Do Clinical Exercise Tests Permit Exercise Threshold Identification in Patients Referred to Cardiac Rehabilitation?
Can J Cardiol
; 39(11): 1701-1711, 2023 11.
Article
em En
| MEDLINE
| ID: mdl-37517474
ABSTRACT
BACKGROUND:
To evaluate the feasibility of "threshold-based" aerobic exercise prescription in cardiovascular disease, we aimed to quantify the proportion of patients whose clinical cardiopulmonary exercise test (CPET) permit identification of estimated lactate threshold (θLT) and respiratory compensation point (RCP) and to characterize the variability at which these thresholds occur.METHODS:
Breath-by-breath CPET data of 1102 patients (65 ± 12 years) referred to cardiac rehabilitation were analyzed to identify peak O2 uptake (VËO2peak; mL·min-1 and mL·kg-1·min-1) and θLT and RCP (reported as VËO2, %VËO2peak, and %peak heart rate [%HRpeak]). Patients were grouped by the presence or absence of thresholds group 0 neither θLT nor RCP; group 1 θLT only; and group 2 both θLT and RCP.RESULTS:
Mean VËO2peak was 1523 ± 627 mL·min-1 (range 315-3789 mL·min-1) or 18.0 ± 6.5 mL·kg-1·min-1 (5.2-46.5 mL·kg-1·min-1) and HRpeak was 123 ± 24 beats per minute (bpm) (52 bpm-207 bpm). There were 556 patients (50%) in group 0, 196 (18%) in group 1, and 350 (32%) in group 2. In group 1, mean θLT was 1240 ± 410 mL·min-1 (580-2560 mL·min-1), 75% ± 8%VËO2peak (52%-92%VËO2peak), or 84% ± 6%HRpeak (64%-96%HRpeak). In group 2, θLT was 1390 ± 360 mL·min-1 (640-2430 mL·min-1), 70% ± 8%VËO2peak (41%-88%VËO2peak), or 78% ± 7%HRpeak (52%-96%HRpeak), and RCP was 1680 ± 440 mL·min-1 (730-3090 mL·min-1), 84% ± 7%VËO2peak (54%-99%VËO2peak), or 87% ± 6%HRpeak (59%-99%HRpeak). Compared with group 1, θLT in group 2 occurred at a higher VËO2 but lower %VËO2peak and %HRpeak (P < 0.05).CONCLUSIONS:
Only 32% of CPETs exhibited both θLT and RCP despite flexibility in protocol options. Commonly used step-based protocols are suboptimal for "threshold-based" exercise prescription.
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Base de dados:
MEDLINE
Assunto principal:
Teste de Esforço
/
Reabilitação Cardíaca
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article