Linked Life Data

9183592

Source:http://linkedlifedata.com/resource/pubmed/id/9183592

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-8-21
pubmed:abstractText
Various QT interval variables and heart rate variability parameters were studied in six patients with ventricular fibrillation but without heart disease and compared with findings in 21 normal persons. QT and QT dispersion (QTd) were measured from conventional 12 lead ECGs: for dynamic QT analysis, QT intervals were automatically measured to the end of the T wave (QTe) on a 24 h ECG recording. The adaptation of the QT interval to changes in heart rate was expressed as the slope of the linear regression lines relating QTc to the RR interval (Sc). The complete 24 h ECG recording and four 6 h segments were studied (morning, day, evening, and night). Ventricular fibrillation patients had slightly prolonged QTmax intervals on the 12 lead ECG, QT dispersion was longer in ventricular fibrillation patients than in normal persons (88 +/- 29 ms vs 59 +/- 26 ms. P < 0.05), and on the 24 h ECG recording, normal persons and ventricular fibrillation patients had a comparable RR. In addition, parameters for long-term (SD, standard deviation of normal RR intervals) and short-term (RMSSD, the root-mean-square successive differences of normal RR intervals heart rate variability were not different. Automatic measurement of the QT interval and the QTc/RR slopes was possible over 24 h and in the 6 h intervals in a large majority of patients (25/27 and 88/108 readings). The mean 24 h QT and the mean 6 h QT interval were comparable in normal subjects and ventricular fibrillation patients except for the day segment. The 24 h Se was significantly lower in ventricular fibrillation patients, compared to normal individuals. Furthermore, Se in the morning and night segment was also significantly lower in ventricular fibrillation patients (both P < 0.05). In conclusion, patients with ventricular fibrillation but without underlying structural heart disease have normal heart rate variability parameters. However, abnormal repolarization behaviour, characterized by an increased QTd and a depressed adaptation of QT to variations in RR (especially during the night and the morning), is present. These findings may help to understand and treat arrhythmias in this patient group.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0195-668X
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
994-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Changes in the QT interval and its adaptation to rate, assessed with continuous electrocardiographic recordings in patients with ventricular fibrillation, as compared to normal individuals without arrhythmias.
pubmed:affiliation
Department of Cardiology, University Hospital Ghent, Belgium.
pubmed:publicationType
Journal Article, Clinical Trial, Comparative Study, Controlled Clinical Trial