Cardiovascular Journal of Africa: Vol 29 No 6 (November/December 2018)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 6, November/December 2018 362 AFRICA
Evaluation of ventricular arrhythmogenesis in children
with acute rheumatic carditis
Mehmet Kucuk, Cem Karadeniz, Rahmi Ozdemir, Timur Meşe
Abstract
Background: Recent studies have shown that the Tp-e interval,
which on an electrocardiogram (ECG) is the interval between
the peak and the end of the T wave, can be used as an index
of transmural dispersion of ventricular repolarisation (TDR).
Both Tp-e/QT and Tp-e/QTc ratios have also been used in
that capacity. However, these novel repolarisation indices have
not previously been studied in children with acute rheumatic
carditis (ARC).
Methods: A hundred and thirty-nine children who were diag-
nosed with ARC and 153 age- and gender-matched healthy
controls were retrospectively reviewed. Twelve-lead ECGs
were used to evaluate P-wave, QT and QTc dispersions, Tp-e
interval, and Tp-e/QT and Tp-e/QT ratios.
Results: The mean age of the patients was 10.9 ± 2.4 years.
The P-wave, QT and QTc dispersions were significantly higher
in patients compared to the healthy control subjects. The Tp-e
interval, and Tp-e/QT and Tp-e/QTc ratios were also signifi-
cantly increased in patients compared to the controls. When
the patients were compared in terms of either one- or two-
valve involvement, we found no difference between the groups
regarding P-wave, QTd and QTc dispersions, Tp-e interval,
and Tp-e/QT and Tp-e/QTc ratios. There was no correlation
between acute-phase reactants, white blood cell count and
these repolarisation parameters.
Conclusions: This study showed that the new transmural
dispersion of ventricular repolarisation parameters, Tp-e
interval, Tp-e/QT ratios and QTd were increased in children
with ARC. Prolongation of the Tp-e interval and an increased
Tp-e/QT ratio might be useful markers for predicting myocar-
dial involvement in children with ARC.
Keywords: acute rheumatic carditis, children, ventricular
arrhythmogenesis, Tp-e interval, Tp-e/QT ratio, PWd, QTd
Submitted 25/11/17, accepted 21/7/18
Published online 30/8/18
Cardiovasc J Afr 2018; 29: 362–365
DOI: 10.5830/CVJA-2018-043
Acute rheumatic fever (ARF), a post-infectious systemic
autoimmune disease, remains a major public health problem.
It is the leading cause of acquired heart disease among children
and young adults in developing countries. Carditis is the most
important complication of rheumatic fever (RF) that is associated
with permanent disability.1-3 An abnormal immune response to
normal heart tissue, which is due to molecular mimicry between
heart tissue antigens and streptococcal antigenic components, is
the suggested mechanism in genetically susceptible individuals.4-6
The electrocardiographic (ECG) findings of ARF have been
well described. However, the relationship of these manifestations
to carditis remains unknown. First-degree atrioventricular
(AV) block is the characteristic conduction disturbance of RF.
One-third of individuals have first-degree AV block, which can
occur regardless of carditis. After inactivation of the disease, the
PR interval can return to normal. 7,8 Changes in ST segments and
reduced-voltage QRS complexes may be found in the presence of
pericarditis and pericardial effusion.7,9 In addition, increased QT
and heart rate-corrected QT (QTc) dispersions that represent the
heterogeneity of ventricular repolarisation and increased P-wave
dispersions (PWd) were found in patients with acute rheumatic
carditis (ARC). 8-10
In addition to the QT and QTc dispersions, the Tp-e interval,
which on an ECG is the interval between the peak and the end of
the T wave, can be used as an index of transmural dispersion of
ventricular repolarisation (TDR). Both the Tp-e/QT and Tp-e/
QTc ratios are also used as indices of ventricular repolarisation.11,12
Ventricular repolarisation in children with rheumatic carditis (RC)
was previously evaluated using both QT and QTc dispersions.8-10
However, the novel repolarisation indices of Tp-e and Tp-e/QT
have not been studied in RC patients previously. In this study, we
aimed to assess the Tp-e interval and the Tp-e/QT ratio in children
with RC, as well as investigate its relationship with inflammation
and the number of valves involved.
Methods
Patients who were diagnosed with ARC between 2006 and 2016
at our centre were reviewed. Cases with insufficient data and
those that did not fulfill the revised Jones criteria13 were excluded.
Demographic features, complete blood count and erythrocyte
sedimentation rate (ESR), as well as ECG and echocardiographic
parameters at the time of diagnosis were collected from the
patients’ data system. All echocardiographic examinations were
performed by three paediatric cardiologists who are experienced
in rheumatic heart disease and followed the guidelines of the
American Society of Echocardiography and the European
Society of Cardiology.14,15 The Vivid S6 Echocardiography System
(General Electric Healthcare, Milwaukee, WI), which is equipped
with an M4S-RS broadband transducer (General Electric
Healthcare Japan Corporation, Hino-shi, Tokyo), was used for
two-dimensional and colour-flow Doppler echocardiography.
Department of Paediatric Cardiology, Dr Behcet Uz
Children’s Hospital, Izmir, Turkey
Mehmet Kucuk, MD,
Cem Karadeniz, MD, Assoc. Prof
Rahmi Ozdemir, MD
Timur Meşe, MD, Assoc. Prof