Mean Number Of Shocks Research Articles

Anteroposterior Versus Anterolateral Electrode Position for Direct Current Cardioversion of Atrial Fibrillation: AMeta-Analysis of Randomised Controlled Trials.

Data regarding optimal electrode positioning for direct current cardioversion (DCCV) of atrial fibrillation (AF) has been inconsistent. This meta-analysis was conducted to systematically compare the efficacy of anteroposterior (AP) versus anterolateral (AL) electrode placement for DCCV of AF. Electronic databases were searched for randomised controlled trials (RCTs) comparing AP versus AL electrode positioning in patients undergoing DCCV for AF. Primary endpoints were first-shock success and overall DCCV success. Subgroup analysis was performed by defibrillator waveform (monophasic versus biphasic). Meta-regression analyses were performed to assess for significant moderators. Twelve (12) RCTs, including a total of 2,046 patients, met inclusion criteria. Neither first-shock success (relative risk [RR] 0.92; 95% CI 0.79-1.07; p=0.28) nor overall DCCV success (RR 1.01; 95% CI 0.96-1.05; p=0.78) were significantly different with AP versus AL electrode positioning. The mean number of shocks (mean difference [MD] 0.3, 95% CI -0.4 to 0.9), energy level of first successful shock (MD 3 joules; 95% CI -20 to 27) and cumulative energy delivered (MD 39 joules; 95% CI -168 to 246) were similar in AP versus AL arms. In subgroup analysis of six RCTs using biphasic defibrillators, improvement in first-shock success (RR 0.85; 95% CI 0.69-1.03; p=0.10) and overall DCCV success (RR 0.97; 95% CI 0.93-1.01; p=0.09) with AL electrode positioning did not reach statistical significance. Meta-regression analyses identified older age, higher body mass index, and longer AF duration as significant moderators favouring AL electrode positioning. Pooled analysis of randomised data overall does not show a significant difference in efficacy between AP versus AL electrode positioning. Meta-regression and subgroup analyses suggest that, in contemporary practice with use of biphasic defibrillators, there may be a subset of AF patients in whom AL electrode positioning improves efficacy of DCCV.

Limited Left Thoracoscopic Sympathectomy Effectively Silences Refractory Electrical Storm

BackgroundAn electrical storm (ES) is a life-threatening condition that affects up to 20% of patients with implantable cardioverter defibrillators. In this small retrospective study, we report our results with left video-assisted thoracoscopic sympathectomy/ganglionectomy (VATSG) to treat refractory ES in low–ejection fraction patients who were not candidates for catheter ablation. MethodsWe identified 12 patients who presented with ES and underwent a total of 14 video-assisted thoracoscopic sympathectomy/ganglionectomy, including 3 patients on venoarterial extracorporeal membrane oxygenation. We reviewed demographic data, survival to discharge, number of cardioversions (before and after VATSG), need for readmissions, and need for right-sided procedures. ResultsIn the 30 days before a left VATSG, mean number of shocks was 22.67 for all patients. For the patients who survived to discharge, the mean was 3.55 since surgery and the median was zero shocks after a median follow-up of 358 days. Six patients did not experience further cardioversions since the last VATSG and 5 were not readmitted for ventricular tachycardia. Two patients had staged bilateral procedures owing to recurrences; of those, 1 did not require further cardioversions. ConclusionsLimited left VATSG is an appropriate and effective initial treatment for ES patients who are not candidates for catheter ablation, including those on venoarterial extracorporeal membrane oxygenation for hemodynamic support.

Emergency extracorporeal shockwave lithotripsy as opposed to delayed shockwave lithotripsy for the treatment of acute renal colic due to obstructive ureteral stone: a prospective randomized trial.

The aim of this study was to assess the efficacy of emergency extracorporeal shockwave lithotripsy (eSWL) as first-line treatment in patients with acute colic due to obstructive ureteral stone. Seventy-four patients were randomized to emergency SWL within 12 hours (eSWL group) and deferred SWL later than 3 days (dSWL group). Follow-up included ultrasound, KUB (kidney-ureter-bladder) radiography and CT (computed tomography) scan at 24 hours, 7 days, 1 and 3 months from the treatment. When necessary, repeated SWL (re-SWL) or ureteroscopy (auxiliary-URS) was performed. Preoperative and postoperative data were compared and stone free rates (SFR) and efficiency quotients (EQ) were evaluated. Analyses were performed using SAS software. Complete data of 70 patients were collected. 36 underwent eSWL and 34 dSWL. The mean patient age was 48.7. Mean stone size was 9.8 mm (CI 95%: 8.9-10.8). 25 (35.7%) were proximal and 45 (64.3%) distal. Mean SWL energy was 19.2 kV (CI 95%: 18.5-19.9) and mean number of shocks was 2657 (CI 95%: 2513-2802). eSWL patients needs less auxiliary-URS than dSWL patients (13.9% vs. 44.1%, P=0.039) and less re-SWL sessions (8.3% vs. 32.4%, P=0.093). SFR at 24 hours was 52.8% and 11.8% (P<0.001) and the EQ at 3 months was 79.1% and 57.5% in the eSWL and dSWL group respectively. Patients from the dSWL group spent more time in the hospital (2.21 vs. 1.36 days, P=0.046) and complication rates between the two groups were similar. eSWL is a safe procedure and delivers high SFR even within 24 hours especially for <10 mm stones. It is able to reduce the number of auxiliary procedures and hospitalization.

Supine versus Prone Position during Extracorporeal Shockwave Lithotripsy for Treating Distal Ureteral Calculi: A Systematic Review and Meta-Analysis

Purpose: We aimed at evaluating the efficacy of extracorporeal shockwave lithotripsy (SWL) for treating distal ureteral calculi performed in supine vs. prone position. Materials and Methods: Eligible studies were identified by 2 reviewers using PubMed, Embase, and Web of Science databases. Outcomes included stone-free rate after the first and the final SWL session, the mean number of shocks per SWL session, the mean percentage of power used in the first SWL session, and the mean number of SWL sessions per patient. Results: Pooled data among the 647 included patients showed that supine SWL was associated with a significantly higher stone-free rate than prone SWL. This difference was consistent for both the first SWL session (OR 4.17; 95% CI 2.53-6.87; p < 0.00001) and the final session (OR 3.02; 95% CI 1.96-4.67; p < 0.00001). No differences in the mean number of shocks per SWL session, the mean percentage of power used in the first SWL session, and the mean number of SWL sessions per patient were observed between the positions. SWL complications were infrequent and the incidence was insufficient for further analysis. Conclusion: SWL is safe and effective for the management of distal ureteral calculi, and supine SWL is more effective than prone SWL for achieving a stone-free status.

Abstract 18147: Association of the First Occurrence of Atrial Fibrillation With Short-Term ICD Therapy and Heart Failure Exacerbation

Background: Atrial fibrillation (AF) predicts inappropriate therapy and mortality in patients (pts) with implantable cardioverter defibrillators (ICDs). The short term effects of AF in pts with ICDs are not known. We sought to determine if AF burden affected 30 day morbidity as defined by heart failure (HF) exacerbations and ICD therapy. Methods: Pts enrolled in the LATITUDE home monitoring system were analyzed. Devices with greater than 1% AF during a 30-day period were included and divided into deciles based on the AF burden. The deciles were compared on number of ICD shocks, blood pressure and heart rate measures, and 6 HF symptom questions from the LATITUDE monitoring system. Symptom questions were scored as “-1” for improved, “0” for same, and “1” for worsened. Results: 4258 pts were identified with an AF burden &gt;1%. Of those, 3197 had heart failure observations recorded before and after the AF episode. Compared with before the 1st AF episode, in the month following, pts had a worsened activity level ( P &lt;0.001), systolic blood pressure ( P &lt;0.001), and heart rate variability ( P =0.005). Pts also reported worsened dizziness ( P &lt;0.001), edema ( P =0.006), exercise capacity ( P =0.01), orthopnea ( P &lt;0.001), and more episodes of nocturnal dyspnea ( P &lt;0.001) The trend for nocturnal dyspnea and fatigue was significant across AF burden deciles (Figure). There was no difference in the mean number of shocks after the analyzed month of AF. Conclusion: Short term AF burden is predictive of worsened HF symptoms but not ICD shocks.

Outcome of shock wave lithotripsy as monotherapy for large solitary renal stones (&gt;2 cm in size) without stenting

Purpose:To evaluate the outcome of shock wave lithotripsy (SWL) as monotherapy for solitary renal stones larger than 2 cm without ureteral stenting.Materials and Methods:Our retrospective study included patients with solitary renal radio opaque stones larger than 2 cm treated with SWL using electromagnetic Dornier Compact S lithotripter device (Wessling, Germany) for a period of 3 years (September 2002-2005). Stone clearance was assessed at 1 week, 1 month, and 3 months with plain X-rays of kidney, ureter, and bladder region, ultrasonography, and tomograms. Stone-free status, morbidity of the procedure, and fate of clinically insignificant residual fragments (CIRF) were studied. A stone-free state was defined as no radiologic evidence of stone. Success was defined as complete clearance + CIRF.Results:Fifty-five patients, aged 11–65 years (mean 49.8) underwent SWL. Of them, only two were children. Male-to-female ratio was 3:1. The stone size was 21–28 mm (average 24 mm). The mean number of shocks were 3732 (range 724–12,100) and average energy level was 14 kV (range 11–16 kV). The mean follow-up was 18 months (range 3–22 months). Over all, stone-free status was achieved in 50% and success in 81% at 3 months. Stone clearance was not affected by stone location. Stones <25 mm had better stone-free rate (54.16% vs. 28.5%) and lesser CIRF (14.6% vs. 28.5%) when compared to larger stones (>26 mm) (P = –0.10). Of 54 patients, 39 developed steinstrasse with mean length of 3.2 cm (range 1.4–6.2 cm) and only four required intervention. Effectiveness quotient (EQ) for SWL monotherapy for solitary renal stones more than 2 cm was 25.3%. The EQ for stones <25 mm and those more than 25 mm were 28.4% and 10% (P = –0.12), respectively. There was a lesser trend of difference between stones with size <25 and more than 25 mm. During the last review, the overall stone-free rate was 67.2%.Conclusions:SWL monotherapy was safe but significantly less effective for solitary renal stones larger than 2 cm. It can only be suggested to those who refuse surgical intervention. Pretreatment DJ stenting is not mandatory when closer follow-up is ensured.

Comparison of Antero-Lateral Versus Antero-Posterior Electrode Position for Biphasic External Cardioversion of Atrial Flutter

External cardioversion is an established and very important tool to terminate symptomatic atrial flutter. The superiority of the biphasic waveform has been demonstrated for atrial flutter, but whether electrode position affects the efficacy of cardioversion in this population is not known. The aim of this trial was to evaluate whether anterior-lateral (A-L) compared with anterior-posterior (A-P) electrode position improves cardioversion results. Of 130 screened patients, 96 (72 men, mean age 62 +/- 12 years) were included and randomly assigned to a cardioversion protocol with either A-L or A-P electrode position. In each group, 48 patients received sequential biphasic waveform shocks using a step-up protocol consisting of 50, 75, 100, 150, or 200 J. The mean energy (65 +/- 13 J for A-L vs 77 +/- 13 J for A-P, p = 0.001) and mean number of shocks (1.48 +/- 1.01 for A-L vs 1.96 +/- 1.00 for A-P, p = 0.001) required for successful cardioversion were significantly lower in the A-L group. The efficacy of the first shock with 50 J in the A-L electrode position (35 of 48 patients [73%]) was also highly significantly greater than the first shock with 50 J in the A-P electrode position (18 of 48 patients [36%]) (p = 0.001). In conclusion, the A-L electrode position increases efficacy and requires fewer energy and shocks in external electrical cardioversion of common atrial flutter. Therefore, A-L electrode positioning should be recommended for the external cardioversion of common atrial flutter.

Impact of electrical shock waveform and paddle positions on efficacy of direct current cardioversion for atrial fibrillation

Direct-current electrical cardioversion is the main method for the conversion of atrial fibrillation. Its success depends on many factors. In several studies, biphasic shock waveforms have been demonstrated to be superior to monophasic shocks for termination of atrial fibrillation; however, information about impact of paddle position is controversial. Initial energy level is an object of discussions. The aim of the study was to compare a truncated exponential biphasic waveform with monophasic damped sine waveform and antero-lateral with antero-posterior paddle positions for cardioversion of atrial fibrillation, to determine its impact on early reinitiation of atrial fibrillation. A total of 224 consecutive patients with atrial fibrillation underwent electrical cardioversion with biphasic (Bi, n=112) or monophasic (Mo, n=112) shock waveform in a randomized fashion. The position of hand-held paddle electrodes was randomly selected in both groups to be anterior-lateral and anterior-posterior. Energies used were 100-150-200-300-360 J (Bi) or 100-200-300-360 J (Mo). If monophasic shock of 360 J was ineffective, we used biphasic shock of 360 J. Early recurrent atrial fibrillation (ERAF) was defined as a relapse of atrial fibrillation within 2 min after a successful cardioversion, acute recurrent - within 24 h. Two study groups (Bi vs Mo) did not differ with regard to age, body mass index, duration of AF episode (mean 98+/-147 days for the Bi group and 80+/-93 days for the Mo group, P=0.26), underlying heart disease, left atrial diameter, left ventricular ejection fraction. In the Mo group, more patients used amiodarone (59.82% vs 41.97%, P=0.002), in the Bi group more patients used propafenone (16.07% vs 8.93%, P=0.033). Cardioversion success rate was 97.32% in the Bi group and 79.46% in the Mo group (P<0.001). After biphasic shock of 360 J in Mo group, the cumulative success rate was 99.11%. Mean delivered energy and mean number of shocks were significantly lower in the Bi group (198.5+/-204.4 J, 1.5+/-0.9 shocks vs 489.1+/-464.2 J, 2.4+/-1.5 shocks). The efficacy of first shock was 66.96% in the Bi group and 37.5% in the Mo group (P<0.0001). Incidence of ERAF was 4.46% in both groups. Paddle position had no impact on efficacy of cardioversion and ERAF. For the cardioversion of atrial fibrillation, biphasic shock waveform has a higher success rate than monophasic shock waveform. We did not observe the influence of paddle positions on efficacy of cardioversion. Shock waveform and paddle position had no impact on ERAF. We recommend starting with biphasic energy of 150 J and monophasic of not less than 200 J for cardioversion of atrial fibrillation.

Use of LMA Stonebreaker as an Intracorporeal Lithotrite in the Management of Ureteral Calculi

LMA Stonebreaker is a new type of ballistic intracorporeal lithotrite that does not need external electric power or access to compressed air. It is small and portable. This study aims to evaluate the efficacy, safety, and cost-effectiveness of this lithotrite in the management of ureteral calculi. A total of 110 patients with ureteral calculi necessitating intracorporeal lithotripsy were prospectively included in the study. The size of the stone, position of the stone, number of shocks needed to fragment the stone to effect complete clearance, and degree of retropulsion were documented in each case, and any evidence of urothelial trauma was noted. All stones were fragmented, and all patients were rendered stone free. The mean number of shocks needed to fragment the stones was eight. The incidence of retropulsion was 6.36%. There was no evidence of urothelial trauma noted in any patient. LMA Stonebreaker is a safe, effective, cost-effective, robust, and portable device for intracorporeal lithotripsy.

A new transportable shock‐wave lithotripsy machine for managing urinary stones: a single‐centre experience with a dual‐focus lithotripter

To assess the efficacy and safety of a transportable extracorporeal shock wave lithotripsy (ESWL) machine, the Modulith SLX-F2(TM) (Storz Medical Italia, Rome, Italy), in the management of solitary urinary calculi. The study included 233 patients (mean age 51 years; 172 male, 61 female) with symptomatic solitary renal (group A, 170, mean diameter 15.5 mm) or ureteric stones (group B, 63, mean diameter 9.5 mm) treated in a tertiary care institution. Exclusion criteria for the analysis were: pelvi-ureteric junction obstruction, multiple stones, stone diameter >2 cm, stones in a lower calyx with unfavourable anatomy, active infection, or impacted ureteric stones. Selected patients had ureteric stenting before treatment, and all patients were treated with no anaesthesia. Hospitalization, complications and subsequent auxiliary procedures were evaluated. Patients were assessed after a single ESWL session and after 3 months by a plain abdominal film and renal ultrasonography. Stone-free status was defined as no evidence of calculi, and clinical success as the presence of stone fragments of <4 mm. An efficiency quotient (EQ) was calculated for the ESWL treatment. Pain was assessed using a visual analogue scale. The mean number of shocks used was 3779 and the mean (range) treatment time was 35 (5-55) min. The overall clinical success rate after one ESWL session was 83.7% and 82.5% for renal and ureteric stones, respectively, and the overall 3-month stone-free rate was 77% and 74.6%, respectively; the overall EQ was 0.64. When risk factors for persistent calculi were analysed simultaneously in a logistic regression model, only stones of >1 cm were statistically significant (P < 0.05). Most patients reported that pain during ESWL was mild to moderate and easily tolerated. Only minor complications occurred, with an overall complication rate of 3.8%. This transportable lithotripter is a safe and effective device for managing solitary stones throughout the urinary tract. Its main advantage is represented by the dual-focus system. Moreover, it shares with other contemporary machines several important features such as outpatient setting, no need for anaesthesia, easy patient positioning, and the capability of ancillary procedures.

Serum troponin I level after external electrical direct current synchronized cardioversion in patients with normal or reduced ejection fraction: No evidence of myocytes injury

External electrical cardioversion (EEC) has been suggested as a cause of myocardial damage, but results from several previously published studies are conflicting. The purpose of the study was to evaluate myocardial electrical injury caused by EEC. After elective EEC for atrial fibrillation (AF), cardiac troponin I (cTnI) was measured in 193 consecutive patients attending the Cardiology Department of the San Maurizio Hospital of Bolzano for elective EEC of AF over a period of 13 months. External electrical cardioversion was performed by one of the attending cardiologists with a synchronized monophasic defibrillator. Blood sample for cTnI was taken 18-20 h after EEC. Of 193 patients, 183 (95%) were successfully cardioverted. Mean number of shocks was 1.46 and the mean total energy discharged per procedure was 379.4 +/- 229.2 J. Cardiac troponin remained under the limit of confidence for all patients with a mean value of 0.017 +/- 0.021 mcrg/l. No correlation between total energy delivered and cTnI was found. In the subgroup of patients with low ejection fraction, none had elevated cTnI, and no difference in cTnI values between these and patients with an ejection fraction > 40% was found. The results of our analysis indicate that EEC caused no myocardial injury even in patients with low ejection fraction.

Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation

In biphasic external cardioversion (CV) of atrial fibrillation (AF), the influence of different electrode positions on efficacy and incidence of early recurrent atrial fibrillation is not known. This study compared anteroposterior (AP) vs anterolateral (AL) electrode positioning. Consecutive patients referred for CV of persistent AF were randomized either to an AP or an AL electrode position. Biphasic external CV was performed with standardized electrode positions and rising energy delivery. Both groups (N = 123, mean age 66 years, 71% male, 83% with structural cardiovascular disease or hypertension) did not differ concerning age, sex, body mass index, chronic antiarrhythmic therapy, duration of AF, left ventricular ejection fraction, and left atrial diameter. Cumulative success rates were comparable (AP 94.9% vs AL 95.2%, P = ns). First-shock efficacy did not differ (AP 78.3% vs AL 74.6%, P = ns). Early recurrent atrial fibrillation (AF relapse < 1 minute after successful CV) occurred in 8.1% (AP 11.6% vs AL 4.8%, P = ns). Mean number of shocks was 1.3 per patient with the AP configuration and 1.4 per patient with the AL configuration (P = ns). Mean cumulative energy delivery was also comparable (AP 171 WS vs AL 198 WS, P = ns). Both electrode positions are similar in biphasic external CV of AF with regard to acute success and early recurrent atrial fibrillation. Also, the number of shocks needed and energy delivery are comparable with both electrode configurations.

Predictors of unsuccessful electrical cardioversion in atrial fibrillation

R of sinus rhythm improves functional capacity and alleviates palpitations in patients with atrial fibrillation (AF). The advantages of direct-current cardioversion include the immediate restoration of sinus rhythm, as opposed to the unpredictable time to cardioversion in pharmacologic intervention, and the avoidance of potential adverse drug reactions. Although direct-current cardioversion is thought to have a higher success rate than pharmacologic intervention, it may fail to restore sinus rhythm in 5% to 30% of procedures. Few data are available regarding the association between clinical variables and the failure of direct-current cardioversion. Also, the relation between abnormalities of cardiac function and the success of direct-current cardioversion has not been studied in a large number of patients. This study assesses the success rate of direct-current cardioversion in patients with AF and the relation between clinical and echocardiographic variables and the success of direct-current cardioversion. • • • We studied 692 patients (459 men [66%] and 233 women [34%], mean age SD 67 13 years) with AF who had a first elective direct-current cardioversion at Mayo Clinic (Rochester, Minnesota). This study was approved by the Institutional Review Board of the Mayo Foundation. The duration of AF was 48 hours in 653 patients (94%) and 48 hours in 39 patients (6%). All patients underwent transthoracic echocardiography before cardioversion. Transesophageal echocardiography was performed in 201 patients (29%) before cardioversion. A history of coronary artery disease was considered present if the patient had had a previous myocardial infarction, myocardial revascularization, significant coronary artery stenosis on angiography, or typical anginal complaints. Valvular heart disease was considered present if the patient had more than mild stenosis or regurgitation of 1 cardiac valve. Idiopathic dilated cardiomyopathy was defined as left ventricular dilatation and global hypokinesia without significant coronary artery disease. The duration of AF was determined by the time of documentation of AF on the electrocardiogram or the onset of symptoms, whichever occurred earlier. Two-dimensional and M-mode imaging were performed with commercially available echocardiographic machines equipped with 2.5and 3.5-MHz phased-array transducers. M-mode echocardiography was used to measure cardiac dimensions and wall thickness. A left atrial diameter of 40 mm defined left atrial dilatation. This was considered mild for values 50 mm and marked for values 50 mm. Ejection fraction at rest was measured using a previously validated modification of the method of Quinones in Dujardin et al or by visual estimation. Structural heart disease was defined as any of the following: valvular heart disease, coronary heart disease, cardiomyopathy, or ejection fraction 50%. All procedures were performed with electrocardiographic monitoring and full equipment for cardiopulmonary resuscitation. Digitalis preparations were withheld for 24 to 48 hours before the procedure. After administration of intravenous sedation, synchronized direct-current monophasic shock was administered using the anteroposterior paddle position (sternal body angle of the left scapula). If sinus rhythm was not restored after the first shock, the procedure was repeated (up to 4 times) using a larger number of joules (up to 360 J). The number of joules with which cardioversion was initiated was determined for each patient according to physician discretion. Electrocardiography was performed before and after the procedure to verify cardiac rhythm. Successful cardioversion was defined as restoration of sinus rhythm after administration of direct-current shock. Unless specified, data are presented as mean values SD or as frequency percentages. The rank sum and chi-square tests were used to compare differences between continuous variables and proportions, respectively. Univariate and multivariate stepwise logistic regression models were used to identify individual and joint predictors of unsuccessful cardioversion. Analyses of success were done using both the patient and the individual shock as the unit of observation to harvest information when multiple shocks were needed. Differences were considered significant if the null hypothesis could be rejected at the 0.05 probability level. These diseases were present in the study population: systemic hypertension in 355 patients (51%), coronary artery disease in 233 patients (34%), valvular heart disease in 227 patients (33%), and cardiomyopathy (idiopathic dilated, restrictive, or hypertrophic) in 125 patients (18%). Cardioversion was successful in 592 patients (86%) and unsuccessful in 100 (14%). The mean number of shocks was 2.1 1.2/patient. The mean number of joules was 222 100. In 74 patients, 50 J was used initially, with success achieved From the Division of Cardiovascular Diseases and Internal Medicine and the Section of Biostatistics, Mayo Clinic, Rochester, Minnesota. Dr. Khandheria’s address is: Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905. Manuscript received June 13, 2001; revised manuscript received and accepted September 6, 2001.

Quality Assurance: Monitoring Lithotriptor Output and its Clinical Implications

Serial acoustic output measurements performed on the an electromagnetic lithotriptor consistently showed significant decreases in the output of the shock heads. A decrease in output during the lifetime of the shock head to less than 50% of its original output was observed. Decreased output was related to a higher number of shocks per treatment and a higher retreatment rate. Quality control of the lithotriptor output was reflected in better clinical results, a lower mean number of shocks per treatment, a lower retreatment rate and less time on the table, which has important clinical and financial implications. Acoustic output measurements on lithotriptors should be mandatory to achieve the best possible clinical results from extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy in 1,178 ureteric calculi patients--lessons learnt.

In the last 40 months 1,178 ureteric stone patients have been treated on the Siemens Lithostar. The commonest site was upper ureter (54%) followed by the lower (24%) and midureter (22%). Patients were stratified into two groups (A and B) chiefly on the basis of calculus size, degree of back pressure changes, presence of infection and associated local or systemic complicating factors. The mean number of shocks and sessions, complications, pre- and posttreatment auxiliary procedures and failure rates were higher in group B. The overall failure rate was 1.27 and 3.5% needed after extracorporeal shock wave lithotripsy auxiliary procedures. We attribute our high success and low complications rate mainly to the liberal use of JJ stent, attempt of retrograde calculus manipulation at the height of expiration and selection of appropriate position for calculus localization based on stone location.

Transoesophageal versus transchest DC cardioversion

Attempted cardioversion via the oesophagus (transoesophageal cardioversion) was compared with the transchest approach (transchest cardioversion) in a randomized trial of 100 consecutive patients with atrial fibrillation. For the transoesophageal group, 30, 50 and 100 J were delivered via an oesophageal electrode with subsequent 200 and 360 J transchest if required. For the transchest group, 50, 100, 200 and 360 J were delivered if required. In the transoesophageal group, 36/50 (72%) of patients cardioverted using the transoesophageal route alone, and in the transchest group, 41/50 (82%) of patients cardioverted (p = NS). First shock success was similar for the transoesophageal and transchest groups: 13/50 (26%) vs. 8/50 (16%) respectively. The mean number of shocks required to achieve successful cardioversion was identical for the transoesophageal and transchest groups (2.6). However, transoesophageal cardioversion was more successful than transchest cardioversion at energies < or = 100 J (36/50 [72%], and 17/50 [34%], p < 0.05). Median total energy for successful cardioversion was lower for patients in the transoesophageal group (180 J) than the transchest group (350 J) and mean peak current at successful cardioversion was also lower for patients in the transoesophageal group (21.7 A) than the transchest group (27.3 A) (p < 0.05). No oesophageal complications occurred. Thus, using an oesophageal electrode, cardioversion can be achieved as successfully as using the transchest route. The transoesophageal approach offers a low impedance, and consequently a low-energy pathway for cardioversion.

Effects of Δ9-tetrahydrocannabinol (THC) on conditioned avoidance responding in mice and rats and the one-trial conflict test in rats

When administered orally to mice, 100.0 mg/kg of Δ9-tetrahydrocannabinol (THC) produced an overall increase in avoidance performance. However, a lower dose, 50.0 mg/kg, demonstrated a slight but nonsignificant (p >.4) decrease in the avoidance performance of mice. In rats, following oral administration, THC produced an increase at 25.0 mg/kg and a decrease at 100.0 mg/kg in avoidance performance. On the other hand, 8.0 mg/kg i.p. of THC produced an increase in the mean number of shocks taken by rats in the one-trial conflict test. This increase was similar to the one observed for diazepam at 2.5 mg/kg. When evaluated with respect to neurotoxic activity as measured in the rotarod test, these data are suggestive of some “disinhibition” activity for THC.

THE EFFECT OF ELECTRIC SHOCK ON MENTAL EFFICIENCY

The present study has attempted to determine the effect of electric shock treatment on mental efficiency. The population studied included 75 patients, suffering from depression, hypomania, or psychoneurosis. The mean age was 41.2 years ; the mean number of shocks was 7.8. On Babcock tests administered an average of 11 days after shock, there was a slight but not significant improvement. On the Shipley test, the improvement was probably significant. When the same tests were administered after a follow-up interval averaging 189 days, there was relatively great and statistically significant improvement on both tests. Babcock scores obtained by the patient group about 6 months after shock were not significantly lower than the scores of a normal population of 17 persons of the same age and vocabulary level. It may be concluded that, for the population studied and under the conditions of the present experiment, electric shock treatment does not produce any significant impairment of mental efficiency after an interval of 6 months. No correlations were found between age and improvement from test period to test period. There was some evidence that patients receiving a greater number of shocks were affected more in mental efficiency than those receiving a lesser number of shocks.