Article Impact Level: HIGH Data Quality: STRONG Summary of Clinical Cardiology, 46(4), 386–389. https://doi.org/10.1002/clc.23977 Dr. Patricia Palau et al.
Points
- Left bundle branch block (LBBB) is associated with adverse cardiovascular events, and this pilot study aimed to evaluate its impact on maximal functional capacity.
- Adults with isolated LBBB demonstrated reduced maximal functional capacity, despite not having cardiac disease and maintaining a moderate to highly active lifestyle.
- The study included 27 participants, with a median age of 62 years and a median time to a screening of 3.4 years from the initial LBBB diagnosis.
- Cardiopulmonary exercise testing (CPET) and the Global Physical Activity Questionnaire (GPAQ) assessed maximal functional capacity and physical activity levels.
- No adverse cardiovascular events occurred during the median 3.1-year follow-up period after CPET, suggesting the need for further research to understand the implications of isolated LBBB on functional capacity.
Summary
Left bundle branch block (LBBB) is commonly associated with adverse cardiovascular (CV) events, but its impact on maximal functional capacity remains poorly understood. This descriptive pilot study aimed to assess the maximal functional capacity of adults with isolated LBBB and compare it to predicted values derived from a healthy population.
A total of 27 participants, comprising 18 women and nine men, were included in the study. Cardiopulmonary exercise testing (CPET) and the Global Physical Activity Questionnaire (GPAQ) were conducted to evaluate maximal functional capacity and physical activity levels. The primary outcome measured was peak oxygen consumption (peakVO2), assessed in relation to population-derived predicted values (pp-peakVO2). The secondary outcome focused on reporting adverse CV events during a median follow-up period of 3.1 years after CPET.
Participants with isolated LBBB were recruited from outpatient clinics at two academic hospitals. The median age of the sample was 62 years, with a median time to a screening of 3.4 years from the initial LBBB diagnosis. The GPAQ scores indicated that 19 patients were highly active, while eight were moderately active. The median peak VO2 was 19.3 ml/kg/min, and the pp-peak VO2 value was 88% of the predicted values (79.3%−104.4%). No adverse CV events, such as CV deaths or hospitalizations, occurred during the follow-up period. These findings highlight the potential impact of isolated LBBB on maximal functional capacity.
In conclusion, adults with isolated LBBB demonstrated reduced maximal functional capacity, despite the absence of cardiac disease and a baseline moderate to highly active lifestyle. The median peak VO2 of 19.3 ml/kg/min indicated a lower maximal oxygen consumption than predicted values. This suggests that isolated LBBB alone may have a detrimental effect on exercise capacity. The absence of adverse CV events during the 3.1-year follow-up after CPET further emphasizes the importance of exploring the functional implications of isolated LBBB. Further research is warranted to understand better the underlying mechanisms contributing to reduced maximal functional capacity and to identify potential interventions for improving exercise performance in individuals with isolated LBBB.
Link to the article: https://onlinelibrary.wiley.com/doi/10.1002/clc.23977
References Palau, P., Mendez, J., Santas, E., Núñez, J., López, L., Briatore, A., & Domínguez, E. (2023). Maximal functional capacity in subjects with isolated left bundle branch block: A pilot study. Clinical Cardiology, 46(4), 386–389. https://doi.org/10.1002/clc.23977
