Four hundred meters walking test in the evaluation of heart failure patients.

UNLABELLED: The best evaluation of the severity and prognosis of heart failure patients is obtained by the maximal exercise stress testing, but for the very large number of HF patients and for evaluation of their daily effort capacity submaximal stress testing, mainly 6 minutes walking test are used. The limit of 6mWT is that during it the patients are not motivated to walk and also, the periphery, so important for heart failure patients, is not equally involved. OBJECTIVE: To compare a new fixed walking test-400m walking test with 6MWT and maximal exercise testing. METHODS: There were investigated 20 patients with dilated cardiomyopathy (DCM). The patients were included in the study after the relief of the congestive syndrome. Each patient was submitted in three consecutive days to a maximal symptom-limited exercise stress test on cycloergometer, a six minutes walking test, a 400 meters walking test. The last one consisted of walking on a corridor 40 meters long, at a speed chosen by the patient himself. The results were expressed in seconds representing the necessary time to cover the established 400 meters of distance. RESULTS: During cycloergometer exercise stress test the calculated mean peak VO2 was 15.2 +/- 1.4 mlO2/kg/min (4.32 METs). The mean distance walked during 6MWT was 350 +/- 34m and the mean time needed to walk 400m (400mWT) was 300 +/- 27 seconds. The correlation between peak VO2 and distance walked during 6MWT was -0.40, a similar but negative value (r = -0.42) being registered between peak VO2 and time registered during 400mWT. Only weak correlation was registered between LVEF and all the three tests. In turn the correlation between distance registered during 6MWT and time registered during 400mWT was excellent: r = -0.60. CONCLUSION: 400mWT is a useful tool for the evaluation of submaximal effort capacity of CHF patients. Its value to evaluate exercise capacity is similar with that of the 6 MWT, but 400mWT can assure a better evaluation of peripheral involvement.

Cardiac peptides during exercise test in ischemic and non-ischemic heart failure patients.

BACKGROUND: Cardiac peptides are increased at rest in heart failure patients representing a useful diagnostic tool for this condition. Recently it has been demonstrated that cardiac peptides increase also during myocardial ischemia. Cardiac peptides increase during exercise in heart failure patients, but it has not been established yet if the increase is the same in ischemic and nonischemic patients. METHODS: There were studied 50 heart failure patients, 32 ischemic and 18 nonischemic, 35 males and 15 females aged 61.8 +/- 11.61 after the relief of congestive syndrome, which was submitted to a symptom-limited exercise stress test on a cycloergometer. Blood samples were obtained at rest and at a peak effort and the plasmatic values of NT-proBNP (NV<250 fmoles/mL) and of NT-proANP (NV<1950 fmoles/mL) were determined using the ELISA method. RESULTS: At rest, both NT-proBNP and NT-proANP were more increased in nonischemic (1104.33 +/- 730; 3275.55 +/- 3424) than in ischemic patients (685.68 +/- 452.01, 2265.0 +/- 2552.32) with significant differences only for NT-proBNP (p=0.016). During exercise NT-proBNP increase from 836.40 +/- 596.34 to 1403.92 +/- 2126.21 and NT-proANP from 2628.80 +/- 2903.41 to 3701.30 +/- 3237.76, the final values being again more increased in nonischemic patients (NT-proBNP-2945.44 +/- 3257.89; NT-proANP-3174 +/- 2905); for NT-proBNP p<0.05. The results suggest that the stretching effect during exercise is more increased at the ventricular level in comparison with the atrial level (67% increase for NT-proBNP and only 40% for NT-proANP). Surprisingly, myocardial ischemia does not increase additionally cardiac peptides either at rest or during exercise. Our data suggest that the intracardiac pressure is more important than ischemia in determining the increase of cardiac peptides in heart failure patients because the left ventricular ejection fraction was lower in nonischemic patients (40.03 +/- 5.5 vs 38.11 +/- 4.07). CONCLUSION: Cardiac peptides are increased, both at rest and during exercise, in nonischemic heart failure patients in comparison with ischemic ones, probably in relationship with the lower left ventricular systolic function.