Impact of Integrative Cardiopulmonary Exercise Testing (18)
Furthermore, exercise training in these patients over a period of four to six months resulted in delayed blood lactate accumulation accompanied by an increased AT by about 20 percent. The authors concluded that the gas exchange AT provides a useful index of change in submaximal exercise performance after an intervention. Their findings were supported by the finding of prolonged duration of constant-work, symptom-limited exercise in those patients with increased AT. Itoh and colleagues reported that in 382 patients with chronic heart failure of various lands, both peak Vo2 and Vo2 at the AT (expressed as percentage of predicted) declined in accordance with the severity of symptoms (NYHA class). antibiotics levaquin
For example, those in NYHA class 1, 2, and 3 had Vo2 at the AT threshold of 90.2 ±15.4 percent, 76.9 ±13.8 percent, and 59.7 ±11.9 percent of predicted, respectively. On the other hand, there was a poor correlation of Vo2 at the AT with resting LV diastolic dimension (r= —0.22) or LV fractional shortening (r = 0.13) determined by echocardiography. Cardiothoracic ratio (r= —0.13) and cineangiographic LV ejection fraction (r = 0.25) also poorly predicted exercise AT. The authors concluded that the AT measurement was a useful index of the severity of heart failure.