Antonio Sergio Tebexreni

Incremental shuttle and six-minute walking tests in the assessment of functional capacity in chronic heart failure

BACKGROUND The incremental shuttle test presents some theoretical advantages over the six-minute walk test in chronic heart failure (CHF), including better standardization and less dependency on collaboration. OBJECTIVES The present study evaluated test-retest repeatability, test accuracy in predicting a peak oxygen consumption (VO(2)) of 14 mL/kg/min or less, as well as the prognostic value of both walking tests in stable CHF patients. METHODS Sixty-three patients (44 men; New York Heart Association functional class II to IV) underwent an incremental treadmill exercise test and, on another day, the walk test in duplicate. RESULTS Patients showed well-preserved functional capacity according to the distance walked in both tests (six-minute walk test 491+/-94 m versus incremental shuttle walk test 422+/-119 m; P<0.001). Interestingly, the six-minute and incremental shuttle walk test differences in distance walked were higher in more disabled patients. The mean bias +/-95% CI of the within-test differences were similar (7+/-40 m and 8+/-45 m, respectively). Peak VO(2), but not distance walked in either test, was associated with survival (P<0.05). CONCLUSIONS The incremental shuttle walk test showed similar repeatability and accuracy in estimating peak VO(2) compared with the six-minute walk test in CHF patients. Direct measurement of peak VO(2), however, remains superior to either walking test in predicting survival--at least in patients with well-preserved functional capacity.

Comparação da freqüência cardíaca máxima medida com as fórmulas de predição propostas por Karvonen e Tanaka

BACKGROUND Equations for predicting maximal heart rate (HRmax) are widely used in exercise testing and for training prescription, but their efficacy remains controversial in the literature. OBJECTIVE To compare maximal heart rate during cardiopulmonary exercise testing (CPET) using the prediction equations developed by Karvonen and Tanaka. METHODS Of the 24,120 maximal treadmill graded exercise tests stored in the CEMAFE database from 1994 to 2006, 2047 HRmax values were analyzed, 1091 of which were from male and 956 from female sedentary subjects. These data were used as a gold standard to compare Karvonens and Tanakas prediction formulas. RESULTS Mean measured maximal heart rates were 181.0 +/- 14.0; 180.6 +/- 13.0, and 180.8 +/- 13.8 for men, women, and both genders combined, respectively. Likewise, mean values from Karvonens equation were 182.0 +/- 11.4; 183.7 +/- 11.5, and 183.9 +/- 11.7; and from Tanakas, 182.0 +/- 8.0; 182.6 +/- 8.0, and 182.7 +/- 8.2. Karvonens and Tanakas equations yielded the same correlation coefficients, as compared with measured maximal heart rate (r = 0.72). CONCLUSION Karvonens and Tanakas equations are similar in predicting maximal heart rate and show good correlation with measured maximal heart rate.FUNDAMENTO: Formulas de predicao da frequencia cardiaca maxima sao amplamente utilizadas em servicos de ergometria e para prescricao de treinamento, contudo ha controversia na literatura sobre a eficacia delas. OBJETIVO: Comparar a frequencia cardiaca maxima obtida pelo teste ergoespirometrico com as equacoes propostas por Karvonen e Tanaka. METODOS: Dos 24.120 testes ergoespirometricos maximos, com protocolo de cargas crescentes, realizados em esteira rolante e armazenados no banco de dados do Cemafe, no periodo de 1994 a 2006, foram resgatados 1.091 resultados da frequencia cardiaca maxima de individuos sedentarios do sexo masculino e 956 do feminino. Esses dados foram utilizados como padrao-ouro na comparacao com as formulas de predicao propostas por Karvonen e Tanaka. RESULTADOS: Os valores medios da frequencia cardiaca maxima medida foram: 181,0 ± 14,0, 180,6 ± 13,0 e 180,8 ± 13,8, para o sexo masculino, feminino e ambos os sexos, respectivamente. Seguindo o mesmo padrao, os valores para equacao de Karvonen foram de 182,0 ± 11,4, 183,7 ± 11,5 e 183,9 ± 11,7; e os de Tanaka 182,0 ± 8,0, 182,6 ± 8,0 e 182,7 ± 8,2. A equacao de Karvonen apresentou valores de correlacao iguais a de Tanaka, quando comparadas com a frequencia cardiaca maxima medida, r = 0,72. CONCLUSAO: As equacoes de Karvonen e Tanaka sao semelhantes para predicao da frequencia cardiaca maxima e apresentam boa correlacao com a frequencia cardiaca maxima medida.

Diferentes padronizações do teste da caminhada de seis minutos como método para mensuração da capacidade de exercício de idosos com e sem cardiopatia clinicamente evidente

OBJECTIVES Evaluate the correlation between peak oxygen consumption (VO2peak), from cardiopulmonary test with the distance covered in the six-minute walk test (6MWT) in healthy elderly and with myocardial infarction (MI). METHODS Thirty individuals were studied, with age range 65-87 years (76.03 +/- 4.75), divided into 2 groups: Group I--14 with clinically evident coronary heart disease (CHD) and Group II--16 without clinically evident CHD. They were submitted to cardiopulmonary test (CPT) and 2 types of 6MWT, standard test 6MWTs. Variables measure at rest and exertion were heart rate (HR) and respiratory rate (RR), blood pressure (BP), distance covered (DC), and Borgs rate subjective perceived exertion (RPE). RESULTS The study showed significant, strong correlation between distances covered for both 6MWT, and (VO2peak) obtained from cardiopulmonary test (CPT) for all elderly included in the study. When comparing the 6MWT with physiotherapist support (6MWTphy) and without support (6MWTw), statistically significant difference was observed, with higher average values of the DC, of the RH and RR and Borgs RPE in the 6MWTphy, both of the groups. Additionally, the RH reached at final the exertion in 6MWTphy was similar to that obtained in CPT (p<0.05) suggesting that the 6MWT stimulates higher cardiovascular performance. CONCLUSION 6MWTw, adopted a worldwide, by being submaximal imposes lower cardiovascular overburden as compared to 6MWTphy and is probably safer for elderly who are cardiopaths.

Respostas cardiopulmonares ao exercício em pacientes com insuficiência cardíaca congestiva de diferentes faixas etárias

OBJETIVOS: Comparar a capacidade funcional cardiorrespiratoria no exercicio, representada pelos indices de limitacao funcional, consumo maximo de oxigenio (VO2max) e limiar anaerobico, em pacientes com insuficiencia cardiaca congestiva (ICC) de diferentes faixas etarias, e comparar as respostas cardiopulmonares ao exercicio maximo. METODOS: Foram avaliados 54 pacientes com ICC, agrupados por faixa etaria, como segue: grupo I - idade entre trinta e 39 anos (n = 12); grupo II - idade entre quarenta e 49 anos (n = 18); grupo III - idade entre cinquenta e 59 anos (n = 17); grupo IV - idade igual ou maior que sessenta anos (n = 7). Os pacientes foram submetidos a um teste cardiopulmonar maximo, em esteira rolante. Para a comparacao entre os diferentes grupos etarios foi realizada uma analise de variância com um fator. RESULTADOS: Nao houve diferenca significante dos valores obtidos de consumo maximo de oxigenio e de limiar anaerobico entre os grupos etarios, bem como dos valores maximos das variaveis producao de dioxido de carbono, pulso de oxigenio, razao de trocas gasosas, ventilacao pulmonar, equivalentes ventilatorios para o oxigenio e para o dioxido de carbono. CONCLUSOES: Os resultados obtidos sugerem que a capacidade funcional cardiorrespiratoria no exercicio de pacientes com ICC, assim como as variaveis cardiopulmonares obtidas no exercicio maximo podem ser afetadas de forma semelhante pela doenca cardiaca em todas as faixas etarias estudadas.

Doença arterial coronariana em diabéticas do tipo 2 assintomáticas: estudo comparativo entre o teste ergométrico, o teste cardiopulmonar e a cintilografia de perfusão miocárdica com dipiridamol na identificação de isquemia

BACKGROUND: Cardiovascular disease is the leading cause of morbidity and mortality among diabetic individuals. Myocardial ischemia is frequently asymptomatic, thus leading to a late diagnosis and worse prognosis. Diabetic women are known to have a cardiovascular death risk higher than that in men. OBJECTIVE: To assess the prevalence of coronary artery disease (CAD) in asymptomatic diabetic women. To compare the results of exercise test (ET), cardiopulmonary exercise test (CPET), and dipyridamole myocardial perfusion scintigraphy (MPS) with the findings of coronary angiography, (ANGI) in order of identify the most accurate method in the detection of significant CAD. METHODS: A total of 104 diabetic women were assessed with ET, CPET and MPS in the period within two months from the ANGI. MIBI-99mTc scintigraphy was performed using the gated-SPECT technique. Pearsons chi-square, Students t tests were used for the statistical analysis and also the logistic regression analysis. RESULTS: The prevalence of CAD in the group studied was 32.7%. For the ET, an effective test (p=0.045), the chronotropic incompetence (p=0.031), and the exercise time performed (p=0.022) showed a significant association with DAC. For CPET, peak VO2 and HR achieved were associated with CAD (p=0.004 and p=0.025, respectively). Most of the MPS variables showed a significant association with CAD (p=0.001, for all). CONCLUSION: The results obtained may suggest a high prevalence of CAD in diabetic women. Thus, this population should be investigated from the cardiovascular point of view even without cardiac symptom. Of the noninvasive diagnostic methods used, dipyridamole MPS was the one that showed the highest discrimination power in relation to diabetic women with CAD.

Estudo comparativo de métodos para a predição do consumo máximo de oxigênio e limiar anaeróbio em atletas

The application of a battery of tests for evaluation of the physical aptitude in laboratory involves a series of highly sophisticated equipment, mainly when the objective is the determination of the aerobic potency (maximum oxygen uptake and anaerobic threshold). The equipment is of high financial cost and requests professionals with good technical and scientific knowledge to handle it, and also, it is impossible to use it in the application of tests in large scale. The analysis of the distance run in a certain period of time or, yet, the time used for a distance set previously, has been a lot used with the goal of estimating or reflecting the aerobic aptitude in children and in adults. The proposal of this study was to analyze the correlation of the Cooper test (CT) with the values of maximum consumption of oxygen (VO2 max) determined through direct method, besides the attempt of validating this field test and another test called the test of 4,000 meters, in anaerobic threshold (AT prediction). Sixty-three players of field soccer were appraised with ages between 15 and 20 years. The athletes were submitted to three tests, one of them was accomplished at the laboratory and the others in the athletics track, in a maximum period of seven days. The laboratory test consisted of the determination of the VO2 max and ventilatory anaerobic threshold (VAT), through analysis of the gaseous changes in a metabolic system analysis on a Vacumed (model CPX Silver edition) Imbramed ergometric treadmill (model ATL 10200), with measurement of the heart rate (HR) with the Polar brand (model Accurex Plus). The first field test followed the protocol determined by Cooper and the second one consisted of a race of 4,000 meters, when determination of the time spent for the preset course was made. The coefficient of linear correlation of Pearson was calculated (r) and the following results were obtained: • The speed of LA showed direct significant correlation (r = 0.60 for p < 0.05) with the medium speed in CT. • The speed of LA showed direct significant correlation (r = 0.74 for p < 0.05) with the medium speed in T 4000. • The VO2 max determined by the direct method did not show significant correlation with the VO2 max (r = 0.23 for p < 0.05) determined through CT. The results suggest that the CT has not the precision required for the prediction of the VO2 max for this population and the possibility of its use for the field tests, like those performed in the present study, in order to obtain the prediction of the anaerobic threshold, and the 4,000 meters test presented larger precision than the CT when the goal is to predict the speed of the anaerobic threshold.

Right coronary artery fistula with congestive heart failure in the neonate. Doppler echocardiographic diagnosis and closure with detachable balloon

We report here a case of coronary artery fistula in a neonate with clinical signs of heart failure. The electrocardiogram showed signs of left ventricular hypertrophy and diffuse alterations in ventricular repolarization. Chest X-ray showed an enlargement of the cardiac silhouette with an increase in pulmonary flow. After echocardiographic diagnosis and angiographic confirmation, closure of the fistulous trajectory was performed with a detachable balloon with an early and late successful outcome.