Work‐rate affects cardiopulmonary exercise test results in heart failure

Abstract

Aims: Cardiopulmonary exercise test (CPET) is used to evaluate patients with chronic heart failure (HF) usually by means of a personalized ramp exercise protocol. Our aim was to evaluate if exercise duration or ramp rate influences the results. Methods and results: Ninety HF patients were studied (peak V O 2 : N20 ml/min/kg, n=28, 15-20 ml/min/kg, n=39 and b15 ml/min/kg, n=23). Each patient did four CPET studies. The initial study was used to separate the subjects into three groups, according to their exercise capacity. In the remaining studies, work-rate was increased at three different rates designed to have the subjects reach peak exercise in 5, 10 and 15 min from the start of the ramp increase in work-rate, respectively. The order was randomized. The work-rate applied for the total population averaged 22.7F8.0, 11.6F3.7, 7.5F2.9 W/min with effective loaded exercise duration of 5 min and 16 sF29 s, 9 min and 43 sF49 s and 14 min and 32 sF1 min and 12 s for the 5-, 10-and 15-min tests, respectively. Peak V O 2 averaged 16.9F4.3*, 18.0F4.4 and 18.0F5.4 ml/min/ kg for the 5-, 10-and 15-min tests, (*=pb0.001 vs. 10 min). The shortest test had the lowest peak heart rate and ventilation and highest peak work-rate. Peak V O 2 and heart rate were lowest in 5-min tests regardless of HF severity. The DV O 2 /Dwork-rate was lowest in 5-min tests and highest in 15-min tests. At all ramp rates, DV O 2 /Dwork-rate was lower for the subjects with the lower peak V O 2 . The V e /V CO 2 slope and V O 2 at anaerobic threshold were not affected by the protocol for any grade of HF. Conclusions: In chronic HF, exercise protocol has a small effect on peak V O 2 and DV O 2 /Dwork but does not affect V O 2 at anaerobic threshold and V e /V CO 2 slope. D 2004 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.Keywords: Exercise; Oxygen consumption; Heart failure In chronic heart failure (HF), a cardiopulmonary exercise test (CPET) is frequently done to evaluate the severity of the disease, and thereby the patient's prognosis, or to test the efficacy of therapy [1][2][3][4][5][6][7][8]. For these purposes, several CPET parameters have been studied including oxygen uptake (V O 2 ) at peak exercise and at anaerobic threshold, work-rate achieved at peak exercise, slope of ventilation (V e ) vs. carbon dioxide output (V CO 2 ), V e /V CO 2 ratio at anaerobic threshold, DV O 2 /Dwork-rate from unloaded cycling to peak, and the oxygen pulse (O 2 p) at peak V O 2 [9]. Some of these parameters are independent of each other and have specific prognostic relevance; as a consequence their combined use improves our capability to evaluate prognosis in HF patients [9,10]. While it is generally recommended to use a personalized exercise protocol in which work-rate is increased in ramp pattern aimed at achieving target time to peak exercise within 8-12 min [9,[11][12][13], the exercise protocol is rarely provided in clinical study reports. Because it is not known if and how the duration, or the rate of increase of e...

Heart Failure Progression in Hypertrophic Cardiomyopathy – Possible Insights From Cardiopulmonary Exercise Testing –

“…A personalized ramp exercise protocol was performed, aiming for a test duration of 10±2 min. 19 The exercise was preceded by few minutes of resting breath-by-breath gas exchange monitoring and by a 3-min unloaded warm-up. In the absence of clinical events, CPET was interrupted when patients stated that they had reached maximal effort.…”

Relationship of resting hemoglobin concentration to peak oxygen uptake in heart failure patients

“…The used load for each individual of the personalized ramp protocol was decided by the physician in charge according to previous test results, if available, or to exercise performance as reported by patients. Tests too short (<5 min) or too long (>14 min) were repeated with a more appropriate ramp protocol [10]. Ventilation ( _ VE), _ VO 2 , and carbon dioxide production ( _ VCO 2 ) were measured breath by breath (V-max 2900 metabolic cart SensorMedics, Yorba Linda CA for tests performed between June 2001 and August 2004 and V-max metabolic cart SensorMedics, Yorba Linda CA for tests performed between September 2004 and March 2009).…”

Teste de esforço cardiopulmonar com protocolo de rampa em adultos com insuficiência cardíaca

“…Such findings indicate that the test performed with the ramp protocol developed presented suitable duration for the cardiopulmonary evaluation in the individuals with HF evaluated as described in the literature 1,3,7,8,15,18,[22][23][24] . The application of the proposed protocol is possible on treadmills which present external command with possibility of concomitant velocity and inclination adjustment.…”