CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 1, February 2012
AFRICA
41
ment with antihypertensive therapy and the presence of periph-
eral stigmata of hypertension, such as locomotor brachialis,
thickened arterial wall, cardiomegaly and loud aortic component
of the second heart sound. All of these patients were on combina-
tion therapy including medications such as diuretics, angiotensin
converting enzyme (ACE) inhibitors, angiotensin receptor block-
ers (ARBs), aspirin or warfarin.
Patients with diabetes, nephrotic syndrome, renal failure,
present or past history of liver disease, and stroke were excluded
from the study. Patients with echocardiographic evidence of
valvular heart disease, dilated cardiomyopathy and restrictive
cardiomyopathy as well as those with incomplete echocar-
diographic examinations and poor image windows were also
excluded.
All subjects were examined and a clinical history was taken.
Two dimensional (2D), M-mode and Doppler echocardiography
were done in the left lateral decubitus position using a 3.5-MHz
probe, according to standard recommendations of the American
Society of Echocardiography.
13
The 2D-derived M-mode was
used to estimate the left ventricular wall and chamber dimen-
sions and assess the ejection fraction and fractional shortening,
using the Teichholz formula.
14
The apical four- and five-chamber
views were used to estimate the transmitral early (E), late atrial
(A) and E/A velocities, deceleration time and isovolumic relaxa-
tion time. The isovolumic contraction time was derived from the
Doppler study and taken as the time interval from the end of
the mitral A wave and the beginning of the ejection time. The
ejection time was obtained by Doppler echocardiography and
was the time interval from the beginning to the end of the left
ventricular outflow.
In our laboratory, the intra-observer concordance correlation
coefficient ranged from 0.80 to 0.96 while that of the inter-
observer concordance ranged from 0.79 to 0.97. Hypertensive
heart failure subjects were categorised, based on the ejection
fraction, into normal ejection fraction, mild heart failure (ejec-
tion fraction 45–55%), moderate heart failure (ejection fraction
35–45%) and severe heart failure (ejection fraction
<
35%). The
Tei index was defined as the sum of the isovolumic relaxation
time and isovolumic contraction time, divided by the ejection
time obtained from the left ventricular inflow and outflow, as
shown in Fig. 1.
15
Ethical approval was obtained for the study. Statistical analy-
sis was done using the Statistical package for Social Sciences 16.
0 (Chicago Ill). Data were summarised as means
±
standard devi-
ation (quantitative) and proportions and percentages (qualitative
data). Comparison between groups was done by the independent
t
-test and chi-square test as appropriate. Statistical relationships
between Doppler echocardiography measurements, Tei index and
echocardiography-derived variables were done by correlation
analysis. A
p
-value
<
0.05 was taken as statistically significant.
Results
The mean age of the subjects with hypertensive heart failure
was 57.8
±
14.2 years (age range 42–87 years) and comprised
26 females (47.3%), compared to 56.4
±
18.6 years, with 19
females (47.5% females) for the control group. They were well
matched in age distribution and gender. Hypertensive heart
failure patients were receiving combination therapy including at
least diuretics, ACE inhibitors and aspirin/warfarin.
Table 1 shows the clinical characteristics of the study partici-
pants. Ejection fraction and fractional shortening were lower
among subjects with hypertensive heart failure compared to
control subjects (48.5
±
25.9, 22.5
±
11.4 vs 70.6
±
12.2, 38.7
±
8.1,
p
< 0.005, respectively). Posterior wall thickness, inter-
ventricular septal thickness, left ventricular internal dimension
in diastole and systole, and left atrial dimensions were higher
Fig. 1. Schematic diagram of the method of estimat-
ing the components of the Tei index. IVCT: isovolumic
contraction time, IVRT: isovolumic relaxation time, ET:
ejection time.
Mitral inflow
Left ventricular
outflow
IVCT = a–b–IVRT
IVRT = c–d
ECG
IVCT
IVRT
a
b
ET
c
d
Index = a–b
b = (IVCT + IVRT)
ET
TABLE 1. CLINICAL CHARACTERISTICS OF STUDY
PARTICIPANTS
Variable
Heart failure
patients (
n
=
55)
Controls
(
n
=
30)
p
Mean age (years)
57.8
±
14.2
56.4
±
18.6 0.571
Gender – female,
n
(%)
26 (47.3)
19 (47.5)
0.889
Mean SBP (mmHg)
125.2
±
18.8 119.8
±
13.4 0.681
Mean DBP (mmHg)
84.2
±
12.7
74.6
±
10.4 0.04*
Mean BMI (kg/m
2
)
27.8
±
11.4
23.2
±
2.1 0.03*
Mean PP (mmHg)
58.8
±
18.5
53.0
±
16.7 0.05
LVDD (mm)
60.9
±
9.6
45.0
±
7.5 0.017*
LVSD (mm)
43.7
±
10.9
31.5
±
7.3 0.029*
EF (%)
48.5
±
25.9
70.6
±
12.2 0.015*
FS (%)
22.5
±
11.4
38.7
±
8.1 0.035*
IVSd (mm)
13.6
±
3.4
11.2
±
2.6 0.024*
PWTd (mm)
12.1
±
2.5
10.4
±
2.1 0.021*
LAD (mm)
43.3
±
10.5
32.2
±
7.1 0.038*
DT (ms)
204.1
±
61.3 172.5
±
38.5 0.021*
IVRT (ms)
96.8
±
32.7
79.7
±
16.5 0.031*
IVCT (ms)
112.6
±
39.5
82.5
±
27.2 0.023*
Mean Tei index
0.91
±
0.33
0.28
±
0.16 0.001**
**Statistically significant. SBP: systolic blood pressure, DBP:
diastolic blood pressure, PP: pulse pressure, BMI: body mass
index, LVDD: left ventricular internal diastolic dimension, LVSD:
left ventricular internal systolic dimension, EF: ejection fraction,
FS: fractional shortening, IVSd: interventricular septal dimension,
PWTd: posterior wall thickness, LAD: left atrial dimension, DT:
deceleration time, IVRT: isovolumic relaxation time, IVCT: isovolu-
mic contraction time.
