ABSTRACT
An electrophysiologic study (EPS) of children and teenagers with paroxysmal supraventricular tachycardia (SVT) and normal electrocardiography (ECG) in sinus rhythm was evaluated. Generally, EPS is performed only before paroxysmal SVT ablation in these patients. In this study, 140 patients (mean age, 15 ± 3 years) with normal ECG in sinus rhythm were studied for SVT by a transesophageal route in baseline state and after isoproterenol. Idiopathic left or right ventricular tachycardia was diagnosed in four patients (3 %). Anterograde conduction over an atrioventricular (AV) left lateral (n = 10) or septal (n = 9) accessory pathway (AP) was noted in 19 patients (13.5 %) at atrial pacing. Orthodromic AV reentrant tachycardia (AVRT) was induced in these children. Five of the patients had a high rate conducted over AP (>240 bpm in baseline state or >290 bpm after isoproterenol). Two of the patients (a 10-year-old girl with well-tolerated SVT and a 17-year-old with syncope-related SVT) had the criteria for a malignant form with the induction of atrial fibrillation conducted over AP at a rate exceeding 290 bpm in baseline state. Of the 140 patients, 74 (53 %) had typical AV node reentrant tachycardia (AVNRT), nine had atypical AVNRT (6 %), 1 had atrial tachycardia (0.7 %), and 33 (23.5 %) had AVRT related to a concealed AP with only retrograde conduction. Electrophysiologic study is recommended for children with paroxysmal SVT and normal ECG in sinus rhythm. The data are helpful for guiding the treatment. Ventricular tachycardia or atrial tachycardia can be misdiagnosed. Masked preexcitation syndrome with anterograde conduction through AP was present in 13.5 % of the patients, and 1.4 % had a malignant preexcitation syndrome.
Subject(s)
Electrophysiologic Techniques, Cardiac/methods , Tachycardia, Supraventricular/physiopathology , Adolescent , Child , Child, Preschool , Electrocardiography , Esophagus , Female , Follow-Up Studies , Humans , Male , Pre-Excitation Syndromes , Retrospective Studies , Tachycardia, Supraventricular/etiology , Young AdultABSTRACT
The extraction of protein from lucerne produces some liquid residue (called lucerne serum), the effects of which were studied on rumen microbial activity in 6 adult fistulated wethers. The introduction of the serum directly into the rumen stimulated cellulolytic activity whereas its incorporation into the lucerne solid residue before dehydration seemed to have no effect.
Subject(s)
Digestion , Medicago sativa , Rumen/metabolism , Rumen/microbiology , Sheep/metabolism , Animals , MaleABSTRACT
The cellulolytic activity in the large intestine of the pony varies according to the form and the composition of the feed. This activity was measured on two caecal and ventral colon-cannulated ponies receiving the following 4 diets during four successive 6-week periods: --6 kg of hay, --4 kg of hay + 1 kg of oats, --6 kg of ground, pelleted hay. --5 kg of a ground, pelleted blend of 80 p. 100 hay and 20 p. 100 oats. Adding oats to a hay feed increased the cellulolytical activity in the caecum and the colon, whereas grinding and pelleting hay alone or hay enriched with oats diminished that activity in the caecum without modifying it in the colon (table 1). The volatile fatty acid production shown in table 2 does not always vary in the same way as cellulolytic activity; this might be due to some variations in the values of the digestive contents in the two compartments.
Subject(s)
Animal Feed , Cellulose/metabolism , Horses/metabolism , Intestine, Large/metabolism , Animals , Cecum/metabolism , Colon/metabolism , Edible Grain , Fatty Acids, Volatile/metabolism , MaleABSTRACT
We studied a caecum-cannulated pony fed hay libitum in order to determine the mineral elements likely to cause deficiencies which decrease microbial activity in the caecum. During four successive 1-month periods, we observed the effects of adding 50 mg of iron, 1 mg of cobalt, 40 mg of copper and 200 mg of zinc, respectively. Except for the introduction of zinc, which greatly diminishes cellulolytic activity measured with the nylon bag technique, there was no significant modification in that activity as shown by pH, NH3-nitrogen, total nitrogen and volatile fatty acid production (table 1). It can be concluded that endogenous secretion in the pre-caecal part of the digestive system of the mineral elements used was sufficient to guarantee good symbiosis between the microbial population of the caecum and the organism.