Dr. Tadeusz Petelenz said the technique, called cough CPR, forces blood to the brain while the heart is starting to fail and keeps patients conscious long enough to call for help. It may also rectify their heart rhythm, he said at a meeting of the European Society of Cardiology.
Other experts said the concept is provocative but unproven, and they doubted whether it would have practical value.
In hospital labs where heart disease patients undergo angiograms to check the state of their arteries, doctors now sometimes ask patients to cough rhythmically and forcefully to get the circulation going when transient slowdowns occur.
Dr. Leo Bossaert, executive director of the European Resuscitation Council, said coughing probably would not be harmful, but it is far too early to recommend people try it at home. The symptoms preceding an attack can be very subtle and hard for people to recognize in the 30 seconds before they lose consciousness, he said.
Every year in the industrialized world, one out of 1,000 people die from sudden cardiac death. Most of the time, the culprit is a type of heart attack brought on by a sudden problem with the heart's rhythm — ventricular fibrillation.
Circulation stops, the victim faints and brain damage occurs within minutes. Deaths usually follows in about 15 minutes.
In three-quarters of cases, the attack happens at home.
Electric shock to the heart, known as defibrillation, is the only real treatment. Cardiopulmonary resuscitation, or CPR, can keep the brain and heart viable for about 10 minutes, long enough for an ambulance to bring a defibrillator.
Only a fraction of cardiac arrest victims get CPR from a bystander and only a few of those will receive the electric shock treatment before suffering irreversible brain damage. The rate of survival without serious brain damage is about 10 percent, said Bossaert, a professor at the University Hospital in Antwerp, Belgium.
About 350,000 people in Europe suffer a sudden cardiac death every year.
"Two out of five victims are alone during ... episodes. Since the onset of the loss of consciousness is very rapid, they usually don't have enough time to call for help," said Petelenz, a professor at the Silesian Medical School in Katowice, Poland. "However, if victims could maintain consciousness until circulation is restored or help arrives their chances of survival would greatly increase."
Petelenz presented results from a study he conducted on 115 people who had previously fainted or come close to losing consciousness because of various heart problems. They were taught how to recognize the symptoms — sudden dizziness and weakness, shortness of breath, sudden sweating and blurred vision — and then taught the proper coughing technique.
The patients used the cough in 365 instances where they thought they were about to faint. The symptoms disappeared in 292 cases and medical attention was required in only 73 cases.
"All patients survived until the follow-up therapy, which included 45 pacemaker implantations, 55 heart surgeries and 15 (drug) interventions," Petelenz said. "Cough CPR should be taught to the general public, as many people are not aware of their heart disease and their fainting may be the first, and most likely last, symptom of the disease, and tragically, the end of life," he said.
Dr. Marten Rosenquist, professor of cardiology at the Karolinska Institute in Stockholm, Sweden and an expert in heart beat abnormalities, said the concept is interesting but that Petelenz presented no evidence that his patients actually had arrhythmias at the times of the incidents.
Rosenquist said he would like to see a good follow up study.
"This could be very interesting because you could gain time. If the call to arrival (of ambulance) time in Europe in most major cities is around seven to nine minutes, you might gain a minute or two by keeping yourself alive."
By Emma Ross