Can DMSO Produce Asystole?
Yes, DMSO can cause asystole and other life-threatening cardiac arrhythmias, particularly when infused rapidly in high concentrations during stem cell transplantation. 1, 2, 3
Documented Cardiac Toxicities
DMSO has been directly associated with severe cardiac complications including:
- Asystole - documented as a fatal complication during cryopreserved stem cell infusion 1, 3
- Cardiac arrest - reported within minutes of DMSO-containing peripheral blood stem cell infusion 2
- Bradycardia and heart block - recognized systemic side effects of DMSO administration 3
- Life-threatening arrhythmias - occurring immediately after infusion of DMSO-cryopreserved products 1
Highest Risk Clinical Scenarios
Patients with pre-existing cardiac disease are at substantially elevated risk. The fatal case involved a patient with severe primary cardiac amyloidosis who developed fatal arrhythmias after the second fractioned infusion (350 mL) of DMSO-cryopreserved stem cells 1. This demonstrates that even fractioned dosing may not prevent catastrophic outcomes in vulnerable cardiac patients.
High-volume, rapid infusions pose the greatest danger. The mechanism appears dose-dependent, with the total amount of transfused DMSO being the major cause of cryoprotectant-related toxicity 4.
Risk Mitigation Strategies
Fractionate the infusion to reduce peak DMSO exposure. Studies using continuous cardiac monitoring during fractioned infusions documented only asymptomatic sinus bradycardia rather than major arrhythmias 4. Split large volumes across multiple days (e.g., 455 mL day 1,350 mL day 2) rather than single bolus administration 1.
Implement mandatory continuous cardiac monitoring during and immediately after any DMSO-containing infusion, as fatal arrhythmias can occur within minutes of infusion initiation 2. Have resuscitation equipment and personnel immediately available 1, 2.
Screen for cardiac contraindications before DMSO administration. Patients with severe cardiac involvement (particularly infiltrative diseases like amyloidosis), end-stage renal failure, or significant structural heart disease require extreme caution or alternative approaches 1.
Mechanism of Toxicity
The cardiovascular effects likely result from multiple mechanisms:
- Hyperosmotic plasma volume expansion causing acute increases in cardiac index, heart rate, and pulmonary capillary wedge pressure 5
- Direct myocardial effects causing decreased systemic vascular resistance 5
- Possible idiosyncratic reactions in susceptible individuals 2
Most hemodynamic changes are transient, returning toward baseline within 10 minutes post-infusion in healthy subjects 5, but this recovery period may be insufficient in patients with compromised cardiac reserve 1.
Critical Clinical Pearls
Do not assume DMSO is benign simply because it is widely used as a solvent. The context of stem cell transplantation involves substantially higher doses (2 g/kg) than typical laboratory or topical applications 3, 5.
Renal failure compounds the risk. The fatal case involved both severe cardiac disease AND end-stage renal failure, suggesting impaired DMSO clearance may potentiate toxicity 1.
Neurological toxicity can accompany cardiac events. Tonic-clonic seizures have been reported immediately before cardiac arrest during DMSO infusion, indicating multi-system toxicity 2.