Márcio Vinícius Lins Barros

Prognostic Value of Signal-Averaged Electrocardiogram in Chagas Disease

Background: The value of signal‐averaged ECG (SAECG) in the risk stratification of Chagas disease (ChD), a potentially lethal illness prevalent in Latin America, remains controversial. The aim of this prospective longitudinal study was to determine the prognostic value of SAECG in ChD, using multivariate models with other established prognostic predictors, and to develop a simple prediction risk score.

Chronotropic incompetence and abnormal autonomic modulation in ambulatory Chagas disease patients.

Background: Chagas disease (ChD) patients might present chronotropic incompetence during exercise, although its physiopathology remains uncertain. We evaluated the heart rate (HR) response to exercise testing in ChD patients in order to determine the role of autonomic modulation and left ventricular dysfunction in the physiopathology of chronotropic incompetence.

Heart Rate Turbulence in Chagas Disease

RIBEIRO, A.L.P., et al.: Heart Rate Turbulence in Chagas Disease. Heart rate turbulence (HRT) quantifies the biphasic response of the sinus node to ventricular premature complexes (VPCs) and is a powerful electrocardiogram related risk predictor. VPCs are frequent in Chagas disease, a potentially lethal illness, and can hamper the analysis by conventional methods of autonomic heart control. The aim of the study was to examine HRT in patients with Chagas disease. Chagas disease patients and healthy controls (group 0, n = 11 ) without other diseases were submitted to a standardized protocol, including electrocardiogram, echocardiography, and 24‐hour Holter monitoring. Chagas disease patients were divided according to their left ventricular systolic function: normal (group 1, n = 103 ) and reduced ejection fraction (group 2, n = 23 ). Two HRT indices, turbulence onset (TO) and turbulence slope (TS), were calculated and compared among groups after adjustment for covariates like the prevalence of VPCs and the mean heart rate. Chagas disease patients had significantly altered TO (group 1: −0.0186, group 2: −0.0126) and TS (group 1: 10.844, group 2: 7.870) values in comparison with controls (TO − 0.0256, TS 19.829); P < 0.001 for both comparisons. In conclusion, HRT data may be useful in the electrocardiographic analysis of autonomic heart control in Chagas disease. Its prognostic value remains to be determined. (PACE 2003; 26[Pt. II]:406–410)

Subclinical rheumatic valvitis: a long-term follow-up.

In order prospectively to investigate the frequency and evolution of subclinical valvitis, we selected 40 consecutive patients suffering their initial attack of rheumatic fever, seen in our clinic from 1992 to 1994, and followed-up until 2001, with a mean period of follow-up of 8.1 years, and a standard deviation of 0.6 year. We also assembled a matched control group of 37 healthy children and adolescents. We discovered a murmur of mitral regurgitation in 28 (70.0%) of the patients. In 3 (7.5%) of these patients, there was also a murmur of aortic regurgitation. In the group of 28 symptomatic patients, Doppler echocardiography showed mitral regurgitation in all, and aortic regurgitation in 17. In the group of 12 patients without clinical evidence of cardiac involvement, Doppler echocardiography identified mitral regurgitation in 2, isolated in one and associated with aortic regurgitation in the other. Thus, the frequency of subclinical valvitis was 16.7%. In patients with subclinical valvitis only the aortic regurgitation regressed during the period of follow-up. In the group of 28 symptomatic patients, mitral regurgitation disappeared in 6 (21.4%), aortic regurgitation in 7 of the 17 having this feature (41.2%), while 2 patients (7.1%) developed mitral stenosis. The sensitivity and specificity of cardiac auscultation were, respectively, 93.3%, with 95% confidence intervals between 72.3% and 97.4%, and 100%, with 95% confidence intervals between 65.5% and 100%, for the diagnosis of mitral regurgitation, and 16.7%, with 95% confidence intervals between 4.4% and 42.3%, and 100%, with 95% confidence intervals between 81.5% and 100%, for that of aortic regurgitation. We conclude that the Doppler echocardiogram is an important means of diagnosing and assessing the evolution of subclinical rheumatic valvar lesions, which are not always transient. We suggest that Doppler echocardiography should be performed in all patients with acute rheumatic fever. Subclinical valvitis should be considered as mild carditis, provided that strict criterions are observed in the differential diagnosis from physiological regurgitation, and Doppler echocardiographic findings are analyzed in the context of the other manifestations of the disease.

Doppler tissue imaging to assess systolic function in Chagas' disease

OBJECTIVE To assess the usefulness of Doppler tissue imaging (DTI) for evaluating the systolic function of chagasic patients with and without electrocardiographic abnormalities, in comparision with echocardiographic study. METHODS We studied 77 patients divided into 3 groups as follows: group 1 - control; group 2 - chagasic patients with normal electrocardiographic findings; and group 3 - chagasic patients with abnormal electrocardiographic findings. The following parameters were assessed: left ventricular dimensions and ejection fraction, left atrial dimensions and diastolic function on echocardiography. Systolic velocity and regional isovolumic contraction time (IVCTr) of the septal, anterior, lateral, posterior and inferior left ventricular walls were assessed on DTI. RESULTS Left ventricular cavitary dimensions, ejection fraction and DTI systolic wave showed significant differences between groups 1 and 3 and between groups 2 and 3, which were not found between groups 1 and 2. IVCTr allowed a statistically significant discrimination among the 3 groups. CONCLUSION DTI allowed discrimination among the different groups assessed, being superior to echocardiography in identifying early abnormalities of contractility, and, therefore, potentially useful for detecting incipient myocardial alterations in chagasic patients with normal electrocardiographic findings.

The prognostic significance of electrocardiographic changes in Chagas disease

INTRODUCTION The meaning of electrocardiographic changes appearing during the clinical follow-up of Chagas disease (ChD) is unknown. In this study, a patient cohort with ChD was followed to describe the electrocardiographic changes that may make it possible to identify patients whose left ventricular function has deteriorated. METHODS The study sample consisted of a prospective cohort followed since 1998 to 1999, involving 220 patients aged 15 to 55 years, 30 controls, and 190 with ChD, without other comorbidities. The group was reexamined between 2004 and 2006, and new electrocardiograms were obtained for 153 patients, 25 (83%) of 30 in the control group and 128 (72%) of 177 in the ChD group. Electrocardiographic variables associated with a significant decrease in ejection fraction (5% or more) were identified. RESULTS A significant decrease in ejection fraction was observed in 21 patients in the ChD group (18.7%) but in none of the non-ChD group (P = .024). Only the presence of a new electrocardiographic abnormality and an increase in QRS duration correlated with a decrease in an ejection fraction of 5% or more. QRS duration was correlated with both an increase in left ventricle diastolic diameter and a deterioration in the ejection fraction (r(s) = 0.225, P = .017, and r(s) = -0.300, P < .001). A QRS increase of 5 milliseconds had 77.8% sensitivity and 62.2% specificity for identifying patients with significant decrease in ejection fraction. CONCLUSION The increase in the duration of the QRS complex and the appearance of new electrocardiographic alterations may help in identifying patients with a significant decrease (of 5% or more) in left ventricle ejection fraction.

Plantar vein thrombosis--evaluation by ultrasound and clinical outcome.

Objective: This study was designed to describe the characteristics and clinical outcome of patients diagnosed with plantar vein thrombosis. Methods: Patients presenting with sudden pain and/or swelling of the foot were evaluated by duplex scanning of the affected leg. All the main foot veins were imaged with high resolution multi-linear array transducers. The location and extent of thrombosis was recorded in detail. All patients were scheduled for clinical and ultrasound follow-up within a week from the diagnosis and at various intervals thereafter. Results: Acute thrombosis was found in the plantar veins in 11 patients of whom 7 were females. Pain was presented in all patients, swelling in 8 and the left foot was involved in 7. From the risk factors evaluated, the most common were recent surgery 4, use of contraceptive pills 3, followed by malignancy, airplane travel, HIV-AIDS infection, and past history of DVT in one each. Plantar veins were exclusively affected in 8, with lower segment of the posterior tibial veins in 2 and the great saphenous vein in 1. In the follow up, there was evidence of thrombosis extension in 3 patients. At six months partial recanalization was found in 9 and complete in 2. Conclusions: Pain and swelling of the foot can be caused by plantar vein thrombosis. Complete or partial recanalization occurs in these patients by 6 months. Thrombi in the plantar veins can progress more proximally with the possibility of postthrombotic events.

índice cronotrópico-metabólico na doença de Chagas

A insuficiencia cronotropica constitui achado comum entre os pacientes chagasicos. Novas metodologias estao sendo empregadas na avaliacao da resposta cronotropica em varios grupos de pacientes. O indice cronotropico-metabolico, um desses novos metodos, quantifica a relacao entre o aumento da frequencia cardiaca e o consumo maximo de oxigenio (VO2 max) durante o teste ergometrico. A resposta normal e linear, com indice em torno de 1,0. Objetivamos avaliar a resposta cronotropica e em individuos saudaveis e pacientes chagasicos com e sem disfuncao ventricular esquerda, utilizando-se do indice cronotropico-metabolico. Foram avaliados 171 pacientes com doenca de Chagas sem doencas associadas e 24 controles submetidos a protocolo clinico e ao teste ergometrico maximo. Os chagasicos foram divididos em dois grupos: Ch1= pacientes com fracao de ejecao (FE) > 39% e Ch 2= FE<40%. A analise e o calculo do indice cronotropico-metabolico foram feitos pelo metodo de Wilkoff. Os pacientes chagasicos apresentaram maior idade e maior prevalencia de bloqueio completo de ramo direito, assim como menor VO2 max ao teste ergometrico. Ambos os grupos de chagasicos apresentaram menor inclinacao do indice cronotropico-metabolico (Ch1: 0,91±0,10, Ch2: 0,89±0,08) do que os controles (1,0±0,12, p< 0,001). Pacientes com doenca de Chagas com e sem disfuncao ventricular esquerda podem apresentar resposta cronotropica deprimida, manifesta por menor inclinacao do indice cronotropico-metabolico.

Infrapopliteal Mycotic Aneurysm Caused by Endocarditis—Case Report and Literature Review

Infrapopliteal mycotic aneurysm resulting from endocarditis is rare, with few reported cases in the literature. We describe a case of ruptured mycotic aneurysm involving the infrapopliteal artery in a patient with aortic and mitral endocarditis. Duplex scanning revealed an oval‐shaped mass at the infrapopliteal segment, consistent with sacular aneurysm. The aneurysm showed signs of rupture and pseudoaneurysm formation, which was confirmed by angio‐MRI and arteriography. The patient was treated by endovascular procedure and remained asymptomatic at the 6‐month follow‐up. (Echocardiography 2010;27:77‐79)

Sinus of valsalva aneurysm with dissection into the interventricular septum.

Maria do Carmo P. Nunes, M.D., Ph.D.,∗ Claudio L. Gelape, M.D.,∗ Felipe Batista L. Barbosa,† Marcio V.L. Barros, M.D., Ph.D.,∗ Graziela Chequer, M.D.,∗ Edmundo C. Oliveira, M.D.,∗ Pedro R. Porto, M.D.,∗ and Antônio L. P. Ribeiro, M.D., Ph.D.∗ ∗Hospital das Clı́nicas of the Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; and †Medical Student at the School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil