Premium
Short‐term response to phenytoin sodium in Andersen‐Tawil syndrome‐1 with a cardiac‐dominant phenotype
Author(s) -
Rai Maneesh K.,
Pai Rohith,
Prabhu Mukund A.,
Pasha Syed Waleem,
Kedambadi Rakshith C.,
Kamath Padmanabh,
Augustine Alfred J.,
Bhavani Gangham SriLakshmi,
Girisha Katta M.
Publication year - 2019
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.13569
Subject(s) - medicine , phenytoin , periodic paralysis , paralysis , anesthesia , cardiology , epilepsy , surgery , psychiatry
Background Andersen‐Tawil syndrome (ATS) is a rare familial periodic paralysis that typically also affects the heart and skeletal system. Ventricular arrhythmias (VAs) are profound and difficult to control, but minimally symptomatic. In this report, we describe an atypical phenotype of ATS in two related families. We also report our experience with phenytoin sodium for the control of resistant VAs in these patients. Methods and Results Between 2014 and 2018, seven siblings were diagnosed with ATS on the basis of cardiac arrhythmias and genetic evaluation. Heterozygous mutation with c.431G > C ( p.G144A ) in exon 2 of KCNJ2 gene was observed in all patients. Characteristic cardiac manifestations were noted in all patients but periodic paralysis or objective neurological involvement was distinctly absent. Phenytoin was considered for control of symptomatic VA in three patients. Intake of oral phenytoin (5 mg/kg/day) for 1 month completely suppressed VA (<1% in 24‐h Holter monitoring) in two patients, and significantly in the third (8% per 24 h) patient. Phenytoin was well‐tolerated in all three patients. Conclusions We describe a cardiac‐predominant phenotype in ATS. ATS should be suspected in patients with typical cardiac manifestations even in the absence of periodic paralysis. Our initial experience with short‐term use of phenytoin for control of resistant VAs is encouraging.