Palpitations Occur Frequently Following Radiofrequency Catheter Ablation for Supraventricular Tachycardia, But Do Not Predict Pathway Recurrence

Radiofrequency ablation of extranodal pathways is an effective treatment for supraventricular tachycardia, but late recurrences of pathway conduction do occur. To determine if recurrence of palpitations following ablation predicts pathway recurrence, we interviewed 77 patients who were at Jeast 4 weeks status-post successful ablation of an accessory pathway (43 overt, 11 concealed)or a slow pathway (23)for AV nodal reentrant tachycardia. Palpitations were reported by 45 (58%)patients postablation, and 28 (36%)patients reported palpitations lasting ≥10 seconds and/or felt their symptoms represented recurrent tachycardia (major palpitations). Repeat electrophysiological testing was performed 3 months postablation in 53 patients, including 34 patients with palpitations (22 with major symptoms). Eight (10%)patients had recurrent pathway conduction demonstrated on repeat testing: two had no symptoms prior to restudy and six had major symptoms. One patient had major symptoms, but was found to have inducible atrial tachycardia and not pathway recurrence on restudy. Thus, 15 (68%)of 22 patients with major symptoms who were restud-ied had no pathway recurrence or inducible arrhythmia to explain their symptoms. Of the 24 patients not restudied, none has had documented recurrent tachycardia or overt pathway conduction by electrocardiogram over a mean follow-up of 335 ± 138 (range 132–616)days. Thus, palpitations, including palpitations reminiscent of preablation symptoms, are common following radiofrequency ablation and often do not predict pathway recurrence. Repeat electrophysiological testing is frequently required to document long-term success of radiofrequency ablation for supraventricular tachycardia in patients with recurrence of major symptoms.     

Contextualising psychological distress among regular ecstasy users: The importance of sociodemographic factors and patterns of drug use

Introduction and Aims. Considerable concern has been raised about associations between ecstasy use and mental health. Studies of ecstasy users typically investigate varying levels of lifetime use of ecstasy, and often fail to account for other drug use and sociodemographic characteristics of participants, which may explain mixed findings. The current study aimed to examine the relationship between patterns of recent (last six months) ecstasy use and psychological distress among current, regular ecstasy users, controlling for sociodemographic risk factors and patterns of other drug use. Design and Methods. Data were collected from regular ecstasy users (n = 752) recruited from each capital city in Australia as part of the Ecstasy and related Drugs Reporting System (EDRS). Psychological distress was assessed using the Kessler Psychological Distress Scale (K10). Data were analysed using multinomial logistic regression. Results. Seven per cent of the sample scored in the ‘high’ distress category and 55% in the ‘medium’ distress category. Patterns of ecstasy use were not independently associated with psychological distress. The strongest predictors of distress were female sex, lower education, unemployment, ‘binge’ drug use including ecstasy (use for >48 h without sleep), frequent cannabis use and daily tobacco use. Discussion and Conclusions. Regular ecstasy users have elevated levels of psychological distress compared with the general population; however, ecstasy use per se was not independently related to such distress. Other factors, including sociodemographic characteristics and other drug use patterns, appear to be more important. These findings highlight the importance of targeting patterns of polydrug use in order to reduce drug‐related harm among regular ecstasy users.[George J, Kinner SA, Bruno R, Degenhardt L, Dunn M. Contextualising psychological distress among regular ecstasy users: The importance of sociodemographic factors and patterns of drug use. Drug Alcohol Rev 2010]     

Canadian Registry of ICD Implant Testing Procedures (CREDIT): Current Practice,Risks, and Costs of Intraoperative Defibrillation Testing

Defibrillation Testing at ICD Implantation. Background: There is uncertainty about the proper role of defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion. Methods: A prospective registry was conducted at 13 sites in Canada between January 2006 and October 2007. Objectives: To document the details of DT, the reasons for not conducting DT, and the costs and complications associated with DT. Results: DT was conducted at implantation in 230 of 361 patients (64%). DT was more likely to be conducted for new implants compared with impulse generator replacements (71% vs 32%, P = 0.0001), but was similar for primary and secondary prevention indications (64% vs 63%, P = NS). Among patients not having DT, the reason(s) given were: considered unnecessary (44%); considered unsafe, mainly due to persistent atrial fibrillation (37%); lack of an anesthetist (20%); and, patient or physician preference (6%). When performed, DT consisted of a single successful shock ≥ 10J below maximum device output in 65% of cases. A 10J safety‐margin was met by 97% of patients, requiring system modification in 2.3%. Major perioperative complications occurred in 4.4% of patients having DT versus 6.6% of patients not having DT (P = NS). ICD insertion was $844 more expensive for patients having DT (P = 0.16), largely due to increased costs ($28,017 vs $24,545) among patients having impulse generator replacement (P = 0.02). Conclusions: DT was not performed in a third of ICD implants, usually due to a perceived lack of need or relative contraindication. (J Cardiovasc Electrophysiol, Vol. 21, pp. 177‐182, February 2010)     

Validating an automated sleep spindle detection algorithm using an individualized approach

The goal of the current investigation was to develop a systematic method to validate the accuracy of an automated method of sleep spindle detection that takes into consideration individual differences in spindle amplitude. The benchmarking approach used here could be employed more generally to validate automated spindle scoring from other detection algorithms. In a sample of Stage 2 sleep from 10 healthy young subjects, spindles were identified both manually and automatically. The minimum amplitude threshold used by the prana ^® (PhiTools, Strasbourg, France) software spindle detection algorithm to identify a spindle was subject‐specific and determined based upon each subject’s mean peak spindle amplitude. Overall sensitivity and specificity values were 98.96 and 88.49%, respectively, when compared to manual scoring. Selecting individual amplitude thresholds for spindle detection based on systematic benchmarking data may validate automated spindle detection methods and improve reproducibility of experimental results. Given that interindividual differences are accounted for, we feel that automatic spindle detection provides an accurate and efficient alternative approach for detecting sleep spindles.     

Bipolar Ablation of the Interventricular Septum is More Efficient at Creating a Transmural Line than Sequential Unipolar Ablation

Introduction: Post infarct ventricular tachycardia (VT) often involves the interventricular septum (IVS) and requires transmural septal ablation. The purpose of this study was to compare the efficacy of bipolar ablation (BIA) versus sequential unipolar ablation (SUA) in creating a transmural ablation line along the IVS scar border.
Methods and Results: Both ablation strategies were compared in a phantom agar model first and then in 10 post infarct sheep. In the phantom agar model BIA lesions were larger, transmural, and less dependent on catheter alignment and contact compared with SUA. Noncontact mapping was used in the animals to identify the septal scar border and create a 30-mm ablation line. In five animals BIA (50 W) was performed between two irrigated catheters on either side of the IVS, and in five control animals SUA (50 W) was performed, first on the left ventricle (LV) septal scar border and then on the opposing right ventricle (RV) septal surface. Electrical block along ablation lines was confirmed with noncontact mapping. BIA required significantly less ablations (12 ± 1 vs 29 ± 7, P = 0.001), ablation time (22 ± 3 vs 48 ± 6 minutes, P < 0.001), and energy (58 ± 7 vs 124 ± 21 kJ, P < 0.001). At pathological examination all ablation lines in both groups were transmural at the IVS border. BIA endocardial ablation lines (LV + RV) were significantly longer than SUA lines (76 ± 10 vs 49 ± 11 mm, P = 0.003).
Conclusion: BIA of the IVS is highly effective at creating a transmural ablation line, requiring less ablation and creating longer lesions than SUA. BIA ablation may have a role for post infarct VT involving the IVS. (PACE 2010; 33:16–26)     

Polarization Color Imaging System for On-Line Quantitative Evaluation of Facial Skin Lesions

BACKGROUND A number of studies have been performed for accurate evaluation of chromophores in skin lesions. Qualitative methods are subjective and cause user-dependent error in evaluation. Quantitative methods have limitations for widely distributed skin lesions due to poor spatial resolution, potential skin blanching, and difficulty in relocating identical sites for subsequent measurements and analysis.
OBJECTIVE The objective was to develop a new imaging modality that provides both qualitative and quantitative methods to evaluate widely distributed skin lesions.
METHODS We have developed a prototype polarization color imaging system named "DermaVision," which provides quantitative on-line image analysis of polarization color images. Herein, we describe the hardware and software of DermaVision in terms of its performance and usefulness for dermatologic applications.
RESULTS Polarization color images were successfully acquired from patients with vascular or pigmented skin lesions. The erythema and melanin index images were successfully computed and quantitatively confirmed the degree of erythema and pigmentation in the skin lesions.
CONCLUSION We believe that DermaVision can be a useful auxiliary tool in dermatology because it simultaneously provides both qualitative and quantitative images of skin lesions.     

HAND ASSISTED LAPAROSCOPIC NEPHRECTOMY: COMPARISON TO STANDARD LAPAROSCOPIC NEPHRECTOMY

Purpose

We report our initial experience with hand assisted laparoscopic nephrectomy, and compare it to our results of standard laparoscopic nephrectomy.

Materials and Methods

The results of 21 hand assisted and standard laparoscopic nephrectomies (15 simple and 4 radical nephrectomies, and 2 nephroureterectomies) were reviewed. Hand assisted laparoscopic nephrectomy was performed with a hand placed intra-abdominally using the Pneumo Sleeve,^* in addition to standard laparoscopic instruments manipulated through laparoscopic ports. Standard laparoscopic nephrectomy was performed using laparoscopic instruments alone. Perioperative data were recorded and questionnaires, including visual analog pain scales, were administered prospectively to 17 of 21 cases.

Results

The average operative time for 13 hand assisted laparoscopic nephrectomies was 240 minutes, which was significantly less than the 325-minute average for 8 standard laparoscopic nephrectomies (p = 0.04). Major complications tended to be more frequent in the standard group (38 versus 8%, p = 0.10). Hospital stay, return to normal activity and corrected 2-week abdominal/flank pain score in the hand assisted group (3.1 days, 14 days and 0.8, respectively) were not significantly different from the standard group (3.0 days, 10 days and 0.2, respectively).

Conclusions

Compared to standard laparoscopic techniques, hand assistance appears to facilitate the operative speed and safety of laparoscopic nephrectomy without sacrificing the benefits of minimally invasive surgery. Hand assistance may make laparoscopic nephrectomy more appealing to urologists without advanced laparoscopic experience, may facilitate the laparoscopic management of demanding pathological conditions and is particularly useful when intact specimens are required. Hand assistance, by improving manipulative ability and tactile sense, is helpful for select cases of laparoscopic nephrectomy.