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Background The global burden of rheumatic heart disease is nearly 33 million people. Telemedicine, using cloud-server technology, provides an ideal solution for sharing images performed by non-physicians with cardiologists who are experts in rheumatic heart disease. Objective We describe our experience in using telemedicine to support a large rheumatic heart disease outreach screening programme in the Brazilian state of Minas Gerais. Methods The Programa de Rastreamento da Valvopatia Reumática (PROVAR) is a prospective cross-sectional study aimed at gathering epidemiological data on the burden of rheumatic heart disease in Minas Gerais and testing of a non-expert, telemedicine-supported model of outreach rheumatic heart disease screening. The primary goal is to enable expert support of remote rheumatic heart disease outreach through cloud-based sharing of echocardiographic images between Minas Gerais and Washington. Secondary goals include (a) developing and sharing online training modules for non-physicians in echocardiography performance and interpretation and (b) utilising a secure web-based system to share clinical and research data. Results PROVAR included 4615 studies that were performed by non-experts at 21 schools and shared via cloud-telemedicine technology. Latent rheumatic heart disease was found in 251 subjects (4.2% of subjects: 3.7% borderline and 0.5% definite disease). Of the studies, 50% were preformed on full functional echocardiography machines and transmitted via Digital Imaging and Communications in Medicine (DICOM) and 50% were performed on handheld echocardiography machines and transferred via a secure Dropbox connection. The average time between study performance date and interpretation was 10 days. There was 100% success in initial image transfer. Less than 1% of studies performed by non-experts could not be interpreted. Discussion A sustainable, low-cost telehealth model, using task-shifting with non-medical personal in low and middle income countries can improve access to echocardiography for rheumatic heart disease. [ABSTRACT FROM AUTHOR]

Background: Rifampicin remains one of the first-line drugs used in tuberculosis therapy. This drug's potential to induce the hepatic cytochrome P450 oxidative enzyme system increases the risk of drug-drug interactions. Thus, although the presence of comorbidities typically necessitates the use of multiple drugs, the co-administration of rifampicin and warfarin may lead to adverse drug events. We report a bleeding episode after termination of the co-administration of rifampicin and warfarin and detail the challenges related to international normalized ratio (INR) monitoring. Case presentation: A 59-year-old Brazilian woman chronically treated with warfarin for atrial fibrillation (therapeutic INR range: 2.0-3.0) was referred to a multidisciplinary anticoagulation clinic at a university hospital. She showed anticoagulation resistance at the beginning of rifampicin therapy, as demonstrated by repeated subtherapeutic INR values. Three months of sequential increases in the warfarin dosage were necessary to reach a therapeutic INR, and frequent visits to the anticoagulation clinic were needed to educate the patient about her pharmacotherapy and to perform the warfarin dosage adjustments. The warfarin dosage also had to be doubled at the beginning of rifampicin therapy. However, four weeks after rifampicin discontinuation, an excessively high INR was observed (7.22), with three-day macroscopic hematuria and the need for an immediate reduction in the warfarin dosage. A therapeutic and stable INR was eventually attained at 50% of the warfarin dosage used by the patient during tuberculosis therapy. Conclusions: The present case exemplifies the influence of rifampicin therapy on warfarin dosage requirements and the increased risk of bleeding after rifampicin discontinuation. Additionally, this case highlights the need for warfarin weekly monitoring after stopping rifampicin until the maintenance dose of warfarin has decreased to the amount administered before rifampicin use. In particular, patients with cardiovascular diseases and active tuberculosis represent a group with a substantial risk of drug-drug interactions. Learning how to predict and monitor drug-drug interactions may help reduce the incidence of clinically significant adverse drug events. [ABSTRACT FROM AUTHOR]

Background: The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated. Objective: To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event. Methods: Following discharge from the Coronary Care Unit, 152 stable asymptomatic patients diagnosed with uncomplicated AMI performed the 6MWT. During the test, in addition to the distance walked, heart rate (HR), blood pressure (BP), and adverse events were also recorded. Electrocardiography was recorded using a Holter monitor in 105 patients. Patients were allocated considering two groups according to the number of days since AMI: Up to 4 Days Group and After 4 Days Group. Results: All patients completed the 6MWT, 66 in the Up to 4 Days Group and 86 in the After 4 Days Group. The walking distance was similar in both groups (85% of the predicted value), as well as the physiological responses (increase in systolic BP and HR), reaching 63% (median) of maximum HR. Only 3.9% of patients had major complications (angina, drop in BP, or ventricular tachycardia), with no difference between the groups. None of the complications regarded as severe led to truly significant complications or death. Conclusion: The 6MWT was proven to be safe and feasible for early functional evaluation following uncomplicated AMI. [ABSTRACT FROM AUTHOR]

This work investigated if methods used to produce a uniformly sampled heart rate variability (HRV) time series significantly change the deterministic signature underlying the dynamics of such signals and some nonlinear measures of HRV. Two methods of preprocessing were used: the convolution of inverse interval function values with a rectangular window and the cubic polynomial interpolation. The HRV time series were obtained from 33 Wistar rats submitted to autonomic blockade protocols and from 17 healthy adults. The analysis of determinism was carried out by the method of surrogate data sets and nonlinear autoregressive moving average modelling and prediction. The scaling exponents α, α1 and α2 derived from the detrended fluctuation analysis were calculated from raw HRV time series and respective preprocessed signals. It was shown that the technique of cubic interpolation of HRV time series did not significantly change any nonlinear characteristic studied in this work, while the method of convolution only affected the α1 index. The results suggested that preprocessed time series may be used to study HRV in the field of nonlinear dynamics. [Copyright &y& Elsevier]