Purpose To verify the effect of unilateral lateral rectus recession for each millimeter according to the tendon width in intermittent exotropia. Methods A total of 37 patients (37 eyes) of 7 to 11 years of age with basic-type intermittent exotropia and a deviation of 16-25 Prism Diopters (PD) were included in this study. Under general anaesthesia, the tendon width of the lateral rectus of the deviating eye near insertion was measured with calipers, prior to dissection of the muscle tendon from the sclera. Patients underwent 6.5-10 mm unilateral lateral rectus recession. The effect of lateral recession for each millimeter was the absolute value of the angle of preoperative deviation plus postoperative deviation on the second day divided by the total amount of recession. Results Mean tendon width of the lateral rectus of a deviating eye was 8.3 mm (range: 6.5-9.5). The mean effect per millimeter of unilateral rectus recession in those 37 patient was 2.9870.42 PD (range: 2.4-4.1). The effect of recession was larger in cases in which the tendon width of the lateral rectus was narrower (P ¼ 0.000, r ¼ 0.72). Conclusion The tendon width of the lateral rectus muscle can be a useful indicator to estimate the effect of lateral rectus recession in intermittent exotropia.
Jae-Beom Lee et al. 535With video compression standards such as MPEG-4, a transmission error happens in a video-packet basis, rather than in a macroblock basis. In this context, we propose a semantic error prioritization method that determines the size of a video packet based on the importance of its contents. A video packet length is made to be short for an important area such as a facial area in order to reduce the possibility of error accumulation. To facilitate the semantic error prioritization, an efficient hardware algorithm for face tracking is proposed. The increase of hardware complexity is minimal because a motion estimation engine is efficiently re-used for face tracking. Experimental results demonstrate that the facial area is well protected with the proposed scheme.
Background/Introduction
Signal-averaged electrocardiography (SA-ECG) is a high-resolution electrocardiography that can detect late ventricular potential, which known to be a noninvasive tool for risk stratification of sudden cardiac death (SCD) by predicting reentrant ventricular tachyarrhythmia. There is a paucity of data with SA-ECG on SCD survivors without structural heart disease, whereas majority of previous studies had been focused on post myocardial infarction survivors.
Purpose
This study assessed the clinical utility of SA-ECG as a risk stratification modality for lethal arrhythmic event in patients at risk of SCD without definite structural heart disease.
Methods
Total 629 patients who experienced or had potential risk of SCD were studied with SA-ECG. Among them, 48 patients who were found to have significant structural heart disease were excluded, except arrhythmogenic right ventricular cardiomyopathy. Major arrhythmic event (MAE) was defined as composite of all-cause death, aborted SCD, and sustained VT during any time either before visit of clinic or during follow up period. Syncope and non-sustained VT was defined as non-major arrhythmic event. SA-ECG was defined positive when fulfilling three or more criterion: (1) unfiltered QRS duration ≥114ms, (2) filtered QRS duration ≥114ms, (3) duration of terminal QRS <40uV exceeding 40ms, and (4) root mean square voltage in the terminal 40ms of ≤20ms.
Results
Among total 581 patients, 145 patients with positive SA-ECG showed higher incidence of MAE compared to patients with negative SA-ECG (21.4% vs. 6.7%, OR 3.816 [95% CI 2.208–6.597], p<0.001, Table). As the number of positive SA-ECG criteria increases, incidence of MAE tended to increase sequentially, which was markedly noted from 2 positive to 3 positive criteria (10.7% to 20.8%, p<0.001, Figure). In particular, patient with inherited arrhythmia showed higher rate of positive late potential compared to those with non-inherited arrhythmia (51.0% vs. 19.3%, p<0.001).
Conclusion
This study showed that at least 3 out of 4 diagnostic criteria in SA-ECG can independently predict lethal arrhythmic events and the positive late potential was associated with lethal arrhythmic event that leads to SCD, suggesting risk prediction for SCD using SA-ECG in patients even without structural heart disease including inherited arrhythmias.
Funding Acknowledgement
Type of funding sources: None.
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