Evaluation of the validity of the Bolton Index using cone-beam computed tomography (CBCT)

Aims: To evaluate the reliability and reproducibility of calculating the Bolton Index using cone-beam computed tomography (CBCT), and to compare this with measurements obtained using the 2D Digital Method. Material and Methods: Traditional study models were obtained from 50 patients, which were then digitized in order to be able to measure them using the Digital Method. Likewise, CBCTs of those same patients were undertaken using the Dental Picasso Master 3D® and the images obtained were then analysed using the InVivoDental programme. Results: By determining the regression lines for both measurement methods, as well as the difference between both of their values, the two methods are shown to be comparable, despite the fact that the measurements analysed presented statistically significant differences. Conclusions: The three-dimensional models obtained from the CBCT are as accurate and reproducible as the digital models obtained from the plaster study casts for calculating the Bolton Index. The differences existing between both methods were clinically acceptable. Key words:Tooth-size, digital models, bolton index, CBCT.     

Idiopathic ventricular fibrillation: inducibility and beneficial effects of class I antiarrhythmic agents

Ventricular fibrillation in patients without recognizable heart disease is uncommon and electrophysiologic data on such patients is limited. Over a 7 year period, five patients (three men and two women, ranging in age from 24 to 52 years) without demonstrable heart disease underwent electrophysiologic studies with pharmacologic drug testing because of single (four patients) or multiple (one patient) documented episodes of ventricular fibrillation. The arrhythmic event was unrelated to myocardial ischemia or infarction, metabolic or electrolyte disturbances, drug toxicity, preexcitation, or prolonged QT syndromes. In all three patients receiving no antiarrhythmic drugs and in two pretreated with amiodarone, a rapid poorly tolerated ventricular tachyarrhythmia requiring cardioversion was induced by programmed ventricular stimulation with up to two extrastimuli. In all instances, addition of either oral quinidine or oral disopyramide prevented the induction of sustained ventricular arrhythmias. All five patients were placed on antiarrhythmic drug regimens found effective during electrophysiologic studies and remained asymptomatic during follow-up periods ranging from 12 to 93 (mean 52) months. We conclude that in the patients with idiopathic ventricular fibrillation in our study: programmed ventricular stimulation reliably replicated the spontaneous arrhythmia, class I antiarrhythmic agents effectively prevented induction of the arrhythmia in the laboratory, and in contrast to the severity of the presenting arrhythmia, a benign clinical course was observed during long-term therapy with class I antiarrhythmic agents.     

Factors associated with poor outcomes in patients with lupus nephritis

The objective of this study was to identify the factors associated with important clinical outcomes in a case-control study of 213 patients with lupus nephritis. Included were 47% Hispanics, 44% African Americans and 9% Caucasians with a mean age of 28 years. Fifty-four (25%) patients reached the primary composite outcome of doubling serum creatinine, end-stage renal disease or death during a mean follow-up of 37 months. Thirty-four percent African Americans, 20% Hispanics and 10% Caucasians reached the primary composite outcome (P < 0.05). Patients reaching the composite outcome had predominantly proliferative lupus nephritis (WHO classes: 30% III, 32% IV, 18% V and 5% II, P < 0.025) with higher activity index score (7 +/- 6 versus 5 +/- 5, P < 0.05), chronicity index (CI) score (4 +/- 3 versus 2 +/- 2 unit, P < 0.025), higher baseline mean arterial pressure (MAP) (111 +/- 21 versus 102 +/- 14 mmHg, P < 0.025) and serum creatinine (1.9 +/- 1.3 versus 1.3 +/- 1.0 mg/dL, P < 0.025), but lower baseline hematocrit (29 +/- 6 versus 31 + 5%, P < 0.025) and complement C3 (54 +/- 26 versus 65 + 33 mg/dL, P < 0.025) compared to controls. More patients reaching the composite outcome had nephrotic range proteinuria compared to controls (74% versus 56%, P < 0.025). By multivariate analysis, CI (hazard ratio [95% CI] 1.18 [1.07-1.30] per point), MAP (HR 1.02 [1.00-1.03] per mmHg), and baseline serum creatinine (HR 1.26 [1.04-1.54] per mg/dL) were independently associated with the composite outcome. We concluded that hypertension and elevated serum creatinine at the time of the kidney biopsy as well as a high CI are associated with an increased the risk for chronic renal failure or death in patients with lupus nephritis.