Study Design	No. of Patients	Type of Arrhythmia	Duration of Arrhythmia	M/F (%)	Age (mean ± SD yrs)	Baseline Mag Status	Study Treatments	Rate of Conversion (%)	Control of Heart Rate
P, R, DB, PC[32]	15	AF	Mag: 6 ± 8 days Pla: 4 ± 6 days (mean ± SD)	47/53	Mag: 67 ± 16 Pla: 59 ± 16	NA	Mag 2 g over 1 min, then 1 g/hr over next 4 hrs, or Pla i.v. over 1 min, then 4-hr infusion, + Dig 0.5 mg × 20 min started 30 min after Mag or Pla infusion	NA	HR decrease at 5 min: Mag -20 bpm(p<0.02) Pla -3 bpm (p=NS) HR decrease at 4 hrs:Maga -39 bpm (p=0.08) Plaa -25 bpm (p=NS)
P, R, DB, PC[33]	30	AF	2-60 mo	60/40	55-82	WNL	HD Mag 2 g over 10 min, then 2 g over 50 min LD Mag 1 g over 10 min, then 1.5 g over 50 min HD and LD Pla i.v. over 10 min, then 50-min infusion	NA	No difference between LD Mag, HD Mag, and Pla
P, R, DB, PC[34]	18	Symptomatic AF	< 7 days, mean NA	56/44	Mag: 59 ± 15 Pla: 56 ± 16	WNL	Mag 2 g over 15 min, then 8 g over next 6 hrs, or Pla i.v. for 15 min, then 6-hr infusion, + Dig 0.375-1.75 mg over 24 hrs	At 24 hrs: Mag: 60 Pla: 38 (p=NS)	HR < 90 bpm at 24 hrs: Mag 100%, Pla 50% (p<0.05)
P, R, C[35]	42	AF (n=26) AFL (n=4) Other (n=12)	> 1 hr, mean NA	62/38	67 ± 15	WNL	Mag 0.037 g/kg over 5 min, then 0.025 g/kg/hr over 24 hrs Amio 5 mg/kg for 15-20 min, then 10 mg/kg over 24 hrs	At 24 hrs: Mag: 77 Amio: 50 (p value not provided)	Not provided
P, R, SB[36]	57	AF (n=35) AFL (n=10) PSVT (n=12)	Mag: 39 ± 60 hrs Ver: 23 ± 44 hrs (mean ± SD)	65/35	Mag: 61 ± 13 Ver: 64 ± 10	WNL	Mag 1.2 g over 5 min + 1.2 g over 10 min, then 9.6 mg/min Ver 5 mg over 5 min + 5 mg over 10 min, then 0.1 mg/min	At 4 hrs: Mag: 58 Ver: 23 (p<0.01)	HR < 100 bpm at 4 hrs: Mag 48%, Ver 28% (p<0.05)
R, O[37]	46	AF	< 12 hrs, mean NA	54/46	Mag: 61 ± 6 Dilt: 64 ± 4	WNL	Mag 2.5 g over 15 min, then 7.5 g over 6 hrs Dilt 25 mg over 15 min, then 12.5 mg/hr over 6 hrs	At 6 hrs: Mag: 57 Dilt: 22 (p=0.03)	No difference between Mag and Dilt
MC, retro, cohort[38]	321	AF (n=202) AFL (n=119)	NA	61/39	66.8 ± 14.3	WNL	Mag 2.2 ± 1.0 g (mean), 1-4 g (range) Ibu 1.55 ± 0.53 mg (mean), 1-2 mg (range)	At 6 hrs: Mag + Ibu: 72.0 Ibu alone: 60.3 (p=0.04)	NA

AF = atrial fibrillation; AFL = atrial flutter; Amio = amiodarone; bpm = beats/min; C = comparative; Dilt = diltiazem; DB = double-blind; Dig = digoxin; HD = high-dose; HR = heart rate; Ibu = ibutilide; LD = low-dose; Mag = magnesium sulfate; MC = multicenter; NA = not available; NS = not significant; O = open-label; P = prospective; PC = placebo-controlled; Pla = placebo; PSVT = paroxysmal supraventricular tachycardia; R = randomized; retro = retrospective; SB = single-blind; Ver = verapamil; WNL = within normal limits.
^aDig added to Mag and Pla at 30 min.

Study Design	No. of Patients	Type of Arrhythmia	Duration of Arrhythmia	M/F (%)	Age (mean yrs)	Baseline Mag Status	Study Treatments	Maintenance of Sinus Rhythm
Phase 1 P, R, DB, PC[43]	170	AF	4.5 mo	68/32	69.5	WNL in 99% of patients	Mag 250 mg p.o. × 7 days, then b.i.d. × 7 days before cardioversion, then b.i.d. × 6 mo Pla p.o. × 7 days, then b.i.d. × 7 days before cardioversion, then b.i.d. × 6 mo	At 1 mo: Mag 41%, Pla 34% At 6 mo: Mag 30%, Pla 27% (log rank p=0.37)
Phase 2 P, R, DB, C[43]	131	Recurrent AF	4.8 mo	69/31	67.1	WNL in 98% of patients	Mag 250 mg p.o. × 7 days, then b.i.d × 7 days before cardioversion, then b.i.d. × 6 mo, or Pla p.o. × 7 days, then b.i.d. × 7 days before cardioversion, then b.i.d. × 6 mo, + Sot with dosage titrated to 160 mg b.i.d.	At 1 mo: Mag + Sot 54%, Pla + Sot 56% At 6 mo: Mag + Sot 51%, Pla + Sot 42% (log rank p=0.64)

AF = atrial fibrillation; C = comparative; DB = double-blind; Mag = magnesium hydroxide; P = prospective; PC = placebo-controlled; Pla = placebo; R = randomized; Sot = sotalol; WNL = within normal limits.

Study Design	No. of Patients	M/F (%)	Age (range or mean ± SD, yrs)	Baseline Mag Status	Evidence of BB Withdrawal	Pre- or Intra- Operative Study Treatment	Postoperative Study Treatment	Rate of Postoperative Atrial Tachyarrhymias (%)	p Value
P, R, OL[50]	378	85/15	62.3-63.8	NA	BB withdrawal observed by authors	Mag 2 g i.v. 30 min after end of CPB	Mag 2 g i.v. on arrival to ICU, then 2 g q.d. i.v. × 4 days Dig 1 mg i.v. (4 divided doses) on day of surgery, then 0.25 mg q.d. i.v. × 4 days Mag + Dig: dosed as above Pro 1 mg i.v. q6h, then 10 mg p.o. q.i.d. × 4 days Mag + Pro: dosed as above	Mag: 38 Dig: 31 Mag + Dig: 37 Pro: 18 Mag + Pro: 19 Con: 38a	Pro vs Mag: 0.01 Pro vs Mag + Dig: 0.02 Pro vs Con: 0.01 Mag + Pro vs Mag: 0.01 Mag + Pro vs Mag + Dig: 0.02 Mag + Pro vs Con: 0.02
P, R[51]	167	77/23	61 ± 10	NA	All patients received BB	None	Mag 18 g i.v. over 24 hrs Pro 20 mg p.o. q.i.d.	Pro + Mag: 22.4 Pro: 19.5	0.65
P, R, DB, PC[52]	140	83/17	54-57	WNL	All patients received BB	None	Mag 9.6 g i.v. for first 24 hrs after surgery, 7.2 g i.v. for next 24 hrs	Mag: 29 Pla: 26b	NS
P, R, DB, PC[53]	200	80.5/19.5	61.4-62.0	WNL	No BB before surgery; 20% received BB after surgery	Mag 1.4 g i.v. day	Mag 1.4 g q.d. i.v. × 5 days before surgery and immediately after end of CPB	Mag: 2 Pla: 21b	<0.001
P, R, DB, PC[54]	99	75/25	59-62	WNL	No BB after surgery	None	Mag 11.5 g i.v. on day of surgery, then 8.6 g i.v. for 25-96 hrs after surgery	Mag: 14 Pla: 28b	NS
P, R[55]	207	86.5/13.5	62-64	WNL	Preop BB discontinued in 23-45% of patients	Mag 1.5 g i.v. after end of CPB	Mag 1.5 g q.d. × 5 days Sot 80 mg b.i.d. × 5 days Mag + Sot: dosed as above	Mag: 14.8 Sot: 11.8 Mag + Sot: 1.9 Con: 38a	Mag + Sot vs Con: <0.0001 Mag + Sot vs Sot: 0.04 Mag + Sot vs Mag: 0.01 Sot vs Con: 0.002 Mag vs Con: 0.007
P, R, DB, PC[61]	200	75/25	57.6 ± 9.7 (41-76)	WNL	Preop BB discontinued in all	Mag 3 g i.v. 12 hrs before surgery, immediately after CPB, and after last graft	Mag 3 g i.v. on day of surgery and on days 1, 2, and 3	Mag: 15 Pla: 16c	0.845

BB = β-Blocker; Con = control; CPB = cardiopulmonary bypass; Dig = digoxin; ICU = intensive care unit; Mag = magnesium sulfate; NA = not available; NS = not significant; OL = open-label; P= prospective; Pla = placebo; PC = placebo-controlled; Pro = propranolol; preop = preoperative; R = randomized; Sot = sotalol; WNL = within normal limits.
^aControl group received no treatment.
^bPlacebo matched to active therapy.
^cMagnesium given pre- and intraoperatively to both groups; matching placebo given postoperatively.