Impaired capacity to increase heart rate (HR) during exercise (ΔHR^ex), and a reduced rate of recovery post-exercise (ΔHR^rec) are associated with higher cardiovascular mortality rates.  A new study has discovered 30 new gene locations that determine how the heart responds to and recovers from exercise.

The study, published in the journal Nature Communications, was conducted using genome-wide association studies (GWASs) for ΔHR^ex and ΔHR^rec in ~40,000 individuals, followed by replication in ~27,000 independent samples, all from UK Biobank. The findings could be used to improve the identification of people with impaired heart rate during recovery and those at higher risk of heart disease mortality.

Six and seven single-nucleotide polymorphisms for ΔHR^ex and ΔHR^rec, respectively, formally replicate. In a full data set GWAS, eight further loci for ΔHR^ex and nine for ΔHR^rec are genome-wide significant (P ≤ 5 × 10⁻⁸). In total, 30 loci are discovered, 8 being common across traits.

The difference in heart rate response to exercise was as much as 3.15 beats per minute, depending on the genetic risk score of an individual, while the difference in heart rate response to recovery differed by as much as 10.4 beats per minute.

Processes of neural development and modulation of adrenergic activity by the autonomic nervous system are enriched in these results. 

Lead researcher said: "Our findings advance our knowledge on key pathways controlling heart rate response to exercise and recovery, information which may be valuable in the future for cardiovascular risk prediction."

The results have implications to target new therapies to treat abnormal heart rhythms and potentially increase heart health.

https://www.nature.com/articles/s41467-018-04148-1