Can a heartbeat predict performance?

Few topics in racing concentrate stakeholder attention as sharply as the cardiac health of the Thoroughbred athlete. Sudden death on the racecourse is rare, but its impact — on owners, trainers, regulators, and on the public's perception of the sport — is disproportionately large. Behind those visible events lies a much wider population of horses whose cardiac function during work may be signalling something, well before any catastrophic outcome.

This issue brings together two articles that look at this terrain from opposite ends.

Dr Emmanuelle van Erck-Westergren addresses the prospective end of the same problem. Her recently published research uses wearable ECG technology to record cardiac rhythm during routine training in more than 70 Thoroughbreds at the Hong Kong Jockey Club. The findings show that exercise-associated arrhythmias are common, that their burden is meaningfully linked to subsequent race performance, and — crucially — that the most clinically informative window is the brief period of peak effort during a training gallop. The implication is direct: a tool now exists to identify horses whose hearts are signalling something during work, before they reach the start gate.

Dr Celia Marr reports on the work of the International Federation of Horseracing Authorities' Fatality Taskforce and its dedicated group on exercise-associated sudden death. Her article sets out what is now understood about the pathology of EASD — the role of fatal pulmonary haemorrhage, the difficulty of attributing causes even with detailed post-mortem data, and the urgent need for higher and more consistent necropsy standards across jurisdictions. It is a forensic argument: better data after the fact, leading to better understanding and, in time, better prevention.

Read together, the two articles describe the same problem at different points in time: one looking back from the necropsy table, the other looking forward from the morning gallop. Both make the case that cardiac welfare in the racing Thoroughbred is now a domain in which active, evidence-based intervention is increasingly possible — and increasingly expected.