Localization of the Sites of Conduction Abnormalities in a Mouse Model of Myotonic Dystrophy
| Autor: | Paul J. Wang, Samir Saba, Charles I. Berul, Sita Reddy, Mark J. Aronovitz, David E. Housman, Mark Estes, N.A. Michael E. Mendelsohn M.D., Brenda Luciano, A B S Brian Vanderbrfnk |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
medicine.medical_specialty
Heart block Stimulation Protein Serine-Threonine Kinases Myotonic dystrophy Myotonin-Protein Kinase Electrocardiography Mice Refractory Heart Conduction System In vivo Physiology (medical) Internal medicine medicine Animals Humans Myotonic Dystrophy Mice Knockout Conduction abnormalities business.industry Heart medicine.disease Electrophysiology Endocrinology Knockout mouse Cardiology and Cardiovascular Medicine business |
| Zdroj: | Journal of Cardiovascular Electrophysiology. 10:1214-1220 |
| ISSN: | 1540-8167 1045-3873 |
| DOI: | 10.1111/j.1540-8167.1999.tb00298.x |
| Popis: | Heart Block in a Mouse Model of Myotonic Dystrophy. Introduction: A mouse strain lacking functional myotonic dystrophy protein kinase (DMPK) has recently been developed. DMPK-/- mice exhibit muscular and conduction abnormalities consistent with the disease; however, the site of abnormal cardiac conduction is unknown. Methods and Results: Nine homozygous DMPK-/- mice and seven age matched wild-type (WT) controls underwent in vivo electrophysiologic studies using an endocardial 2-French catheter. Baseline intervals as well as Wenckebach and 2:1 cycle lengths were measured to assess AV and ventriculoatrial (VA) conduction. Effective refractory periods (ERP) and functional refractory periods were determined during atrial and ventricular premature stimulation. His-bundle recordings were obtained on all the studied animals (16/16). DMPK-/- mice bad significantly prolonged PR (48.1 ± 5.5 vs 40.9 ± 3.9 msec, P = 0.010) and AH (36.7 ± 4.0 vs 31.6 ± 4.8 msec, P = 0.037) intervals compared to WT controls. HV intervals were very significantly prolonged as well (14.7 ± 2.0 vs 10.3 ± 0.8 msec; P < 0.0001). Three of 9 DMPK-/- and I of 7 WT mice exhibited VA block. Atrial ERP was reached before AV node ERP in 2 (22%) of 9 of the knockout mice and 5 (71%) of 7 of the controls (P = 0.06). Only one mouse (DMPK-/-) exhibited infra-Hisian block on premature atrial stimulation. Conclusion: In this mouse model of myotonic dystrophy, AV conduction abnormalities were localized to the supra-Hisian and infra-Hisian conduction tissues, with a higher predilection to the latter, a finding similar to the human form of the disease. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text