[Usefulness of a complete echographic evaluation of the atrial dimensions for the diagnosis of idiopathic atrial fibrillation]. / Utilità di una valutazione ecografica completa delle dimensioni atriali per la diagnosi di fibrillazione atriale "idiopatica".

Left atrial enlargement may occur sometimes through only the increase of the supero-inferior (S-I) diameter, with normality of the antero-posterior (A-P) and latero-medial dimensions. In this study, both the largest dimensions of the left atrium and S-I and transversal dimensions of the left atrium and S-I and transversal dimensions of the right atrium were investigated, among the 98 pts suffering from recurrent paroxysms of atrial fibrillation (FAP). On the basis of the clinical, ECGraphic and echocardiographic data, a subgroup of 78 pts has been found, with FAP reliable to heart disease, which mostly appeared as accompanying a finding of atrial enlargement--left or right or both--. The remaining 20 pts distinguished, by means of the echocardiographic findings, as following: a) "idiopathic" FAP, neither dependent on heart disease nor on atrial enlargement (no. 11 pts); b) FAP dependent on "unexplained" atrial enlargement, i.e. unreliable to definite cardiac pathology (no. 9 pts). Among the b) pts, 7 showed the only, isolated S-I dimension increased. Therefore, the determination of the all largest dimensions of the atria, in pts with recurrent FAP, appeared able to more carefully distinguish the true cases of "idiopathic" FAP.

[Differences in the symptomatology of paroxysmal supraventricular tachycardias in relation to the different sites of localization of the arrhythmic reentry circuit. Clinical picture, semiologic and genetic aspects]. / Diversità di sintomatologia nelle tachicardie parossistiche sopraventricolari (TPSR) correlata alla differente localizzazione del circuito aritmico di rientro. Analisi del quadro clinico e considerazioni semeiogenetiche.

Transesophageal, electrophysiologic studies were conducted in 47 patients, with clinical and ECGgraphic diagnosis of paroxysmal reciprocating supraventricular tachycardia. After admission to hospital, the patients were enrolled in the study in accordance with the criterion concerning the exclusion of patients with signs and symptoms of severe heart pump failure (ie, NYHA III and IV class were excluded). The transesophageal study was performed during paroxysmal tachycardia in each patient to measure the V-A interval and to localize the site of reentry. Thereby, the patients could be grouped into 2 subsets, ie those with A-V nodal reentrant tachycardia (no. 30 patients) and those with accessory pathway reentrant tachycardia (no. 17 patients). Moreover, the prevalence in both subsets was evaluated in the following signs and symptoms: palpitations, dyspnoea, chest pain, pulsations in the neck, significant increase in urinary output, hypotension, dizziness, near-syncope, syncope, shock, focal brain injury. From the data analysis, significantly greater prevalence of palpitations in the neck resulted in the subset of patients with reentry confined to the A-V node (no. 20 cases) compared with those suffering from reentry via accessory pathway (no. 4 cases). Moreover the arterial pressure, in A-V nodal reentrant tachycardia, showed the lowest values and the best decreases, together with the finding of a more rapid trend to decline in comparison with the accessory pathway subset. On the other hand, no significant differences could be seen about the remaining symptoms. In an attempt to provide the reliable explanation for the differences found between the 2 subsets of study, concerning both the unpleasant pulsations in the neck and the pressure decrease, we postulated a remarkable role for the length of arrhythmic circle movement. The smaller dimensions of circuit limbs, in A-V nodal reentrant tachycardia, are likely to be the principle cause of the different clinical features of 2 types of reentry. We speculate actually that in susceptible patients the critical event is most likely to be A-V functional dissociation due to early and unphysiologic activation of atria by stimulus rapidly reentrant from the bottom portion of the AV node: the simultaneous occurrence, frequent in A-V node reentry, of both, atrial and ventricular mechanical activation, would result, however, in impairment of atrial haemodynamics due to development of cannon A waves, able either to activate a vasodepressor reflex from the atria or to stimulate instantaneous release of atrial natriuretic factor in the circulation. Further studies, however, are necessary to be performed on large cases-records, to confirm our hypothesis.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effect of the chronic treatment with L-acetylcarnitine in Down's syndrome]. / Effetti del trattamento cronico con L-acetilcarnitina nella sindrome di Down.

Neuropsychologic tests were performed in subjects with Down syndrome in order to assess the effect of a 90-day treatment with L-acetyl-carnitine (LAC). Findings were evaluated statistically (Wilcoxon test) and compared to three further groups of subjects: untreated Down syndrome, mental deficiency due to other cases treated and not treated with LAC (Mann-Whitney U-test). Treated Down syndrome patients showed statistically significant improvements of visual memory and attention both in absolute terms and in comparison with the other groups. No improvement was found in mentally deficient non-Down subjects, so that the favourable effect of LAC appears to be specific for Down patients. In view of the analogies of the pathology and neurochemistry between Down syndrome and Alzheimer degenerative deficiency (deficit of cholinergic transmission) it is suggested that the action of LAC in these pathologies is related to its direct and indirect cholinomimetic effect.