Nota: Estas diretrizes se prestam a informar e não a substituir o julgamento clínico do médico que, em última análise, deve determinar o tratamento apropriado para seus pacientes.
Background:Chagas disease continues to be a serious public health problem, and accounts
for 25-30% of the indications for cardiac stimulation in Brazil.Objective:To assess clinical and epidemiological characteristics of patients with
Chagas disease, younger than 18 years, who had undergone pacemaker
implantation in Brazil between 1994 and 2011, and its temporal trend.Methods:This was a cross-sectional analysis of data from the Brazilian Pacemaker
Registry database. The following variables were analyzed: year when
pacemaker was implanted, location, age, sex, ethnic group, functional class
and the main electrocardiographic findings at baseline.Results:In a total of 183,123 implants performed between 1994 and 2011, 214 implants
of cardiac stimulation device in Chagas disease patients aged younger than
18 years were identified. Mean age at implantation was 5.6 ± 6.2
years. Second- and third-degree atrioventricular blocks corresponded to 71%
of indications for pacemaker implantation. Fifty-six percent of the
procedures were performed in the southeast region. Regarding the total
number of pacemaker implants per year, there was a remarkable increase in
the implants for all causes. However, time series analysis of the implants
in Chagas disease patients younger than 18 years revealed a significant
reduction in the annual number of implants.Conclusion:There has been an important reduction in the number of pacemaker
implantations among children and adolescents with Chagas disease, suggesting
a reduction in the vertical transmission of the parasite.
Introduction:
Masquerading bundle branch block (MBBB) is a rare cardiac conduction anomaly characterized in the Electrocardiogram (EKG) by Right Bundle Branch Block in the precordial leads and Left Bundle Branch Block in frontal leads. The available evidence indicates that it carries poor prognosis and that it is often underdiagnosed. We studied epidemiological peculiarities, electrocardiographic features and prognosis of this rare kind of ventricular conduction delay.
Methods:
In a review of over 600,000 EKGs from the database of Tele-Electrocardiography department of Dante Pazzanese Institute of Cardiology during the last seven years, we found twenty-five cases of MBBB. Diagnostic criteria were presence of QRS ≥ 0.12 s, dominant positive waves in V1, left axis deviation and absent or minimal S wave in DI and aVL. Epidemiological data was collected for each EKG and the follow-up of patient′s health status was assessed by telephone contact. Kaplan-Meier survival curves were based on the following endpoints: mortality, pacemaker implantation and the composite of both.
Results:
We identified twenty-five cases (21 males and 4 females) of MBBB. The average age was 69 (±14) years. Sinus rhythm was present in 17 patients (68%), atrial fibrillation in 7 (28%) and atrial flutter in one (4%). Average heart rate, PR interval, QRS length, QTc and QRS axis were, respectively: 70 (±17) bpm, 205 (±50) ms, 159 (±24) ms, 463 (±37) ms and -76° (±6) degrees. Follow-up data was successfully obtained from 15 patients: 4 (26.6%) had a pacemaker implanted, 7 (46.6%) died and 9 had combined endpoints (60%). According to the Kaplan-Meier survival curve, at 48 months, the estimated ratios of death, pacemaker implantation or combined endpoints were 41.4%, 38.9% and 80.2%, respectively.
Conclusions:
MBBB represents a high-risk condition and, although rare, this EKG pattern should be taken into consideration due to the poor prognosis associated with its presence.
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