ID 98230
Title Transcription
コウテンセイ QT エンチョウ ショウコウグン ノ ビョウタイ
Title Alternative
The clinical state of acquired long QT syndrome
Author
Yamamoto, Hirofumi Department of Cardiology, Tokushima Prefectural Miyoshi Hospital
Keywords
acquired long QT syndrome
torsade de pointes
magnesium
isoproterenol
reentry mechanism
Content Type
Journal Article
Description
The definition of long QT syndrome depends on demonstration of QT prolongation and recurrent syncope due to life-threatening ventricular arrhythmia . Acquired long QT syndromes are those due to drugs ( antiarrhythmic agents , antibiotics and phenothazines ), electrolyte abnormalities , acute ischemia and heart block. The ventricular arrhythmia is of a unique type known as torsade de pointes (TdP), which is characterized by rapid rates and gradually changing QRS morphology. Recently, It is reported that the cause of congenital long QT syndrome was abnormalities of gene coded myocardial ion channel, and some of acquired long QT syndrome was associated with congenital abnormalities of ion channel gene. In treatment of acquired long QT syndrome, the first step is to stop administration of the causative drug if can be identified. The aim of the therapy of TdP is to shorten and unify the uneven ventricular repolarization ; that is to correct the underlying electrophysiological disorder . Ventricular pacing and isoproterenol frequently prevent recurrent episodes of TdP by shortening action potential duration. Magnesuim is useful in treating TdP. The antiarrhythmic effect of magnesuim is due to shortening of the duration of ventricular vulnerable period during the cardiac cycle and prevention of ventricular arrhythmias related to reentry mechanism.
Journal Title
四国医学雑誌
ISSN
00373699
NCID
AN00102041
Publisher
徳島医学会
Volume
61
Issue
5-6
Start Page
135
End Page
139
Sort Key
135
Published Date
2005-12-20
Remark
FullText File
language
jpn