CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 4, July/August 2010
188
AFRICA
ous aetiologies, including systemic hypertension, Puwanant
et al.
recently reported that 58% of the patients had reduced TAPSE
(
<
15 mm), in contrast to our finding of 29.6%.
19
However, our
study was exclusively on patients with HHD, and a history of
diabetes mellitus (DM) was found in only 8.6%. In comparison,
51% of the patients in the series by Puwanant
et al.
had coronary
artery disease, 37% had DM and 32.5% had cardiomyopathies.
In addition, the patients in the latter study were older than ours
(mean age of 72
±
14 vs 55.94
±
17.00 years), and we have
shown that older age predicted reduced TAPSE. Furthermore,
differences in the aetiology of heart disease in the two studies
could have amplified the disparities in TAPSE.
19
It is possible that RV disease develops in parallel with a simi-
lar process on the left side in hypertensive patients, likely as a
result of ventricular interdependence. This is supported by the
close correlation we found between the TAPSE and the indices
of LV long-axis function, lateral and septal APSE (
r
=
+
0.534
and
+
0.541, respectively,
p
<
0.001 for both). Ventricular inter-
dependence is defined as the forces that are transmitted directly
from one ventricle to the other through the myocardium and peri-
cardium, independent of neural, humoral or circulatory effects. It
is a consequence of the close anatomical association between the
ventricles, which are encircled by common muscle fibres, they
share a septal wall, and are enclosed within the pericardium.
20
Future studies are however needed to corroborate our finding
and to explore other explanations.
To the best of our knowledge, our study is the first, at least in
Africans, to group and compare hypertensives based on normal
TABLE 1. BASELINE CHARACTERISTICS
Group 1
n
=
131 (70.4%)
Group 2
n
=
55 (29.6%)
p
-value
All patients
Males/females
67/64
22/33
0.199
89/97
Mean age (years)
53.50
±
17.10
61.78
±
15.38
0.002*
55.94
±
17.00
Urban residence
112 (85.5%)
42 (76.4%)
0.141
154 (82.8%)
Duration of hypertension (years)
5.57
±
6.62
7.87
±
8.83
0.054
6.24
±
7.21
Dyspnoea (NYHA III or IV)
46 (35.1%)
33 (60.0%)
0.002*
79 (42.5%)
Peripheral oedema
34 (26.0%)
30 (54.6%)
<
0.001*
64 (34.4%)
Smoking
6 (4.6%)
1 (1.8%)
0.676
7 (3.8%)
Alcohol
13 (9.9%)
4 (7.3%)
0.681
17 (9.1%)
Diabetes mellitus
11 (8.4%)
5 (9.1%)
0.878
16 (8.6%)
Stroke/TIA
15 (11.5%)
2 (3.6%)
0.103
17 (9.1%)
Anaemia
19 (14.5%)
18 (32.7%)
0.016*
37 (19.1%)
Renal failure
20 (15.3%)
15 (27.3%)
0.101
35 (18.8%)
Systolic BP (mmHg)
156.61
±
30.50
149.25
±
28.16
0.150
154.54
±
29.97
Diastolic BP (mmHg)
95.11
±
20.26
93.19
±
18.51
0.570
100.88
±
86.80
Pulse pressure (mmHg)
61.54
±
22.95
56.06
±
18.35
0.141
60.00
±
21.85
Heart rate
88.52
±
16.45
102.58
±
19.45
<
0.001*
92.47
±
18.41
PCV (%)
28.67
±
10.67
30.46
±
8.61
0.534
29.57
±
9.63
Serum urea (mmol/l)
14.30
±
11.21
14.16
±
10.98
0.963
14.24
±
11.00
Serum creatinine (
µ
mol/l)
585.72
±
789.49
333.33
±
383.36
0.155
477.55
±
654.72
*
p
-value statistically significant; PCV: packed-cell volume. All values are expressed as means
±
standard deviations, or as proportions, or as
numbers with percentages in parentheses.
TABLE 2. ECHOCARDIOGRAPHIC FEATURES
Group 1
n
=
131
(70.4%)
Group 2
n
=
55
(29.6%)
p
-value
RVOTd (mm)
28.83
±
5.50 31.02
±
7.03 0.024*
TAPSE (mm)
21.00
±
4.60 11.82
±
2.24
<
0.001*
Left atrium (mm)
38.31
±
7.50 43.04
±
7.76
<
0.001*
IVSd (mm)
11.25
±
3.85 10.65
±
4.43 0.358
LVPWd (mm)
9.64
±
3.02 9.22
±
2.99 0.383
LVEDD (mm)
51.69
±
11.45 57.07
±
13.51 0.006*
LVEF (%)
57.88
±
16.82 42.42
±
19.00
<
0.001*
PV acceleration time (ms) 119.71
±
39.54 86.41
±
27.10
<
0.001*
LV lateral APSE (mm)
12.38
±
4.11 8.80
±
2.52
<
0.001*
Septal APSE (mm)
11.50
±
3.99 7.06
±
4.04
<
0.001*
*
p
-value statistically significant; LVEF: left ventricular ejection frac-
tion; RVOTd: right ventricular out-flow tract dimension at end-dias-
tole; TAPSE: tricuspid annular plane systolic excursion; IVSd: inter-
ventricular septal thickness at end-diastole; LVPWd: left ventricular
posterior wall thickness at end-diastole; LVEDD: left ventricular end-
diastolic dimension; PV: pulmonary valve. All values are expressed as
means
±
standard deviations.
TABLE 3. FINDINGS IN THE RESTING
ELECTROCARDIOGRAMS
Characteristic
Group 1
n
=
30 (16.1%)
Group 2
n
=
156 (83.9%)
p
-value
PR interval (ms)
165.09
±
30.96 136.15
±
42.41
<
0.001*
QRS duration (ms)
94.91
±
18.99 99.84
±
23.59 0.218
QT
c
interval (ms)
432.17
±
47.31 455.97
±
42.71 0.009*
Atrial fibrillation/ flutter
4 (3.1%)
11 (20.0%)
<
0.001*
Other SVT
1 (0.8%)
3 (5.5%)
0.043*
Complete heart block
2 (1.5%)
0
–
Complete LBBB
4 (3.1%)
4 (7.3%)
0.196
Complete RBBB
4 (3.1%)
1 (1.8%)
0.635
1st degree heart block
8 (6.1%)
1 (1.8%)
0.214
SVT: supraventricular tachycardias; LBBB and RBBB: left and right
bundle branch block respectively. All values are expressed as means
±
standard deviations or as numbers with percentages in parentheses.
