Relationship Between Atrial Conduction Defects and Fractionated Atrial Endocardial Electrograms in Patients with Sick Sinus Syndrome

The relationship between abnormal atrial electrograms (AAE) recorded during sinus rhythm by endocardial calheter mapping of the right atrium and the afrial conduction defects of sinus impulses or single atrial extrastimuli was investigated in 44 patients with sick sinus syndrome. The patients were divided into two groups on the basis of the presence (n = 29) or absence (n = 15) of AAE recorded during sinus rhythm. The P wave duration in the AAE (+) Group patients was 137 ± 14 msec, and 125 ± 15 msec in (he AAE (−) Group; P < 0.02. The intraatrial conduction time of sinus impulses in the AAE (+) Group was 54 ± 12 msec, and 39 ± 9 msec in the AAE (−) Group; P < 0.001. The interatrial conduction time in the AAE (+) Group was 101 + 14 msec, and 78 ± 16 msec in the AAE (−) Group; P < 0.001. In the AAE (+) Group, H (38%) patients ha d a sinus node recovery time > 4 seconds, whereas in the AAE (−) Group there was only one (6%) patient; P < 0.03. AAE showed a specificity of 93% and a positive predictive accuracy of 91% in predicting inducibility of atrial fibrillation. The sensitivity was 35% and the negative predictive accuracy was 42%. Sustained atrial fibrillation was induced in ten (35%) patients of the AAE (+) Group, and in one (7%) patient of the AAE (−) Group; P < 0.05. These data suggest that in patients with sick sinus syndrome who possess abnormal endocardial eJectrograms in sinus rhythm within the right atrium have: (1) a significantly longer P wave duration: (2) a significantly longer intraatrial and interafrial conduction time of sinus impulses; and (3) a significantly greater sinus node dysfunction and higher incidence of induction of sustained atriai fibrillation. It is concluded that there are significantly greater atrial conduction defects in patients with sick sinus syndrome who possess AAE within the right atrium during sinus rhythm.     

A Case of Early Gastric Carcinoma with Lymphoid Stroma: Diagnostic Usefulness of Endosonography

Abstract: A case of early gastric carcinoma with lymphoid stroma (GCLS) showing features of submucosal tumor is reported here. A characteristic endoscopic ultrasonographic (EUS) finding was helpful for preoperative diagnosis. The patient, a 75-year-old woman without any previous complaints, visited our hospital for detailed examination of a small gastric lesion. Upper Gl studies revealed a submucosal tumor-like lesion measuring about 1.8 cm with a central slight depression on the greater curvature of the middle gastric body. Histologic findings of the specimens obtained by conventional biopsy indicated a poorly differentiated adenocarcinoma, although the possibility of malignant lymphoma was not completely ruled out. EUS examination was, therefore, performed in order to obtain further detailed information about the tumor. EUS disclosed that the tumor, which existed in the third layer, was composed of many small round clustered lesions, the echogenicity of which was lower than that of the muscle layer, and was almost covered with a normal mucosal layer. Taking these findings into consideration, a gastric cancer with lymphoid stroma whose invasion would be limited within the submucosa was highly suspected. It was proven by histological analysis of a surgically resected specimen that this peculiar multiple small round hypoechoic lesion was equivalent to the lymphoid aggregates infiltrating the GCLS. Since it has been reported that the prognosis of GCLS is better than that of common gastric cancers, accurate diagnosis is important for the selection of optimal treatment. While it is still not definitively proven that EUS is useful for diagnosis of GCLS, this procedure may potentially provide an excellent image of this special tumor and be of use for preoperative diagnosis.     

Effects of acetazolamide on the sleep apnea syndrome and its therapeutic mechanism

Abstract Twenty male patients with sleep apnea syndrome were treated with acetazolamide (AZM), a carbonic anhydrase inhibitor. In 14 of the patient a significant decrease was found in the number of apnea, apnea index and % apnea time (percentage of time spent with apnea to the total sleep time) with improvement in sleep structure, clinical symptoms, such as insomnia, daytime excessive sleepiness and snoring. A significant decrease was also observed in arterial blood pH and HCO⁻₃ in the 14 improved patients. On the other hand, no improvement occurred in the parameters of sleep apnea and sleep with AZM in the remaining six patients. Moreover, metabolic acidosis and an improvement in arterial blood gases did not occur with AZM in the six patients.     

Anti-inflammatory effect of roxithromycin in patients with aspirin-intolerant asthma

BACKGROUND: Fourteen-membered macrolides, such as roxithromycin, have been reported to exhibit other pharmacological activity including anti-asthmatic effects, besides antibiotic activity. OBJECTIVE: This study was designed to investigate the protective effect of roxithromycin on airway responsiveness to the sulpyrine provocation test and to investigate whether this protective activity is associated with a reduction in aspirin-induced excretion of urinary leucotriene E4 (u-LTE4), a marker of cysteinyl leucotriene overproduction that participates in the pathogenesis of aspirin-intolerant asthma. Also, the present study was designed to examine whether or not its anti-asthmatic activity was associated with a reduction in eosinophilic inflammation. METHODS: For 8 weeks before analysis, subjects received 150 mg of roxithromycin or matching placebo twice daily. We assessed the effects of pretreatment with roxithromycin on bronchoconstriction precipitated by inhalation of sulpyrine in 14 adult patients with mild or moderate aspirin-intolerant asthma; those who were in stable clinical condition and were hyperresponsive to sulpyrine provocation test were allocated to this study. A double-blind, randomized, crossover design was used. Urinary LTE4 was measured by a combined reverse-phase high-performance liquid chromatography (rp-HPLC) enzyme immunoassay on sulpyrine provocation testing day. Blood and sputum samples were taken in the morning on the sulpyrine provocation testing day. Eosinophil counting and measurement of eosinophilic cationic protein (ECP) were performed. RESULTS: After the 8 weeks of treatment with roxithromycin, patients' symptoms, blood eosinophils, serum ECP, sputum eosinophils, and sputum ECP were significantly decreased. On the other hand, values of PC20-sulpyrine did not improve after roxithromycin at all. Furthermore, although challenge with sulpyrine caused a significant increase in u-LTE4, pretreatment with roxithromycin or placebo did not affect excretion of u-LTE4. CONCLUSION: Although roxithromycin does not have antileucotriene effects, it has an antibronchial inflammatory effect associated with eosinophilic infiltration. This study raises further interesting therapeutic possibilities and warrants further trials of new approaches to the treatment of aspirin-intolerant asthma.     

Double Ventricular Responses to a Single Atrial Depolarization in a Patient with Dual AV Nodal Pathways

Electrophysiological study was performed in a patient with atrioventricular nodal reentrant tachycardia (AVNRT). Double ventricular responses through dual AV nodal pathways were observed by atrial extrastimulus technique followed by initiation of AVNRT. The difference in conduction time between the slow and fast AV nodal pathways was longer than 320 msec. A ventricular extrastimulus delivered during sinus rhythm, which was not followed by ventriculoatrial conduction, also induced AVNRT. These findings indicated the presence of an antegrade critical delay and retrograde block in the slow AV nodal pathway, criteria necessary for the occurrence of a double ventricular response.     

Exacerbation of pemphigus by rifampicin

Rifampicin therapy caused exacerbation of skin lesions, rising serum pemphigus antibody titres, and decreased serum betamethasone levels in a 59-year-old man with pemphigus vulgaris. Exacerbation of pemphigus was confined to the period of rifampicin therapy and seems to be best explained by the effect of rifampicin on the metabolism of betamethasone. Physicians prescribing rifampicin for the treatment of tuberculosis should be aware of its potential to produce such an important adverse reaction.     

Relation of Serum and Erythrocyte Magnesium Levels to Blood Pressure and a Family History of Hypertension A Follow-up Study in Japanese Children, 12-14 Years Old

Abstract. Serum and erythrocyte magnesium concentrations (S-Mg, E-Mg) were measured in 122 junior high school students followed up for two years from 12 to 14 years of age, and the relationship to blood pressure and a family history of hypertension were investigated. The subjects who had high S-Mg and E-Mg levels at the first examination two years prior tended to show high levels after this follow-up. There were significant positive correlations between two intraindividual values of S-Mg and E-Mg. A similar tendency was found for blood pressure. Tracking phenomena were observed with these measures. The subjects who had high E-Mg levels at the first examination showed no blood pressure elevation during the two- year period. The subjects with a family history of hypertension [FH(+)] showed a higher degree of blood pressure rise during two years than those with no family history [FH(-)], with a significant difference in systolic blood pressure at the age of 14. E-Mg tended to be lower in the FH(+) group than in the FH(-) group with a significant difference in 14-year-old girls. These results suggest that a hereditary predisposition to hypertension is related to magnesium metabolism and that intracellular magnesium deficiency may influence blood pressure elevation in the FH(+) children.