Determinants of successful ablation of idiopathic ventricular tachycardias with left bundle branch block morphology from the right ventricular outflow tract

The aim of the study was to define the factors that may predict the outcomes of radiofrequency ablation from the right ventricular outflow tract (RVOT) in patients with idiopathic VT with a QRS morphology of LBBB. Endocardial mapping and RF ablation from the RVOT were performed in 35 patients (14 men, mean age 41 +/- 14 years), and VT was successfully ablated in 30 patients. There was no significant difference with regard to clinical characteristics and electrophysiological findings between patients with successful and failed ablation. The VTs with successful ablation showed an rS (n = 16) or QS (n = 14) pattern in lead V1, and all five VTs with failed ablation showed an rS pattern in lead V1. Although the absence of an R wave in lead V1 did not differ between patients with successful and failed ablation (P = 0.13), the absence of an R wave in lead V1 predicted VT successfully ablated from the RVOT (positive predictive value 100%; negative predictive value 24%). The VTs with successful ablation had a median precordial transitional zone at lead V4 (range V3-V6), whereas all five VTs with failed ablation had precordial transition zones at lead V3 (P = 0.004). Furthermore, a presence of an R wave in lead V1 associated with a precordial transition zone at lead V3 predicted VT not successfully ablated from the RVOT (positive predictive value 100%; negative predictive value 100%). In conclusion, some VTs with LBBB and inferior or normal axis cannot be ablated from the RVOT. The presence of an R wave in lead V1 associated with a precordial transition zone at lead V3 suggest that some VTs may not arise from the RVOT.     

Development of the multi-attribute Pediatric Asthma Health Outcome Measure (PAHOM).

OBJECTIVE: To develop a multi-attribute outcome measure for children with asthma that allows for the calculation of quality-adjusted life years in cost-effectiveness studies and can also be used to assign preference weights to asthma-symptom-free days. STUDY DESIGN: A literature review and two interviewer-administered surveys. SETTING: Homes or community centers of participants in Seattle, United States. MAIN MEASURE: Visual analog scale (VAS), standard gamble (SG), and relative risk attitude equation techniques were used to estimate two sets of preference weights for 10 health states. The PAHOM was used to record health states of pediatric asthma patients. RESULTS: A total of 94 subjects provided complete responses without any illogical ratings to VAS questions and 101 provided the same to SG questions. The VAS preference weights of the health states range from a maximum of 1 for perfect health to a minimum of 0.03 for severe asthma symptoms, emotional problems, and activity limitations. Those based on the relative risk attitude equation constructed with both VAS and SG preference weights range from 1 to 0.06. The mean PAHOM scores of pediatric asthma patients based on VAS and converted SG preference weights were 0.70 and 0.83, respectively. CONCLUSIONS: The PAHOM calendar can be used to identify asthma patients' health outcomes, to calculate the preference weights of asthma patients' health states, and to estimate the number of symptom-free days. These factors make the PAHOM a promising instrument for use in effectiveness and cost-effectiveness studies in children with asthma.     

Severe anaphylactic reactions in patients receiving oxaliplatin therapy: a rare but potentially fatal complication

Goals The most well-known adverse events of oxaliplatin are hematologic toxicity, gastrointestinal tract toxicity, and sensory neuropathy. However, hypersensitivity reaction of oxaliplatin, especially severe anaphylactic reactions (SAR), was less often reported. Materials and methods Three hundred and three patients with colon cancer treated by oxaliplatin-containing chemotherapy in one institution were analyzed. Patients were considered to have oxaliplatin-induced SAR if they suffered from at least one of the following symptoms after oxaliplatin infusion: symptomatic bronchospasm, allergy-related edema/angioedema, unstable blood pressure, or anaphylaxis. The reported cases in published literatures that met our definition were also reviewed. Result There were 4 out of 303 patients suffering from SAR after receiving oxaliplatin infusion, with an estimated incidence of 1.32%. Two of them became unconscious and had hypertensive crisis, and one patient had consciousness loss with hypotension. All four patients needed various level of oxygen support. Twenty-seven cases of oxaliplatin-induced SAR were found from Medline. Among the 31 reported cases, the most frequent SAR symptom was hypotension. However, we reported two unique SAR cases with hypertension crisis. In only four out of ten cases, patients could tolerate rechallenge of oxaliplatin. There is no association between the occurrence of oxaliplatin-induced SAR and metastatic sites. Conclusion Oxaliplatin-induced SAR is a rare but potentially fatal complication. Hypertension crisis can be one of the oxaliplatin anaphylactic reactions. Only few patients suffering this complication could tolerate subsequent treatment of oxaliplatin by prolonged infusion time or using a desensitization schedule, thus changing regimen might be a better alternative for them.     

Microarray for molecular typing of Salmonella enterica serovars

We describe the development of a spotted array for the delineation of the most common 14 disease-causing Salmonella serovars in the United States. Our array consists of 414 70 mers targeting core genes of Salmonella enterica, subspecies I specific genes, fimbrial genes, pathogenicity islands, Gifsy elements and other variable genes. Using this array we were able to identify a unique gene presence/absence profile for each of the targeted serovar which was used as the serovar differentiating criteria. Based on this profile, we developed a Matlab programme that compares the profile of an unknown sample to all 14 reference serovar profiles and give out the closest serovar match. Since we have included probes targeting most of the virulence genes and variable genes in Salmonella, in addition to using for serovar detection this array could also be used for studying the virulence gene content and also for evaluating the genetic relation between different isolates of Salmonella.     

Sonographic patterns of splenic abscess: an analysis of 34 proven cases

Background: The sonographic patterns of splenic abscess are seldom reported. We report the different sonographic patterns in 34 proven cases. Methods: From 1984 to June 2000, 42 patients were diagnosed with splenic abscess by abscess aspiration or pathologic findings of surgical specimens. Among them, 34 cases underwent sonographic studies. Results: Fifteen cases had typical abscess echo patterns that included gas in the abscess (two cases) and debris in the abscess cavity (13 cases). Five cases of abscess showed subcapsular lesions with or without echo in the lesion. Two cases of abscess showed a thickened wall mimicking a tumor with central necrosis. Two cases showed a pattern suggesting a cyst. Ten cases showed a pattern suggesting tumor: eight had multiple lesions and two had solitary lesions. Of those 10 cases, seven multifocal abscesses were hypoechoic, and two solitary and one multifocal abscess were mixed echoic. Mortality from multiple splenic abscesses was higher than that from solitary abscess (p = 0.032). Both patients with gas in the abscess expired. Conclusion: Sonography of a splenic abscess is variable. A typical pattern was seen in only 44.1% (15 of 34) of patients in our series. We suggest using needle aspiration in each suspected case. Multiple and gas-containing abscesses indicate a poor prognosis. Received: 19 October 2001/Accepted: 12 December 2001