The frequent occurence of sudden cardiac events in patients with long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, a long chain fatty acid oxidation disorder (LCFAOD), was discussed in the final session of the 2022 lecture series held by the International Network for Fatty Acid Oxidation Research and Management (INFORM). 

Medical geneticist Gabriela Elizondo, MD, presented a retrospective descriptive analysis of records obtained from a fatty acid oxidation disorders repository focusing on the cardiac phenotype of 15 patients with LCHAD deficiency. 

Among the 15 patients, 4 had cardiomyopathy, corresponding to a little more than a quarter (26.6%) of all patients, which is less than what is reported for fatty acid oxidation disorders. However, 9 of the patients had a sudden cardiac event, which included all 4 of the patients with cardiomyopathy. The sudden cardiac events included sudden cardiac death that occurred in 2 patients, sudden cardiac arrest that occurred in 6 patients, and syncope that occurred in 1 patient.

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Dr. Elizondo stressed that cardiac symptoms are a late complication of LCHAD deficiency and that sudden cardiac events occur without acute metabolic decompensation.

Read more about the etiology of the different types of LCFAOD

Infant cardiomyopathy seems to be a risk factor for a sudden cardiac event in these patients, Dr. Elizondo said,  “but not the only thing to keep in mind.”

It is still not known why these arrhythmias and cardiomyopathies are happening, she added, and speculated that they could be due to a chronic energy deficiency, a starved heart, or an accumulation of toxic lipids in the body.

“It’s also important to know that these are all teenagers,” Dr. Elizondo said and touched on the potential effect of diet compliance issues, hormonal changes, rapid growth, and changing metabolic needs that could all be contributing to the occurrence of these sudden cardiac events.


Cardiac phenotype in young adults with LCHADD. Lecture presented as part of International Network for Fatty Acid Oxidation Research and Management (INFORM) 2022 lecture series: June 20, 2022; Virtual.