Cardiovascular Journal of Africa: Vol 24 No 2 (March 2013)

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CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 2, March 2013 AFRICA e1
Case Report
ST–T-wave alternans in Brugada electrocardiogram type I
pattern during the resolution of febrile states
YIFENG ZHOU, JIALI WANG, XIANLUN LI, YONG WANG
Abstract
Brugada syndrome is often electrocardiographically charac-
terised by ST-segment elevation in the right precordial leads.
The characteristic Brugada electrocardiogram pattern is
often dynamic and concealed, and may be revealed during
febrile states or under the challenge of drugs that have a sodi-
um channel-blocking effect. In this report, we describe two
cases of exposure of the Brugada electrocardiogram pattern
during febrile states. When the patients’ body tempera-
ture decreased and before the ST-elevation disappeared,
ST-segment and T-wave alternans in the right precordial
leads were observed, especially in lead V2.
Keywords: ST-segment elevation, body temperature, right
precordial leads
Submitted 9/10/10, accepted 26/9/12
Cardiovasc J Afr 2013; 24: e1–e3
DOI: 10.5830/CVJA-2012-065
Brugada syndrome, an inherited cardiac disease causing life-
threatening ventricular tachyarrhythmias in patients with a
structurally normal heart, is often electrocardiographically
characterised by ST-segment elevation in the right precordial
leads. The characteristic Brugada electrocardiogram pattern
is often dynamic and concealed, and may be revealed during
febrile states or under the challenge of drugs that have a sodium
channel-blocking effect.1
In this report, we describe two cases of exposure of the
Brugada electrocardiogram pattern during febrile states.
Furthermore, ST-segment and T-wave alternans in the Brugada
electrocardiogram were observed when the body temperature
decreased.
Case report
Case 1 was a 45-year-old man with fever due to pulmonary
infection, who was admitted to our hospital. Two hours before
admission, he experienced two episodes of syncopal polymorphic
ven­tricular tachycardia in a local hospital, which were terminated
by electric cardioversion. Case 2 was a 33-year-old man with
fever due to a common cold. He presented to the emergency
room with chest pain; no syncopal episode occurred.
Both patients’ temperatures were above 38.5°C on arrival,
and the electrocardiograms showed the characteristic Brugada
pattern in leads V1–V3, characterised by a J wave and coved-
type ST-segment elevation of 2 mm or more, followed by a
negative T wave.2 The haematological and biochemical tests,
including cardiac enzymes and electrolytes, were within normal
limits.
There was no evidence of structural heart disease on
echocardiographic examination. Neither of the patients had a
history of palpitations, syncope, febrile seizures, or a family
history of sudden cardiac death. Coronary angiography revealed
normal findings in patient 1.
The two patients were treated with intravenous antibiotics on
the following days, and their temperature returned to normal.
Repeat electrocardiogram tracings showed regression of the
Brugada pattern to normal, and syncope and chest pain did not
recur.
When the body temperature decreased but before the
ST-elevation disappeared, ST-segment and T-wave alternans in
the right precordial leads were observed, especially in lead V2.
The ST-segment alternans were characterised by beat-to-beat
alteration in the coved and saddle-back type of morphology. The
T-wave alternans were characterised by beat-to-beat alteration in
the amplitude and polarity (Figs 1, 2).
The patients were discharged without surgery. During a follow
up of 10 months, neither experienced sudden cardiac death.
Discussion
ST-segment elevation in Brugada syndrome is caused by a shift in
the balance of ionic current and the creation of a voltage gradient
between the epicardium and the endocardium. Mutations in
the cardiac sodium channel gene SCN5A, the gene encoding
for the alpha subunit of the cardiac sodium channel, have been
identified in 15 to 30% of patients with Brugada syndrome.
The ionic mechanism of Brugada syndrome has been shown to
be temperature dependent. Febrile states may accelerate the decay
of the sodium current and be associated with syncopal malignant
ventricular tachyarrythmias.3,4 Unmasking of a concealed
Brugada syndrome by fever suggests that some patients may be
more at risk during febrile states, such as patient 1.5
T-wave alternans are considered a sign of electrical instability
and can be a mode of risk stratification for ventricular arrhythmia.
T-wave alternans in the setting of Brugada syndrome, particularly
Department of Cardiology, China–Japan Friendship
Hospital, Chaoyang District, Beijing, China
YIFENG ZHOU, MD, PHD
JIALI WANG, MD
XIANLUN LI, MD
YONG WANG, MD,