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.

First Year's Experience of the Post, Operative Cardiac Care Unit, Schneider Children's Medical Center

O. Dagan, E. Birk, J. Katz, B. Vidne

Cardiothoracic Pediatric Service, Schneider Children's Medical Center, Petah Tikva

In the past 10 years there has been a growing preference for early, complete correction of congenital heart disease. The first year of operation of this cardiac unit is described. 216 operations were performed: 15% in the neonatal age group and 35% in the newborn to l-year-old groups; 2% were palliative procedures. Mortality was 4.9%. Average stay in the ICU was 3.2  days, with a median of 2.25. Average length of ventilation was 35 hours, with a median of 17.5. Complications were: diaphragm paralysis in 13 (6%), 2/3 of which were recurrent operations; in 2 patients (0.9%) we had to plicate the diaphragm. There was severe neurological damage in 2, which deteriorated to brain death in 1. There was peripheral, reversible neurological damage in 4 (1.8%), and acute renal failure in 3%, with half of them requiring dialysis. 75% of these children died and there was superficial infection in 4.1%, deep wound infection in 1.3%, bacteremia in 4.1%, superior vena cava syndrome in 3 (1.3%) and chylothorax in 2 of them (0.9%). 1 patient (0.45%) required a ventricle-peritoneal shunt after acute viral meningitis. We are encouraged by our results to offer early complete correction to all children with congenital heart disease.

Effect of the Yom Kippur Fast on Parturition

A. Wiser, E. Maymon, M. Mazor, I. Shoham-Vardi, T. Silberstein, A. Wiznitzer, M. Katz

Depts. of Obstetrics and Gynecology and of Epidemiology, Soroka Medical Center, and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba

Food-withdrawal has been proposed as a possible mechanism for initiating the onset of labor in animals and humans. The hypothesis was based upon the reported increase in deliveries of infants during the Yom Kippur fast. We studied the effect of the fast on full term deliveries of Jewish women, with non-fasting Bedouin women as controls (1988-1995, 1,313 Jewish and 1,091 Bedouin deliveries). To determine the effect of Yom Kippur itself, delivery rates on Sukkot and Yom Kippur were compared in both groups. The mean delivery rate in the Jewish population was significantly higher during Yom Kippur and the day after, than during the 7 days before Yom Kippur (15.1±5.1 and 14.6±4.7 vs 10.7±3.5, p<0.04 and p<0.01, respectively). There was an increase in delivery rate during the 6 hours before the end of the fast. In the Bedouin women there were no changes in delivery rate during any of these periods. There were no significant differences in the rates of deliveries during the Sukkot festival between Jewish and Bedouin women. We conclude that fasting is associated with a significant increase in the rate of deliveries at term.

Effect of Chlorocresol VS Caffeine on Muscle Contracture in Malignant Hyperthermia Susceptible Patients

R. Ben-Abraham, R.M. Krivosic-Horber, G. Haudcoeur, A. Perel, P.J. Adnet

Dept. of Anesthesiology and Intensive Care, Chaim Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University; and Dept. d'Anesthesie-Reanimation Chirurgicale, Laboratoire de Pharmacologie Hospitaliere, et Service des Urgence, Centre Hospitalier Universitaire, Lille Cedex, France

The phenotype of susceptibility to malignant hyperthermia (MHS); can only be detected reliably by the in vitro caffeine-halothane contracture test (CHCT). Enhanced sensitivity of the calcium-induced calcium release mechanism is responsible for the exaggerated contracture response of skeletal muscle fibers from MHS patients to halothane and caffeine. Chlorocresol was demonstrated to be a potent activator of Ca++release from skeletal muscle sarcoplasmic reticulum. This effect is probably mediated through action on a ryanodine sensitive Ca++ release channel known to be more sensitive in MH. We studied the effect of chloroscresol on the mechanical contracture response of skeletal muscle from patients presenting for the in vitro CHCT. Chlorocresol induces contracture response in a concentration 1/200 of that of caffeine in muscle strips from MH patients. By adding chlorocresol to the protocol of the CHCT, there is clearer discrimination between the responses of MH patients and normal subjects can be achieved. 

Acute Effusive Constrictive Pericarditis in Influenza A

N. Reichman, N. Kaufman, E. Flatau

Dept. of Medicine B, Central Emek Hospital, Afula and Technion Faculty of Medicine, Haifa

Constrictive pericarditis may complicate the course of several viral infections, mainly Coxsackie virus group B, as well as in rheumatoid disease, radiation and neoplasm. Perimyocardial involvement during influenzal infections is usually mild and does not progress to constriction or tamponade. A single case of cardiac tamponade caused by influenza A was reported in 1986. We report a case of acute effusive-constrictive pericarditis due to influenza A infection. Corticosteroids resulted in some benefit, but did not relieve constriction, which required extensive pericardiectomy.