CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 1, February 2012
42
AFRICA
among subjects with hypertensive heart failure than control
subjects. The Tei index was significantly higher among hyper-
tensive heart failure subjects than controls (0.91
±
0.33 vs 0.28
±
0.16,
p
<
0.0001).
Table 2 shows the echocardiographic parameters of the
subjects with hypertensive heart failure, categorised by ejection
fraction, according to the degree of systolic dysfunction. Left
ventricular internal diastolic dimension, left ventricular internal
systolic dimension, ejection fraction, fractional shortening and
left atrial dimension were significantly different among the
groups. The Tei index increased significantly as the degree of
systolic dysfunction worsened in the study participants.
Table 3 shows the linear correlation of the echocardiographic
variables and echo-derived indices of systolic and diastolic func-
tion with the Tei index. Ejection fraction and fractional shorten-
ing were well correlated with the Tei index and these were statis-
tically significant. Echocardiographic parameters of diastolic
function, such as the mitral E/A ratio and deceleration time were
also shown to be significantly correlated with the Tei index.
Discussion
Heart failure is a major and growing public health concern glob-
ally. The aetiologies of heart failure in Africans include hyperten-
sion, cardiomyopathies and rheumatic heart disease, as reported
by Ntusi
et al.
and Amoah
et al.,
with hypertension remaining the
commonest cause.
16,17
This study shows that the Tei index of myocardial perfor-
mance is significantly different between patients with hyperten-
sive heart failure and normotensive subjects. It also shows that
the higher the degree of systolic dysfunction, the higher the Tei
index. Another important finding was that the Tei index corre-
lated significantly with other conventional indices of systolic
and/or diastolic dysfunction among Africans with hypertensive
heart failure. It may therefore be a clinically useful index of
overall dysfunction among black Africans with heart failure, in
a similar way that ejection fraction, fractional shortening, decel-
eration time and isovolumic relaxation time are useful for risk
estimation, treatment evaluation and prognosis in subjects with
heart failure.
Traditionally, assessment of left ventricular function has
focused on measurement of ejection fraction and diastolic indi-
ces using Doppler measurements for risk stratification and treat-
ment evaluation.
18
These measurements provide important prog-
nostic information regarding clinical outcome in patients with
heart failure. However, assessment of left ventricular diastolic
dysfunction may be more challenging because diastolic function
is more difficult to estimate and varies with age and loading
conditions.
19
Heart failure is usually associated with both systolic
and diastolic dysfunction and a combined index of overall risk
estimation may be more useful in risk stratification, treatment
evaluation and prognosis.
The Tei index is a function of cardiac intervals derived from
ejection time, contractility and relaxation period. It therefore
indicates combined systolic and diastolic dysfunction and
appears to be a more ideal test for overall dysfunction in heart
failure. It has been shown to be independent of ventricular load-
ing conditions, is easily reproducible, and assesses the overall
function of the heart.
20
The Tei index has been shown to correlate
with combined systolic and diastolic dysfunction in several heart
diseases, including dilated cardiomyopathy and amyloidosis.
10-12
TABLE 2. ECHOCARDIOGRAPHIC PARAMETERS OF STUDY PARTICIPANTSACCORDING
TOTHE SEVERITY OF SYSTOLIC DYSFUNCTION
Variable
Normal EF (
n
=
12)
Mild HF
(EF 45–55%) (
n
=
11)
Moderate HF
(EF 35-45%) (
n
=
19)
Severe HF
(EF
<
35%) (
n
=
13)
p
Age (years)
59.1
±
13.8
56.7
±
10.7
56.3
±
11.3
55.1
±
19.0
0.887
LVDD (mm)
45.5
±
12.3
53.9
±
6.8
59.7
±
8.9
63.2
±
9.7
<
0.001 **
LVSD (mm)
27.6
±
11.0
35.2
±
7.5
41.5
±
9.5
53.2
±
8.9
<
0.001 **
EF (%)
71.8
±
9.7
49.2
±
8.7
36.6
±
9.5
24.2
±
6.5
<
0.001 **
FS (%)
36.9
±
9.2
20.4
±
4.3
14.4
±
3.8
7.1
±
3.7
<
0.001**
LAD (mm)
36.8
±
10.0
43.6
±
9.8
50.1
±
7.9
40.1
±
10.9
<
0.001**
MEARAT
1.1
±
0.9
1.6
±
0.6
1.4
±
0.61
1.6
±
1.5
0.278
DT (msec)
174.2
±
72.6
155.2
±
53.8
139.8
±
65.5
154.4
±
59.4
0.917
IVRT (ms)
112.0
±
23.5
84.0
±
36.0
89.6
±
25.5
85.7
±
40.6
0.104
IVCT (ms)
99.7
±
31.3
121.6
±
30.4
110.4
±
24.7
126.2
±
24.9
0.307
BMI (kg/m
2
)
27.7
±
14.8
25.0
±
5.0
24.2
±
6.0
25.0
±
8.5
0.622
Tei index
0.69
±
0.12
0.82
±
0.23
0.98
±
0.29
1.30
±
0.34
<
0.001 **
**Statistically significant. HF: heart failure, LVDD: left ventricular internal diastolic dimension, LVSD: left ventricular internal systolic dimen-
sion, EF: ejection fraction, FS: fractional shortening, IVSd: interventricular septal dimension in diastole, PWTd: posterior wall thickness in dias-
tole, LAD: left atrial dimension, MEARAT: mitral E/A ratio, DT: deceleration time, IVRT: isovolumic relaxation time, TEARAT: tricuspid E/A
ratio, BMI: body mass index, HF: heart failure.
TABLE 3. CORRELATION OF ECHOCARDIOGRAPHIC
PARAMETERSWITHTHE DERIVED TEI INDEX
IN THE STUDY POPULATION
Variable
Correlation
(r)
p
LVDD
0.414
0.002 **
LVSD
0.596
<
0.001 **
EF
–0.697
<
0.001 **
FS
–0.580
0.001 **
LAD
0.155
0.267
MEARAT
0.246
0.030 *
DT
0.219
0.032 *
*Statistically significant. LVDD: left ventricular internal diastolic
dimension, LVSD: left ventricular internal systolic dimension, EF:
ejection fraction, FS: fractional shortening, LAD: left atrial dimen-
sion, MEARAT: mitral E/A ratio, DT: deceleration time.
