[Freiburg Cardiac Arrest Receiving Team (CART) : Interdisciplinary solution for the acute management of non-traumatic out-of-hospital cardiac arrest]. / Freiburger Cardiac Arrest Receiving Team (CART) : Konzept zur Strukturierung des Behandlungsablaufs nach nichttraumatischem außerklinischem Herz­Kreislauf-Stillstand in einem interdisziplinären Team.

Standard procedures and guidelines provide specific instructions for basic and advanced cardiac life support. Recommendations for the admission of patients from preclinical into clinical structures after successful cardiopulmonary resuscitation (CPR) are available, but only a few are detailed. In the presence of ST-elevation myocardial infarction after return of spontaneous circulation (ROSC), coronary angiography must be performed as soon as possible. However, acute management and consecutive diagnostic procedures after hospital admission are up to the doctor on duty, who can rely on standard internal hospital procedures at best. Despite the enormous progress and new findings in intensive care and emergency medicine, intra-hospital mortality, as well as long-term survival, after CPR remains low and depends on a wide variety of influencing factors. To optimize in-hospital acute care of successfully resuscitated patients, an interdisciplinary admission team, a so-called cardiac arrest receiving team (CART), has been implemented at the University Hospital of Freiburg, Germany. The aim of the CART is to provide primary care to resuscitated patients as quickly and in as standardized a manner as possible with predefined diagnostic and therapeutic pathways by a team with special expertise in the field of CPR and post-resuscitation management. Accordingly, clear criteria for procedures and the location of primary care (e.g. emergency room vs. cardiac catheter laboratory), the composition of the CART and concrete treatment measures were defined.

[Immunoadsorption in thrombangiitis obliterans: a promising therapeutic option: results of a consecutive patient cohort treated in clinical routine care]. / Immunadsorption bei Thrombangiitis obliterans - eine vielversprechende therapeutische Option. Behandlungsergebnisse einer konsekutiven Patientenkohorte der klinischen Routineversorgung.

BACKGROUND: Thrombangiitis obliterans or Buerger's disease is a segmental inflammatory disease affecting small and medium-sized veins and arteries, which most often affects young smokers leading to thrombophlebitis and acral ischaemic syndromes, inducing high amputation rates. Based on positive results of a former pilot study we report on our results of immunoadsorption (IA) in clinical routine care, where IA was offered as a treatment option. PATIENTS AND METHODS: The uncontrolled course of 12 consecutive TAO-patients treated by IA on a series of 5 consecutive days was observed. Follow-up period was 14.1 (ranging from 1-26) months. RESULTS: Eight patients were treated with one, four patients completed 2 IA-series. In 9 patients an early onset and lasting clinical improvement and an improvement of ischaemia was noted. The intake of pain-relievers (especially opioids) sank drastically. Eight patients returned to work. Retrospectively, in two out of three treatment failures the correct diagnosis of TAO was questionable. CONCLUSION: IA seems to be a promising treatment option for patients suffering from TAO which should be further evaluated in controlled clinical trials.

Relations between haemoglobin mass, cardiac dimensions and aerobic capacity in endurance trained cyclists.

AIM: Chronic endurance exercise triggers increased cardiac dimensions, blood volumes and haemoglobin mass (Hb mass). Cardiac output and Hb mass are considered as independent contributors to aerobic performance. Therefore, increased Hb mass could counterbalance for a relative deficiency in cardiac adaptation. The purpose of the present study is to investigate relations between Hb mass and cardiac dimensions in a group of endurance athletes with respect to aerobic capacity. METHODS: Two groups of highly trained cyclists featuring high (HHB group, N.=13) and low (LHB group, N.=13) Hb mass (measured by a CO-rebreathing method) were compared for measures of aerobic performance, cardiac wall thickness, cavity size and left ventricular mass (determined by 2-D-echocardiography). Lean body mass (LBM) was chosen as anthropometrical reference for Hb mass. RESULTS: HHB featured higher cardiac wall thickness than LHB, but no difference appeared in cardiac cavity size, left ventricular mass and the performance parameters. Normalising Hb mass for body weight instead of LBM improved correlations between Hb mass and performance parameters. CONCLUSIONS: Our data provides new evidence for a connection between cardiac wall thickness and Hb mass in endurance athletes but no further evidence for a counterbalance between Hb mass and cardiac adaptation was found. Moreover, we postulate that Hb mass loses predictive value for aerobic performance when normalised for LBM.

Prevalence of cerebral microemboli in systemic lupus erythematosus: transcranial Doppler.

OBJECTIVE: To determine the prevalence and predictors of microemboli on transcranial Doppler (TCD) in patients with systemic lupus erythematosus (SLE). METHODS: One hundred sixty-seven patients with SLE underwent TCD testing. RESULTS. Fifteen of 153 patients (9.8%) who successfully underwent TCD testing had microembolic events. Predictors of TCD microemboli included valve repair or replacement (p < 0.0001) and higher SLE Disease Activity Index (p = 0.07). Antiphospholipid antibodies and atherosclerotic plaque on carotid duplex were not associated with TCD microemboli. CONCLUSION: TCD microemboli may represent a noninvasive method to ascertain risk of stroke in SLE. TCD microemboli are not associated with traditional stroke risk factors. Longitudinal studies are needed to determine if TCD microemboli are predictive of future stroke in SLE.

Lead- and device-related complications in the antiarrhythmics versus implantable defibrillators trial.

BACKGROUND: Implantation of transvenous implantable cardioverter defibrillators (ICDs) by use of a nonthoracotomy approach has become routine therapy for survivors of life-threatening tachyarrhythmias. The purpose of this study was to identify and prospectively characterize the frequency of lead- and ICD-related complications from the Antiarrhythmics versus Implantable Defibrillators (AVID) Trial. METHODS AND RESULTS: Between June 1, 1993, and April 7, 1997, 539 patients received nonthoracotomy ICDs either as initial treatment assignment (477) or as crossover from medical management (62). A total of 62 first complications occurred. The subclavian route of insertion resulted in more complications than the cephalic vein route, 46 of 339 (14%) versus 6 of 135 (4%), P = .005, as did the abdominal versus pectoral generator site, 31 of 238 (13%) versus 17 of 291 (6%), P<.02. Most dislodgements and system infections tended to occur in the 3 months after implantation, whereas lead fractures continued to occur throughout follow-up. Failure to use perioperative antibiotics was a predictor of system infection (P = .001). CONCLUSIONS: These data suggest that cephalic vein access and pectoral generator site may result in fewer complications. The continued occurrence of lead fractures and the need for premature system revision supports the practice of close routine ICD system surveillance.

Do baseline characteristics accurately discriminate between patients likely versus unlikely to benefit from implantable defibrillator therapy? Evaluation of the Canadian implantable defibrillator study implantable cardioverter defibrillatory efficacy score in the antiarrhythmics versus implantable defibrillators trial.

OBJECTIVE: Our purpose was to evaluate whether baseline characteristics predictive of implantable cardioverter defibrillator (ICD) efficacy in the Canadian Implantable Defibrillator Study (CIDS) are predictive in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. BACKGROUND: ICD therapy is superior to antiarrhythmic drug use in patients with life-threatening arrhythmias. However, identification of subgroups most likely to benefit from ICD therapy may be useful. Data from CIDS suggest that 3 characteristics (age > or =70 years, ejection fraction [EF] < or =0.35, and New York Heart Association class >II) can be combined to reliably categorize patients as likely (> or =2 characteristics) versus unlikely to benefit (<2 characteristics) from ICD therapy. METHODS: The utility of the CIDS categorization of ICD efficacy was assessed by Kaplan-Meier analysis and Cox hazards modeling. The accuracy of the CIDS score was formally tested by evaluating for interaction between categorization of benefit and treatment in a Cox model. RESULTS: ICD therapy was associated with a significantly lower risk of death in the 320 patients categorized as likely to benefit (relative risk [RR] 0.57, 95% confidence interval [CI] 0.37-0.88, P =.01) and a trend toward a lower risk of death in the 689 patients categorized as unlikely to benefit (RR 0.70, 95% CI 0.48-1.03, P =.07). Categorization of benefit was imperfect, as evidenced by a lack of statistical interaction (P =.5). Although 32 of the 42 deaths prevented by ICD therapy in AVID were in patients categorized as likely to benefit, all 42 of these patients had EF values < or =0.35. Neither advanced age nor poorer functional class predicted ICD efficacy in AVID. CONCLUSION: Of the 3 characteristics identified to predict ICD efficacy in CIDS, only depressed EF predicted ICD efficacy in AVID. Thus physicians faced with limited resources might elect to consider ICD therapy over antiarrhythmic drug use in patients with severely depressed EF values.

Recipient to donor conduction of atrial tachycardia following orthotopic heart transplantation.

We report a case of atrial tachycardia in a 60-year-old male 8 years postorthotopic heart transplantation. At electrophysiology study, the clinical rhythm was found to arise from the remnant of the recipient atrium and was successfully terminated by delivery of radiofrequency energy. Surgical scars formed at the anastomosis of the recipient and donor atrium during the time of orthotopic heart transplantation are thought to electrically isolate the two areas. Although rarely recognized, dysrhythmias originating from the recipient atrial remnant may occur more often than previously thought.

Safety and efficacy of radiofrequency modification of slow pathway conduction in children < or = 10 years of age with atrioventricular node reentrant tachycardia.

This study evaluated procedural considerations, risks, and long-term efficacy of radiofrequency modification of slow pathway conduction for treatment of atrioventricular node reentrant tachycardia in children < or = 10 years of age. Using a combined anatomic and electrographic mapping approach, modification of slow pathway conduction was achieved in 25 consecutive patients, although 4 had some form of transient atrioventricular block, indicating the need for caution in patient selection, catheter manipulation, and ablation.

Use of implantable cardioverter-defibrillators in the congenital long QT syndrome.

We surveyed the use of implantable cardioverter-defibrillators in patients with congenital long QT syndrome. The implantable cardioverter-defibrillator was used primarily in high-risk persons and appeared safe and effective over a mean 31-month follow-up.

Optimal electrode position for transvenous defibrillation: a prospective randomized study.

OBJECTIVES: This study was performed to determine the optimal position for the proximal electrode in a two-electrode transvenous defibrillation system. BACKGROUND: Minimizing the energy required to defibrillate the heart has several potential advantages. Despite the increased use of two-electrode transvenous defibrillation systems, the optimal position for the proximal electrode has not been systematically evaluated. METHODS: Defibrillation thresholds were determined twice in random sequence in 16 patients undergoing implantation of a two-lead transvenous defibrillation system; once with the proximal electrode at the right atrial-superior vena cava junction (superior vena cava position) and once with the proximal electrode in the left subclavian-innominate vein (innominate vein position). RESULTS: The mean (+/- SD) defibrillation threshold with the proximal electrode in the innominate vein position was significantly lower than with the electrode in the superior vena cava position (13.4 +/- 5.7 J vs. 16.3 +/- 6.6 J, p = 0.04). Defibrillation threshold with the proximal electrode in the innominate vein position was lower or equal to that achieved in the superior vena cava position in 75% of patients. In patients with normal heart size (cardiothoracic ratio < or = 0.55), the improvement in defibrillation threshold with the proximal electrode in the innominate vein position was more significant than in patients with an enlarged heart (innominate vein 13.0 +/- 6.5 J vs. superior vena cava 17.9 +/- 5.1 J, p < 0.01). In patients with an enlarged heart, no difference between the two sites was observed (innominate vein 13.9 +/- 4.5 J vs. superior vena cava 13.6 +/- 8.3 J, p = NS). CONCLUSIONS: During implantation of a two-lead transvenous defibrillation system, positioning the proximal defibrillation electrode in the subclavian-innominate vein will lower defibrillation energy requirements in the majority of patients.

In vivo pharmacokinetics and in vitro production of cocaethylene in pregnant guinea pigs.

Simultaneous exposure to cocaine and ethanol results in the formation of cocaethylene, an active metabolite of cocaine. The concurrent abuse of both cocaine and ethanol is common during human pregnancy, but the kinetics of elimination and formation of this ethyl ester of cocaine have not been studied during pregnancy in any species. In the late gestation guinea pig (61 to 63 days), cocaethylene, at doses of 2 to 4 mg.kg-1, is rapidly eliminated with a half-life of 29 min and a total body clearance of 77 ml.min-1.kg-1. It is formed enzymatically by hepatic microsomal preparations from fetal, neonatal and maternal guinea pigs. The maximum rate of cocaethylene production (apparent Vmax) when either ethanol or cocaine are varied while the other substrate is held constant, increases with age, from the late fetal period (65 days gestation, term 70 days) to adulthood. However, the Michaelis-Menten constant (apparent KM) does not change with age. The rapid elimination of cocaethylene, coupled with the slow rate of formation (apparent Vmax of 140 pmol.min-1.mg microsomal protein-1) and the small amount of plasma analyzed most likely explains the inability to detect coacethylene in vivo after concomitant cocaine and ethanol administration.

Use of adenosine to identify patients at risk for recurrence of accessory pathway conduction after initially successful radiofrequency catheter ablation.

OBJECTIVE: The use of adenosine after radiofrequency catheter ablation of accessory pathways was prospectively studied to determine its utility for identifying patients at risk for recurrence of accessory pathway conduction and to guide therapy that might reduce late recurrence in this group. BACKGROUND: Accessory pathway conduction recurs in 5%-12% of patients following initially "successful" radiofrequency catheter ablation. Adenosine may facilitate conduction over accessory pathways that have been modified by radiofrequency delivery, thus identifying patients at risk for recurrence. METHODS: Radiofrequency catheter ablation was performed in 109 patients. Prior to ablation, 12-18 mg of adenosine was administered. After ablation, when all evidence of accessory pathway conduction remained absent for at least 30 minutes, adenosine 12-18 mg was again administered. RESULTS: Adenosine given prior to radiofrequency catheter ablation did not block accessory pathway conduction in any patient. Adenosine given after elimination of accessory pathway conduction induced complete atrioventricular and ventriculoatrial block in 95 patients; 11 (11.6%) subsequently had recurrence of accessory pathway function. Accessory pathway conduction was unmasked by adenosine in 12 patients (11.2%). After further deliveries of radiofrequency energy, 7 of these 12 patients subsequently demonstrated adenosine induced atrioventricular and ventriculoatrial block; 1 of these 7 patients experienced recurrence of accessory pathway conduction. The remaining 5 patients demonstrated persistent accessory pathway conduction only with adenosine; all experienced clinical recurrence of accessory pathway function. CONCLUSION: The use of adenosine after presumed successful radiofrequency catheter ablation may reveal persistent accessory pathway conduction. Elimination of this latent accessory pathway conduction reduces the risk for recurrence.

Mechanisms of AV node reentrant tachycardia in young patients with and without dual AV node physiology.

Recent advances in electrophysiological mapping and radiofrequency catheter ablation have demonstrated the participation of perinodal atrial tissue or pathways in atrioventricular node reentrant tachycardia (AVNRT). Current concepts of the role of these pathways in the genesis of the various forms of AVNRT continue to evolve. In view of these recent advances, this study investigated the electrophysiology of AVNRT in young patients, and factors potentially associated with variant forms of this arrhythmia. Detailed programmed stimulation and catheter mapping were performed in 35 consecutive young patients with AVNRT. This group consisted of 15 male and 20 female patients, with a mean age of 12.1 +/- 4.2 years (range 3-18 years). Of the 35 patients, 23 demonstrated dual AV node physiology, either in response to a critically timed extrastimulus (n = 17) or to rapid pacing (n = 6). The common form (antegrade slow-retrograde fast) of AVNRT was demonstrated in 21 of these 23 patients. Antegrade fast-retrograde slow (n = 1) and antegrade slow-retrograde slow (n = 1) forms of AVNRT were identified in the 2 other patients. In contrast, only 5 of the 12 patients who did not demonstrate dual AV node physiology had the common form of AVNRT (P = 0.03). Five of these patients also had the slow-slow form of AVNRT, while 1 patient each had a fast-slow and fast-fast form of AVNRT.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of body surface area as a determinant of impedance during radiofrequency catheter ablation in adults and children.

Since most radiofrequency (RF) generators used for catheter ablation approximate a constant voltage output, applied power is inversely proportional to the impedance load of the system. Knowledge of the expected impedance load for a patient may facilitate selection of safer and more effective voltage output. Preliminary observations suggest that in adults, impedance is directly proportional to body surface area (BSA), thus prompting this study to determine whether this relation was maintained in smaller patients undergoing RF catheter ablation. Prospective analysis of impedance from 949 RF deliveries in 76 patients (BSA, 0.69-2.3 m2) revealed the mean impedance for all deliveries to be 103 +/- 8 ohms. Two-phase linear regression analysis revealed a significant, direct correlation between impedance and BSA in patients with a BSA > or = 1.5 m2 (P = .001); however, for patients with a BSA < 1.5 m2 there was no correlation. These results indicate that as patient size decreases below 1.5 m2, impedance is constant. Radiofrequency catheter ablation procedures in children may require selection of a voltage output similar to that used in adults in order to produce effective RF lesions.

Comparison of radiofrequency catheter ablation procedures in children, adolescents, and adults and the impact of accessory pathway location.

Radiofrequency (RF) catheter ablation is an accepted treatment for supraventricular tachycardia. However, the determinants of success, difficulty, or risk of complication associated with ablation have not been defined. This study evaluated patient age and location of the accessory or extranodal pathway as determinants of these procedural variables. Patients were stratified by age, with those aged 2 to 12 years classified as children, those aged 13 to 19 years as adolescents, and those > or = 20 years as adults. Locations were defined as right, septal, or left free wall accessory pathways, or extranodal slow pathways associated with atrioventricular node reentrant tachycardia. A total of 443 RF ablation procedures performed in 413 patients were evaluated. All procedures were performed in the same laboratory by the same group of physicians. Success rates for ablation of supraventricular tachycardia did not differ among the 3 age groups, ranging from 93% to 95%. Procedural aspects, including total procedure time, fluoroscopy time, and number of applications of RF energy also did not differ by age group. However, analysis of outcome and procedural complexity with respect to pathway location demonstrated that ablation of right free wall and septal accessory pathways was significantly more difficult than left free wall or slow pathway (success rates of 85% and 88% vs 97% and 98%, respectively, p = 0.01 and 0.02), irrespective of age. Additionally, right free wall pathways required significantly greater procedure time (mean = 5.1 hours), fluoroscopy time (mean = 78 minutes), and RF applications (median = 16) than ablations performed at other sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrent cardiac events in survivors of ventricular fibrillation or tachycardia. Implications for driving restrictions.

OBJECTIVE: To determine when survivors of ventricular tachycardia (VT) or ventricular fibrillation (VF) might most safely return to driving. DESIGN: Consecutive case series of 501 VT and VF survivors discharged alive between August 1978 and October 1989 and followed from 0 to 117 months (mean, 26 months). SETTING: Cardiac arrhythmia service of a university hospital. PATIENTS: The study group comprised 290 consecutive patients with sustained VT and 211 patients with VF who underwent electrophysiological studies and were discharged alive (78% male; mean age, 59 years). The mean ejection fraction (available in 338 patients) was 0.42. INTERVENTIONS: Antiarrhythmic drug testing for all patients was guided by serial electrophysiological testing. Overall, 227 patients (45%) were discharged on conventional antiarrhythmic agents, 115 (23%) on amiodarone, 39 (8%) received an implantable defibrillator, and 120 (24%) received no specific antiarrhythmic therapy. MAIN OUTCOME MEASURES: Main outcomes included any event that could hamper a patient's ability to operate a motor vehicle. Specifically, these events included recurrent VF, poorly tolerated, hemodynamically unstable VT, syncope, sudden cardiac death, and implantable defibrillator discharge. RESULTS: Event risks were assessed during the first year after hospital discharge because that is when most patients decide whether to begin driving again. The 1-year outcome event rate for all 501 patients was 17%. Three distinct periods of risk were identified. The monthly hazard rate was highest in the first month after hospital discharge (4.22% per month), intermediate in months 2 through 7 (1.81% per month), and lowest in months 8 through 12 (0.63% per month). The 191 patients for whom no successful conventional antiarrhythmic drug could be found during electrophysiological testing experienced a persistently high monthly event risk (1.6%) during months 8 through 12. CONCLUSIONS: All survivors of VT or VF should refrain from driving during the first month after hospital discharge when the hazard for events that could impair their ability to drive is greatest. Our data would support restricting driving for most patients until the eighth month after hospital discharge, when risk becomes lowest. Restriction might be lengthened in patients for whom electrophysiological testing finds no satisfactory conventional antiarrhythmic agent because their risk remains higher than average even after 7 months. Individualized recommendations should be allowed because the accident rate for patients who actually suffer sudden death is low.