Document Detail

Ultrastructure of electrophysiologically identified human sinoatrial nodes.
MedLine Citation:
PMID:  3190658     Owner:  NLM     Status:  MEDLINE    
The ultrastructure of freshly excised human sinus node tissue was studied. In three female patients (ages 20, 30, and 36 years) medically refractory disabling episodes of inappropriate sinus tachycardia were surgically treated by extirpation of the sinus node. Each patient underwent intraoperative electrophysiological mapping to determine the area of earliest atrial activation. This area corresponded anatomically to the region of the sinoatrial node and was excised in each patient, the defect repaired using a pericardial patch. The freshly excised SA nodes underwent ultrastructural study. Three types of myocardial cells were identified: pacemaker or polygonal cells with clear cytoplasm, few mitochondria and sparse numbers of contractile elements (P cells); a transitional cell with slightly increased numbers of myofibrils (T cells); and typical atrial myocardial cells with normal numbers of contractile elements. These cell types have previously been identified in post-mortem studies of presumed SA node. The current study confirms the cell types in electrophysiologically documented SA nodes. The one abnormal finding observed in transitional cells in all patients was an increased number of lipofuscin-laden vacuoles. These vacuoles are considered a sign of cell degeneration and their occurrence was totally unexpected in these young adults. In summary, ultrastructural study of electrophysiologically documented human SA nodes confirmed the cell types identified in post-mortem studies. Furthermore, lipofuscin-laden vacuoles were increased in these three patients and this finding may serve as an ultrastructural marker associated with the syndrome of inappropriate sinus tachycardia.
J E Lowe; T Hartwich; M Takla; J Schaper
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Basic research in cardiology     Volume:  83     ISSN:  0300-8428     ISO Abbreviation:  Basic Res. Cardiol.     Publication Date:    1988 Jul-Aug
Date Detail:
Created Date:  1988-11-28     Completed Date:  1988-11-28     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0360342     Medline TA:  Basic Res Cardiol     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  401-9     Citation Subset:  IM    
Duke University Medical Center, Durham, NC.
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MeSH Terms
Microscopy, Electron
Myocardium / pathology,  ultrastructure*
Sinoatrial Node / pathology,  physiopathology,  ultrastructure*
Tachycardia, Sinus / pathology*,  physiopathology
Tachycardia, Supraventricular / pathology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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