Study on six-minute walk test and cardiac output response against exercise in patients with chronic heart failure / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the significance of cardiac output (CO) response against exercise determined by IGR method and LVEF, 6 MWT distance in patients with chronic heart failure (CHF).</p><p><b>METHOD</b>To adopt 6 MWT, and before and after the test measuring the CO by the IGR method, furthermore, measure LVEF to 36 patients (heart failure group) with CHF, compare with the health groups (control group).</p><p><b>RESULTS</b>The 6MWT distance of heart failure group (333.00 +/- 49.64) m decrease compared with the control group (582.56 +/- 67.97) m (P < 0.01), moreover, the distance of NYHA class III (314.82 +/- 36.27) m is significantly shorter than II (361.57 +/- 55.42) m (P < 0.05). The LVEF of heart failure group (47.0 +/- 0.4)% reduce compared with the control group (66.9 +/- 5.2)% (P < 0.01), and the data of NYHA class III (43.3 +/- 10.3)% is significantly lower than II (52.8 +/- 7.6)% (P < 0.01). The increase in CO response against exercise of heart failure group (5.97 +/- 1.89) L/min decrease compared with control group (8.88 +/- 0.52) L/min (P < 0.01), furthermore, the value of NYHA class III (5.31 +/- 1.52) L/min, compared with II (7.01 +/- 1.98)L/min, is obviously lower (P < 0.01). The 6MWT distance correlates positively with the increase in CO response against exercise (r = 0.63, P < 0.01), but the correlation is not found between the increase CO response against exercise and the LVEF (r = 0.11, P > 0.05).</p><p><b>CONCLUSION</b>Our results show that CO response against exercise measured by IGR method, with the advantages of being noninvasive, safe, convenient and accurate, combining with the 6MWT can evaluate cardiac reserve in patient with CHF.</p>