Torsades de Points: análise de 105 episódios / Torsades de Pointes: analysis of 105 episodes
Arq. bras. cardiol
; 56(6): 451-456, jun. 1991. ilus, tab
Article
em Pt
| LILACS
| ID: lil-107795
Biblioteca responsável:
BR1.1
ABSTRACT
Purpose - To analyze episodes of Torsades de Pointes (TP), in search of its electrocardiographic characteristics. Patients and Methods - We analyzed 105 episodes of TP, in 4 patients using quinidine and diuretics, recorded by 24-hour Holter monitoring The following parameters were studied; ventricular repolarization out of TP, rhythm disturbances before TP; EKG characteristics of the onset, the bouts and the end of the TP. Results - Ventricular repolarization, out of the TP, was abdormal, with the presence of U-waves at the end of the T-waves, resulting in prolongation of the QT (QU) interval. The U-wave voltage was noted to be cycle-lenght dependent. Ventricular bigeminy preceded TP in 100 episodes (95%) and the mean interval between both parameters was 18 ±16 min. The onset of the TP episodes showed the "short/long/ short cycle rale", hereby called "pre-pause cycle", "preparing cycle" and "trigger cycle" respectively. The rotatory QRS-T morphology around the baseline, was seen in 75% of episodes, at the beginning or throughtout the bout. Monomorphic ventricular tachycardia pattern was seen in the other 25% of episodes. Termination of bouts was sudden in all cases, and persistent ventricular bigeminy led to another bout in 90 episodes (85% ). Conclusion - In TP patients, there is enlargement of QT intervals mostly due to U-waves appearence. The U-waves seen in these cases, probably have an important role in the genesis of TP and are probably related to ventricular after potentials (triggered activity). Ventricular bigeminy is a premonitory sign of TP in patients using class 1A antiarrhythmic drugs Persistent ventricular bigeminy post-TP episoaes is a strong indicator of another bout of TP. The onset of TP is more important than its morphology for the correct diagnosis of this arrhythmia
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Torsades de Pointes
Tipo de estudo:
Observational_studies
Limite:
Female
/
Humans
/
Male
Idioma:
Pt
Revista:
Arq. bras. cardiol
Assunto da revista:
CARDIOLOGIA
Ano de publicação:
1991
Tipo de documento:
Article
País de publicação:
Brasil