תוצאת חיפוש

Circadian Fluctuations of the Signal-Averaged ECG

Ehud Goldhammer, Edward Abinader

Cardiology Dept., Bnei-Zion Medical Center and Bruce Rappaport Faculty of Medicine, The Technion, Haifa

Circadian periodicity for the time of onset of acute myocardial infarction has been shown; the early morning peak of infarction coincides with the onset of other related phenomena, including sudden cardiac death, ventricular arrhythmias, thrombotic stroke, etc. Late potentials detected by the signal-averaged ECG are considered to be independent markers of vulnerability to ventricular arrhythmias. The signal-averaged ECG enables the amplifying and recording of small bioelectric signals of cardiac origin, while eliminating extraneous electrical "noise." To determine whether late potentials are themselves subject to circadian influence, 31 patients (age range 41-79) who had had an old or recent myocardial infarction underwent late potential assessment by the signal-averaged ECG. 4 indices were studied: duration of late LPD potentials (LPD), total QRS duration (TQRS), and root mean square voltage of the last 40 msec, and of the last 50 msec (RMS 40 and RMS 50). These indices were assessed 3 times, during the early morning hours, at noon and during the evening. Morning LPD differed significantly from noon and evening LPD and the morning RMS 40 similarly differed from noon and evening values. TQRS and RMS 50, even though remaining in the normal range, also showed a tendency to abnormal values during morning hours. These findings could possibly be related to the early morning incidence peaks of severe ventricular arrhythmia and sudden cardiac death, since abnormal late potentials constitute the physiopathological basis for certain ventricular arrhythmias.

Balance Disturbances in Children with Middle Ear Effusions

Avishay Golz, Batia Angel-Yeger, Henri Zvi Joachims, Aviram Netzer, S. Parush

Dept. of Otolaryngology and Head and Neck Surgery, Rambam Medical Center and Faculty of Medicine, Technion-Israel Institute of Technology, Haifa

Vertigo and dizziness are not common complaints in childhood, but probably present more often than has been thought. These symptoms, caused mainly by otitis media (OM) and middle ear effusion (MEE), are 2 of the most common diseases in children, and until recently had long been neglected in the literature and in practice. We determined objectively the incidence of balance-related symptoms in children with long-lasting MEE, and resolution following insertion of ventilation tubes (VT). 36 children, aged 4-9 years, were studied using electronystagmography (ENG) and the Bruininks-Oseretsky tests for motor proficiency, before and after ventilation of the middle ear. Results were compared to those in 74 healthy children with no history of middle ear disease. Abnormal ENG findings were found in 58%, and 71% had low Bruininks-Oseretsky (BO) test scores. The ENG was abnormal in only 3 of the controls, 1 of whom also had low BO test scores. The symptoms and signs of balance disturbances resolved in 96% following VT insertion. These results indicate that balance-related symptoms often encountered in young children may result from chronic MEE, and that they resolve following evacuation of the effusion and ventilation of the middle ear.