Commotio Cordis: Evaluation of Chest Wall Protectors and Wayne State Mechanical Surrogate

Principal Investigator: Mark S. Link, MD, Professor of Medicine

Institution: Tufts University School of Medicine

Title: Commotio Cordis: Evaluation of Chest Wall Protectors and Wayne State Mechanical Surrogate

Abstract: Sudden cardiac death resulting from chest wall blows (commotio cordis) is an increasingly recognized risk of sports participation. Most events are due to blows from projectiles such as baseballs or lacrosse balls, with a substantial proportion occurring despite a chest protector. In our experimental model of commotio cordis, commercially available baseball and lacrosse chest protectors dating from 2002 were ineffective in preventing sudden cardiac death. More recently, manufacturers are claiming to have improved their chest protectors, and some are purporting that they will now protect against commotio cordis. Over the last several years, using data from our experimental laboratory, a mechanical surrogate has been developed at Wayne State. In this surrogate several newer chest protectors appear to provide increased protection. This surrogate was funded by and licensed to NOCSAE and it is hoped that this surrogate will be utilized to develop a standard for chest protectors. This standard will be controlled by NOCSAE.

Aims: The aim of the current proposal is to evaluate current chest wall protectors to assess whether they are more capable of preventing sudden cardiac death. In addition, this protocol will also seek to validate the Wayne State surrogate, and also help define the acceptable threshold for safety in the Wayne State model.

Study Design: Fifteen to 20 kg male swine will have pressure monitoring of the left ventricle. These animals will be placed in a sling and monitored with a 6 lead surface electrocardiograms. Impact occurs with a lacrosse ball thrown at 40 mph during the vulnerable time period for sudden cardiac death.

Materials and Methods: Four commercially available chest protectors (2 of which tested superior in the Wayne State Model, one of which moderate, and one poorly), along with a control of no chest protector will be randomized to be sequentially placed on the swine chest.

Main Outcome Measures: The primary endpoint of the study will be the induction of ventricular fibrillation. Secondary endpoints will be the induction of non-sustained ventricular fibrillation and peak left ventricular pressure caused by the blow.

Significance: Data from this experiment will address the claim that current chest wall protectors are more protective against commotio cordis and help refine the current Wayne State/NOCSAE surrogate. The results can be utilized to validate the mechanical surrogate and help define at what level of impact attenuation the NOCSAE standard for safety should be set.