Multicenter Evaluation of Fixed-Wire PTCA Catheters with Modified Distal Tips: Initial and 2-Month Follow-Up Results

Lesions in the distal portion of coronary arteries are technological challenges with currently available percutaneous transluminal coronary angioplasty (PTCA) equipment. A study was performed at multiple centers to determine if new "fixed-wire" devices with a modified distal tip (a 2-cm flexible tip and 1-cm standard tip) would be useful in these situations. Three hundred twenty-three patients were included in the study, 75% male, mean age 63 ± 11 years. Four hundred ninety-three lesions were attempted; the overall success rate was 85%. Forty-six (14.2%) clinical complications occurred including: 5 deaths (1.1%); 2 nonfatal myocardial infarctions (0.6%); and 6 emergency coronary artery bypass grafting procedures (2.6%). A device malfunction was noted in 32 patients (9.9%), and included: 8 balloon ruptures or perforations (2.0%); 6 bent or damaged tips (1.9%); and 4 shaft/manifold leaks (1.2%). Two-month follow-up assessment for restenosis was done in 352 of 371 (95%) patients and at that time 89% were asymptomatic, had a negative functional test, or patent PTCA site by angiography. The new fixed-wire PTCA catheters with 1- and 2-cm flexible tips hold promise for dilating lesions in distal locations with an acceptable rate of complications. Additional investigation is needed to determine their role in the treatment of coronary artery disease with PTCA.     

Demonstration of the Feasibility of Implantation of a Skeletal Muscle Pulse Generator for Fecal Incontinence in a Patient with an Implanted Unipolar DDD Pacemaker

Electromagnetic fields and myopotentials from skeletal muscle may interfere with the function of a cardiac pacemaker. A 65-year-old woman with a unipolar DDD cardiac pacemaker underwent dynamic graciloplasty (transposition of the gracilis muscle around the anal canal and subsequent implantation of a bipolar pulse generator to stimulate the gracilis muscle), for the treatment of fecal incontinence. This gracilis pulse generator is turned "off" with an external magnet to allow defecation. Appropriate functioning of these two pulse generators (the cardiac pacemaker and the gracilis pulse generator) was tested during implantation of the gracilis pulse generator and afterwards. It was demonstrated that the combination could be used safely in this patient.     

Absence of Developmental Effects in CF-1 Mice Exposed to Aspartame in Utero

Aspartame (L-aspartyl-L-phenylalanine methyl ester) is a widelyused high potency dipeptide sweetener. Developmental toxicologystudies have been performed in several species documenting noeffects of high doses of aspartame. Recently, a study by Mahalikand Gautieri ((1984) Res Commun. Psychol Psychiatry Behav. 9,385–403) reported a delay in the achievement age for thevisual placing response in mice pups after maternal administrationof high dosages of aspartame during late gestation. In the presentstudy developmental parameters were determined in offspringof CF-1 mice after maternal administration of aspartame at 500,1000, 2000, and 4000 mg/kg body wt by oral gavage. Aspartamewas administered on Days 15 through 18 of gestation. Maternalbody weight, food consumption, gestation length, reproductiveindices, and litter size were not affected by aspartame treatment.In the pups, body weights, negative geotaxis, and surface andmidair righting reflexes were not altered by treatment. Therewas no delay in the development of the visual placing responseregardless of the method employed for assessment (grid or rope)or the manner by which the data were analyzed. There were alsono changes in time of eye opening, reflex pupil closure, andophthalmoscopic examination in the offspring. Thus, neitherphysical nor functional development was altered in mice afterin utero exposure to extremely large dosages of aspartame. Morespecifically, in utero exposure to aspartame did not affectthe development of the visual system in mice.     

Molecular detection of t(8;21)/AML1-ETO in AML M1/M2: correlation with cytogenetics,morphology and immunophenotype

The t(8;21) identifies a subgroup of acute myeloid leukaemia (AML) with a relatively good prognosis which may merit different treatment. It is associated predominantly, but not exclusively, with AML M2, and corresponds to rearrangements involving the AML1 and ETO genes. AML1-ETO positive, t(8;21) negative cases are well recognized but their incidence is unknown. In order to determine optimal prospective AML1-ETO RT-PCR screening strategies, we analysed 64 unselected AML M1 and M2 cases and correlated the results with other biological parameters. Molecular screening increased the overall detection rate from 8% to 14%. AML1-ETO was found in 3% (1/32) of AML M1 and 25% (8/32) of M2, including three patients without a classic t(8;21) but with chromosome 8 abnormalities. It was more common in younger patients. Correlation with morphology enabled development of a scoring system which detected all nine AML1-ETO-positive cases with a false positive rate of 7% (4/55). Although certain AML1-ETO-positive cases demonstrated characteristic immunological features (CD19 and CD34 expression, CD33 negativity), each of these markers was insufficiently specific to permit prediction in an individual case. We conclude that initial routine prospective molecular screening for AML1-ETO in all AMLs, combined with standardized morphological and immunological analysis, is desirable in order to produce improved prognostic stratification and to determine whether screening can ultimately be restricted to appropriate subgroups.     

Radiofrequency Ablation of Idiopathic Left Anterior Fascicular Tachycardia

Left Anterior Fascicular Tachycardia. Introduction: A 45-year-old man with idiopathic ventricular tachycardia (VT) having a right bundle branch block configuration with right-axis deviation underwent au electrophysiologic test.
Methods and Results: Mapping demonstrated a site on the auterobasal wall of the left ventricle where there was an excellent pace map and an endocardial activation time of -20 msec, hut radiofrequency catheter ablation at this site was unsuccessful. At a nearby site, a presumed Purkinje potential preceded the QRS complex by 30 msec during VT and sinus rhythm, and catheter ablation was effective despite a poor pace map and an endocardial ventricular activation time of zero.
Conclusion: Idiopathic VT with a right bundle branch configuration and right-axis deviation may originate in the area of the left anterior fascicle. A potential presumed to represent a Purkinje potential may he more helpful than endocardial ventricular activation mapping or pace mapping in guiding ablation of this type of VT.