Document Detail

Apparent bradycardia-dependent sinoatrial block associated with respiration.
MedLine Citation:
PMID:  11099362     Owner:  NLM     Status:  MEDLINE    
In our previous patients, apparent bradycardia-dependent block has been shown in the atrioventricular (AV) junction and in the accessory pathway. It was suggested that these previous cases were not of true bradycardia-dependent block; namely, that, as a result of periodic increases in vagal tone associated with respiration, conductivity in the AV junction or in the accessory pathway was depressed to a greater degree than automaticity in the sinus node. In the present article, 3 patients with frequent sinoatrial (SA) block were reported. In 1 patient, sinus escape-capture bigeminy caused by SA block was found. In these present patients, when the sinus cycle lengthened, SA block occurred. The purpose of the present article is to show that the patients have apparent bradycardia-dependent SA block, namely, not true bradycardia-dependent SA block. In all patients, the respiration curve was recorded simultaneously with the electrocardiogram. In all patients, during inspiration, the sinus cycle gradually shortened; on the other hand, during expiration, the sinus cycle gradually lengthened, and then a sinus impulse was blocked in the SA junction. These findings suggested that increased vagal tone during expiration depressed conductivity in the SA junction to a greater degree than automaticity in the sinus node.
T Katoh; S Kinoshita; Y Tsujumura; Y Sasaki
Publication Detail:
Type:  Case Reports; Comparative Study; Journal Article    
Journal Detail:
Title:  Journal of electrocardiology     Volume:  33     ISSN:  0022-0736     ISO Abbreviation:  J Electrocardiol     Publication Date:  2000 Oct 
Date Detail:
Created Date:  2001-03-06     Completed Date:  2001-05-31     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0153605     Medline TA:  J Electrocardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  375-80     Citation Subset:  IM    
Katoh Cardiovascular Clinic, Ohtsu, Japan.
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MeSH Terms
Bradycardia / diagnosis,  physiopathology*
Diagnosis, Differential
Middle Aged
Sinoatrial Block / diagnosis,  physiopathology*
Sinoatrial Node / physiopathology
Vagus Nerve / physiopathology

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