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Entries in Cardiac Arrhythmia (2)

Tuesday
Jan042011

Twenty Percent of ICD Patients Do Not Meet Criteria for Use

Photo Courtesy - Getty Images(CHICAGO) – A new study suggests that around 20 percent of patients with an implantable cardioverter-defibrillator do not meet certain guidelines for use of the device.

The ICD, a small electrical impulse generator, is most effective when implanted in patients with advanced systolic heart failure and are therefore at a high risk of cardiac death. The device is not recommended for use in primary prevention or in patients with severe heart failure symptoms and those who have had a recent diagnosis of heart failure.

The study, however, concluded that about 20 percent of more than 100,000 patients who were studied did not meet criteria for its use, and therefore had a significantly greater risk of in-hospital death.

The research, conducted by a group at the Duke Clinical Research Institute, examined cases from January 2006 to June 2009. Results showed that the 22.5 percent of patients who did not meet guidelines for the device had a .57 percent risk of in-hospital death compared to .18 percent in those who did meet criteria for use. The risk of post-procedure complications in those who did not meet criteria was also higher.

“Although the absolute difference in complications between the two groups is modest, these complications could have significant effects on patients’ quality of life and health care use, including length of hospital stay and costs,” wrote the authors.  “While a small risk of complications is acceptable when a procedure has been shown to improve outcomes, no risk is acceptable if a procedure has no demonstrated benefit.”

Copyright 2011 ABC News Radio

Tuesday
Oct262010

Fran Crippen Death: Likely Heat Stroke or Heart

Photo Courtesy - Getty Images(NEW YORK) -- Doctors may never know precisely what killed open water swimmer Fran Crippen, the 26-year-old who died during a race in Abu Dhabi over the weekend, but they agree that strenuous exercise in hot water could result in fatal heat stroke.

Had a safety boat been near the elite swimmer when he lost consciousness, he might have been cooled down and been saved, they say.

"It's pretty straightforward -- he died of one of two things," said Dr. Mark Morocco, associate professor of emergency medicine at the UCLA School of Medicine.

"He drowned of a cardiac arrhythmia or he died of drowning because he passed out," said Morocco, who has never treated Crippen. "Both were directly related to over-exertion, which is a terrible garbage-can diagnosis and does not speak to what happened."

"In the age of kayaks, jet skis and outboard motors, this sort of thing should never happen to an elite swimmer," he said. "No one was there to help him up out of the water."

USA Swimming said Monday it would commission a full, independent investigation into Crippen's death.

Some earlier reports indicated that the Olympic-bound athlete died of a heart attack. The findings of an autopsy by local authorities have not been released, and even that may not give definitive answers.

Heat stroke, for example, could only be determined if doctors got an internal body temperature right after Crippen died. His body wasn't found until two hours after the race ended -- about 400 meters from the finish line.

The International Swimming Federation (FINA) said doctors ruled the cause of death as severe fatigue.

Crippen's sister Maddy, herself an Olympic swimmer, told ABC News that her brother had been voicing concerns for months about inadequate safety.

Crippen had told Shoulberg just 12 hours before the race that the outside temperature was 100 degrees and that the water was 87 degrees. Several swimmers complained of dehydration and disorientation and three were taken to the hospital.

"l have heard lot people complaining about the water being too warm," said Bill Volckening, a former editor of Swimmer magazine for U.S. Masters swimming. "There are some dangers of hyperthermia that have not really come to light yet and I hope there is some major reform in the sport of open water swimming with regard to safety."

Those who trained with Crippen said he also used GU energy gel, a replenishing liquid that contains high amounts of caffeine. The swimmer reportedly consumed 10 to 15 packs during a typical two-hour swim.

Doctors say, however, that caffeine is generally "pretty safe."

"It's probably not that likely, but certainly a possible factor in the picture," said Morocco. "Caffeine can cause arrhythmias in sensitive individuals."

The more likely cause of death was hyperthermia, which led to heat stroke.

"During physical exertion as the muscles are working, part of the byproducts is heat, like a power plant," said Dr. Ted Benzer, chief of clinical operations in the emergency department and attending physician at Massachusetts General Hospital.

"The challenge is to get rid of the heat and the body doesn't have that many ways to do that," he said. "The human body underwater is not like a fish or a whale. The primary way it releases heat is through evaporative losses like sweating."

Sweat on the surface of the body creates a cooling effect on blood just under the skin. Unlike a dog, humans can't pant to get rid of the heat.

"It is an intriguing concern that [Crippen] had major exertion submersed under very hot water," said Benzer. "But this is very unusual -- I have never seen this in all the years I have worked in emergency medicine."

When the body's temperature reaches 106 to 107 degrees, it starts to cause death of tissue and organ failure.

One of the first warning signs is confusion and delirium as the brain begins to dysfunction. If not treated by cooling the body down, it can cause death.

"It's hard to say what happened," said Benzer. "Who knows who was watching and how closely. Basically, he may have become confused and his actions might have been unpredictable. Maybe he started getting heat stroke, was delirious and then drowned."

However, doctors say there are other conditions that can cause sudden death in a young athlete -- heart valve problems, an electrolyte imbalance, congenital thickening of the heart muscle, cerebral aneurysms and even undetected arrhythmias like long QT syndrome.

UCLA's Morocco agrees that many of those medical events could have been treated had there been more attention paid to safety.

"A lot of the responsibility is on the folks who put the race together," he said. "When you are 500 feet in the water, you are as far away as being in wilderness 20 miles in Yosemite. If you don't have someone in a rescue boat, you are in trouble. Anything can happen."

"The other problem is elite athletes are not very good patients," said Morocco. "They don't want to get out of the race, even if they feel poorly. They are well-trained, but are also pressured to perform. Oftentimes a great athlete cannot advocate for himself. But those running the race should advocate for him."

Copyright 2010 ABC News Radio







ABC News Radio