ABSTRACT
To investigate the value of ventricular tachycardia (VT) score in diagnosing pre-excited tachycardia. Methods: Twelve-lead electrocardiograph results were obtained from 30 patients at pre-excited tachycardia attacking stage who were diagnosed by electrophysiology. We scored pre-excitation tachycardia based on the VT score. To analyze the electrocardiogram of pre-excited tachycardia using 7 diagnostic indicators of the VT score and calculate the specificity of 7 diagnostic indicators and right superior axis (-90º to ±180º), the differences were compared among VT score of 2 points and brugada, Wellens, and Vereckei algorithms in diagnosing pre-excited tachycardia. According to the specificity of Vereckei, Wellens, and Brugada algorithms, and VT scores from low to high, their prediction value and differences were analyzed. Results: Single indicator such as atrioventricular (AV) dissociation or right superior axis (-90º to ±180º) showed the highest specificity (100%) for identifying pre-excited tachycardia. No patient with VT score was ≥3 points, and the specificity was 100%. The specificity of VT score of 2 point was higher than that of Brugada, Wellens, or Vereckei algorithms in the diagnosing pre-excited tachycardia (76.7% vs 50.0%, 23.3% or 20.0%, P<0.05). The specificity of Vereckei, Wellens, and Brugada algorithms and VT score were gradually increased after each of stepwise individually eliminated VT (20.0%, 40.0%, 66.7%, 83.3%, P<0.05). However, there was no significant difference in the specificity in the remaining false positive cases between the 4 methods and VT score. Conclusion: VT score ≥3 points can identify pre-excited tachycardia and VT with 100% specificity. VT score of 2 points cannot completely distinguish pre-excited tachycardia from VT, but specificity of VT score with 2 points is obviously higher than that of Brugada, Wellens, and Vereckei algorithms.
Subject(s)
Humans , Algorithms , Diagnosis, Differential , Electrocardiography , Sensitivity and Specificity , Tachycardia, Ventricular , DiagnosisABSTRACT
Objective To determine whether pupil response to dilute tropicamide could be used as a diagnostic test for Alzheimer's disease (AD). Methods Pupil diameters of both eyes were measured simultaneously by an infra red automatic pupil diameter recorder and analyzer every 0 1 second for 30 minutes after instillation of 0 01% tropicamide to one eye and normal saline to the other. Three groups of patients were studied: 52 patients with AD, 33 with vascular dementia (VD), and 58 elderly controls. The percent change in pupil diameter of the treated eye was examined automatically by the analyzer. After finding the cut off point for differential diagnosis by receiver operator characteristic curve (ROC), its sensitivity, specificity and Kappa coefficient were calculated. Results Mean percent change in diameters of the treated eye showed a trend of fastest maximum dilation in AD group, and was significantly different from other groups at all the measurement time points after 10th minute instillation. The difference was most significant at the 18th minute after instillation, and 15% was used as a cut off point, the sensitivity was 0 81,specificity 0 79 0 82, and Kappa coefficient 0 62 0 67. Conclusions Pupil dilation test could be used as a screening method in the diagnosis of Alzheimer's disease, or as a tool for differential diagnosis between AD and VD.