Histological comparison of pulpal inflammation in primary teeth with occlusal or proximal caries

Objective.  A number of clinical and histological studies have investigated caries-related changes in the primary tooth pulp, but the effect of caries site, as a clinical variable, has not been previously considered. This study sought to compare inflammatory changes within the pulp of primary molars according to the location of the caries lesion (occlusal or proximal).
Methods.  Eighty-three primary molars were extracted under general anaesthesia for caries and/or orthodontic reasons, and were split immediately after removal and fixed in 10% formalin. Teeth were then decalcified, sectioned, and stained with haematoxylin and eosin for histological examination using light microscopy. Caries depth was measured using a graticle, and the site of the caries lesion noted as occlusal or proximal. Samples were further classified into one of five subgroups according to the observed degree of pulpal inflammation.
Results.  Key findings were that where caries depth was less than 50% of the total dentine thickness, there were no significant differences in inflammatory status according to caries site. In contrast, marked inflammatory changes were significantly more likely throughout the coronal pulp of teeth with proximal caries compared to teeth with occlusal caries where caries depth was equal to, or greater than, 50% of the total dentine thickness ( P  = 0.017, Fisher's exact test).
Conclusion.  Primary teeth with proximal carious lesions extending more than 50% through the dentine thickness appear to have more extensive inflammatory pulpal changes than teeth with occlusal caries of a similar depth. This finding has clinical implications and may help inform treatment decisions in the management of primary teeth with deep carious lesions.     

Left Atrial Ablation at the Anatomic Areas of Ganglionated Plexi for Paroxysmal Atrial Fibrillation

Background: Modification of left atrial ganglionated plexi (GP) is a promising technique for the treatment of paroxysmal atrial fibrillation (AF) but its therapeutic efficacy is not established. This study aimed at evaluating the effectiveness of anatomic GP modification by means of an implantable arrhythmia monitoring device. Methods: In 56 patients with paroxysmal AF, radiofrequency ablation at anatomic sites, where the main clusters of GP have been identified in the left atrium, was performed. In all patients, an electrocardiogram monitor (Reveal XT, Medtronic Inc., Minneapolis, MN, USA) was implanted before (n = 7) or immediately after (n = 49) AF ablation. Results: Average duration of the procedure was 142 ± 18 min and average fluoroscopy time 20 ± 7 min. In total, 53–81 applications of RF energy were delivered (mean of 18.2 ± 3.8 at each of the four areas of GP ablation). Heart rate variability was assessed in 31 patients. Standard deviation of RR intervals over the entire analyzed period, the root mean square of differences between successive RR intervals, and high frequencies decreased, while HRmin, HRmean, and LF to HF ratio increased immediately postablation; these values returned to baseline 6 months after the procedure. At end of 12‐month follow‐up, 40 (71%) patients were free of arrhythmia recurrence. Ten patients had AF recurrence, two patients had left atrial flutter, and four patients had episodes of flutter as well as AF recurrence. Duration of episodes of AF after ablation gradually decreased over the follow‐up period. Conclusions: Regional ablation at the anatomic sites of the left atrial GP can be safely performed and enables maintenance of sinus rhythm in 71% of patients with paroxysmal AF for a 12‐month period. (PACE 2010; 33:1231–1238)     

A PRELIMINARY CLINICAL STUDY OF CT1341--A STEROID ANAESTHETIC AGENT

The effects of a new steroid anaesthetic agent (CT1341) werestudied in twenty volunteers divided into three groups. In groupI, serial measurements were made of heart rate, blood pressureand respiratory rate. In group II, detailed haemodynamic studieswere made in patients undergoing diagnostic cardiovascular investigations.These studies included measurement of cardiac output, strokevolume and arterial blood gases. In group III, time from inductionto "true recovery" was measured following a single intravenousinjection of the drug. This agent produced a stable anaestheticstate in all cases. Anaesthesia was characterized by a risein respiratory rate and pulse rate with a slight fall in systolicand diastolic blood pressure. A significant fall in Pa_o2 occurredin those patients breathing air. The mean recovery time in sixpatients was 24.3 min. CT1341 produced safe and stable anaesthesiain all twenty cases and is worthy of further clinical trial.     

Automated On-Line Measurement of Electrophysiologic Intervals During Cardiac Catheterization

A small dedicated, computer-controlled waveform analyzer was used to automatically measure the R-R cycle length, low right atrium to His, and His to ventricle intervals obtained during electrophysiologic studies on 35 patients. These measurements were compared to intervals hand-measured separately and found to correlate well (0.92, 0.83, and 0.75, respectively). The sources of error, possible pitfalls, and future uses of this technique are discussed.     

Performance of Dedicated Versus Integrated Bipolar Defibrillator Leads with CRT-Defibrillators: Results from a Prospective Multicenter Study

Introduction: Right ventricular (RV) anodal stimulation may occur in cardiac resynchronization therapy defibrillators (CRT-D) when left ventricular (LV) pacing is configured between the LV lead and an electrode on the RV defibrillator lead. RV defibrillator leads can have a dedicated proximal pacing ring electrode (dedicated bipolar) or utilize the distal shocking coil as the proximal pacing electrode (integrated bipolar). This study compares the performance of integrated versus dedicated leads with respect to anodal stimulation incidence, sensing, and inappropriate ventricular tachyarrhythmia detection in patients implanted with CRT-D.
Methods: Two hundred ninety-two patients were randomly assigned to receive dedicated or integrated bipolar RV leads at the time of CRT-D implantation. Patients were followed for 6 months.
Results: Patients with dedicated bipolar RV leads exhibited markedly higher rates of anodal stimulation than did patients with integrated leads. The incidence of anodal stimulation was 64% at implant for dedicated bipolar RV leads compared to 1% for integrated bipolar RV leads. The likelihood of anodal stimulation in patients with dedicated leads fell progressively during the 6-month follow-up (51.5%), but always exceeded the incidence of anodal stimulation in patients with integrated leads (5%). Clinically detectable undersensing and oversensing were very unusual and did not differ significantly between lead designs. There were no inappropriate ventricular tachyarrhythmia detections for either lead type.
Conclusion: Integrated bipolar RV defibrillator leads had a significantly lower incidence of RV anodal stimulation when compared to dedicated bipolar RV defibrillation leads, with no clinically detectable oversensing or undersensing, and with no inappropriate ventricular tachyarrhythmia detections for either lead type.