Toronto Hospital researchers find breathing machine helps improve heart and diaphragm function in heart failure patients.
(Toronto, January 18, 1996)-Researchers at The Toronto Hospital have found that patients who have both congestive heart failure and a sleep disorder known as sleep apnea have dramatic improvement in heart function following the use of a breathing aid at night to treat the sleep apnea.For more information please contact:
The study also showed for the first time that by using Continuous Positive Airway Pressure (CPAP), the weakness of the respiratory muscle (diaphragm), usually found in patients with congestive heart failure, is reversed. In addition, the subjects in the study had improved breathing, improved quality of sleep and improved quality of life. CPAP is a machine which delivers air through a mask to the lungs at night and is a non-drug therapy for sleep apnea.
Sleep apnea is a condition in which the throat collapses during sleep causing the individual to stop breathing temporarily. The intermittent periods of suffocation cause people to wake up and leave them feeling tired. However, not only do people with sleep apnea complain of tiredness, many also suffer from cardiovascular disease including congestive heart failure. The cardiovascular disease is worsened by the excess pressure the heart undergoes during the intermittent periods of apnea. Approximately 40 per cent of heart failure patients have sleep apnea compared to 6 per cent of the non-heart failure population.
"This study shows that by using CPAP, patients with heart failure who are on maximum drug therapy for their cardiovascular disease had great improvement in their overall heart function, and strengthened their diaphragm muscle as well," says Dr. Douglas Bradley, Director of the Cardiorespiratory Sleep Disorder Clinic at The Toronto Hospital, and lead investigator of the study. An Associate Professor of Medicine at the University of Toronto, Dr. Bradley's specialty is respirology. "The strengthened diaphragm muscle also reduced shortness of breath which is the main symptom of heart failure." Dr. Bradley also directs a second research lab at Queen Elizabeth Hospital.
Heart failure is a weakness of the heart muscle that impedes its ability to pump blood for proper circulation causing patients to experience fatigue and shortness of breath. It frequently occurs following a heart attack and is the fastest growing cardiovascular disease. Heart failure affects 5 per cent of Canadians and 50 per cent of these die within four years of diagnosis. Little is understood about the cause and progression of this debilitating heart muscle disease. The only eventual treatment is heart transplantation.
"The use of CPAP allows the heart and diaphragm muscles to rest and recover strength," Dr. Bradley explains. "Basically we are dealing with fatigued muscles and by giving them a rest they are able to function better. This is what causes the improvement in the function of these muscles."
Nine patients with heart failure were enrolled in the study and were compared to nine healthy people in a control group. The patients in the study used CPAP for six hours a night. Both groups were followed over a three-month period. Patients also completed a detailed questionnaire which measured their quality of life. These questionnaires showed a dramatic improvement in quality of life, Dr. Bradley says. Dr. Bradley worked in collaboration with Dr. Peter Liu, a Toronto Hospital cardiologist, and Dr. John Granton, a Toronto Hospital respirologist. The study was published in the January 7 issue of the American Journal of Respiratory and Critical Care Medicine.
Josey Panetta
Senior Media Relations Officer
The Toronto Hospital
Public and Community Affairs
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Toronto, Ontario Canada M5G 2C4
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Research Subjects Needed for New Study
on Congestive Heart Failure
The Toronto Hospital is recruiting people with congestive heart failure to participate in a new study on a sleep disorder known as sleep apnea. The participants need not have sleep apnea to be part of the study.For more information please contact:
Previous studies have shown an improvement of heart function in patients with congestive heart failure who also have sleep apnea following the use of Continuous Positive Airway Pressure. This is a machine which delivers air through a mask to the lungs at night and is a non-drug therapy for sleep apnea. Dr. Douglas Bradley, a respirologist and Director of the Cardiorespiratory Sleep Disorder Clinic at The Toronto Hospital, believes the same benefits may be seen in patients with congestive heart failure even if they do not have sleep apnea.
Sleep apnea is a condition in which the throat collapses during sleep causing the individual to stop breathing temporarily. The intermittent periods of suffocation cause people to wake up and leave them feeling tired. However, not only do people with sleep apnea complain of tiredness, many also suffer from cardiovascular disease including congestive heart failure. The cardiovascular disease is aggravated by the excess pressure on the heart during the intermittent periods of apnea. Approximately 40 per cent of heart failure patients have sleep apnea compared to 6 per cent of the non-heart failure population.
Approximately 70 patients are needed for the study which is funded by the Medical Research Council of Canada.