Cardioversion of atrial fibrillation does not affect obstructive sleep apnea

Figures & data

Table 1. Baseline characteristics.

	All (n = 23)	Sinus rhythm at follow-up (n = 16)	Atrial fibrillation at follow-up (n = 7)
Male, n (%)	14 (61)	10 (62)	4 (57)
Age (years)	62 ± 7	62 ± 8	61 ± 4
Body mass index (kg/m^2)	27 ± 4	28 ± 4	30 ± 5
Hypertension, n (%)	12 (52)	8 (50)	4 (57)
Diabetes mellitus, n (%)	5 (21)	3 (19)	2 (29)
Ischemic heart disease, n (%)	2 (9)	1 (6)	1 (14)
Stroke, n (%)	1 (4)	0 (0)	1 (14)
Heart failure, n (%)	1 (4)	0 (0)	1 (14)
Echocardiography
Normal or slightly impaired (LVEF >45%), n (%)	22 (96)	16 (100)	6 (86)
Moderately impaired (LVEF 30%–44%), n (%)	1 (4)	0 (0)	1 (14)
Medication (baseline)
Beta-blockers, n (%)	17 (83)	13 (81)	14 (86)
Calcium antagonists, n (%)	6 (26)	4 (25)	2 (29)
Digoxin, n (%)	5 (18)	4 (25)	1 (14)
ACE inhibitors or ARB, n (%)	11 (48)	7 (44)	4 (57)
Diuretics, n (%)	7 (30)	4 (25)	3 (43)
Warfarin, n (%)	23 (100)	16 (100)	7 (100)
Statins, n (%)	7 (39)	3 (19)	4 (57)
Apnea-hypopnea index (AHI), events/h	24 ± 16	23 ± 16	28 ± 17
Obstructive AHI, events/h	18 ± 14	18 ± 15	18 ± 17
Central AHI, events/h	6.3 ± 14	4.8 ± 12	10 ± 17

Data are presented as means ± standard deviation for continuous variables, or numbers and percentages for dichotomous variables.

ACE: angiotensin-converting enzyme; AHI: apnea-hypopnea index; ARB: angiotensin II receptor blocker; LVEF: left ventricular ejection fraction.

Figure 1. Mean obstructive and central apnea-hypopnea index among the 16 of 23 patients who were in atrial fibrillation at baseline and in sinus rhythm at follow-up.

Table 2. Sleep apnea and sleep in subjects who had atrial fibrillation at baseline and sinus rhythm at follow-up.

	Baseline: atrial fibrillation (n = 16)	Follow-up: sinus rhythm (n = 16)	P value
Sleep apnea (AHI ≥5 events/h), n (%)	13 (81)	14 (88)	1.0
Obstructive sleep apnea, n (%)	11 (69)	13 (81)	0.5
Central sleep apnea, n (%)	2 (12)	3 (19)	1.0
Apnea-hypopnea index (AHI), events/h	23 ± 16	21 ± 14	0.918
Obstructive AHI, events/h	18 ± 15	18 ± 14	0.569
Central AHI, events/h	4.8 ± 12	3.4 ± 6.9	0.593
Total sleep time (TST) (min)	382 ± 67	378 ± 100	0.857
Sleep efficiency (%)	77 ± 15	79 ± 24	0.644
Stage 1 (% of TST)	14 ± 6.7	15 ± 8.7	0.339
Stage 2 (% of TST)	55 ± 12	55 ± 10	0.988
Stage 3 (% of TST)	11 ± 7.5	12 ± 7.7	0.640
REM (% of TST)	19 ± 7.9	18 ± 7.1	0.293
Supine position (% of TST)	27 ± 24	33 ± 19	0.397
Epworth Sleepiness Scale	7.7 ± 5.2	6.7 ± 5.0	0.216

Data are presented as means ± standard deviation for continuous variables, or numbers and percentages for dichotomous variables.

AHI: apnea-hypopnea index; central sleep apnea: central apnea-hypopnea index ≥5 events/h; obstructive sleep apnea: obstructive apnea-hypopnea index ≥5 events/h; TST: total sleep time.