Medical first: Discovery of warning symptoms for usually fatal heart rhythm malfunction

Human heart. Credit: copyright American Heart Association

More than half of patients who have a sudden cardiac arrest ignore symptoms occurring up to a month prior to the usually fatal heart rhythm malfunction even though medical intervention potentially could save their lives, according to new research published by the Annals of Internal Medicine.

22 dec 2015--Although medical science has long regarded sudden cardiac arrest as a deadly condition that strikes without warning, a new study led by an associate director of the Cedars-Sinai Heart Institute shows for the first time that many patients experience warning symptoms up to a month before having a cardiac arrest.
"Sudden cardiac arrest in middle age hits society hard since most who are affected are their families' primary breadwinners," said Sumeet S. Chugh, MD, medical director of the Heart Rhythm Center in the Cedars-Sinai Heart Institute and the Pauline and Harold Price Chair in Cardiac Electrophysiology Research. "Fewer than 7 percent survive a sudden cardiac arrest, which has historically made it difficult to pinpoint symptoms. These research findings suggest that we could use an entirely novel approach to predict and prevent this devastating condition."
The study performed in 839 patients between the ages of 35 and 65 outlines the most common symptoms, including intermittent chest pain and pressure, shortness of breath, palpitations and ongoing influenza-like indicators such as nausea and abdominal and back pain.
"These new findings give good reason not to ignore unusual sensations, as vague as they may be," said Eduardo Marbán, MD, PhD, director of the Cedars-Sinai Heart Institute. "Better to seek medical attention early than to risk dying suddenly."
Approximately 350,000 people in the U.S. die each year from sudden cardiac arrest, accounting for 50 percent of all cardiovascular deaths nationally.
Although 'heart attack' and 'sudden cardiac arrest' are often used interchangeably, the terms are not synonymous. A heart attack—myocardial infarction—is typically caused by clogged coronary arteries that reduce blood flow to the heart muscle. Sudden cardiac arrest is the result of defective electrical activity of the heart. Patients may have little or no warning, and the disorder usually causes instantaneous death. Sudden cardiac arrest has been blamed for the deaths of journalist Tim Russert and filmmaker John Hughes.
"We already have the implantable defibrillator, a surgically implanted device that is a long-term lifesaver for many patients who suffer sudden cardiac arrest down the road," Chugh said. "Now that we realize that sudden death may not be so sudden, there is also potential for new shorter-term approaches by increasing awareness and education of patients and their healthcare providers."
Over recent years, Chugh and his team of researchers have been the first to identify several risk factors for sudden cardiac arrest, including levels of sex hormones in the blood, genetic markers and electrical and structural abnormalities of the heart.
In addition to his leadership role at the Cedars-Sinai Heart Institute, Chugh heads the Oregon Sudden Unexpected Death Study, a comprehensive, 16-hospital, multiyear assessment of cardiac deaths in the Portland metropolitan area, home to 1 million people. The study has been underway for more than a decade. Data collected from it provides Chugh and his team with unique, community-based information to mine for answers to what causes sudden cardiac arrest.
In the new study, Chugh and his researchers analyzed data on 839 patients included in the Oregon assessment. The researchers also interviewed first responders and patients' family members. Results include:

• 51 percent of patients experienced warning symptoms, predominately chest pain, prior to the cardiac arrest.
• In the group that experienced symptoms, 93 percent experienced them again in the 24 hours preceding the cardiac arrest.
• Only 19 percent of those who experienced symptoms called emergency medical services.
• The patients who experienced symptoms and sought medical help had a survival rate of 32 percent. Those who did not seek medical treatment for symptoms had a survival rate of 6 percent.

Provided by Cedars-Sinai Medical Center

Uninterrupted chest-compressions key to survival in cardiac arrest outside hospital setting

DALLAS 29 sept 2009– Maximizing the proportion of time spent performing chest compressions during cardiopulmonary resuscitation (CPR) substantially improves survival in patients who suffer cardiac arrest outside a hospital setting, according to a multicenter clinical study that included UT Southwestern Medical Center.

The findings, available in today's issue of Circulation, come from the largest clinical investigation to evaluate the association between chest compressions by emergency medical service (EMS) providers before the first attempted defibrillation and survival to hospital discharge. Out-of-hospital cardiac arrest is a leading cause of premature death worldwide, and survival is often less than 5 percent.

One of the most important aspects of quality CPR is the proportion of time spent performing chest compressions, but EMS providers typically perform chest compressions only 50 percent of the total time spent on resuscitative efforts.

"It's a common problem, because rescuers are involved in so many other tasks – checking for a pulse, starting intravenous therapy and giving ventilation, among other things," said Dr. Ahamed Idris, professor of emergency medicine at UT Southwestern and a pioneer in resuscitation research and CPR. Dr. Idris also is the principal investigator for the Dallas portion of the new study, conducted at seven clinical centers across North America.

"Compressions are being interrupted half of the time or more, and that has a detrimental effect on the survival of patients," Dr. Idris said. "This study reinforces that interrupting chest compressions has a bad effect on survival. It also provides a rationale for relatively simple changes to CPR training and practice, that if implemented are likely to improve survival."

Dallas-area paramedics and firefighters are being trained to begin CPR immediately and to administer uninterrupted chest compressions for two minutes before re-checking the heart rhythm or using a defibrillator to shock the heart. UT Southwestern's emergency medicine program provides medical oversight for EMS providers in more than a dozen Dallas-area cities.

In this study, researchers studied data from patients in the Resuscitation Outcomes Consortium (ROC) who had suffered from cardiac arrest with a heart rhythm indicating ventricular fibrillation or ventricular tachychardia. The researchers focused on the effect of the number of chest compressions paramedics administered per minute before they shocked the heart.

"People who received chest compressions 60 to 80 percent of the time during CPR did better than those who received fewer chest compressions," Dr. Idris said.

Previous animal studies have demonstrated that interruptions in chest compressions decrease coronary and cerebral blood flow. Based on further clinical and laboratory observations, the American Heart Association and the European Resuscitation Council Guidelines for Cardiopulmonary Resuscitation in 2005 recommended increasing the proportion of time spent delivering chest compressions.

In 2008 the American Heart Association updated its CPR guidelines and now advocates that bystanders only perform continuous chest compressions for cardiac arrest instead of combining chest compressions with mouth-to-mouth ventilation.

###

The data for this study was collected from the ROC, which is comprised of 11 regional clinical centers funded by the National Institutes of Health and several U.S. and Canadian agencies to test lifesaving interventions for critical trauma and sudden cardiac arrest.

In addition to UT Southwestern in Dallas, the other U.S. resuscitation centers are in Birmingham, Ala.; Iowa City, Iowa; Milwaukee; Portland, Ore.; Seattle and King County, Wash.; Pittsburgh; and San Diego. Toronto and Ottawa also have resuscitation centers.

Gasping After Cardiac Arrest Associated with Improved Survival

By Todd Neale
TUCSON, Ariz.,30 nov 2008- Out-of-hospital cardiac arrest patients who gasp or have labored breathing derive the most survival benefit from immediate chest compressions, a retrospective analysis showed.
Of patients who received compressions from a bystander, those who were gasping were more likely to survive to hospital discharge than those who were not breathing at all (39% versus 9.4%; OR 5.1, 95% CI 2.7 to 9.4), Gordon Ewy, M.D., of the University of Arizona, and colleagues reported online in Circulation: Journal of the American Heart Association.
"Gasping is an indication that the brain is still alive," Dr. Ewy said, "and it tells you that if you start and continue uninterrupted chest compressions, the person has a high chance of surviving."
Witnesses to cardiac arrest sometimes interpret gasping as normal breathing and don't call 911 or start chest compressions as quickly as they should, according to the researchers.
"These results suggest that the recognition and importance of gasping should be taught to bystanders and emergency medical dispatchers so as not to dissuade them from initiating prompt resuscitation efforts when appropriate," the researchers said.
This is especially important because chest compressions may cause a patient to begin gasping, Dr. Ewy said.
"This scares many people and they stop pressing on the chest," he said. "This is bad because gasping is an indication that you're doing a good job."
To determine the occurrence of gasping after out-of-hospital cardiac arrest, the researchers examined transcripts from the Phoenix Fire Department Regional Dispatch Center.
Of 113 patients who had a witnessed or non-witnessed cardiac arrest, 38.9% gasped or had labored breathing.
In a separate analysis, the researchers looked at emergency medical services' first-care reports of 1,218 patients who had a witnessed cardiac arrest.
Overall, 191 gasped and 1,027 didn't. The two groups did not differ significantly by age, arrest location, or receipt of bystander CPR.
For those who collapsed after EMS personnel arrived, 32.8% started gasping.
Rates of gasping declined as arrival time increased. There were 20.1% who had labored breathing when the arrival time was less than seven minutes, 13.9% when it was seven to nine minutes, and 7.4% when it was greater than nine minutes.
Gasping was significantly more common in the witnessed ventricular fibrillation group than in patients who had a witnessed arrest with a different rhythm (18.4% versus 13.6%; OR 1.7, 95% CI 1.2 to 2.4).
Survival to hospital discharge was significantly higher in patients who had some residual breathing than in those who did not (28.3% versus 7.8%; OR 3.4, 95% CI 2.2 to 5.2).
Of patients who were gasping when EMS personnel arrived, those who were receiving chest compressions from a bystander were more likely to survive than those who were not (39% versus 21%, P<0.01).
Patients who had gasping or labored breathing still had a survival advantage even if they weren't receiving CPR from a bystander (21.1% versus 6.7%; OR 2.4, 95% CI 1.2 to 4.3).
The researchers said that the results call into question the importance of rescue breathing for cardiac arrest patients, especially in light of previous findings of no survival benefit from rescue breathing.
"Interruptions for rescue breathing make CPR efforts more complicated and result in fewer compressions during this crucial period when perfusion is key to successful resuscitation," they said.
In addition, gasping is likely more beneficial than rescue breathing, Dr. Ewy said.
"When the patient gasps, there is a negative pressure in the chest, which not only sucks air into the lungs but also draws blood back to the heart," he explained.
"In contrast, mouth-to-mouth breathing creates overpressure in the chest and actually inhibits blood flow back to the heart," he continued. "Gasping during cardiac arrest is much better than mouth-to-mouth breathing."
The authors acknowledged that the study was limited by the possibility that the EMS reports did not accurately record the presence or absence of gasping.
In addition, they said, gasping is not diagnostic of ventricular fibrillation arrest.
Dr Bobrow has received salary support from the Arizona Department of Health Services via the Mayo Clinic Foundation for support of his position as medical director of the Bureau of Emergency Medical Services and Trauma System. Dr Ewy is a co-investigator on an unrestricted grant from the Laerdal Foundation of Stavanger, Norway, and on unrestricted grants to the University of Arizona Foundation. The other authors reported potential conflicts of interest with the Anaesthesieverein of the Department of Anesthesia and Intensive Care of University Hospital in Basel, Switzerland, the Laerdal Foundation, the National Heart, Lung, and Blood Institute, Medtronic, the AHA National Registry of CPR, Zoll, and PhysioControlInc.
Primary source: Circulation: Journal of the American Heart AssociationSource reference:Bobrow B, et al "Gasping during cardiac arrest in humans is frequent and associated with improved survival" Circulation 2008; DOI: 10.1161/CIRCULATIONAHA.108.799940. Additional Coronary Artery Disease Coverage

Hospital Cardiac Arrest Response Often Too Slow

By DENISE GRADY
When patients in the hospital suddenly go into cardiac arrest, the staff often takes too long to respond, increasing the risk of brain damage and death, a new study finds.
The research, being published on Thursday in The New England Journal of Medicine, has implications for several hundred thousand people a year in the United States
Doctors analyzed the records of 6,789 patients at 369 hospitals whose hearts stopped because of conditions that could be reversed with an electrical shock from a defibrillator — a favorite device in TV hospital dramas, when a “code blue” is called and doctors and nurses come running with a crash cart and paddles to shock the victim back to life.
In the real world, doctors and nurses do not always run fast enough. Expert guidelines say the shock should be given within two minutes after the heart stops, but the study found that it took longer in 30 percent of the cases. The consequences were striking. When the defibrillation was delayed, only 22.2 percent of the patients survived long enough to be discharged from the hospital, as opposed to 39.3 percent when the shock was given on time.
Delays were more likely in patients whose hearts stopped at night or on the weekend, who were admitted for noncardiac illnesses, in hospitals with fewer than 250 beds and in units without heart monitors.
Being black also increased the odds of a delay, but the researchers said that finding probably reflected the type of hospitals in areas where most blacks live and are treated, rather than a decision by medical staff to drag their feet because of a patient’s race.
Nationwide, the problem may be even worse, with delays more common than the 30 percent figure in the study, said Dr. Paul S. Chan, an author of the report, from Saint Luke’s Mid-America Heart Institute in Kansas City, Mo., and the University of Michigan. He said the hospitals in the study probably performed better than average, because all had joined a national registry on cardiac arrest, meaning that they were already putting special efforts into trying to meet resuscitation guidelines.
The registry, created by the American Heart Association, keeps the data anonymous, Dr. Chan said, so it not possible to name hospitals that performed especially well or poorly in the study.
In an editorial accompanying the study, Dr. Leslie A. Saxon, the chief of cardiology at the University of Southern California, said most people probably assumed that a hospital would be the safest place to have a cardiac arrest. But, she said, the assumption turns out to be incorrect.
“I think it’s something doctors have always known but not thought about,” she said, adding that Dr. Chan’s team had conducted a “great study” that would help doctors recognize the problem.
“This is the kind of data we need to say, let’s make sure these preventable things never happen on our watch,” Dr. Saxon said.
From 370,000 to 750,000 hospitalized patients have a cardiac arrest and undergo resuscitation every year in the United States. In about half, the arrest is caused by an abnormal, too-fast rhythm that can be corrected with a shock, Dr. Chan said; the rest need drugs or other treatments.
Dr. Chan said: “We know what works, what saves lives. We have the technology available, and certainly the knowledge and skilled personnel in the hospital to shock patients back to normal rhythm.”
But it will take “political will” for hospitals to put those resources to better use, he said.
Dr. Chan said researchers thought they knew some of the reasons for delays. Sometimes, he said, especially nights and weekends, not enough personnel were available. In some hospitals, nurses outside the intensive care unit are not allowed to use defibrillators, and must wait for a doctor to show up.
“In a small hospital in the middle of the night, the only doctor may be in the emergency room,” Dr. Chan said.
He said hospitals with the best track records might keep their staffs sharp by conducting resuscitation drills or “mock codes,” and might have rapid-response teams, which are specially trained groups that take care of all cardiac arrests.
Another factor is the type and amount of resuscitation equipment available, he said. Traditional defibrillators used in hospitals require that a doctor or nurse look at the patient’s electrocardiogram, verify that the problem is “shockable,” adjust the machine and deliver the shock.
By contrast, the automatic defibrillators that have come into use in public places like airports and casinos during the past decade or so are meant to be used by ordinary people — trained employees or even bystanders. Connected to the chest of someone who has collapsed, the machine senses electrical activity in the heart and delivers a shock only if it is needed. These devices are designed to be essentially foolproof and to make it impossible to harm someone by firing off an unnecessary shock.
Dr. Saxon said the technology existed to offer more people the type of heart monitoring now given mostly to cardiac patients. Not everyone needs it, she said, but it may be in order for those who are very ill with kidney problems, diabetes or pneumonia, even without a history of heart problems. Their information would be transmitted to a computer network that would send out an alert if needed. In addition, she said, automatic defibrillators could be installed in every hospital room.
“You can get them for $500 on eBay,” she said. “It wouldn’t even take a nurse. You could train the cafeteria workers if you wanted to.”

More Support for Chest-Compression-Only Resuscitation for Out-of-Hospital Cardiac Arrest

Steve Stiles
December 18, 2007 — Two observational studies published online December 10, 2007 in Circulation concluded that the conventional method of cardiopulmonary resuscitation (CPR) that calls for mouth-to-mouth assisted ventilation is no more effective than a chest-compression-only approach [1,2]. The findings support a good deal of international research supporting use of the latter method, which is less complicated and may be more appealing to potential bystander rescuers.
In their retrospective analysis of almost 10,000 cases of bystander resuscitation for cardiac arrest in which one or the other method was used [1], Katarina Bohm (Karolinska Institute, South General Hospital Stockholm, Sweden) and colleagues saw no significant difference in the odds that the victim would survive to be hospitalized or in one-month survival.
The findings support the use of the "simpler version of CPR," which can be especially useful "in dispatcher-assisted CPR and in cases involving elderly bystanders, in which the simplest algorithm is probably also the best," the group writes.
They point to "two large, independent, prospective, randomized trials" comparing the two methods that are ongoing in the US, Finland, and Sweden. "We therefore suggest waiting for the results of these randomized trials before starting any new discussion to change guidelines."
In the longer-term prospective study of about 4900 cases of witnessed out-of-hospital arrests by Dr Taku Iwami (National Cardiovascular Center, Suita, Japan) and associates [2], the chances of one-year survival with "favorable" neurologic outcomes was similarly increased with either method, compared with no bystander resuscitation — by 72% using the compression-only or "cardiac-only" technique, and by 57% with standard CPR.
"If cardiac-only resuscitation is simply as effective as conventional CPR, is there any reason to change lay CPR programs to focus on cardiac-only resuscitation? Perhaps," the group writes.
"Conventional CPR is a complex psychomotor task, and it typically is provided for <25% of out-of-hospital arrests," observe Iwami et al. "Specific educational campaigns to teach cardiac-only resuscitation may increase the rate of bystander CPR and improve the quality of cardiac-only resuscitation, thereby improving survival from out-of-hospital cardiac arrest.
Dr Gordon A Ewy (University of Arizona College of Medicine, Tucson), a longtime advocate of chest-compression-only resuscitation [3], who wasn't associated with either study, said that no randomized trial is needed for the technique to be recommended.
He pointed out to heartwire that the most current guidelines, published in 2005 [4], had updated the conventional-CPR recommended ratio from 15 chest compressions to two ventilations to 30 chest compressions to two ventilations. Whether 15 or 30 compressions, he said, the guidelines were based on consensus, not data.
But Ewy's group recently published data in a pig model suggesting that the continuous-compression technique, which he calls "cardiocerebral resuscitation," yields better outcomes than 30:2 CPR [5]. That, combined with the abundant supporting observational data, he said, showed that bystander CPR improves survival, and survival is better using the compression-only method.
"There's no question in my mind that the guidelines need to change, and they need to change now," Ewy said.
In Bohm et al's analysis of 8902 cases of out-of-hospital standard CPR and 1145 cases of compression-only resuscitation, 19.6% and 20% of patients, respectively, made it to the hospital alive; the adjusted odds ratio (OR) for CPR vs chest-compression-only was 1.03 (95% confidence interval [CI], 0.86 - 1.23). The one-month survival rates were 7.2% for standard CPR and 6.7% for the simpler technique (adjusted OR, 1.18 [95% CI, 0.89 - 1.56]).
In the prospective, population-based study of 4902 witnessed cardiac arrests in Japan, there were 783 cases in which bystanders performed conventional CPR and 544 in which only chest compressions were used; there were no bystander attempts in the remainder. Excluding arrests lasting >15 minutes, the one-year rate of survival with favorable neurologic outcomes was 4.1% for standard CPR, 2.5% for no resuscitation (OR 1.57 [95% CI, 0.95 - 2.60]), and 4.3% for compression only (OR 1.72 [95% CI, 1.01 - 2.95]).
Ewy, like Iwami et al, observes that regardless of inherent efficacy, the compression-only method is likely to save more lives than standard CPR, if only because it's more likely to be carried out. "People are afraid of getting an infection, or they just don't like doing mouth-to-mouth on a stranger, or they don't know how or are afraid they'll do harm. For whatever reason, it's being done in only one out of five cases in certain societies, and two out of five in others," according to Ewy. "And if you just call 911 and don't do anything until the paramedics get there, you might as well sign the patient's death certificate."
The Ministry of Education, Science, Sports, and Culture, Japan, and the Ministry of Health, Labor, and Welfare, Japan, supported the study by Iwami and colleagues. The study authors have disclosed no relevant financial relationships.
Sources
Bohm K, Rosenqvist M, Herlitz J, et al. Survival is similar after standard treatment and chest compression only in out-of-hospital bystander cardiopulmonary resuscitation. Circulation. Published online before print December 10, 2007.
Iwami T, Kawamura T, Hiraide A, et al. Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest. Circulation. Published online before print December 10, 2007.
Be a lifesaver with continuous chest compression CPR tutorial. University of Arizona Sarver Heart Center. Available at http://www.heart.arizona.edu/publiced/lifesaver.htm.
ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2005 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2005; 112:IV1-IV203.
Ewy GA, Zuercher M, Hilwig RW, et al. Improved neurological outcome with continuous chest compressions compared with 30:2 compressions-to-ventilations cardiopulmonary

CPR Without Mouth-to-Mouth Found Effective in Cardiac Arrest

STOCKHOLM, Dec. 10 -- When bystanders try to help a person in cardiac arrest, a simpler version of CPR using chest compression only appears to work as well as full-scale resuscitation, two studies showed.
Action Points --->
Explain to interested patients that CPR is known to improve survival when people suffer cardiac arrest, but outside of a hospital setting many people are reluctant to administer it, either because they don't know how or because they fear infection.
Note that these studies suggest a simpler form of CPR may be as effective in saving lives, without the fear of infection from mouth-to-mouth contact.
In one retrospective and one prospective study published in the Dec. 18/25 issue of Circulation, chest compression without mouth-to-mouth breathing led to survival rates similar to standard CPR.
The findings may save lives, researchers involved in both studies said, because many people hesitate to perform mouth-to-mouth resuscitation for fear of infection.
While waiting for ambulance crews, bystanders used standard CPR in 73% of the cases and chest compression only in 10% of the cases, said Katarina Bohm, R.N., of the Karolinska Institute, who was lead author of a 15-year retrospective study of 11,275 out-of-hospital cardiac arrests in Sweden.
Bohm and colleagues found that there was no significant difference in one-month survival between the two techniques: 7.2% of those who got standard CPR were alive a month later and so were 6.7% of those who got chest compression only.
In 17% of cases, bystanders used mouth-to-mouth alone, without chest compression, but that resulted in a 4.5% survival rate, which was significantly worse (P<0.0001)
Additional source: CirculationSource reference: Bohm K, et al "Survival is similar after standard treatment and chest compression only in out-of-hospital bystander cardiopulmonary resuscitation" Circulation 2007; DOI: 10.1161/CIRCULATIONAHA.107.710194.