High Cardiorespiratory Optimal Point Values Are Related to Cardiovascular Mortality in Men Aged 46 to 70 Years: a Prospective Cohort Study

Abstract Background: Several hemodynamic and respiratory variables measured during cardiopulmonary exercise testing (CPX) have been shown to predict survival. One such measure is the cardiorespiratory optimal point (COP) that reflects the best possible circulation-respiration interaction, but there are still limited data on its relationship with adverse outcomes. Objective: To assess the association between COP and cardiovascular mortality in men aged 46 to 70 years. Methods: A sample of 2201 men who had anthropometric, clinical, and COP data obtained during cycling CPX between 1995 and 2022 was extracted from the CLINIMEX Exercise cohort. COP was identified as the minimal minute-to-minute VE/VO2 during CPX. Vital data were censored on October 31, 2022 for ICD-10-identified cardiovascular deaths. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs). Results: The mean ± standard deviation age was 57 ± 6 years and the median COP value was 24 (interquartile range = 21.2 to 27.4). During a mean follow-up of 4688 ± 2416 days, 129 (5.6%) patients died from cardiovascular causes. The death rates for low (< 28), high (28 to 30), and very high (> 30) categories of COP were 3.2%, 9.6%, and 18.7%, respectively. Following adjustment for age, history of myocardial infarction, diagnosis of coronary artery disease, and diabetes mellitus, the HR (95% CI) for cardiovascular mortality comparing very high versus low COP was 2.76 (1.87 to 4.07; p < 0.001). Conclusions: Our data indicate that, for a general population-based sample of men, COP > 30 represents a considerably higher risk for cardiovascular death. Information on COP could assist cardiovascular risk assessment in men.

Respiratory gas kinetics in patients with congestive heart failure during recovery from peak exercise

Abstract Background Cardiopulmonary Exercise Testing (CPX) is essential for the assessment of exercise capacity for patients with Chronic Heart Failure (CHF). Respiratory gas and hemodynamic parameters such as Ventilatory Efficiency (VE/VCO2 slope), peak oxygen uptake (peak VO2), and heart rate recovery are established diagnostic and prognostic markers for clinical populations. Previous studies have suggested the clinical value of metrics related to respiratory gas collected during recovery from peak exercise, particularly recovery time to 50% (T1/2) of peak VO2. The current study explores these metrics in detail during recovery from peak exercise in CHF. Methods Patients with CHF who were referred for CPX and healthy individuals without formal diagnoses were assessed for inclusion. All subjects performed CPX on cycle ergometers to volitional exhaustion and were monitored for at least five minutes of recovery. CPX data were analyzed for overshoot of respiratory exchange ratio (RER=VCO2/VO2), ventilatory equivalent for oxygen (VE/VO2), end-tidal partial pressure of oxygen (PETO2), and T1/2 of peak VO2 and VCO2. Results Thirty-two patients with CHF and 30 controls were included. Peak VO2 differed significantly between patients and controls (13.5 ± 3.8 vs. 32.5 ± 9.8 mL/Kg*min−1, p < 0.001). Mean Left Ventricular Ejection Fraction (LVEF) was 35.9 ± 9.8% for patients with CHF compared to 61.1 ± 8.2% in the control group. The T1/2 of VO2, VCO2 and VE was significantly higher in patients (111.3 ± 51.0, 132.0 ± 38.8 and 155.6 ± 45.5s) than in controls (58.08 ± 13.2, 74.3 ± 21.1, 96.7 ± 36.8s; p < 0.001) while the overshoot of PETO2, VE/VO2 and RER was significantly lower in patients (7.2 ± 3.3, 41.9 ± 29.1 and 25.0 ± 13.6%) than in controls (10.1 ± 4.6, 62.1 ± 17.7 and 38.7 ± 15.1%; all p < 0.01). Most of the recovery metrics were significantly correlated with peak VO2 in CHF patients, but not with LVEF. Conclusions Patients with CHF have a significantly blunted recovery from peak exercise. This is reflected in delays of VO2, VCO2, VE, PETO2, RER and VE/VO2, reflecting a greater energy required to return to baseline. Abnormal respiratory gas kinetics in CHF was negatively correlated with peak VO2 but not baseline LVEF.

Outcomes of Ahmed glaucoma valve and transscleral cyclophotocoagulation in neovascular glaucoma

Purpose: To determine the outcomes of Ahmed glaucoma valve (AGV) and transscleral diode cyclophotocoagulation (CPC) in neovascular glaucoma (NVG). Methods: This was a single?center retrospective comparative case series involving chart review of consecutive patients who underwent AGV or CPC for treatment of NVG and had ?6 months of follow?up. Surgical failure at 6 months, defined as an IOP of >21 or <6 mm Hg with hypotony maculopathy after 1 month, progression to no light perception (NLP) vision, glaucoma reoperation, or removal of AGV were the main outcome measures. Results: In total, 121 eyes of 121 patients were included (70 AGV and 51 CPC). Baseline demographics, visual acuity (VA), and intraocular pressure (IOP) were comparable between groups. At 6 months, failure was significantly higher in the CPC group than in the AGV group (43.1% vs. 17.1%, P = 0.020). Both groups had similar IOP and medication number at 6 months, but VA was significantly lower in the CPC group compared to the AGV group (2.4 � 0.8 vs. 1.9 � 1.0, P = 0.017). More CPC eyes required reoperation for glaucoma than AGV eyes (11.8% vs. 1.4%, P = 0.041). Multivariate regression analysis identified higher preoperative IOP (P = 0.001) and CPC surgery (P = 0.004) as independent predictors of surgical failure at 6 months. Age, sex, race, NVG etiology, bilaterality of the underlying retinal pathology, perioperative retina treatment, and prior or combined vitrectomy were not significant. Conclusion: AGV and CPC had comparable IOP and medication reduction in NVG eyes at 6 months. CPC was more frequently associated with failure, reoperation for glaucoma, and worse visual outcomes. High preoperative IOP and CPC surgery independently predicted surgical failure.

Speed and Grade Increment During Cardiopulmonary Treadmill Testing: Impact on Exercise Prescription

Maximal oxygen uptake (VO2max) and both first (VT1) and second (VT2) thresholds have been used as reference points for exercise prescription in different populations. Objective: We aimed to test the hypothesis that exercise prescription, based on VTs determined by treadmill cardiopulmonary exercise testing (CPET), is influenced by the rate of increase in treadmill workload. Methods: Nine healthy individuals underwent two CPETs, followed by two sessions of submaximal exercise, both in randomized order. For the "speed" protocol, there was an increment of 0.1 to 0.3 km.h-1 every 15s. The "grade" incremental protocol increased 1% every 30s and 0.1 km.h-1 every 45s. This was followed by submaximal exercise sessions lasting 40min at an intensity corresponding to heart rate (HR) between the VT1 and VT2. Results: The "speed" protocol resulted in higher VT1 (p = 0.01) and VT2 (p = 0.02) when compared to the "grade" incremental protocol, but there was no effect on VO2max. The target HR for the submaximal exercise sessions was higher in the "speed" protocol compared to the "grade" incremental protocol (p < 0.01) and remained stable during the two steady-state exercise sessions. Blood lactate remained stable during the submaximal exercise sessions, with higher values observed during the "speed" protocol than those "grade" incremental protocol (p < 0.01). Conclusions: Compared to a grade-based protocol, a speed-based protocol resulted in higher VT1 and VT2, which significantly affected cardiorespiratory and metabolic responses to prescribed exercise intensity in healthy young adults

Ponto ótimo cardiorrespiratório em futebolistas profissionais: uma nova variável submáxima do exercício / Cardiorespiratory optimal point in professional soccer players: a novel submaximal variable during exercise

O consumo máximo de oxigênio (VO2 max) e o limiar anaeróbico (LA) obtidos no teste cardiopulmonar de exercício (TCPE) são utilizados na avaliação de atletas. Todavia, dificuldades na identificação e mensuração dessas variáveis dificultam sua utilização prática. O ponto ótimo cardiorrespiratório (POC) é uma variável submáxima do TCPE de mensuração objetiva e com significado clínico prognóstico. Contudo, é desconhecido o seu comportamento em atletas.Descrever o comportamento do POC em jogadores profissionais de futebol e sua associação com VO2 max e LA. Análise retrospectiva de 198 futebolistas submetidos a TCPE máximo em esteira rolante com protocolo em rampa, divididos pela posição em campo: goleiro, zagueiro, lateral, meio-campo e atacante. Foram determinados VO2max, LA e POC. O POC correspondeu ao menor valor de ventilação/consumo de oxigênio em um dado minuto do TCPE. Variáveis contínuas foram comparadas pelo teste t de Student não emparelhado ou ANOVA, ou teste de Mann-Whitney ou de Kruskal-Wallis dependendo na distribuição das mesmas, e variáveis categóricas foram comparadas pelo teste do qui-quadrado. A correlação de Pearson foi utilizada para testar a associação entre POC e outras variáveis ventilatórias. Adotou-se um nível de 5% para significância estatística. O POC (média ± desvio-padrão) foi de 18,2 ± 2,1 a uma velocidade 4,3 ± 1,4 km.h-1 menor do que a do LA. Enquanto o VO2 max (62,1 ± 6,2 mL.kg-1.min-1) tendeu a ser menor nos goleiros (p < 0,05), o POC não variou conforme a posição em campo (p = 0,41). Não houve associação significativa entre POC e VO2max (r = 0,032,p = 0,65) nem com LA (r = -0,003, p = 0,96).O POC pode ser facilmente determinado em exercício submáximo realizado com velocidades incrementais em futebolistas e não varia pela posição em campo. A ausência de associação com VO2max e LA indica que o POC traz uma informação distinta e complementar a essas variáveis. Estudos futuros são necessários para determinar implicações práticas do POC na avaliação de atletas

Maximal oxygen consumption (VO2max) and ventilatory threshold (VT) obtained during a cardiopulmonary exercise test (CPX) are used in the evaluation of athletes. However, the identification of these variables may sometimes be unreliable, which limits their use. In contrast, the cardiorespiratory optimal point (COP) is a submaximal variable derived from CPX with objective measurement and prognostic significance. However, its behavior in athletes is unknown. To describe the behavior of COP in professional soccer players and its association with VO2max and VT. VO2max, VT and COP were obtained retrospectively from 198 soccer players undergoing maximal treadmill CPX using ramp protocol. COP was defined as the lowest value of the ventilation/oxygen consumption ratio in a given minute of the CPX. The soccer players were stratified according to their field position: goalkeeper, center-defender, left/right-back, midfielder and forwarder. Continuous variables were compared using unpaired Student t test or ANOVA, or Mann-Whitney test or Kruskal-Wallis test depending on their distribution, and categorical variables were compared using chi-square test. Pearson correlation was used to test the association between COP and other ventilatory variables. A level of 5% was used for statistical significance. COP (mean ± SD) was 18.2 ± 2.1 and was achieved at a speed 4.3 ± 1.4 km.h-1 lower than that achieved at the VT. While VO2max (62.1 ± 6.2 mL.kg-1.min-1) tended to be lower in goalkeepers (p < 0.05), the COP did not vary according to field position (p = 0.41). No significant association was observed between COP and VO2max (r = 0.032, p = 0.65) or between COP and VT (r = -0.003, p = 0.96). COP can be easily determined during submaximal exercise performed with incremental speed in soccer players and does not vary according to the athlete's field position. The absence of association with VO2max and VT indicates that COP provides distinct and complementary information to these variables. Future studies are needed to determine the practical implications of COP in assessing athletes

Ponto Ótimo Cardiorrespiratório em Futebolistas Profissionais: Uma Nova Variável Submáxima do Exercício / Cardiorespiratory Optimal Point in Professional Soccer Players: A Novel Submaximal Variable During Exercise

O consumo máximo de oxigênio (VO2max) e o limiar anaeróbico (LA) obtidos no teste cardiopulmonar de exercício (TCPE) são utilizados na avaliação de atletas. Todavia, dificuldades na identificação e mensuração dessas variáveis dificultam sua utilização prática. O ponto ótimo cardiorrespiratório (POC) é uma variável submáxima do TCPE de mensuração objetiva e com significado clínico prognóstico. Contudo, é desconhecido o seu comportamento em atletas. Objetivo: Descrever o comportamento do POC em jogadores profissionais de futebol e sua associação com VO2max e LA. Materiais e Método: Análise retrospectiva de 198 futebolistas submetidos a TCPE máximo em esteira rolante com protocolo em rampa, divididos pela posição em campo: goleiro, zagueiro, lateral, meio-campo e atacante. Foram determinados VO2max, LA e POC. O POC correspondeu ao menor valor de ventilação/consumo de oxigênio em um dado minuto do TCPE. Variáveis contínuas foram comparadas pelo teste t de Student não emparelhado ou ANOVA, ou teste de Mann-Whitney ou de Kruskal-Wallis dependendo na distribuição das mesmas, e variáveis categóricas foram comparadas pelo teste do qui-quadrado. A correlação de Pearson foi utilizada para testar a associação entre POC e outras variáveis ventilatórias. Adotou-se um nível de 5% para significância estatística. Resultados: O POC (média ± desvio-padrão) foi de 18,2 ± 2,1 a uma velocidade 4,3 ± 1,4 km.h-1 menor do que a do LA. Enquanto o VO2max (62,1 ± 6,2 mL.kg-1.min-1) tendeu a ser menor nos goleiros (p < 0,05), o POC não variou conforme a posição em campo (p = 0,41). Não houve associação significativa entre POC e VO2max (r = 0,032, p = 0,65) nem com LA (r = -0,003, p = 0,96). Conclusão: O POC pode ser facilmente determinado em exercício submáximo realizado com velocidades incrementais em futebolistas e não varia pela posição em campo. A ausência de associação com VO2max e LA indica que o POC traz uma informação distinta e complementar a essas variáveis. Estudos futuros são necessários para determinar implicações práticas do POC na avaliação de atletas

Maximal oxygen consumption (VO2max) and ventilatory threshold (VT) obtained during a cardiopulmonary exercise test (CPX) are used in the evaluation of athletes. However, the identification of these variables may sometimes be unreliable, which limits their use. In contrast, the cardiorespiratory optimal point (COP) is a submaximal variable derived from CPX with objective measurement and prognostic significance. However, its behavior in athletes is unknown. Objective: To describe the behavior of COP in professional soccer players and its association with VO2max and VT. Methods: VO2max, VT and COP were obtained retrospectively from 198 soccer players undergoing maximal treadmill CPX using ramp protocol. COP was defined as the lowest value of the ventilation/oxygen consumption ratio in a given minute of the CPX. The soccer players were stratified according to their field position: goalkeeper, center-defender, left/right-back, midfielder and forwarder. Continuous variables were compared using unpaired Student t test or ANOVA, or Mann-Whitney test or Kruskal-Wallis test depending on their distribution, and categorical variables were compared using chi-square test. Pearson correlation was used to test the association between COP and other ventilatory variables. A level of 5% was used for statistical significance. Results: COP (mean ± SD) was 18.2 ± 2.1 and was achieved at a speed 4.3 ± 1.4 km.h-1 lower than that achieved at the VT. While VO2max (62.1 ± 6.2 mL.kg-1.min-1) tended to be lower in goalkeepers (p < 0.05), the COP did not vary according to field position (p = 0.41). No significant association was observed between COP and VO2max (r = 0.032, p = 0.65) or between COP and VT (r = -0.003, p = 0.96). Conclusion: COP can be easily determined during submaximal exercise performed with incremental speed in soccer players and does not vary according to the athlete's field position. The absence of association with VO2max and VT indicates that COP provides distinct and complementary information to these variables. Future studies are needed to determine the practical implications of COP in assessing athletes

Effect of physical training on the recovery of acute exercise, among patients with cardiovascular disease / Efecto del entrenamiento físico en la recuperación del ejercicio agudo, en pacientes con enfermedad cardiovascular

Abstract: Introduction: Physical training programs (PTP) have shown several beneficial effects for patients with cardiovascular disease (CVD), particularly by increasing survival and quality of life. Physiological response during the effort and recovery phases of an exercise testing, is one of the strongest prognostic markers among patients with CVD. A reasonable mechanism that explains those training effects on survival is through the adaptations seen on heart rate recovery (HRR) and oxygen uptake kinetics at the post-exertional phase (RVO2). Objective: Compare the HRR and RVO2 values before and after a PTP in patients with CVD. Methods: We studied a cohort of patients included in a cardiac rehabilitation program, whom performed a cardiopulmonary exercise testing (CPX). Then, risk stratification and an individualized exercise training program were performed. The exercise training program included 20 sessions of aerobic exercise, 30 min a day, five times a week, at moderate intensity. Finally, a second CPX was performed. Results: A total of 215 patients were included. Peak oxygen uptake values rose 2.2 ± 5.2 ml/kg/min (p < 0.001), HRR increased 1.6 ± 10 bpm (p < 0.05) and RVO2 improved −21 ± 98 s (p < 0.001). A post-hoc analysis show that the percentage of maximum heart rate remained statistically associated with HRR increment. Furthermore, diabetes and sedentarism were strongly related to RVO2 improvement. No correlation between HRR and RVO2 was found (R2 = 0.002). Conclusion: Physical exercise was associated with a beneficial effect on HRR and RVO2. Nevertheless, both variables were statistically unrelated.

Resumen: Introducción: Los programas de entrenamiento físico han demostrado efectos benéficos en pacientes con enfermedad cardiovascular, particularmente debido al aumento de la supervivencia y calidad de vida. La respuesta fisiológica durante la prueba de esfuerzo cardiopulmonar tanto en las fases de ejercicio como de recuperación son de los principales marcadores pronósticos debido a la adaptación en la recuperación de la frecuencia cardiaca (RFC) y la cinética de recuperación de oxígeno en la fase de postesfuerzo (RVO2). Objetivo: Comparar los valores de RFC y RVO2 antes y después de un programa de entrenamiento físico. Métodos: Se estudió una cohorte de pacientes incluidos en un programa de rehabilitación cardiaca, que hayan realizado una prueba de esfuerzo cardiopulmonar. El programa de entrenamiento consistió en 20 sesiones de ejercicio aeróbico de 30 min diarios, 5 veces a la semana de intensidad moderada. Por último, se realizó una segunda prueba de esfuerzo cardiopulmonar. Resultados: Se incluyeron 215 pacientes. El consumo pico de oxígeno aumentó en 2.2 ± 5.2 ml/kg/min (p < 0.001), la RFC se incrementó 1.6 ± 10 lpm (p < 0.05) y mejoró la RVO2 −21 ± 98 seg (p < 0.001). En el análisis post-hoc se observó que el porcentaje de la frecuencia cardiaca máxima se mantuvo asociado con el incremento de la RFC. Por otra parte, la diabetes y el sedentarismo estuvieron fuertemente asociados con la mejora de la RVO2. No se observó correlación entre RFC y RVO2 (R2 = 0.002). Conclusiones: El ejercicio físico se asoció con un efecto benéfico sobre la RFC y la RVO2. Sin embargo, ambas variables no se relacionaron estadísticamente.

Cardiopulmonary exercise testing in healthy children and adolescents at moderately high altitude / Prueba de esfuerzo cardiopulmonar a niños y adolescentes sanos en altitud moderadamente elevada

Objective: Cardiopulmonary exercise testing is a tool that helps clinicians to establish diagnosis and calculate risk stratification in adults. However, the utility of this test among children with congenital heart disease has not been fully explored. The goal of this study was to describe reference values for cardiopulmonary performance of healthy children. Methods: This study included 103 apparently healthy children (aged from 4 to 18 years; 61 boys), who underwent cardiopulmonary test using a treadmill protocol. All tests took place at 2240m above sea level (Mexico City). Results: Exercise time was 11 ± 4 min. There were no complications. Peak oxygen uptake correlated closely with height in both genders (girls r = 0.84; boys r = 0.84, p < 0.001). A multivariable linear regression model showed that body surface area, exercise time, gender and heart rate reserve were significant predictors of peak oxygen uptake (R² =0.815, p<0.001). Peak oxygen uptake was strongly associated with age even among children younger than thirteen years (r = 0.74, p <0.001). Conclusion: This study provides physiological values for the major cardiopulmonary variables obtained from exercise testing using a treadmill among healthy children. Cardiopulmonary exercise test can be safely and effectively performed in young children even as young as 4 years old. Variables including age, gender and height are strongly associated with exercise time, peak heart rate and peak oxygen uptake. Regression equations for predicting peak heart rate and peak oxygen uptake are presented as reference values that allow researchers to compare children with heart disease versus those who are healthy.

Objetivo: La prueba de esfuerzo cardiopulmonar es una herramienta que ayuda a los médicos a establecer el diagnóstico y estratificar el riesgo en adultos. Sin embargo, su utilidad en los niños no se ha explorado a fondo. El objetivo fue describir los valores de esta prueba en niños sanos en altitud moderadamente alta. Métodos: Se realizaron pruebas de esfuerzo cardiopulmonar a 103 niños sanos (4 a 18 años, 61 varones) mediante tapiz rodante y a 2240m sobre el nivel del mar (Ciudad de México). Resultados: El tiempo de ejercicio fue de 11 ± 4 min, sin complicaciones. El consumo de oxígeno pico se correlacionó estrechamente con la talla en ambos géneros (niñas r = 0.84; niños r = 0.84, p < 0.001). El modelo multivariado que incluyó superficie corporal, tiempo de ejercicio, género y la frecuencia cardíaca de reserva fue un fuerte predictor del consumo de oxígeno pico (R²=0.815, p<0.001). Conclusión: Las pruebas de esfuerzo cardiopulmonar mediante tapiz rodante se pueden realizar con seguridad y eficacia en niños, incluso de 4 años de edad. Variables como la edad, el género y la talla están fuertemente asociados con el tiempo de ejercicio, la frecuencia cardiaca máxima y el de oxígeno pico. Las ecuaciones de regresión obtenidas para calcular la frecuencia cardíaca máxima y el consumo de oxígeno pico pueden ayudar, tanto a clínicos como a investigadores, a comparar el comportamiento de niños con cardiopatías frente a los que no las tienen.

La evolución del valor pronóstico de la prueba de esfuerzo cardiopulmonar en los pacientes con insuficiencia cardíaca / The evolution of the prognostic value of CPX in patients with heart failure

Hace 20 años, en el importante estudio de Donna Mancini, se demostró el valor pronóstico de la prueba de esfuerzo cardiopulmonar (PECP) en pacientes con insuficiencia cardíaca. En ese ensayo se evaluó la utilidad del consumo máximo de oxígeno para definir el riesgo de mortalidad en una cohorte de 114 enfermos con insuficiencia cardíaca. La repercusión de los resultados iniciales influyó sobre la práctica clínica durante más de una década, durante la cual el consumo máximo de oxígeno era en general la única variable de la PECP que se consideraba para la estratificación del riesgo. A lo largo de los últimos 20 años, se ha demostrado en gran cantidad de investigaciones la importancia de otras variables de la PECP en el pronóstico. Los restantes parámetros relevantes de la PECP en la insuficiencia cardíaca incluyen los índices de eficacia ventilatoria (pendiente VM/CO2, presión parcial de dióxido de carbono en el aire espirado, ventilación oscilante en el ejercicio), frecuencia cardíaca, respuesta electrocardiográfica y de otros parámetros hemodinámicos, y la sintomatología. Entre los investigadores que evalúan la PECP en pacientes con insuficiencia cardíaca, se reconoce que el abordaje multivariado debe aplicarse para una óptima definición del pronóstico. Los clínicos responsables del tratamiento de los pacientes con insuficiencia cardíaca han comenzado a aplicar este enfoque. En esta revisión, se describe la evolución del uso de la PECP en los sujetos con insuficiencia cardíaca en estos 20 años.

Bloqueio completo do ramo esquerdo esforço-induzido: prevalência e prognóstico / Exercise-induced left bundle branch block: prevalence and prognosis / Bloqueo completo de la rama izquierda esfuerzo-inducido prevalencia y pronóstico

FUNDAMENTO: O bloqueio completo do ramo esquerdo esforço-induzido (BCRE E-I) é um achado infrequente ao teste de exercício e sua prevalência e significado prognóstico não são claros. OBJETIVO: Avaliar de forma longitudinal a prevalência e o significado prognóstico do BCRE E-I em homens americanos veteranos de guerra. MÉTODOS: Avaliamos 9.623 pacientes que realizaram ergometria em esteira (TE) entre 1987 e 2007. Os desfechos foram comparados entre aqueles com TE NL, os com BCRE E-I e os que apresentaram Dep ST anormal. A mortalidade e a causa das mortes foram identificadas de forma cega para os resultados do TE. RESULTADOS: Nesta coorte prospectiva, 6922 indivíduos apresentaram TE NL (57,2 ± 11,4 anos), 1.739 apresentaram Dep ST anormal (62,7 ± 9,8 anos) e 38 casos de BCRE E-I foram identificados (65,2 ± 11,9 anos). A prevalência do BCRE E-I foi 0,38 por cento. Após 8,8 anos, ocorreram 1.699 mortes por todas as causas e 610 mortes cardiovasculares (CV). Doença arterial coronária e insuficiência cardíaca foram mais prevalentes nos pacientes com BCRE E-I. Pacientes com BCRE E-I tiveram razão de azar de 2,37 (p = 0,002) para mortalidade por todas as causas, mas a mesma não foi significativa quando ajustada para idade ou quando a mortalidade cardiovascular foi o desfecho avaliado. CONCLUSÃO: BCRE E-I é um achado raro. Indivíduos com BCRE E-I apresentam maior mortalidade por todas as causas quando comparados aqueles com TE NL. No entanto, tal fato é explicado por esses pacientes serem significativamente mais velhos e por apresentarem mais enfermidades cardiovasculares associadas.

BACKGROUND: Exercise-induced left bundle branch block (EI-LBBB) is an infrequent finding. Its prevalence and prognostic significance are not clear. OBJECTIVE: To evaluate, in a longitudinal study, the prevalence and prognostic significance of EI-LBBB in American war veterans. METHODS: We evaluated 9,623 patients submitted to an exercise test (ET) in treadmill between 1987 and 2007. The outcomes were compared between those with normal TE, the ones with EI-LBBB and the ones with down-sloping ST-segment. Mortality and causes of death were identified while blinded to the ET results. RESULTS: In this prospective cohort, 6,922 individuals had normal ET results (57.2 ± 11.4 years), 1,739 had abnormal ST-segment depression (62.7 ± 9.8 years), and 38 had EI-LBBB (65.2 ± 11.9 years). The prevalence of EI-LBBB was 0.38 percent. After 8.8 years, there were 1,699 deaths due to all-cause mortality and 610 cardiovascular (CV) deaths; coronary artery disease and heart failure were more prevalent in patients with EI-LBBB. Patients with EI-BCRE had a hazard ratio of 2.37 (p = 0.002) for all-cause mortality, but it was not significant when adjusted for age or when the CV death was the assessed outcome. CONCLUSION: EI-LBBB is a rare clinical finding. Individuals with BCRE-EI have higher all-cause mortality when compared to those with normal ET results. However, this fact is explained by the fact that these patients are significantly older and have more associated cardiovascular diseases.

FUNDAMENTO: El bloqueo completo de rama izquierda esfuerzo-inducido (BCRI E-I) es un hallazgo infrecuente en el test de ejercicio y su prevalencia y significado pronóstico no son claros. OBJETIVO: Evaluar de forma longitudinal la prevalencia y el significado pronóstico del BCRI E-I en los hombres norteamericanos veteranos de guerra. MÉTODOS: Evaluamos 9.623 pacientes que realizaron ergometría en cinta (TE) entre 1987 y 2007. Los resultados fueron comparados entre aquellos con TE normal (TE NL), los con BCRI E-I y los que presentaron infradesnivel del segmento ST (Dep ST) anormal. La mortalidad y la causa de las muertes fueron identificadas de forma ciega para los resultados del TE. RESULTADOS: En esta cohorte prospectiva y después de las exclusiones, 6.922 individuos presentaron EC NL (57,2 ± 11,4 años), 1739 tuvieron Dep ST anormal (62,7 ± 9,8 años), y 32 casos de BCRI E-I fueron identificados (65,2 ± 11,9 años). La prevalencia del BCRI E-I fue del 0,38 por ciento. Después de 8,8 años, ocurrieron 1699 muertes por todas las causas y 610 muertes cardiovasculares (CV). La enfermedad arterial coronaria y la insuficiencia cardíaca fueron las más prevalentes en los pacientes con BCRI E-I. Los pacientes con BCRI E-I presentaron azar de 2,37 (p = 0,002) para la mortalidad por todas las causas, pero ella no fue significativa cuando se ajustó para la edad o cuando la mortalidad cardiovascular fue el desenlace evaluado. CONCLUSIÓN: BCRI E-I es un hallazgo raro. Los individuos con BCRI E-I presentan una mayor mortalidad por todas las causas cuando se les compara con los de EC NL. Sin embargo, ese hecho se explica porque esos pacientes son significativamente más viejos y por presentar más enfermedades cardiovasculares asociadas.

Adaptação cultural de instrumento para avaliação da capacidade física em cardiopatas / Adaptación cultural de instrumento para evaluación de la capacidad física en cardiópatas / Cultural adaptation of an instrument to assess physical fitness in cardiac patients

OBJETIVO: Validar o conteúdo e avaliar a confiabilidade do instrumento Veterans Specific Activity Questionnaire, adaptado culturalmente para uso na população brasileira de cardiopatas. MÉTODOS: O instrumento foi traduzido, retrotraduzido e analisado por comitê de juízes para avaliação das equivalências semântico-idiomática e cultural. As atividades físicas indicadas no instrumento incomuns ao cotidiano da população-alvo foram substituídas. Outro comitê de especialistas analisou a equivalência metabólica das atividades substituídas. A proporção de concordância de avaliação dos juízes foi quantificada pelo Índice de Validade de Conteúdo. O pré-teste foi realizado em duas etapas (n1 e n2 = 15). A confiabilidade foi avaliada por meio do teste re-teste (intervalo de 7-15 dias, n = 50). RESULTADOS: Na avaliação das equivalências semântico-idiomática e cultural, os itens com Índice de Validade de Conteúdo < 1 foram revisados até obtenção de consenso entre os juízes. Constatou-se 100 por cento de concordância do segundo comitê na análise da equivalência metabólica entre as atividades originais e as substituídas. Análise do teste re-teste apontou coeficiente de concordância kappa (k = 0,86; p < 0,001), sugerindo estabilidade temporal do instrumento. CONCLUSÕES: A versão validada do Veterans Specific Activity Questionnaire apresentou evidências de confiabilidade segundo critério de estabilidade temporal e conteúdo cultural adequado.

OBJETIVO: Validar el contenido y la confiabilidad del instrumento Veterans Specific Activity Questionnaire, adaptado culturalmente para uso en la población brasileña de cardiópatas.MÉTODOS: El instrumento fue traducido y retro traducido y analizado por comité de árbitros para evaluación de las equivalencias semántico-idiomática y cultural. Las actividades físicas indicadas en el instrumento, no comunes a lo cotidiano de la población de interés fueron sustituidas. Otro comité de especialistas analizó la equivalencia metabólica de las actividades sustituidas. La proporción de concordancia de evaluación de los árbitros fue cuantificada por el Índice de Validez de Contenido. La pre-test fue realizada en dos etapas (n1 y n2=15). La confiabilidad fue evaluada por medio de la prueba re-test (intervalo de 7-15 días, n=50). RESULTADOS: En la evaluación de las equivalencias semántico-idiomática y cultural, los itens con Índice de Validez de Contenido < 1 fueron revisados hasta la obtención de consenso entre los árbitros. Se constató 100% de concordancia del segundo comité en el análisis de la equivalencia metabólica entre las actividades originales y las sustituidas. Análisis de la prueba re-test señaló coeficiente de concordancia Kappa (k=0,86; p<0,001), sugiriendo estabilidad temporal del instrumento.CONCLUSIONES: La versión validada del Veterans Specific Activity Questionnaire presentó evidencias de confiabilidad según criterio de estabilidad temporal y contenido cultural adecuado.

Noninvasive measurement of cardiac performance in recovery from exercise in heart failure patients

OBJECTIVE: To examine the association between cardiac performance during recovery and the severity of heart failure, as determined by clinical and cardiopulmonary exercise test responses. METHODS: As part of a retrospective cohort study, 46 heart failure patients and 13 normal subjects underwent cardiopulmonary exercise testing while cardiac output was measured using a noninvasive device. Cardiac output in recovery was expressed as the slope of a single exponential relationship between cardiac output and time; the recovery-time constant was assessed in relation to indices of cardiac function, along with clinical, functional, and cardiopulmonary exercise responses. RESULTS: The recovery time constant was delayed in patients with heart failure compared with normal subjects (296.7 + 238 vs. 110.1 +27 seconds, p <0.01), and the slope of the decline of cardiac output in recovery was steeper in normal subjects compared with heart failure patients (p,0.001). The slope of the decline in cardiac output recovery was inversely related to peak VO2 (r = -0.72, p<0.001) and directly related to the VE/VCO2 slope (r = 0.57, p,0.001). Heart failure patients with abnormal recovery time constants had lower peak VO2, lower VO2 at the ventilatory threshold, lower peak cardiac output, and a heightened VE/VCO2 slope during exercise. CONCLUSIONS: Impaired cardiac output recovery kinetics can identify heart failure patients with more severe disease, lower exercise capacity, and inefficient ventilation. Estimating cardiac output in recovery from exercise may provide added insight into the cardiovascular status of patients with heart failure.

Long-term stability of the oxygen pulse curve during maximal exercise

INTRODUCTION: Exercise oxygen pulse (O2 pulse), a surrogate for stroke volume and arteriovenous oxygen difference, has emerged as an important variable obtained during cardiopulmonary exercise testing. OBJECTIVES: We hypothesized that the O2 pulse curve pattern response to a maximal cycling ramp protocol exhibits a stable linear pattern in subjects reevaluated under the same clinical conditions. METHODS: We retrospectively studied 100 adults (80 males), mean age at baseline of 59 + 12 years, who performed two cardiopulmonary exercise testings (median interval was 15 months), for clinical and/or exercise prescription reasons. The relative O2 pulse was calculated by dividing its absolute value by body weight. Subjects were classified into quintiles of relative O2 pulse. Cardiopulmonary exercise testing results and the O2 pulse curve pattern, expressed by its slope and intercept, were compared among quintiles of relative O2 pulse at both cardiopulmonary exercise testings. RESULTS: After excluding the first minute of CPX (rest-exercise transition), the relative O2 pulse curve exhibited a linear increase, as demonstrated by high coefficients of determination (R² from 0.75 to 0.90; p<0.05 for all quintiles). Even though maximum oxygen uptake and relative O2 pulse were significantly higher in the second cardiopulmonary exercise testing for each quintile of relative O2 pulse (p<0.05 for all comparisons), no differences were found when slopes and intercepts were compared between the first and second cardiopulmonary exercise testings (p>0.05 for all comparisons; except for intercept in the 5th quintile). CONCLUSION: Excluding the rest-exercise transition, the relative O2 pulse exhibited a stable linear increase throughout maximal exercise in adults that were retested under same clinical conditions.

The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players

INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight) curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45). Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10 percent of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20 percent of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40 percent complete (p<.01). Although the slopes of the lines were similar (p = .25), the regression intercepts differed (p<.01) between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20 percent of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.