CARDIOVASCULAR JOURNAL OF AFRICA • Vol 22, No 6, November/December 2011
300
AFRICA
or mild LVSD, those with severe LVSD were older, more likely
to be men, had larger left atrial diameter, larger LV dimensions
and LV mass, and as expected, lower fractional shortening and
ejection fraction. This finding was consistent in both genders
and progressed from normal LVSF to severe LVSD (Tables 3, 4).
We developed a linear regression model for the whole popula-
tion (as the pattern was similar in both genders). LVEF was used
as the dependent variable, while independent variables were
taken from clinical variables (age, gender, body mass index,
body surface area) and echocardiographic variables [left atrial
diameter, LV internal dimensions, LV mass, relative wall thick-
ness (RWT)] that were significant in the univariate analysis.
Although LV dimensions were significantly related to LVEF
in the univariate analysis, they were not added in the final model
since these parameters were used in the determination of LVM.
Categorical variables such as gender and presence or absence of
diabetes mellitus were entered as indicator variables. None of
the blood pressure variables were significant in the univariate
analysis.
In the univariate analysis, EF was related to age [B (unstand-
ardised regression coefficients)
=
–0.84,
b
(standardised regres-
sion coefficient)
=
–0.72,
p
= 0.036]; gender (B
=
–5.42,
b
=
–1.84,
p
<
0.0001); BMI (B
=
0.31,
b
=
0.13,
p
=
0.0002); left
atrial diameter (B
=
–5.72,
b =
–0.25,
p
<
0.0001); end-diastolic
diameter (B
=
–7.70,
b
=
–0.45,
p
<
0.0001), end-systolic diam-
eter (B
=
–11.97,
b
=
–0.76,
p
≤
0.0001); LVM (B
=
–0.48,
b
=
–0.32,
p
<
0.0001); and RWT (B
=
14.38,
b =
0.19,
p
<
0.0001).
In a multivariate analysis, lower LVEF was independently
related to BMI, gender, LV mass, left atrial diameter and relative
wall thickness.
TABLE 3. LV FINDINGS IN MALE SUBJECTSACCORDINGTO FUNCTIONAL STATUS
Parameter
Normal LVSF
Mild LVSD Moderate LVSD Severe LVSD
ANOVA
p
-value
AO diameter (cm)
3.10 (0.44)
3.25 (0.41)*
3.07 (0.39)
3.15 (0.45)
NS
LA diameter (cm)
3.78 (0.58)
4.03 (0.58)*
4.34 (0.79)*
4.45 (0.67)*
<
0.0001
IVSd (cm)
1.20 (0.31)
∞
1.32 (0.25)
1.13 (0.23)
∞
1.20 (0.34)
NS
IVSs (cm)
1.59 (0.39)
1.47 (0.33)
1.30 (0.16)*
1.41 (0.48)*
0.0003
LVIDd (cm)
4.67 (0.69)
5.24 (0.86)*
6.11 (0.98)*
∞
6.06 (1.11)*
∞
<
0.0001
LVIDs (cm)
3.01 (0.61)
4.15 (0.88)*
5.07 (0.87)*
∞
5.20 (1.13)*
∞
<
0.0001
PWTd (cm)
1.28 (0.36)
1.27 (0.41)
1.29 (0.31)
1.32 (0.41)
NS
PWTs (cm)
1.85 (0.38)
1.66 (0.37)*
1.61 (0.39)*
∞
1.66 (0.43)
∞
0.0003
FS (%)
35.7 (8.0)
21.1 (7.1)*
17.0 (4.5)*
∞
14.4 (8.3)*
∞
<
0.0001
EF (%)
65.9 (9.3)
45.0 (2.8)*
33.6 (2.5)*
∞
23.5 (7.0)*
∞
<
0.0001
LVM (g)
221.0 (91.2)
286 (121.6)*
337.1 (122.1)*
∞
356.4 (169.6)*
∞
<
0.0001
LVM/BSA (g/m
2
)
119.6 (48.6)
155.3 (62.9)*
201.8 (78.3)*
∞
203.0 (99.9)*
∞
<
0.0001
LVM/HT
2.7
(g/m
2.7
)
54.3 (22.1)
68.9 (27.0)*
85.6 (29.8)*
∞
89.7 (45.1)*
∞
<
0.0001
AO
=
aortic root, LA
=
left atrium, IVSd
=
interventricular septum in diastole, IVSs
=
interventricular septum in systole, LVIDd
=
left ventricular
internal diameter in diastole, LVIDs
=
left ventricular internal diameter in systole, PWTd
=
posterior wall thickness in diastole, PWTs
=
posterior
wall thickness in systole, FS
=
fractional shortening, EF
=
ejection fraction, LVM
=
left ventricular mass, BSA
=
body surface area, HT
=
height.
NS
=
not significant, *
p
<
0.05 vs normal LVSF,
∞
p
<
0.05 vs mild LVSD.
TABLE 4. LV FINDINGS IN FEMALE SUBJECTSACCORDINGTO FUNCTIONAL STATUS
Parameter
Normal LVSF
Mild LVSD Moderate LVSD Severe LVSD
ANOVA
p
-value
AO diameter (cm)
3.08 (0.44)
3.22 (0.42)
3.07 (0.39)
3.15 (0.45)
NS
LA diameter (cm)
3.75 (0.58)
4.01 (0.56)*
4.34 (0.79)*
4.45 (0.67)*
<
0.0001
IVSd (cm)
1.20 (0.31)
∞
1.33 (0.25)
1.13 (0.23)
∞
1.20 (0.34)
0.027
IVSs (cm)
1.57 (0.38)
1.47 (0.32)
1.30 (0.16)*
1.20 (0.34)*
0.0006
LVIDd (cm)
4.63 (0.71)
5.25 (0.87)*
6.11 (1.00)*
6.06 (1.11)*
<
0.0001
LVIDs (cm)
2.99 (0.62)
4.17 (0.85)*
5.07 (0.87)*
5.20 (1.13)*
<
0.0001
PWTd (cm)
1.27 (0.52)
1.24 (0.40)
1.29 (0.31)
1.66 (0.43)
NS
PWTs (cm)
1.84 (0.38)
1.67 (0.36)*
1.61 (0.39)*
1.66 (0.43)
0.0003
FS (%)
35.6 (7.9)
21.0 (6.6)*
17.0 (4.5)*
14.4 (8.3)*
<
0.0001
EF (%)
65.9 (9.3)
44.7 (2.7)*
33.5 (2.5)*
23.5 (2.5)*
∞
<
0.0001
LVM (g)
145.7 (38.3)*
174.3 (73.0)*
198.1 (77.5)
218.3 (48.8)*
<
0.0001
LVM/BSA (g/m
2
)
113.5 (45.9)
128.3 (48.8)
145.7 (38.3)*
174.3 (73.0)*
∞
0.0001
LVM/HT
2.7
(g/m
2.7
)
56.5 (22.5)
64.023.6)*
73.4 (18.2)*
81.8 (30.5)*
∞
<
0.0001
AO
=
aortic root, LA
=
left atrium, IVSd
=
interventricular septum in diastole, IVSs
=
interventricular septum in systole, LVIDd
=
left ventricular
internal diameter in diastole, LVIDs
=
left ventricular internal diameter in systole, PWTd
=
posterior wall thickness in diastole, PWTs
=
posterior
wall thickness in systole, FS
=
fractional shortening, EF
=
ejection fraction, LVM
=
left ventricular mass, BSA
=
body surface area, HT
=
height.
NS
=
not significant, *
p
<
0.05 vs normal LVSF,
∞
p
<
0.05 vs mild LVSD.
