Baltimore cardiologist explains what's behind cardiac arrest

People from around the country continue to show support for Buffalo Bills safety Damar Hamlin, who suffered cardiac arrest moments after tackling a Cincinnati Bengals player Monday night. It appeared to be the kind of hit that happens regularly in football. So, what happened to make Hamlin collapse? Dr. Kate Elfrey, a cardiologist at Mercy Medical Center, who is not involved in treating Hamlin, shares her impression of what happened and explains what happens next. Subscribe to WBAL on YouTube now for more: http://bit.ly/1oJSRCN Get more Baltimore news: http://www.wbaltv.com Like us:   / wbaltv11   Follow us:   / wbaltv11   Instagram:   / wbaltv11