睡眠呼吸暂停 Obstructive Sleep Apnea

For twenty some years, I have always been a "light sleeper." It's hard for me to fall and stay asleep. I am extrenely sensitive to noise, light, and the enronment. This sleeplessness goes back to my college years in my late teen age. Nowadays, I frequently wake up at least twice at night, almost always at around 2am and 4am to go to the restroom. As a result I become sleepy, tired, and even easily irritated during the day time. I have complained about this to my doctors many times in the past, especially the fact that I have to wake up twice each night. Most doctors suspect a kidney or urine track-related problem, suggesting me to see a urinology specialist, which I did. No one suggested a sleep study until last week when I saw my cardiologist specialist at The Heart Institute of St. Luke Hospital of Houston medical center. Dr. G prescribed for a sleep study right away to see if I have apnea problems, which once diagnosed, are curable and should help my heart condition.

The sleep diagnosis lab called me for an appointment early last week. The appointment was set for last night, Friday, June 10, at a Homewood Suites hotel near my home. I was given instructions by email two days before the appointment. I arrived at the hotel room exactly at my appointment time, 9:30pm. It's a regular hotel suite room. The temperature in the bedroom was set very cold . The living area was warmer, and set up as an office for the technician, where there were monitors, desks, computers, equipment, and many medical accessories. The technician mounted about 30 electrode leads on my body, two on my legs, a few around my chest and most around my face and head. She also hooked up a reader for oxygen saturation on one my fingers. I was then instructed to go to sleep. Luckily I was allowed to take a sleeping pill otherwise it would be difficult to fall asleep wearing so many wires. The whole process was monitored through a camera mounted near the ceiling.

I had a great sleep - better than normal. The bed was very comfortable. The room temperature was so low that I felt it was like winter time. I did woke up twice as usual for the restroom, but I was able to go back to sleep quickly afterwards at both times. The whole test was supposed to be completed by 6am. I had a hard time to get up and couldn't tell the time in the morning until the technician came in and said it's time to get up. She removed all the electrodes and sensors quickly.

Preliminary conclusion shows that indeed I have sleep apnea, which literally means "without breath". That explains all the complaints I have had over the years. Apnea means from time to time when I sleep, my breathing may stop ("pause") (while heart still pumping) for a short period, the oxygen level in my blood would decrease which sends a signal to my brain to wake me up to catch up with breathing again. That is why I am not a deep sleeper and very easy to wake up at night.

To cure this problem, I'll most likely have to wear a mask connected to a machine that would increase the air pressure and prevent the obstructive sleep apnea (OSA). The device is called CPAP. I'll probably have to do this test one more time to test the pressure settings for the machine. I can't wait to get into that phase, having great, deep sleep every night and feeling rejuvenated every morning. No more waking up at middle of the night and feeling tired and sleepy at work.

I thought the sleep test was quite simple and reasonable comfortible. It turns out that the technician had stayed up in the living room area for the night. She has to work from 7pm to 8am each night for 7 days a week. During the night she would monitor the patient's progress and has to stay awake the whole night. I thought that is a tough job. This test costs about $2000 and I had to pay about $500 co-pay, but it is totally worth it. Doing such tests at a hotel room instead of in a hospital makes sense. It makes the patients more comfortable and probably costs less money for the operator. The hotel offers free breakfast, including warm dishes. I had a big breakfast before leaving.

After coming back from the test, I immediatley googled for "apnea." The other common symptoms of OSA include: snoring (I do sometimes as I was told), increased urination (I do), obesity (I don't), morning headaches (I don't), etc. This condition could get worse and cause other problems over time if not properly treated. It affects 3-4% of women and 6-7% of men. There are currently no effective drugs for this problem. The effective treatment is through some physical intervention. CPAP (continuous positive airway pressure) is the most common treatment.

Obviously I am most anxious to see if this condition has anything to do with my heart condition (diagnosed with dilated cardiomyopthy about two years ago). Here is what I found from the Wiki website:

"The most serious consequence of untreated obstructive sleep apnea is to the heart. In severe and prolonged cases, there are increases in pulmonary pressures that are transmitted to the right side of the heart. This can result in a severe form of congestive heart failure (cor pulmonale). One prospective study showed that patients with obstructive sleep apnea, compared with healthy controls, initially had statistically significant increases in vascular endothelial growth factor (P=.003) and significantly lower levels of nitrite-nitrate (P=.008), which might be pathogenic factors in the cardiovascular complications of obstructive sleep apnea.^[34] These factors reversed to normal levels after 12 weeks of treatment by continuous positive airway pressure, but further long-term trials are needed to assess the impact of this therapy.^[35]

"Elevated arterial pressure (commonly called high blood pressure) can be a consequence of obstructive sleep apnea syndrome.^[36] When high blood pressure is caused by OSA, it is distinctive in that, unlike most cases of high blood pressure (so-called essential hypertension), the readings do not drop significantly when the individual is sleeping.^[37] Stroke is associated with obstructive sleep apnea.^[38] Sleep apnea sufferers also have a 30% higher risk of heart attack or death than those unaffected.^[39]

"Many studies indicate that it is the effect of the "fight or flight" response on the body that happens with each apneic event that increases these risks. The fight or flight response causes many hormonal changes in the body; those changes, coupled with the low oxygen saturation level of the blood, cause damage to the body over time."


I also found these literature linking DCM and OSA online:

"On the other hand at least one trial has shown that Left Ventricular Ejection Fraction is improved by CPAP in people who have both OSA and idiopathic cardiomyopathy. This was ages ago but I'm sure there's been other's since. ---Malone et al Obstructive sleep apnoea in patients with dilated cardiomyopathy: effects of continuous positive airway pressure. Lancet 1991 338 1480-1484"

"Mehta S. Liu PP. Fitzgerald FS. Allidina YK. Douglas Bradley T. Effects of continuous positive airway pressure on cardiac volumes in patients with ischemic and dilated cardiomyopathy. [Journal Article] American Journal of Respiratory & Critical Care Medicine. 161(1):128-34, 2000 Jan. "

"Mohsenin V. Sleep disordered breathing and cardiomyopathy. [Review] [37 refs] [Journal Article. Review. Review, Tutorial] Monaldi Archives for Chest Disease. 53(5):589-92, 1998 Oct. UI: 9861827 "

"Cardiovascular disease is common in patients with obstructive sleep apnea.²⁸ Hypertension and obesity increase the risk of cardiac disease and are frequent findings in patients with this sleep disorder. Although hypertension is the best documented cardiovascular condition in obstructive sleep apnea, some studies have shown that patients with the disorder are also at increased risk for cardiac arrhythmias,⁴ including severe bradycardias, during apneic episodes. Furthermore, the prevalence of angina and myocardial infarction is increased in patients with apnea. Obstructive sleep apnea has been shown to cause dilated cardiomyopathy, which is reversible with successful treatment of the sleep disorder.²⁹

"usually a damage to the heart from sleep apnea has a distinctive pattern and echo cardiologist should be able to comment from your echo whether there is room to suspect whether your cardiomyopathy is from sleep apnea or not. "


Bingo! If this is true, I may have found the root cause for my heart problem which has been ischemic, meaning without a known cause (to be confirmed with my cardiologist soon). I'll do more testing and consulting with my doctors in the coming weeks. Stay tuned.

I think I am lucky again that I got this sleeping problem diagnosed. I want to thank my Dr. G for suggesting this test. I feel thankful that we live in a country and time with the convenience of advanced medical care.

I hope by writing my sleep apnea story, it will help others to diagnose and get better. If you are not a good sleeper, snore, and often sleepy during the day, I highly suggested to get yourself a sleep study!