Purpose of review
Dramatic advances have been made in understanding of both the genetics
and the phenotypic expression of congenital long QT
syndrome. This paper reviews recent clinically relevant literature.
Recent findings Long QT
syndrome is one of the leading causes of sudden cardiac death. This syndrome, once diagnosed by a clinical profile, has been more clearly defined by specific gene defects causing ion channel
abnormalities in the beating heart. Genetic testing for long QT
syndrome, once available only through research laboratories, is now commercially available. Diagnosis, risk assessment, and management are increasingly being guided by gene-specific diagnoses. In a family with suspected disease, the genetic test will determine the defect in as many as 75% of subjects. Once the diagnosis is made, the mainstay of therapy continues to be β-blockers. Implantable cardioverter-defibrillators are indicated in patients at high risk for malignant arrhythmias.
Summary Long QT
syndrome is one of the first cardiovascular diseases to see the dramatic changes that bench research can bring to the clinical arena. Future research is needed to determine the gene defect in the remaining 25% of patients with suspected long QT
syndrome and in risk stratification.