ABSTRACT
Abstract Objectives Refractory angina (RA) is a chronic condition clinically characterized by low effort tolerance; therefore, physical stress testing is not usually requested for these patients. Cardiopulmonary exercise testing (CPET) is considered a gold standard examination for functional capacity evaluation, even in submaximal tests, and it has gained great prominence in detecting ischemia. The authors aimed to determine cardiorespiratory capacity by using the oxygen consumption efficiency slope (OUES) in patients with refractory angina. The authors also studied the O2 pulse response by CPET and the association of ischemic changes with contractile modifications by exercise stress echocardiography (ESE). Methods Thirty-one patients of both sexes, aged 45 to 75 years, with symptomatic (Canadian Cardiovascular Society class II to IV) angina who underwent CPET on a treadmill and exercise stress echocardiography on a lower limb cycle ergometer were studied. ClinicalTrials.gov: NCT03218891. Results The patients had low cardiorespiratory capacity (OUES of 1.74 ± 0.4 L/min; 63.9±14.7% of predicted), and 77% of patients had a flattening or drop in O2 pulse response. There was a direct association between Heart Rate (HR) at the onset of myocardial ischemia detected by ESE and HR at the onset of flattening or drop in oxygen pulse response detected by CPET (R = 0.48; p = 0.019). Conclusion Patients with refractory angina demonstrate low cardiorespiratory capacity. CPET shows good sensitivity for detecting abnormal cardiovascular response in these patients with a significant relationship between flattening O2 pulse response during CEPT and contractile alterations detected by exercise stress echocardiography. Highlights OUES analysis is useful for assessing functional capacity in refractory angina. O2 pulse curve is correlated with contractile alterations in exercise echocardiogram. Cardiopulmonary exercise test is useful toll in patients with refractory angina.
ABSTRACT
FUNDAMENTO: Pouco se sabe sobre a resposta cardiorrespiratória e metabólica em crianças saudáveis durante teste de esforço progressivo máximo. OBJETIVO: Testar a hipótese de que as crianças apresentam respostas diferentes nos parâmetros cardiorrespiratórios e metabólicos durante teste de esforço progressivo máximo em comparação aos adultos. MÉTODOS: Vinte e cinco crianças saudáveis (sexo, 15M/10F; idade, 10,2 ± 0,2) e 20 adultos saudáveis (sexo, 11M/9F; idade, 27,5 ± 0,4) foram submetidos a um teste cardiopulmonar progressivo em esteira ergométrica até a exaustão para determinar a capacidade aeróbia máxima e limiar anaeróbio ventilatório (LAV). RESULTADOS: A carga de pico (5,9 ± 0,1 vs 5,6 ± 0,1 mph, respectivamente; p > 0,05), tempo de exercício (9,8 ± 0,4 vs 10,2 ± 0,4 min, respectivamente, p > 0,05), e aptidão cardiorrespiratória (VO2pico, 39,4 ± 2,1 vs 39,1 ± 2,0 ml.kg-1.min-1, respectivamente, p > 0,05) foram semelhantes em crianças e adultos. No limiar anaeróbio ventilatório, a frequência cardíaca, VO2 ml.kg-1.min-1, a frequência respiratória (FR), o espaço morto funcional estimado (VD/VT), o equivalente ventilatório de oxigênio (VE/VO2) e a pressão expiratória final do oxigênio (PETO2) foram maiores nas crianças, enquanto o volume corrente (VC), pulso de O2 e a pressão expiratória final do dióxido de carbono (PETCO2) foram menores. No pico do exercício, as crianças apresentaram FR e VD/VT superiores. No entanto, o pulso de O2, o VC, a ventilação pulmonar, o PETCO2 e a razão de troca respiratória foram menores nas crianças do que em adultos. CONCLUSÃO: Respostas cardiorrespiratórias e metabólicas durante o teste de esforço progressivo são diferentes em crianças em comparação aos adultos. Especificamente, essas diferenças sugerem que as crianças têm menor eficiência cardiovascular e respiratória. No entanto, as crianças apresentaram maior eficiência metabólica durante o teste de esforço. Em resumo, apesar das diferenças observadas, ...
BACKGROUND: Little is known about cardiorespiratory and metabolic response in healthy children during progressive maximal exercise test. OBJECTIVE: To test the hypothesis that children show different responses in cardiorespiratory and metabolic parameters during progressive maximal exercise test when compared with adults. METHODS: Twenty-five healthy children (gender, 15M/10F; age, 10.2 ± 0.2) and 20 healthy adults (gender, 11M/9F; age, 27.5 ± 0.4) underwent a progressive treadmill cardiopulmonary test until exhaustion to determine the maximal aerobic capacity and ventilatory anaerobic threshold (VAT). RESULTS: The peak workload (5.9±0.1 vs 5.6±0.1 mph, respectively; p>0.05), exercise time (9.8±0.4 vs 10.2±0.4 min, respectively; p>0.05), and relative aerobic fitness (VO2peak, 39.4±2.1 vs 39.1±2.0 ml.kg-1.min-1, respectively; p>0.05) were similar in children and adults. At ventilatory anaerobic threshold, the heart rate, VO2 ml.kg-1.min-1, respiratory rate (RR), functional estimate of dead space (VD/VT), ventilatory equivalent for oxygen (VE/VO2) and end-tidal pressure for oxygen (PETO2) were higher in children, while tidal volume (VT), O2 pulse and end-tidal pressure for carbon dioxide (PETCO2) were lower. At peak of exercise, children showed higher RR and VD/VT. However, O2 pulse, VT, pulmonary ventilation, PETCO2 and respiratory exchange ratio were lower in children than adults. CONCLUSION: Cardiorespiratory and metabolic responses during progressive exercise test are different in children as compared to adults. Specifically, these differences suggest that children have lower cardiovascular and ventilatory efficiency. However, children showed higher metabolic efficiency during exercise. In summary, despite the differences observed, children showed similar levels of exercising capacity when compared with adults.