ABSTRACT
Aims: Several published investigations demonstrated that a longer T-peak to T-end interval (Tpe) implies increased risk for ventricular tachyarrhythmia (VT/VF) and mortality. Tpe has been measured using diverse methods. We aimed to determine the optimal Tpe measurement method for screening purposes. Methods and results: We evaluated 305 patients with LVEF ≤ 35% and an implantable cardioverter-defibrillator implanted for primary prevention. Tpe was measured using seven different methods described in the literature, including six manual methods and the automated algorithm '12SL', and was corrected for heart rate. Endpoints were VT/VF and death. To account for differences in the magnitude of Tpe measurements, results are expressed in standard deviation (SD) increments. We evaluated the clinical utility of each measurement method based on predictive ability, fraction of immeasurable tracings, and intra- and interobserver correlation. >Over 31 ± 23 months, 82 (27%) patients had VT/VF, and over 49 ± 21 months, 91 (30%) died. Several rate-corrected Tpe measurement methods predicted VT/VF (HR per SD 1.20-1.34; all P < 0.05), and nearly all methods (both corrected and uncorrected) predicted death (HR per SD 1.19-1.35; all P < 0.05). Optimal predictive ability, readability, and correlation were found in the automated 12SL method and the manual tangent method in lead V2. Conclusion: For the prediction of VT/VF, the utility of Tpe depends upon the measurement method, but for the prediction of mortality, most published Tpe measurement methods are similarly predictive. Heart rate correction improves predictive ability. The automated 12SL method performs as well as any manual measurement, and among manual methods, lead V2 is most useful.
Subject(s)
Death, Sudden, Cardiac/prevention & control , Electric Countershock , Electrocardiography , Heart Rate , Primary Prevention , Tachycardia, Ventricular/diagnosis , Ventricular Dysfunction, Left/diagnosis , Ventricular Fibrillation/diagnosis , Action Potentials , Aged , Aged, 80 and over , Death, Sudden, Cardiac/etiology , Defibrillators, Implantable , Electric Countershock/instrumentation , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Primary Prevention/instrumentation , Risk Assessment , Risk Factors , Stroke Volume , Tachycardia, Ventricular/mortality , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/therapy , Ventricular Dysfunction, Left/mortality , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/therapy , Ventricular Fibrillation/mortality , Ventricular Fibrillation/physiopathology , Ventricular Fibrillation/therapy , Ventricular Function, LeftABSTRACT
Evidence-based medicine is an important aspect of continuing medical education. This article reviews previous and current examples of conflicting topics that evidence-based medicine has clarified to allow us to provide the best possible patient care.
ABSTRACT
A 55-year-old man with pulmonary Mycobacterium avium intracellulare infection developed decreased vision to 3/200 in the right eye, and 20/200 in the left eye, 11 months after starting ethambutol, rifampin, and isoniazid. A diagnosis of presumed ethambutol optic neuropathy was made, and the medications were discontinued. Visual acuity gradually improved to 20/30 and 20/70 over a period of 34 months. Despite improved central vision and visual field, the patient developed progressive bilateral optic disc cupping, disc pallor, and diffuse nerve fiber layer loss on optical coherence tomography. The observed optic nerve head structural changes in this patient did not correlate with the markedly improved visual function. Visual improvement may occur in ethambutol optic neuropathy despite progressive structural changes.
Subject(s)
Antitubercular Agents/adverse effects , Ethambutol/adverse effects , Optic Nerve Diseases/chemically induced , Optic Nerve Diseases/physiopathology , Humans , Male , Middle Aged , Mycobacterium avium-intracellulare Infection/drug therapy , Neurotoxins/adverse effects , Optic Nerve Diseases/pathologyABSTRACT
Approximately 10% of patients with AIDS present with some neurological deficit as their initial complaint, and up to 80% will have CNS involvement during the course of their disease. Toxoplasmosis is the most common cause of cerebral mass lesions in patients with AIDS, but appears to be an uncommon cause of spinal cord disease. The incidence of myelopathy may be as high as 20%, with 50% of the cases reported post-mortem. We present a unique case of spinal cord disease as the initial presentation of AIDS. We also present a comprehensive literature review of this topic, its diagnosis and treatment. This is a retrospective chart review case report. After a detailed case presentation, several diagnostic and therapeutic aspects of this unique case are thoroughly discussed. Although spinal cord toxoplasmosis is uncommon, it has been suggested that most patients with AIDS that present with evolving myelopathy, characterized by extremity weakness, sensory involvement, spinal cord enlargement, enhancing lesions in brain or spinal cord CT or MRI, have toxoplasmic myelitis.
