CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 7, August 2013
280
AFRICA
Prevalence and significance of early repolarisation in
a black African population: data of 246 individuals with
cardiovascular morbidity
AIME BONNY, DOMINIQUE NOAH NOAH, SYLVIE NDONGO AMOUGOU, CECILE SAKA
Abstract
Background:
Early repolarisation (ER) is commonly seen on
electrocardiograms (ECG). Recent reports have described
the relationship between ER and sudden cardiac death
(SCD). The prevalence and significance of ER have not been
studied in black Africans.
Methods:
We matched clinical and ECG records of subjects
over 18 years of age who consulted a cardiac unit in two
medical centres of Douala, Cameroon.A questionnaire focus-
ing on past history of syncope or family history of sudden
unexplained death (SUD) was filled in by each subject. A
12-lead ECG was recorded by a trained nurse and analysed
by two independent physicians.
Results:
Of the 752 ECGs recorded, we studied 246 index
cases. The mean age of subjects was 45
±
16 years and 53%
were female. Almost 57% had hypertension, 41% had palpi-
tations and 18% reported a history of syncope. ER pattern
was found in 20% [slurring in three (3%), notching in 13%
and both in three (7%)]. ER subjects were younger than
those without (41
±
16 vs 49
±
16 years,
p
=
0.0048). Lead
localisation was predominantly the laterals for the slurring
pattern, whereas the inferior and lateral leads were equally
involved for the notching pattern. Negative T waves in the
infero-lateral leads were associated with ER (
p
=
0.00025).
Among the subjects with syncope, 41% displayed ER and
13% did not have ER (
p
=
0.00014). The notching pattern
seemed to be associated with syncope (
p
=
0.00011).
Conclusion:
Early repolarisation is frequent in black
Africans, especially in the setting of cardiovascular morbid-
ity. Early repolarisation may be associated with a past history
of syncope, especially the notched pattern.
Keywords:
early repolarisation, syncope, ethnicity, blackAfricans
Submitted 30/11/12, accepted 15/8/13
Cardiovasc J Afr
2013;
24
: 280–285
DOI: 10.5830/CVJA-2013-063
Early repolarisation (ER) is an electrocardiographic pattern that
consists of early onset as well as an elevation of the transitional
QRST–ST junction over 0.1 mV (J-point elevation or JPE)
between the depolarisation end and the repolarisation onset
of the ventricles.
1,2
This electrophysiological phenomenon is
recorded in a surface electrocardiogram (ECG) as J-point
elevation, followed by ST-segment elevation and frequently
T-wave inversion. The J-point elevation displays two types,
including the notching and slurring patterns (Fig. 1).
Interest in this ECG feature is on the increase since it seems
not always to be a benign phenotype,
3-5
as was previously
thought.
6-9
Indeed, there is growing interest in establishing a
correlation between ER and adverse outcomes (Fig. 2).
10-13
As
the prevalence of ER is common in the general population
and thought to occur more in blacks (Fig. 3),
1
management of
subjects with unexplained syncope and ER in their ECGs may
be challenging, particularly in black populations.
We aimed to assess the prevalence and significance of ER
patterns in a black African population in the setting of tertiary
hospitals in Cameroon.
Methods
Over a two-week period, we matched ECG and clinical data
from a sample of patients fulfilling the following inclusion
Faculty of Medicine and Phamaceutical Sciences, University
Hospital of Douala, Douala, Cameroon
AIME BONNY, MD,
Department of Gastroenterology, Central Hospital of
Yaoundé, Yaoundé, Cameroon
DOMINIQUE NOAH NOAH, MD
Services de réanimation et de cardiologie, Centre Hospitalo-
Universitaire de Yaoundé, Yaoundé, Cameroon
SYLVIE NDONGO AMOUGOU, MD
Laboratory of Electrocardiography, Hôpital Laquintinie,
Douala, Cameroon
CECILE SAKA, MSc
Fig. 1. Two distinct variants of early repolarisation in the
lateral leads with the J-point elevation
≥
1 mm. On the left,
the ‘notch’ variant, which consists of a positive hump in
the QRS–ST junction (a prominent J point resembling an
Osborn wave). On the right, the ‘slur’ variant, which is a
smooth deflection resembling a delta wave in the termi-
nal portion of the descending part of an R wave.
