One-to-Two Atrioventricular Conduction Causing Nonreentrant Tachycardia: Successful Treatment with Radiofrequency Ablation

The anatomical substrate for AV nodal reentrant tachycardia (AVNRT) is well known and is due to anterograde conduction through a siow conducting pathway and retrograde conduction using a fast conducting path way. In this report, we describe a patient with AVNRT who also presented with frequent episodes of paroxysmal nonreentrant tachycardia due to the occurrence of two conducted ventricular beats for each sinus depolarization. Palpitations and arrhythmias were abolished after radiofrequency ablation of the slow pathway.     

Identification of a 94-kilodalton antigen on Leishmania promastigote forms and its specific recognition in human and canine visceral leishmaniasis

We have analysed by immunoblotting sera from humans and dogs with visceral leishmaniasis, from the Old World as well as the New. When lysates of promastigotes are used as antigens, antibodies against a 94 kDa Leishmania component are detected, regardless of the age and geographical origin of the patient, the serum antibody titre as measured by indirect immunofluorescence, and the number of arcs in counterimmunoelectrophoresis. Low dilutions of sera from patients with Old and New World cutaneous leishmaniasis did not react with the 94-kDa antigen, whatever the species of Leishmania used as antigens. Sera from patients with other infections than leishmaniases, or without infection, are negative, even at low dilution. Anti-94 kDa antibodies were detected in the sera of Leishmania-infected dogs from both the Old and the New World. When lysates of Leishmania mexicana axenic amastigotes are used as antigens, the 94-kDa antigen was little or none identified by sera from humans and dogs with visceral leishmaniasis, and never recognized by control sera. Thus, the specific recognition of the 94-kDa promastigote antigen in human and canine visceral leishmaniasis suggests that this antigen could be a potential candidate in the differential immunodiagnosis of the disease.     

Differences between men and women in reporting of symptoms during an asthma exacerbation

STUDY OBJECTIVE: Compared with men, women presenting to the emergency department with acute asthma are more likely to be admitted and to have a longer hospital stay. This study compares peak expiratory flow rate (PEFR) with reported symptom severity between men and women with acute asthma. The null hypothesis was that men and women report similar severity symptoms for similar levels of airway obstruction. METHODS: This study combined data from 4 prospective cohort studies performed from 1996 to 1998 as part of the Multicenter Airway Research Collaboration. Using a standardized protocol, investigators at 64 EDs in 21 US states and 4 Canadian provinces provided 24-hour per day coverage for a median of 2 weeks. RESULTS: Of the 1,291 patients with moderate to severe exacerbations (initial percentage of predicted PEFR <80%), 62% were women. Women were more likely than men to report "severe" complaints in terms of symptom frequency, symptom intensity, and resulting activity limitations (all P <.05). Women with moderate exacerbations were especially likely to describe their exacerbation as causing "severe" activity limitations (sex-PEFR interaction, P =.05). CONCLUSION: Men are less likely than women to report severe asthma symptoms and activity limitations in the presence of airway obstruction. This finding supports use of objective measures of airway obstruction when managing patients with asthma so that those whose symptoms do not reflect the severity of their obstruction can be recognized and properly treated. It also reconfirms the need for increased research on differences between men and women in acute asthma.     

Trisomy 3 in marginal zone B-cell lymphoma: a study based on cytogenetic analysis and fluorescence in situ hybridization

Trisomy 3 represents the most frequent and consistent chromosomal abnormality characterizing the recently defined entity marginal zone B-cell lymphoma (MZBCL). By cytogenetic analysis and/or fluorescence in situ hybridization (FISH) on interphase nuclei we found an increased copy number of chromosome 3 in 22/36 (61%) successfully analysed cases, including 8/12 cases with extranodal MZBCL, 8/13 cases with nodal MZBCL, and 6/11 patients with splenic MZBCL. Sensitivity of interphase cytogenetics was somewhat higher than that of conventional cytogenetic investigation. Structural chromosomal changes involving at least one chromosome 3 were seen in 11/20 cases with an increased copy number of chromosome 3: +del(3)(p13) was demonstrated in three cases, and was the sole chromosomal abnormality in one of them; +i(3)(q10) was seen in two other patients; and rearrangements involving various breakpoints on the long arm of chromosome 3 were found in the remaining cases. FISH on metaphase spreads confirmed these structural abnormalities and additionally showed two unexpected translocations involving chromosome 3. We conclude that: (1) trisomy 3 occurs in a high proportion of extranodal, nodal and splenic MZBCL; (2) FISH on interphase nuclei is an additional and sensitive tool in detecting an increased copy number of chromosome 3 in MZBCL; (3) additional structural abnormalities involving the long arm of chromosome 3 are frequent but non-recurrent and are perhaps secondary changes; and (4) abnormalities such as +del(3)(p13) and +i(3)(q10) suggest that genes located on the long arm of chromosome 3 are of particular importance in the pathogenesis of MZBCL.     

Transseptal Implantation of a Left Ventricular Pacing Lead for an Ectopic Location of the Coronary Sinus Ostium in the Left Atrium

Congenital abnormalities of the coronary sinus (CS) are rare but can be responsible for unsuccessful implantation of a cardiac resynchronization therapy device. We report the case of an ectopic drainage of the CS in the left atrium. A left ventricular lead was implanted by the transseptal route. (PACE 2013; 36:e51–e52)