Another rare channelopathy that I was not previously aware of, but that carries the same risks of sudden death as long-QT syndromes.
This is a longitudinal observational study of the European Short QT Registry – which has a grand total of 53 patients – who were followed for, on average, 5 years. The diagnosis of short QT does not have a generally accepted definition, but typically means a QTc less than 340 or 360, and the other literature shows a high association with sudden death and QTc less than 340. In their registry 23% had a HERG gain-of-function mutation identified, and there is also an autosomal dominant inheritance pattern identified.
Based on their follow-up for events, or for cardiac events recorded by implantable defibrillators, there was a 4.9% incidence of syncope, defibrillator shocks, or nonsustained polymorphic ventricular tachycardia. Prophylactic treatment involves either the implantable defibrillator or daily hydroquinidine therapy to prolong QT.
Something new to look for on EKGs that you’ll probably never see, but will seem really smart if you do.
“Long-term follow-up of patients with short QT syndrome”
www.ncbi.nlm.nih.gov/pubmed/21798421