A Gentler Jolt to the Heart

(Inside Science TV) -- Each year, more than 200,000 cardiac defibrillators are implanted in patients to prevent death from an arrhythmia.  The devices deliver a high voltage shock that saves lives but can also be very painful.  Now, scientists have developed a nicer, less painful way to reset the heart.

Each year, more than 850,000 people are hospitalized for an irregular heartbeat, called an arrhythmia.  In order to correct this condition, a defibrillator sends a high voltage shock to the heart to restart its rhythm. The shock is lifesaving, but uncomfortable for the patient.  “The shocks themselves are number one painful, and number two, recent evidence has shown that these shocks can actually have a damaging effect on the ventricular muscle,” said Ronald Berger, a cardiac electrophysiologist at Johns Hopkins University. 

Now Berger and his team say there is a gentler way to shock the heart with is good news for patients like Andy Golden who need a shock about once a year.  "The doctors tell you when you first get your defibrillator that it’s like getting kicked in the chest by a horse," said Golden.

The researchers demonstrated their new technique in lab experiments using heart tissue.  During an arrhythmia, a high frequency alternating current was applied which put the beating cells in a suspended state. When the current was turned off, the cells immediately returned to an organized heartbeat rhythm.

“If we can make the device terminate these arrhythmias with a form of electrical current that’s not only less painful but less damaging to the heart muscle that would be a benefit as well," said Berger.   

A smaller shock will also be less damaging to the heart muscle and less worry for patients like Andy.  “I think probably worse than the shock itself is the anxiety of knowing it’s coming.” 

​Science helps save lives one heartbeat at a time.  More testing is needed before a new defibrillator device is developed.