Sudden Cardiac Arrest: Timing is everything

Sudden cardiac arrest, SCA, occurs when the heart stops beating, abruptly and without warning. If this happens, blood stops flowing to the brain and other vital organs. As a result more than 350,000 deaths occur each year, according to John N. Catanzaro, MD, a cardiac electrophysiologist at the UF Health Cardiovascular Center.

SCA claims one life every two minutes, taking more lives each year than breast cancer, lung cancer or AIDS. Catanzaro shared the warning signs related to SCA as well as how to respond and prevent the condition from occurring.

“Timing is critical when considering the chance of survival for an SCA victim,” Catanzaro said. “Ninety-five percent of those who experience SCA die because they do not receive life-saving defibrillation within four-to-six minutes.”  If sudden cardiac arrest occurs, the heartbeat must be restored with an electrical shock immediately.

It may be difficult to distinguish between sudden cardiac arrest and a heart attack, but each condition has separate signs and symptoms.

“A heart attack affects the ‘plumbing’ of the heart,” Catanzaro said. “It is caused by a blockage in a blood vessel that interrupts the flow of blood causing an area of the heart muscle to die.” Typical signs often include chest pain, discomfort in other areas of the upper body such as one or both arms, the neck, back, jaw or stomach, and shortness of breath.

However, the heart’s electrical system is what is affected when SCA occurs. During SCA, the heart stops beating and no blood is pumped to the rest of the body. There are no symptoms prior to sudden cardiac arrest. Someone affected with this condition will collapse suddenly, have no pulse, they won’t be breathing and they will lose consciousness.

“While both cause serious problems and possible death, SCA often occurs abruptly and without warning,” Catanzaro said.  “In fact, two-thirds of SCA deaths occur without any prior indications of heart disease, while heart attacks often have previous signs and symptoms.”

UF Health Jacksonville offers comprehensive treatment and prevention of sudden cardiac arrest.  Different types of implantable cardiac defibrillators are available depending upon the indication for a variety of patients. For more information, please visit

Featured Faculty

John N. Catanzaro, MD, FACC, FESC, FHRS

John N. Catanzaro, MD, FACC, FESC, FHRS

Assistant Professor
Associate Medical Director, Electrophysiology Program; Interim Program Director, Clinical Cardiac Electrophysiology Fellowship; Associate Program Director, Clinical Cardiac Electrophysiology Fellowship