Classification of Farnsworth-Munsell 100-hue test results in the early treatment diabetic retinopathy study

PURPOSE: To classify and describe clinically meaningful classes of color vision defects using pretreatment Farnsworth-Munsell 100-hue results from the Early Treatment Diabetic Retinopathy Study (ETDRS) patients using standard statistical techniques. DESIGN: The ETDRS was a randomized trial investigating retinal photocoagulation and oral aspirin in diabetic retinopathy. METHODS: Farnsworth-Munsell (FM) 100-hue test was successfully administered before initiation of study treatment in each eye of 2701 of the 3711 ETDRS patients. Test results were converted into a Fourier series, classified by cluster analysis in the deferred-treatment group of eyes, and verified in the immediate-treatment group of eyes as separate samples. RESULTS: Cluster analysis uncovered thirteen distinct patterns. Pattern A (51% or 1366 of the eyes) showed unimpaired hue discrimination and was comprised of younger patients with no or little macular edema. Pattern B eyes (10% or 262) showed generalized impairment of hue discrimination with no main axis defect. Patterns C (C1, C2, C3), comprising 26% (or 698) of the eyes, showed increasing severity of the yellow-blue diabetic retinopathy defect, associated with increasing mean age and increasing macular edema severity. Patterns D (D1, D2), comprising 6% (or 164) of the eyes, were similar to the C patterns but showed a stronger yellow-blue defect. Patterns E (E1, E2, E3), or approximately 2% (or 38) of the eyes and predominantly male, exhibited the expected pattern for congenital protan defect. Patterns F, G, and H, approximately 6% (or 153) of the eyes, showed distinct patterns of one-sided axes. The nomenclature is arbitrary. CONCLUSIONS: Cluster analysis of FM 100-hue test results has found 13 patterns of impaired hue discrimination, helpful in understanding color vision defects in diabetes mellitus.     

Two year prognosis of sarcoidosis: the ACCESS experience

A cohort of 215 sarcoidosis patients from the ACCESS study underwent a clinical evaluation at study enrollment and two years later. Approximately 80% of subjects had an improved or stable FVC, FEV1, chest radiograph determined by Scadding stage, and dyspnea scale. African-Americans had less improvement in FVC than Caucasians (p = 0.04). Patients with erythema nodosum at presentation were more likely to have improvement in the chest radiograph at two-year follow-up (p = 0.007). Patients with a lower annual family income were more likely to worsen with respect to dyspnea (p = 0.01) and more likely to have new organ involvement at two-year follow-up (p = 0.045). The development of new organ involvement over the two year follow-up period was more common in African-Americans compared to Caucasians (p = 0.002) and more likely in those with extrapulmonary involvement at study entry (p = 0.003). There was an excellent concordance between changes in FVC and FEV1 over the two-year period. However, changes in FVC alone were inadequate to describe the change in pulmonary status of the patients, as changes in chest radiographic findings or the level of dyspnea did often but not always move in the same direction as FVC. In conclusion, data from this heterogeneous United States sarcoidosis population indicate that sarcoidosis tends to improve or remain stable over two years in the majority of patients. Several factors associated with improved or worse outcome over two years were identified.     

Lessons from the post coronary artery bypass graft study in evaluating and controlling technical variability in angiographic trials. Post CABG Investigators

Although many investigators have evaluated the technical variability of quantitative angiographic techniques used to study atherosclerosis regression in native coronary arteries, few have studied the variability inherent in repeated studies of atherosclerotic saphenous vein grafts. This study describes 2 studies performed during the course of the Post Coronary Artery Bypass Graft (CABG) Clinical Trial that were designed to assess the reproducibility of: (1) repeated angiographic views within a short time period; and (2) reproducibility of the total process of quantitative analysis of saphenous vein graft angiograms. Statistical methods are described that provide a more meaningful assessment of the impact of measurement variability in the analytic process versus the variability related to changes induced by pharmacologic interventions. One such method, the increase in standard deviation (SD) among patients (ISDP), showed that repeated angiographic views increased the variability of calculation of lesion minimal diameter by 1.5%, whereas the ISDP for repetition of the entire process of quantitative angiographic readings increased variability 6.4%. These data from the Post CABG trial reveal that technical variability is small and has negligible impact on the conclusions of the study.     

Respiratory function after repair of congenital diaphragmatic hernia

Respiratory function studies were carried out in 22 infants who had successful repair of diaphragmatic herniae of the Bochdalek type. Thoracic gas volume was initially reduced in only 3 of these, but subsequent studies showed that improvement occurred. There were no consistent abnormalities in either dynamic compliance or mean pulmonary conductance. This is evidence that there is rapid adaptation which compensates for any alteration in the parenchymatous tissue in the lungs or abnormalities in the bronchial tree in infants soon after the repair of congenital diaphragmetic herniae. Further studies are necessary to determine the changes in these lungs with growth.     

Postbiopsy renal transplant arteriovenous fistulas: color Doppler US characteristics

Color Doppler ultrasound (US) with point-spectral analysis was performed on eight patients with postbiopsy renal transplant arteriovenous fistulas. Waveform analysis of the supplying artery documented decreased resistive indices in all cases and increased flow velocities in seven. The peak-systolic flow velocity in the arteries supplying the fistulas ranged from 55 to 180 cm/sec (mean, 92 cm/sec), while the range in normal arteries was 20-52 cm/sec (mean, 32 cm/sec). The resistive indices of the arteries supplying the fistulas ranged from 0.31 to 0.50 (mean, 0.45), while the resistive indices of the normal arteries ranged from 0.60 to 0.92 (mean, 0.74). Arterialization of the venous waveform from the draining vein was also documented in all cases. In six cases, the increased flow velocities resulted in increased color saturation toward white in the supplying artery (n = 2) or in both the artery and the draining vein (n = 4), which was detectable on the realtime image. In six cases, flow turbulence resulted in localized tissue vibration, which appeared as random color assignment in extravascular renal parenchyma adjacent to the fistula. Knowledge of these imaging and Doppler characteristics should aid in the identification of renal transplant arteriovenous fistulas with color Doppler US.     

Pace-Termination and Pacing for Prevention of Atrial Tachyarrhythmias: Results from a Multicenter Study with an Implantable Device for Atrial Therapy

INTRODUCTION: Patients with bradycardia requiring permanent pacing frequently suffer from additional atrial tachyarrhythmias (ATs). This study evaluated the safety and efficacy of atrial antitachycardia pacing (ATP) and the performance of pacing for AT prevention implemented into a new pacemaker. METHODS AND RESULTS: In patients with conventional indications for permanent pacing, an investigational DDDRP pacemaker (Medtronic AT500, model 7253) was implanted. The primary study objectives were to determine the safety of overall device functioning and its efficacy in terminating spontaneous AT. A secondary endpoint was to determine the reliability of AT detection. Pacemaker memory functions were used to analyze the impact of dedicated pacing algorithms on AT prevention. In 33 European and Canadian centers, 325 patients were enrolled (mean follow-up 2.3+/-1.3 months). Complication-free survival at 3 months was 88%. In 2,145 episodes stored with atrial electrograms, AT detection was confirmed in 97%. The algorithm for continuous overdrive pacing increased the percentage of atrial pacing to 97%. After ATP activation, 16,683 of 52,468 AT episodes were treated (120 patients). Of these, 8,903 episodes (53%) were terminated successfully by ATP. No proarrhythmic effect of preventive pacing or atrial ATP was observed. Preventive pacing algorithms increased the median percentage of atrial pacing from 62% to 97%. However, the number of AT/AF (atrial fibrillation) episodes (4.1 vs 4.1 per patient per day) and the time in AT/AF (13.7% vs 12.8%) was not significantly different before and after activation of preventive pacing. CONCLUSION: DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.     

Ossicular erosions in the dry ear: CT diagnosis

Erosions of the ossicular chain that occurred as a complication of noncholesteatomatous chronic otitis media were studied with computed tomography (CT) in 55 patients. The incus (particularly the long and lenticular processes) was the ossicle most commonly involved (50 cases). Coronal and axial CT sections were complementary in the diagnosis of these erosions. Fibrous replacement of the incudostapedial articulation was diagnosed in four cases on axial CT scans when an unusually wide joint was present.