Sudden cardiac arrest as a presentation of Brugada syndrome unmasked by thyroid storm

Abstract

An 18-year-old man suffered a sudden cardiac arrest with ventricular fibrillation and was successfully resuscitated. He had neither a medical nor family history of cardiac disease/sudden death, but was known to have Graves' disease, for which he was treated with radioactive iodine. Recently, block-and-replacement therapy had been discontinued to evaluate thyroid functioning. On admission, thyroid hormone levels were markedly elevated, suggesting thyroid storm due to residual Graves' disease. The patient was treated with propylthiouracil, hydrocortisone and Lugol solution. ECG showed repolarisation patterns suggestive of an underlying type 1 Brugada syndrome (BS). These findings were confirmed by an additional ajmaline test. An implantable cardioverter defibrillator was implanted to prevent future arrhythmias. The patient underwent total thyroidectomy 9 months later and recovered completely. To the best of our knowledge, this is the first reported case of a sudden cardiac arrest as a presentation of BS unmasked by thyroid storm.

J wave syndromes as a cause of malignant cardiac arrhythmias

“…Together, these data suggest the possibility that in the individual patient, BrS and the susceptibility to VF and SCD may not be due to a single mutation but rather to inheritance of multiple BrS‐susceptibility variants (oligogenic) acting in concert through one or more mechanistic pathways . In addition to the multifactorial nature of the genetics, expressivity of the syndrome is multifactorial in that phenotypic expression can be importantly modulated by hormonal factors including testosterone, and thyroxine as well as by other environmental factors and structural remodeling involving development of fibrosis …”

J‐Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge

“…This also fits with the findings of Probst et al [210] that in 5 of 13 large families with a putative SCN5A mutation, the genotype did not co-segregate with the phenotype. In addition to the multifactorial nature of the genetics, expressivity of the syndrome may be multifactorial in that the genetic predisposition can be modulated by hormonal (testosterone [211] , [212] , thyroxine [213] ) and other environmental factors, as well as morphologic changes (fibrosis) [76] .…”

J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge

“…167 This also fits with the findings of Probst et al that in 5 out of 13 large families with a putative SCN5A mutation, the genotype did not co-segregate with the phenotype. 210 In addition to the multifactorial nature of the genetics, expressivity of the syndrome may be multifactorial in that the genetic predisposition can be modulated by hormonal (testosterone, 211, 212 thyroxine 213 ) and other environmental factors, as well as morphological changes (fibrosis). 76 …”