March 19, 2012
Using a face mask to gently force air into breathing passages can help reverse heart damage caused by sleep apnea, according to a new study.
Using a breathing machine to treat sleep apnea can improve heart function and may prevent heart failure, according to British researchers.
Patients with obstructive sleep apnea stop breathing momentarily while they are sleeping.
To treat the condition, doctors sometimes prescribe a mechanical therapy known as continuous positive airway pressure, or CPAP. It uses a face mask to gently force air into the breathing passages, to keep them open.
In a new study, published online by the American Heart Association, Britain's University of Birmingham researchers used echocardiogram exams to study heart structures and function in sleep apnea patients before and after CPAP therapy, and compared their results with data on patients with high blood pressure and a healthy control group.
Gregory Lip, who led the study, said they observed heart damage in the sleep apnea patients, even though they had no overt symptoms."Moderate to severe sleep apnea did cause significant structural and functional changes, comparable to that seen in high-blood-pressure patients."
The apnea patients were treated for an average of six months with CPAP, and then given another echocardiogram. The scan revealed that much of the heart damage had been reversed.
"CPAP therapy did reduce the thickness of the heart muscle wall," Lip said. "We showed also an improvement in the cardiac function, and also the stiffness of the cardiac chambers."
Patients with moderate to severe obstructive sleep apnea should be considered for CPAP therapy, even if they don't have any symptoms of cardiac problems, given the therapy’s apparent role in improving heart structure and function, according to Lip.
"These improvements, we hope, would be translated to a significant reduction in stroke and coronary artery disease risk," he said, "but clearly this would need to be proven in a large, prospective randomized trial."
passage (n) 通路;水路;出入口 * breathing passage 呼吸道
reverse (v) 使倒退；反轉
apnea (n) 呼吸暫停
這個字要注意發音; sleep apnea 是「睡眠呼吸停止症」
obstructive (a) 阻礙的;堵塞的
mechanical (a) 機械的
overt (a) 公然的；公開的
cardiac chamber (n phr) 心室
given (prep) 假如;考慮到
coronary artery (n phr) 冠狀動脈
prospective (a) 未來的，將來的
英國的研究人員指出，使用輔助呼吸器來治療睡眠呼吸停止症(sleep apnea)可以強化心臟功能，還能避免心臟衰竭(heart failure)。
醫生治療睡眠呼吸停止症時，常會使用一種機械式療法(mechanical therapy)，簡稱為CPAP的連續式正壓呼吸治療(continuous positive airway pressure)。
研究人員Gregory Lip指出，觀察睡眠呼吸中止症的病人的心臟受損程度，其中也包含還沒有明顯心臟病症狀的病人(overt symptoms)，他們發現輕度(moderate)到嚴重的睡眠呼吸停止症都會引起顯著的心臟結構性與功能性的改變 (significant structural and functional changes) ，程度可跟高血壓病人身上看到的心臟受損做比較(comparable to that seen in high-blood pressure patients)。
實驗結果發現，CPAP治療法可以減少心臟肌肉壁的厚度(reduce the thickness of the heart muscle wall)，在心臟功能還有心室硬化上都有改善(stiffness of the cardiac chambers)。
Gregory Lip認為，考量這個治療法在強化心臟結構與功能有明顯的作用 (given the therapy’s apparent role in . . .)，所以從輕度到重度的睡眠呼吸停止症病人都應該考慮接受CPAP療法，即使他們還沒有顯現任何心臟方面的問題和症狀。