosterone levels were higher in patients with PCOS
than in the control group [75.5 (14.7–314) vs 17.2 (2.5–44) ng/dl,
p
<
0.001]. Heart rate (82.02
±
13.15 vs
74.24
±
11.02 bpm,
p
=
0.014) and Pd were significantly increased in PCOS patients (27
±
5 vs 24
±
6 ms).
Echocardiographic findings of the study population are
given in Table 2. LV diastolic and systolic diameters, ejection
fraction, fractional shortening, LA diameters, and E and A
waves were similar in both groups. The transmitral E/A ratio was
significantly lower in PCOS patients than in the controls (1.5
±
0.3 vs 1.7
±
0.4,
p
=
0.023). The peak systolic myocardial velocity
was higher in patients with PCOS (0.09
±
0.01 vs 0.08
±
0.01 m/s,
p
=
0.02). The myocardial early diastolic wave (E’) and E/E’ ratio
were similar in both groups.
There were no differences in LA V
max
, LA V
min
, and Vp
between the groups. The LA active emptying volume and active
emptying fraction were similar. The passive emptying volume
(12.54
±
4.39 vs 15.28
±
3.85 ml/m
2
,
p
=
0.004) and passive
emptying fraction [54.4 (21–69) vs 59.1 (28–74)%,
p
=
0.008] were