Alterações eletrocardiográficas na hipotermia acidental em região urbana e tropical

• Autor(a) principal: Souza, Dilma do Socorro Moraes de [UNIFESP]
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/23632
• topic: Hipotermia; Eletrocardiografia; Onda

Hypothermia is defined as the condition in which the core temperature (rectal, esophageal or tympanic) reaches values below 36°C. This may be accidental, metabolic or therapeutic. The accidental form is frequent in cold-climate countries, being rare in those with a tropical or subtropical climate. Purpose: The aim of this study was to evaluate electrocardiographic changes of patients with accidental hypothermia. Methods: In 59 patients with hypothermia the following electrocardiogram (ECG) parameters were analyzed: rhythm and heart rate, P wave characteristics, PR interval, duration of the QRS complex, presence of J wave and its characteristics, and correlation with the degree of hypothermia, changes in T wave regarding its polarity and characteristics, duration of the QT interval corrected for heart rate using Bazett’s and Fridericia`s formula, and the eventual presence of both supraventricular or ventricular arrhythmias. Results: In six patients the ECG was normal. Sinus bradycardia was observed in 54,2% of the patients. J wave was present in 51 patients and its voltage correlated inversely and statistically significantly with the core temperature. Changes in T wave were observed in 47.4% of the cases. The QT interval, adjusted corrected for heart rate by Bazett’s formula was prolonged in 74,5%, and by Fridericia’s formula in 71,1% of the cases. Idioventricular rhythm was found in six cases, total atrioventricular block in three and junctional rhythm and atrial fibrillation in two patients. Conclusions: ECG changes in accidental hypothermia are frequent and characteristic for this entity improving diagnosis in unconscious patients.