The effectiveness of CPAP-therapy on recurrence of atrial fibrillation after cardioversion in patients with central sleepapnea

In sleepapnea (SA) the sleep is disturbed bij impaired breathing during
nightsleep. Within this impaired breathing it is possible to see apneas
(stopped breathing) as well as hypopneas (reduced breathing). Sleepapnea is
differentiated in obstructive (OSA) and central sleepapneas (CSA). OSA is a
result of collaps of the upper airway due to sleep related muscle relaxation,
The upper airway collaps can be caused bij muscle relaxation in aging, obesity
or anatomical problems such as loose palate, polyps or a too large tongue. This
is characterised by an apnea during a minimum of 10 seconds with thorax
expansion. CSA is caused by a disturbed cerebral regulation of respiration.
This is characterised by an apnea during a minimum of 10 seconds without thorax
expansion.
These rules, recorded bij the American Academy of Sleep Medicine (AASM), are
importent when analyzing the polysomnography (PSG). A PSG is a sleeptest where
an number of topics are registered, such as brainactivity, respiration,
blood-oxygenlevels and heartfrequency.
The severeness of SA is determined according to the apnea-hypopnea-index (AHI),
calculated by hour, determined during PSG. AHI < 5/hour is normal.
The diagnosis sleepapnea is made at a AHI above five times an hour. The mixed
form, central combined with obstructive, is frequently seen. The treatment for
OSAS consists of conservative treatment like changes in lifestyle in obesity
(motion, healthy weight, healthy nutrition) and/or surgical treatment like
enlarging the space in oral cavity and pharynx. In addition it is possible to
treat with continuous positive airway pressure (CPAP), where patients sleep
with a mask over their nose and mouth which is connected to a machine that
supports every inhalation with enough overpressure to abolish the apnea.
Because CSA is caused by disturbed cerebral regulation of respiration,
conservative treatment doesn*t work and CPAP is used as treatment. The
CPAP-mechanism in CSA is based on using overpressure to create good ventilation
and diffusion of oxygen to the bloodstream and carbonic back to exhalation.
Then chemoreceptors in the body use this balance of oxygen and carbonics in the
bloodstream to encourage the brain to respiratory stimulus.
Patients with heart and vascular disease have increased incidence to develop
CSA and vice versa. CSA gives aggravation of heartfailure due to exposure of
the heart to variable oxygen supply, increased burden on the heart, activation
of sympathic nervous system and damage to endothelial tissue. Literature says
there is a strong association between sleeapnea and atrial fibrillation (AF), a
arrhythmia from the atria of the heart. The prevalence of AF is higher in
CSA-patients than it is in OSA-patients. AF can be treated with anti-arrhytmic
medication or cardioversion. The medication attempts to restore and sustain
normal rhytm (sinusrhytm). If this is not sufficient a cardioversion is
considered. Cardioversion is a non-invasive intervention. The patient, under
light narcosis, is given an electric shock aiming to restore sinusrythm. AF can
recur after treatment. This possible shortly after the treatment or at a later
date.

The objective of this study is evaluation of the effectiveness of CPAP-therapy
on recurrence of atrial fibrillation after cardioversion in patients with
central sleepapnea and in case of proven effectiveness possibly using
CPAP-therapy as standard treatment.

Pilotstudy, randomized clinical trial (RCT)

No risks, burden of a checklist, an intake, polysomnography and 3 follow-up
appointments.