Correlação entre o teste de caminhada de 6 minutos e as variáveis do teste ergométrico em pacientes com insuficiência cardíaca: estudo piloto / Correlation between six-minute walk test and exercise stress testing variables in patients with heart failure: a pilot study

Objetivo: Correlacionar a distância percorrida no teste de 6 minutos (TC6M) com as variáveis do testeergométrico (TE). Métodos: Foram estudados 21 pacientes, sendo 66%brancos, 62% homens, com média de idade de 60±11 anos, 38% diabéticos e com dislipidemia e 57% com hipertensãoarterial, com insuficiência cardíaca isquêmica (33%) e nãoisquêmica(67%), nas classes funcionais II (90%) e III (10%) da NYHA, com fração de ejeção = 0,35±0,058, utilizandoseo teste de caminhada de 6 minutos (TC6M) e o teste ergométrico (Bruce modificado). Foram excluídos ospacientes não otimizados com terapêutica medicamentosa,problemas ortopédicos, doença vascular periférica ou quaisquer limitações para esforço. Analisou-se no TC6Ma distância total percorrida, sendo o paciente submetido a 3 testes com intervalos de 20 minutos. Foi comparado o valor de distância média alcançada no TC6M com a distância percorrida no teste ergométrico; o consumo deoxigênio máximo (VO2) e o equivalente metabólico máximo (MET) do TE. Para a análise estatística foram utilizados: o teste do qui-quadrado, de Mann-Whitney e a correlação de Pearson. Resultados: Houve significativas correlações positivas entre a distância percorrida no TC6M e a distância percorrida no teste de esforço (p=0,0001; r=0,76); e entreo VO2 máximo (p=0,001; r=0,68) e o MET máximo (p=0,001; r=0,68) neste grupo de pacientes. Conclusão: O TC6M é um teste reprodutível, de fácil realização e de baixo custo que pode ser utilizado para a avaliação de pacientes com IC, podendo fornecer informações valiosas que normalmente são obtidassomente com o TE. O aumento da amostra poderá determinar o verdadeiro valor dessas informações.

Objective: To correlate the distance on Six-minute walk test (6-MWT) with parameters obtained during exercise stress testing (EST) with a Bruce-modified protocol. Methods: We studied 21 patients, of whom 66% were white, 62% male, age 60±11 years, 38% diabetic and with dyslipidemia and 57% with arterial hypertension, 33% with with ischemic and 67% with nonischemicHF, NYHA class II (90%) and III (10%), with ejection fraction= 0.35±0.058. We excluded patients with suboptimal therapy, orthopedic disability, peripheral vascular disease or unable to exercise. Patients weresubmitted to 6-MWT for three times, with a 20-minute interval, and mean distance value was considered forcomparisons with distance, maximal oxygen uptake (maxVO2) and maximal metabolic equivalent (MET) during EST. Chi-square, Mann-Whitney and Pearson’scorrelation tests were used. Results: We observed significant positive correlationsbetween mean distance on 6-MWT and EST distance (p=0.0001; r=0.76), EST maxVO2 (p=0.001; r=0.68) and EST MET (p=0.001; r=0.68). Conclusion: On heart failure patients, 6-MWT is a reproducible, low-cost and easily obtainable test that can provide valuable information, usually only available on EST. Future studies with larger samplesizes will validate the present study results.

Comparison of Silent Patients with Painful Patients in Patients with Coronary Artery Stenoses during Exercise Myocardial Perfusion Scintigraphy

BACKGROUND AND OBJECTIVES: The angiographic profiles and myocardial ischemic variables were compared between patients with and without chest pain during exercise myocardial perfusion scintigraphy in patients with coronary artery stenoses. MATERIALS AND METHODS: Study population were 102 consecutive patients who have significant luminal stenoses (> 50%) on coronary angiography. They underwent symptom-limited treadmill exercise test and myocardial perfusion single photon emission computed tomography (SPECT). Tc-99m methoxylisobutyl isonitrile (MIBI) was injected intravenously at rest and one minute before the termination of exercise. Tomographic images were acquired within 1 hour of tracer injection. Electrocardiographic variables, scintigraphic summed reversibility scores and angiographic profiles were compared between patients with and without chest pain during exercise. RESULTS: Silent ischemia was noted in 52/102 (51%) of the subjects. The summed reversibility score of myocardial SPECT was not significanlty different between patients with (6.0+/-4.2) and without (5.1+/-5.0) chest pain. The extent, vessel distribution and stenosis severity of coronary artery disease were not significantly different between two groups. ST segment depression was more prominent in patients with chest pain (1.51+/-1.49 mm) than without chest pain (0.5+/-1.1 mm) during exercise stress testing. CONCLUSION: The degree of coronary stenoses and scintigraphic myocardial ischemia was not different between patients with and without chest pain during exercise stress testing.

RESULTS OF TWENTY FOUR HOURS AMBULATORY MONITORING OF ELECTROCARDIOGRAM AND EXERCISE STRESS TESTING IN PVC SCHOOL CHILDREN WITHOUT ORGANIC HEART DISEASE / 体力科学

Twenty four hours ambulatory monitoring of electrocardiogram and exercise stress testing were performed in 60 children who were refered to our hospital because of isolated premature ventricular contractions (PVCs) .<BR>Complex ventricular ectopy was found in 28 out of 60 PVC children. Out of 28 subjects with complex ventricular ectopies 21 had PVCs originated from the right ventricle.<BR>Frequency of PVCs per day was high in primary ventricular tachycardia and low in ventricular tachycardia with organic heart disease and there was statistical significance (p<0.01) between these two groups.<BR>There was no characteristics in coupling interval, prematurity index and vulnerability index which could specify ventricular tachycardia, couplets PVCs and isolated PVC.<BR>VT rate in exercise stress testing was higher than that in twenty four hours ambulatory monitoring of electrocardiogram (Holter recording) . Both exercise stress testing and twenty four hours monitering of electrocardiogram should be done to control VT school children.