Extreme physiology
The Ashley lab maintains an interest in the study of extreme cardiovascular physiology, not only in the most diseased but also in the healthiest hearts. We believe that the study of healthy hearts pushed to the limit is not only interesting in its own right but can shed light on what goes wrong, and what can be made right, when diseased hearts are asked to do the same. Together with collaborators from the Universities of Oxford, Glasgow, and Toronto, Duke University, the Veterans Affairs Palo Alto Health Care System, and the English Institute of Sport, our team studied the relationship between ACE genotype and cardiovascular responses to 300 miles (approximately 90 hours of continuous exercise) of multi-disciplinary adventure racing through the Scottish highlands in 86 athletes. Athletes homozygous for the intron-16 insertion polymorphism in ACE had significantly a greater extent of reversible sub-clinical LV dysfunction and less enhanced sympathovagal balance than individuals homozygous for the deletion; heterozygous individuals demonstrated an intermediate phenotype. This study, featured in the BBC science documentary “Tomorrow’s World”, and future work in extreme athletics may help shed light on the interplay between genetic polymorphisms and cardiac physiology, cardiomyopathy, and athletic performance.
We are also interested in the cardiovascaular response to de-conditioning in elite athletes, who may have cardiac morphology that is difficult to distinguish from that of hypertrophic cardiomyopathy. We hope that this work will clarify clinical expectations for the cardiovascular response to a period of de-conditioning, which is a recommendation for distinguishing physiological from pathological hypertrophy that currently yields often confusing results. This study is a natural extension of the work on cardiovascular screening that we perform in the Stanford student athlete population, as well as a recently formed collaboration with Dr. Antonio Pellicia, medical director of the Institute of Sports Medicine of the Italian National Olympic Committee.