| First Author | Markandeya YS | Year | 2016 |
| Journal | Heart Rhythm | Volume | 13 |
| Issue | 11 | Pages | 2228-2236 |
| PubMed ID | 27498076 | Mgi Jnum | J:319201 |
| Mgi Id | MGI:6863128 | Doi | 10.1016/j.hrthm.2016.08.007 |
| Citation | Markandeya YS, et al. (2016) Inhibition of late sodium current attenuates ionic arrhythmia mechanism in ventricular myocytes expressing LaminA-N195K mutation. Heart Rhythm 13(11):2228-2236 |
| abstractText | BACKGROUND: Lamin A and C are nuclear filament proteins encoded by the LMNA gene. Mutations in the LMNA gene cause many congenital diseases known as laminopathies, including Emery-Dreifuss muscular dystrophy, Hutchinson-Gilford progeria syndrome, and familial dilated cardiomyopathy (DCM) with conduction disease. A missense mutation (N195K) in the A-type lamins results in familial DCM and sudden arrhythmic death. OBJECTIVE: The purpose of this study was to investigate the ion current mechanism of arrhythmia and DCM caused by the LaminA-N195K variant. METHODS: A homozygous mouse line expressing the Lmna-N195K mutation (Lmna(N195K/N195K)) that exhibited arrhythmia, DCM, and sudden death was used. Using whole cell patch-clamp technique, we measured action potential duration (APD), Na(+) currents (INa) in ventricular myocytes isolated from Lmna(N195K/N195K), and wild-type mice. RESULTS: Both peak and late INa were significantly (P <.05) increased in Lmna(N195K/N195K) ventricular myocytes. Similarly, Lmna(N195K/N195K) ventricular myocytes exhibited significant (P <.005) prolongation of APD (time to 50% [APD50] and 90% [APD90] repolarization) and triggered activity. Acute application of ranolazine inhibited late INa, shortened APD, and abolished triggered activity in Lmna(N195K/N195K) ventricular myocytes. CONCLUSION: Inhibition of late INa may be an effective therapy in preventing arrhythmia in patients with LmnaN195K mutation-related DCM. |
