Arrhythmia
Supplements studied for arrhythmia.
Overview
Two supplements are indexed for arrhythmia across 29 studies.
Magnesium sulfate (WA 68, medium ratings) is a safe and effective treatment for torsades de pointes associated with prolonged QT interval, typically given intravenously as a slow injection with possible continuous infusion. L-Carnitine (WA 48; low effect size, medium evidence, medium trust) has weaker evidence from small studies suggesting oral doses of 2 grams two or three times daily may reduce premature ventricular contractions.
Most arrhythmia supplement evidence centers on magnesium for this specific rhythm disturbance. See the heatmap and evidence reviews below for full trial detail.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Magnesium | ★★★★★ | Medium |
| L-Carnitine | ★★★★★ | Low |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
2 supplements for and rated at least stars. All purchase bands. No minimum star filter.
MagnesiumView supplement →
Consider purchase·★★★★★
How we scored this▸
- Magnesium sulfate is a safe and effective treatment for a type of irregular heartbeat called torsades de pointes, which occurs when the heart's rhythm is disturbed due to a prolonged QT interval.
- It is given through a vein as a slow injection, usually 2 grams over a few minutes, and often followed by a continuous drip to keep magnesium levels steady.
- This medicine helps calm the heart and stop the dangerous rhythm quickly.
- Doctors also make sure potassium levels are normal since low potassium can worsen the condition.
- Magnesium sulfate is the preferred medicine for this specific heart rhythm problem.
Browse 26 studies·15 meta-analyses
MetaEfficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis2023n=1,048
A meta-analysis of 9 RCTs (1,048 patients) found IV magnesium plus standard care improved rate control (OR 1.87) and rhythm control (OR 1.45) in non-postoperative atrial fibrillation vs placebo.
- Effect
- Benefit
- Population
- Patients with atrial fibrillation
- Participants
- 1,048
MetaInterventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery2023n=17,364
An updated Cochrane meta-analysis of 118 cardiac surgery studies (17,364 participants) found multiple agents including beta-blockers, amiodarone, and magnesium reduce postoperative atrial fibrillation, with varying effect sizes.
- Effect
- Benefit
- Population
- Adults
- Participants
- 17,364
MetaMagnesium prophylaxis of new-onset atrial fibrillation: A systematic review and meta-analysis2023n=4,713
A meta-analysis of 5 RCTs (4,713 patients) outside cardiac surgery found magnesium prophylaxis did not significantly reduce new-onset atrial fibrillation vs placebo (OR 0.72, 95% CI 0.48–1.09).
- Effect
- No Benefit
- Population
- Patients at risk of new-onset atrial fibrillation
- Participants
- 4,713
Systematic reviewThe Effect of Magnesium on Reperfusion Arrhythmias in STEMI Patients, Treated With PPCI. A Systematic Review With a Meta-Analysis and Trial Sequential Analysis2021n=336
A meta-analysis of 3 PPCI-era RCTs (336 STEMI patients) found periprocedural magnesium did not significantly reduce reperfusion ventricular tachycardia (OR 1.36, p=0.263) or improve ejection fraction.
- Effect
- No Benefit
- Population
- STEMI patients
- Participants
- 336
RCTComparison of the Efficacy of Oral versus Intravascular Magnesium in the Prevention of Hypomagnesemia and Arrhythmia after CABG2018n=82
An RCT of 82 CABG patients found 1,600 mg oral magnesium before surgery as effective as 2 g IV magnesium sulfate for preventing postoperative hypomagnesemia and arrhythmia (13.9% vs 6.5% arrhythmia rates).
- Effect
- Benefit
- Dose
- 2 g/day
- Population
- Patients undergoing CABG
- Participants
- 82
RCTA double-blind randomized clinical trial comparing different doses of magnesium in cardioplegic solution for prevention of atrial fibrillation after coronary artery bypass graft surgery2016n=120
A double-blind RCT of 120 CABG patients found 100 mg/kg magnesium in cardioplegic solution during cross-clamp most effectively reduced postoperative atrial fibrillation (5.4%) vs 60 mg/kg (26.3%) or 80 mg/kg (10%).
- Effect
- Benefit
- Duration
- 3 days
- Dose
- 60 mg/day
- Population
- Patients undergoing CABG
- Participants
- 120
RCTEffect of prophylaxis of magnesium sulfate for reduction of postcardiac surgery arrhythmia: Randomized clinical trial2016n=80
An RCT of 160 cardiac surgery patients found 30 mg/kg IV magnesium sulfate significantly reduced postoperative arrhythmia incidence vs saline control (p=0.037).
- Effect
- Benefit
- Dose
- 30 mg/kg
- Population
- Cardiac surgery patients
- Participants
- 80
MetaInterventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery2013n=18,364
An updated Cochrane meta-analysis of 118 cardiac surgery studies (17,364 participants) found multiple agents including beta-blockers, amiodarone, and magnesium reduce postoperative atrial fibrillation, with varying effect sizes.
- Effect
- Benefit
- Population
- Adults
- Participants
- 18,364
MetaMeta-analysis of randomized controlled trials on magnesium in addition to beta-blocker for prevention of postoperative atrial arrhythmias after coronary artery bypass grafting2013n=1,251
A meta-analysis of 5 RCTs (1,251 CABG patients) found adding IV magnesium to beta-blockers did not reduce postoperative atrial arrhythmia (OR 1.12) and was associated with more adverse events (OR 2.80).
- Effect
- No Benefit
- Population
- Patients undergoing CABG
- Participants
- 1,251
MetaProphylactic magnesium does not prevent atrial fibrillation after cardiac surgery: a meta-analysis2013n=713
A meta-analysis restricted to 5 high-quality CABG trials (1,423 patients) found magnesium did not prevent postoperative atrial fibrillation (OR 0.94, p=0.77), resolving heterogeneity seen in broader prior analyses.
- Effect
- No Benefit
- Participants
- 713
MetaIntravenous magnesium prevents atrial fibrillation after coronary artery bypass grafting: a meta-analysis of 7 double-blind, placebo-controlled, randomized clinical trials2012n=1,028
A meta-analysis of 7 double-blind CABG RCTs (1,028 patients) found IV magnesium reduced postoperative atrial fibrillation by 36% (RR 0.64, 95% CI 0.50–0.83).
- Effect
- Benefit
- Population
- Adults
- Participants
- 1,028
MetaSystemic magnesium to reduce postoperative arrhythmias after coronary artery bypass graft surgery: a meta-analysis of randomized controlled trials2012n=3,696
A meta-analysis of 20 studies (3,696 CABG patients) found systemic perioperative magnesium reduced supraventricular arrhythmias in lower-quality studies (OR 0.47, NNT 8) but not in higher-quality studies (OR 0.85).
- Effect
- No Benefit
- Population
- Patients undergoing CABG
- Participants
- 3,696
Systematic reviewIntravenous magnesium sulphate and sotalol for prevention of atrial fibrillation after coronary artery bypass surgery: a systematic review and economic evaluation2008n=1,070
A systematic review of 15 CABG magnesium vs placebo trials (2,101 patients) found magnesium reduced postoperative AF risk (OR 0.65, 95% CI 0.53–0.79), with 21% vs 30% AF rates in pooled groups.
- Effect
- Benefit
- Dose
- 9 g/day
- Population
- CABG patients
- Participants
- 1,070
MetaMeta-analysis of magnesium therapy for the acute management of rapid atrial fibrillation2007n=476
A meta-analysis of acute AF trials (n=476) found IV magnesium improved rate control (OR 1.96) and rhythm control (OR 1.60) vs placebo, with 86% vs 56% achieving overall response.
- Effect
- Benefit
- Population
- Patients with atrial fibrillation
- Participants
- 476
RCTA randomized controlled trial of magnesium sulfate, in addition to usual care, for rate control in atrial fibrillation2005n=97
An RCT of 199 emergency department patients with rapid AF found IV magnesium (2.5 g bolus + 2.5 g infusion) increased pulse rate <100 bpm (65% vs 34%) and sinus rhythm conversion (27% vs 12%) vs placebo, with more adverse events (15% vs 5%).
- Effect
- Benefit
- Dose
- 2.5 g/day
- Population
- Adults
- Participants
- 97
MetaEffects of magnesium on atrial fibrillation after cardiac surgery: a meta-analysis2005n=2,490
A meta-analysis of 20 cardiac surgery RCTs (2,490 patients) found magnesium reduced postoperative AF from 28% to 18% (OR 0.54) without affecting hospital stay or mortality.
- Effect
- Benefit
- Population
- Cardiac surgery patients
- Participants
- 2,490
MetaImpact of intravenous magnesium on post-cardiothoracic surgery atrial fibrillation and length of hospital stay: a meta-analysis2005n=6
A meta-analysis of 7 cardiothoracic surgery RCTs found magnesium prophylaxis reduced postoperative AF (OR 0.66) and shortened hospital stay by 0.29 days, with greatest benefit from lower doses given preoperatively.
- Effect
- Benefit
- Population
- Cardiothoracic surgery patients
- Participants
- 6
MetaIntravenous magnesium for prevention of atrial fibrillation after coronary artery bypass surgery: a systematic review and meta-analysis2005
A meta-analysis of 8 CABG RCTs found IV magnesium associated with 36% lower postoperative atrial fibrillation risk (RR 0.64, 95% CI 0.47–0.87).
- Effect
- Benefit
MetaPharmacologic prophylaxis for postoperative atrial tachyarrhythmia in general thoracic surgery: evidence from randomized clinical trials2005n=1,294
A meta-analysis of 11 thoracic surgery RCTs (1,294 patients) found calcium-channel blockers and beta-blockers reduced postoperative atrial tachyarrhythmia; magnesium showed benefit in one unblinded trial (RR 0.4).
- Effect
- Benefit
- Population
- General thoracic surgery patients
- Participants
- 1,294
MetaMagnesium prophylaxis for arrhythmias after cardiac surgery: a meta-analysis of randomized controlled trials2004n=2,069
A meta-analysis of 17 cardiac surgery trials (2,069 patients) found prophylactic magnesium reduced supraventricular arrhythmias by 23% (RR 0.77), atrial fibrillation by 29%, and ventricular arrhythmias by 48%.
- Effect
- Benefit
- Dose
- 1.4 mg/day
- Population
- Cardiac surgery patients
- Participants
- 2,069
RCTThe value of P dispersion on predicting atrial fibrillation after coronary artery bypass surgery; effect of magnesium on P dispersion2003n=93
A clinical trial of 148 heart bypass surgery patients found that 1.5 g/day IV magnesium sulfate (Infusion in 100 mL 0.9 NaCl solution, 25 mL/hr) applied the day before surgery, post-surgery, and once daily for 4 days following surgery, reduced the rate of atrial fibrillation from 36% (Placebo: 100 mL 0.9 NaCl solution, 25 mL/hr) to 2%.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 1.5 g/day
- Population
- Patients undergoing CABG
- Participants
- 93
RCTDose-related cardiac electrophysiological effects of intravenous magnesium. A double-blind placebo-controlled dose-response study in patients with paroxysmal supraventricular tachycardia2000n=36
A dose-response RCT of 36 PSVT patients found IV magnesium at 5 mmol prolonged the atrial-His interval with no additional effect at 10–20 mmol, and sex-dependent effects on atrial refractory period were observed.
- Population
- Patients with paroxysmal supraventricular tachycardia
- Participants
- 36
RCTHypomagnesemia in heart failure with ventricular arrhythmias. Beneficial effects of magnesium supplementation2000n=78
A study showing magnesium supplementation reduced ventricular arrhythmias in heart failure patients with low magnesium. A study of 68 patients found that intravenous administration of magnesium (Magnesium sulfate 8 g in 50 mL of 5% glucose) over 12 hours reduced the number of ventricular ectopic beats (P<0.0001), couplets (P<0.003) and episodes of nonsustained ventricular tachycardia (P<0.01).
- Effect
- Benefit
- Duration
- 12 hours
- Dose
- 8 g/day
- Population
- Heart failure patients
- Participants
- 78
RCTUsefulness of intravenous magnesium for multifocal atrial tachycardia in patients with chronic obstructive pulmonary disease1998
An RCT found IV magnesium effective for rate control in multifocal atrial tachycardia in COPD patients and may help restore sinus rhythm.
- Effect
- Benefit
- Population
- COPD patients
RCTAntiarrhythmic effects of increasing the daily intake of magnesium and potassium in patients with frequent ventricular arrhythmias. Magnesium in Cardiac Arrhythmias (MAGICA) Investigators1997n=232
A 3-week double-blind RCT of 232 patients with frequent ventricular arrhythmias found oral magnesium/potassium aspartate (6/12 mmol daily) reduced ventricular premature beats by 17.4% vs 7.4% on placebo (p=0.001).
- Effect
- Benefit
- Duration
- 3 weeks
- Population
- Patients with frequent ventricular arrhythmias
- Participants
- 232
Magnesium and potassium therapy in multifocal atrial tachycardia1985
A clinical study of 8 patients with multifocal atrial tachycardia given IV magnesium sulfate (7–12 g over 5 hours) found 7 of 8 converted to sinus rhythm or sinus tachycardia.
- Effect
- Benefit
- Dose
- 7–12 g/day
- Population
- Patients with multifocal atrial tachycardia
L-CarnitineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some small studies suggest that taking L‑carnitine by mouth may help reduce abnormal heartbeats in people with premature ventricular contractions.
- Tested doses included 2 grams twice a day for nearly a year or 2 grams three times a day for 2 weeks.
Browse 3 studies
RCTTherapy of arrhythmia induced by myocardial ischemia. Association of L-carnitine, propafenone and mexiletine1995n=50
A randomized controlled trial in 50 patients with effort angina and ventricular ectopic beats demonstrated that oral L-carnitine (2 g × 3 daily) significantly reduced the number of ventricular ectopic beats and potentiated the anti-arrhythmic effects of propafenone and mexiletine when combined.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 2 g/day
- Population
- Patients with effort angina and ventricular ectopic beats
- Participants
- 50
RCTThe evaluation of the antiarrhythmic activity of L-carnitine and propafenone in ischemic cardiopathy1993n=30
In 30 ischemic heart disease patients with arrhythmias, L-carnitine reduced ventricular extrasystoles versus baseline over the treatment period in a randomized evaluation with propafenone reference.
- Effect
- Benefit
- Dose
- 900 mg/day
- Population
- Patients with ischemic heart disease
- Participants
- 30
- Avg age
- ~64
Controlled trialThe benefits of L-carnitine therapy in essential arterial hypertension with diabetes mellitus type II1989
A clinical trial in patients with essential hypertension and type II diabetes mellitus treated with 2 g twice daily L-carnitine for 45 weeks showed a reduction in cardiac arrhythmias (extrasystoles, A-V conduction disorders) and improvement in symptoms such as asthenia, with good tolerability.
- Effect
- Benefit
- Duration
- 45 weeks
- Dose
- 2 g 2×/day
- Population
- Patients with diabetes
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Magnesium | ★★★★★68% | 26 | 15 | 90% |
| L-Carnitine | ★★★★★48% | 3 | 0 | 10% |