Left ventricular mechanics in humans with high aerobic fitness: adaptation independent of structural remodelling, arterial haemodynamics and heart rate.

Individuals with high aerobic fitness have lower systolic left ventricular strain, rotation and twist ('left ventricular (LV) mechanics') at rest, suggesting a beneficial reduction in LV myofibre stress and more efficient systolic function. However, the mechanisms responsible for this functional adaptation are not known and the influence of aerobic fitness on LV mechanics during dynamic exercise has never been studied. We assessed LV mechanics, LV wall thickness and dimensions, central augmentation index (AIx), aortic pulse wave velocity (aPWV), blood pressure and heart rate in 28 males (age: 21±2 years SD) with a consistent physical activity level (no change>6 months). Individuals were examined at rest and during exercise (40% peak exercise capacity) and separated post hoc into a moderate and high aerobic fitness group (˙V(O2peak): 49 ± 5 and 63 ± 7ml kg−1 min−1, respectively, P <0.0001). At rest and during exercise, there were no significant differences in gross LVstructure, AIx, blood pressure or heart rate (P >0.05).However, for the same AIx, the high ˙V(O2peak) group had significantly lower LV apical rotation (P =0.002) and LV twist (P =0.003) while basal rotation and strain indices did not differ between groups (P >0.05).We conclude that young males with high aerobic fitness have lower LVapical rotation at rest and during submaximal exercise that can occur without changes in gross LV structure, arterial haemodynamics or heart rate. The findings suggest a previously unknown type of physiological adaptation of the left ventricle that may have important implications for exercise training in older individuals and patient populations in which exercise training has previously failed to show clear benefits for LV function.

Clinical guideline for retained button batteries.

OBJECTIVE: To design a clinical guideline for the emergency management of retained button batteries (RBBs) through analysis of UK National Health Service hospital guidelines and published literature. METHOD: 49 acute hospitals were contacted, and their guidelines were analysed. A consensus guideline was then created with multidisciplinary input. The final guideline was independently peer reviewed by the British Association of Otorhinolaryngology and Head and Neck Surgery (ENT UK) clinical guidelines committee. RESULTS: 40 (82%) trusts responded. 28 had a guideline for the management of a RBB in the aerodigestive tract. Significant variation between guidelines assessment, investigation and management of a RBB was identified. CONCLUSION: A single-page guideline was designed to improve frontline healthcare professional's immediate investigation and management of a RBB on presentation to emergency care. This has been published by ENT UK as a clinical guideline.

Progression of hearing loss in neurofibromatosis type 2 according to genetic severity.

OBJECTIVES/HYPOTHESIS: This study set out to describe the progression of hearing loss in patients with neurofibromatosis type 2 (NF2), treated in a quaternary multidisciplinary clinic. It also aimed to compare hearing loss across patients grouped according to a known genetic severity score to explore its utility for prognostication. STUDY DESIGN: Retrospective cohort study. METHODS: We conducted a study of 147 patients with confirmed NF2 diagnosis for a mean observational period of 10 years. Pure-tone average (PTA), optimum discriminations scores (ODS), and genotype data were collected. Patients were classified according to hearing class (American Academy of Otolaryngology), their candidacy for auditory implantation (UK National NF2 consensus) and grouped by genetic severity as: 1 = tissue mosaic, 2A = mild classic, 2B = moderate classic, and 3 = severe. Survival analysis investigated the effect of genetic severity on the age of loss of serviceable hearing. RESULTS: Genetic severity was a significant predictor of hearing outcomes such as ODS, hearing classification, and maximum annual PTA deterioration. Although the overall median age of loss of serviceable hearing was 78 years, there was significant variation according to the genetic severity; the median for severe patients was 32 years compared to a median of 80 for tissue mosaic patients. CONCLUSIONS: This is the first description of long-term hearing outcomes in a clinical setting across a large heterogeneous cohort of patients with NF2. The results highlight the potential importance and benefit of considering the genetic severity score of patients when undertaking treatment decisions, as well as planning future natural history studies. LEVEL OF EVIDENCE: 2c Laryngoscope, 129:974-980, 2019.