Table 1. Characteristics of LQTS-3 patients reported in this study.
Parameters | Patient NP0012 | Patient NP0016 |
---|---|---|
Mutation and location | c.1604GA; p.R535Q in the intracellular linker region between DI and DII | c.718GA; p.V240M in the cytoplasmic loop between S4 and S5 within the DI |
Gender | Female | Male |
Date of birth | 1972 | 1976 |
QTc (ms) | 540 | 440 |
Clinical phenotype | At age of 32, the patient presented with several episodes of syncopes and torsades de pointes tachycardia, and survived one sudden cardiac death event. This patient developed DCM* in the later course of the disease. | This patient presented with frequent syncopes at age of 23 and at age of 30 with recurrent tachycardias. The patient was resuscitated from one sudden cardiac death event. |
Therapy | Class IB anti-arrhythmic drug (mexiletine); β1-adrenergic antagonist (metoprolol); K+ and Mg2+ supplementation; ICD implantation. Despite medication the ICD recorded frequent VES and terminated recurrent VT. | Antiarrhythmic drug (phenytoin); β1-adrenergic antagonist (metoprolol); K+ and Mg2+ supplementation; ICD implantation. Despite medication episodes of torsades de pointes VT recurred and were terminated adequately by the ICD. |
Abbreviations: QTc – corrected QT interval; DCM – dilated cardiomyopathy; ICD - implantable cardioverter defibrillator; VES - ventricular extrasystoles; VT – ventricular tachycardias.
* Mutations in typical DCM-causing genes could not be identified in this patient.