IntroductionChagas disease is one of the most important endemic parasitic diseases in Latin America. In its chronic phase, progression to cardiomyopathy has high morbidity and mortality. The persistence of a normal electrocardiogram (ECG) provides a similar prognosis to that of a non-diseased population. Benznidazole (BNZ) is the only drug with trypanocidal action available in Brazil.Materials/Methods/ResultsA group of 310 patients with chronic Chagas disease who had normal ECGs at the first medical visit performed before 2002 were included. There were 263 patients treated with BNZ and 47 untreated. The follow-up period was 19.59 years. Univariate analyses showed that those treated were younger and predominantly male. As many as 79.08% of those treated and 46.81% of those untreated continued with normal electrocardiograms (p <0.0001). The occurrence of electrocardiographic abnormalities and relevant clinical events (heart failure, stroke, total mortality, and cardiovascular death) was less prevalent in treated patients (p <0.001, p: 0.022, p: 0.047 respectively). In multivariate analyses, the parasiticide treatment was an independent variable for persistence of a normal ECG pattern, which was an independent variable in the prevention of significant clinical events. The immunofluorescence titers decreased with the parasitological treatment. However, the small number of tests in untreated patients did not allow the correlation of the decrease of these titers with electrocardiographic alterations.ConclusionThese data suggest that treatment with benznidazole prevents the occurrence of electrocardiographic alterations. On the other hand, patients who develop ECG abnormalities present with more significant clinical events.

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Introduction The search for markers that can serve as screening methods for young practitioners of physical activity has always raised an intense discussion between pediatricians and cardiologists. Thus, the ideal investigation algorithm should identify patients at high risk also among asymptomatic patients and be of low cost to society. This would only be possible by including a low cost diagnostic method and largely accessible. In this context, telemedicine systems and in particular tele-electrocardiogram (tele-EKG) systems have low cost and agility and can collaborate to solve this problem. Purpose To analyze the electrocardiographic pattern in asymptomatic patients aged between 10 and 20 years old who underwent EKG by the tele-EKG system between 2007 and 2014 Methods All EKG valid results from asymptomatic patients aged between 10 and 20 years old from 2007 and 2014 sent to the tele-EKG system of a large tertiary hospital were analysed aiming to determine the prevalence of abnormal findings. Results Of the 797,115 exams on the analysed period 25,326 were from patients aged between 10 and 20 years old and 11,058 (55% male) of them were asymptomatic. Regarding disorders of rhythm, ventricular arrhythmias were found in 0.54% and atrial premature beats in 0.47% of the exams. There were 5 episodes of supraventricular tachycardia (0.04%) and one episode of atrial fibrillation. Atrioventricular blocks were: first degree (0.71%) and second degree (0.03%). There was 1 case of 2:1 AV Block and 1 case of advanced AV block. Short PR interval was observed in 0.76% of the exams, with 15 of them showing ventricular pre-excitation (0.13%). Regarding morphological changes in EKG pattern, right bundle branch disorders were present in 7.5% of the patients and left bundle branch in 0.04%. Right bundle branch block occurred in 0.63% and left bundle branch block in only 1 case. Repolarization changes occurred in 1.8% of patients. We found left ventricular overload in 0.25% and right ventricular overload in 0.14% of cases. Only 5 patients had typical EKG of septal hypertrophy (0.045%). There were 1751 diagnostics overall, representing 15.8% of the sample. The most prevalent was right bundle branch abnormalities, followed by repolarization abnormalities (graphic below). Conclusion EKG screening in asymptomatic adolescents is a low cost and feasible method to identify individuals with electrical alterations and who require detailed clinical evaluation. This also may contribute to reduce risk of sudden events during sports activities. Funding Acknowledgement Type of funding sources: None.

BackgroundLeft bundle-branch block (LBBB) and the presence of systolic dysfunction are the major indications for cardiac resynchronization therapy (CRT). Mechanical ventricular dyssynchrony on echocardiography can help identify patients responsive to CRT. Left bundle-branch block can have different morphologic patterns. ObjectiveTo compare the prevalence of mechanical dyssynchrony in different patterns of LBBB in patients with left systolic dysfunction. MethodsThis study assessed 48 patients with ejection fraction (EF) < 40% and LBBB consecutively referred for dyssynchrony analysis. Conventional echocardiography and mechanical dyssynchrony analysis were performed, interventricular and intraventricular, with ten known methods, using M mode, Doppler and tissue Doppler imaging, isolated or combined. The LBBB morphology was categorized according to left electrical axis deviation in the frontal plane and QRS duration > 150 ms. ResultsThe patients' mean age was 60 ± 11 years, 24 were males, and mean EF was 29% ± 7%. Thirty-two had QRS > 150 ms, and 22, an electrical axis between −30° and +90°. Interventricular dyssynchrony was identified in 73% of the patients, while intraventricular dyssynchrony, in 37%-98%. Patients with QRS > 150 ms had larger left atrium and ventricle, and lower EF (p < 0.05). Left electrical axis deviation associated with worse diastolic function and greater atrial diameter. Interventricular and intraventricular mechanical dyssynchrony (ten methods) was similar in the different LBBB patterns (p = ns). ConclusionIn the two different electrocardiographic patterns of LBBB analyzed, no difference regarding the presence of mechanical dyssynchrony was observed.

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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