Isotretinoin and Heart Rate
Isotretinoin does not appear to affect heart rate or cause clinically significant cardiac arrhythmias in the vast majority of patients, though rare cases of premature ventricular contractions have been documented. 1, 2
Evidence on Cardiac Effects
Heart Rate Studies
The most robust evidence demonstrates no significant impact on heart rate:
A prospective study of 45 patients receiving 0.8 mg/kg/day of isotretinoin for 6 months found that mean heart rates remained stable throughout therapy, with no changes in QT intervals or QT dispersion. 1 This finding is particularly reassuring as it indicates no increased risk for polymorphic ventricular tachycardia.
A separate 24-hour Holter monitoring study of 22 patients showed normal sinus rhythm was maintained in all patients, with mean heart rates of 79 beats/min at baseline and 81 beats/min at 3 months—a clinically insignificant difference. 2 No supraventricular tachycardia or atrial arrhythmias were detected.
Rare Arrhythmic Events
Despite the reassuring data above, isolated case reports suggest caution:
Two documented cases describe premature ventricular contractions (PVCs) temporally associated with isotretinoin use, with resolution after drug discontinuation. 3, 4 One case involved a 17-year-old boy and another a 33-year-old woman, both developing PVCs during treatment that disappeared within 2 weeks of stopping isotretinoin.
An extremely rare case report describes dilated cardiomyopathy and renal infarction in an 18-year-old after 5 months of isotretinoin use, though causality remains uncertain. 5
Guideline Perspective on Cardiovascular Risk
The American Academy of Dermatology guidelines acknowledge "cardiovascular risk factors" as a speculative adverse effect of interest but provide no specific recommendations for cardiac monitoring. 6 The guidelines note that while there is no proof of long-term cardiovascular risk from short-term elevation of triglycerides and cholesterol during isotretinoin therapy, routine monitoring of serum lipid profiles should continue. 6
Clinical Implications
Monitoring Recommendations
Routine cardiac monitoring (ECG or Holter monitoring) is not warranted for asymptomatic patients based on current evidence. 1, 2
Standard monitoring should focus on lipid profiles and liver function tests at baseline and 2 months into treatment, with more frequent monitoring as clinically indicated. 7
When to Consider Cardiac Evaluation
If patients develop palpitations, chest pain, or other cardiac symptoms during isotretinoin therapy, obtain an ECG and consider Holter monitoring. 3, 4 The temporal association and resolution after drug cessation in reported cases suggests a potential causal relationship in susceptible individuals.
Important Caveats
The lipid abnormalities induced by isotretinoin (hypertriglyceridemia in 25-50% of patients) do not appear to correlate with cardiac rhythm disturbances. 7, 1
Patients with pre-existing cardiac conditions or risk factors should be counseled about the rare possibility of arrhythmias, though the absolute risk appears very low. 3, 4
The vast majority of isotretinoin's well-documented side effects involve mucocutaneous, musculoskeletal, and ophthalmic systems—not cardiac effects. 6, 7