Heart & Stroke funded researcher discovers interesting findings on resuscitation

A new study has found novel ways to get stopped hearts racing, which could potentially save people not responding to traditional defibrillation.

Heart & Stroke funded researcher Dr. Sheldon Cheskes presented a first-ofits-kind scientific study at the American Heart Association Resuscitation Science Symposium on the use of two defibrillators to restart a heart on someone experiencing cardiac arrest.

Dr. Cheskes is a scientist at St. Michael’s Hospital in Toronto and his research was conducted through Sunnybrook’s Institute of Research.

“Most people who survive cardiac arrest survive when their heart goes into a rhythm known as ventricular fibrillation. So when you go to the airports or their gym, and you see those defibrillators on the wall, and you apply them to patients, and shock them with the defibrillator, the vast majority of patients who survived cardiac arrest survive it when they get shocked by a defibrillator,” said Cheskes.

While many patients require one to three shocks, if they remain unresponsive, survival rates drop off sharply for each additional shock, said Cheskes.

“So what we did in this particular research studies, we wanted to look at: could you do to fibrillation, the the application of a shock differently in those patients, and improve their survival, as opposed to just continuing to shock people with the sort of the shock or the pads on the chest in the same position,” explained Cheskes.

The techniques studied were changing the position of the pads for further shocks, as well as a method of administering two shocks in quick succession using a second defibrillator.

“We found that the survival in the group that got the dual shock was 30.4%, whereas the survival in the group that got the standard shock was 13% or so,” said Cheskes. “So there was this huge improvement in survival by using this new innovative technique. So that was sort of what we looked at in that... the technique of just switching the pads, also improves survival to just over 21%. So essentially, we looked at two normal techniques to apply the fibrillation or shocks in patients who had already failed three shocks prior to this.”

The study was conducted over the course of four years and included over 4000 paramedics and first responders across six cities in Ontario, who Cheskes credits as making this discovery possible.

“I’ve never run a trial, where the paramedics embrace the study more than they did. And the reason for that, I think, is three things. One is, for them, it was cool, right? This is something novel to defibrillators attached to patients like it’s not, I’m gonna give a little bit more drug or a little less drug. This was something completely novel,” said Cheskes. “The paramedics saw the outcome of their intervention, meaning when they shocked the patient, they saw the patient regains circulation, and go into a normal rhythm, where in their previous history doing the standard, that patient wouldn’t have done that.”

The final piece is that the study was showing immediate benefit, which Cheskes believes was heartening to the paramedics and helped with buy-in for attempting the novel method. Part of what made this easy is that these new techniques were to be used after the patient proved not to respond to traditional defibrillation, so there was little risk of there being no benefit or a negative effect by deviating from the current standard.

Cheskes will be moving on to present his findings to various guidelines setting boards, in hopes of incorporating this novel method into practice. He is hopeful that this will be put into place, and hopefully result in better outcomes for cardiac arrest patients.

“People have to understand that, right, you’re saving lives,” said Cheskes. “And to me, I’m now looking at it. Like, if I was a patient, and I knew these results, why would I want to get continued standard to fibrillation knowing that in highly done trial results, results were much better at this with these two alternative strategies, that would be the question.”