Development of curative therapies for Ewing sarcomas by interdisciplinary cooperative groups in Europe.

Curative therapies for Ewing sarcoma have been developed within cooperative groups. Consecutive clinical trials have systematically assessed the impact and timing of local therapy and the activity of cytotoxic drugs and their combinations. They have led to an increase of long-term disease-free survival to around 70% in patients with localized disease. Translational research in ES remains an area in which interdisciplinary and international cooperation is essential for future progress. This article reviews current state-of-the art therapy, with a focus on trials performed in Europe, and summarizes novel strategies to further advance both the cure rates and quality of survival.

Observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT): assessment and evaluation as predictive factor for acute postnatal outcome-a single center study.

Introduction: To assess the observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) and to explore its value as a potential predictive factor for postnatal outcome. Methods: A retrospective single-center study was conducted on pregnancies complicated by CAKUT between 2007 and 2018. The lung-to-head ratio (LHR) was calculated for each fetus by two independent observers. Correlations between O/E LHR and various perinatal outcome factors were assessed with Spearman's rank correlation. Furthermore, nominal logistic regression was performed to assess O/E LHR as predictive factor for respiratory distress in newborn. Results: Of 64 pregnancies complicated by CAKUT, 23 were terminated. In the 41 cases of continuation of pregnancy, newborn presenting respiratory distress with need for respiratory support in the delivery room showed earlier gestational age at onset of amniotic fluid abnormalities and at birth. Although median O/E LHR and median single deepest pocket (SDP) of amniotic fluid were significantly smaller in newborn that did develop respiratory distress with need of respiratory support in the delivery room, neither O/E LHR nor SDP were accurate predictors for the development of respiratory distress. Conclusions: Our data show that O/E LHR alone cannot serve as a predictive marker for fetal outcome in pregnancies complicated by CAKUT, though it might still be a helpful parameter together with detailed renal ultrasound evaluation, onset of amniotic fluid abnormality and SDP, particularly in its extreme values.

Relation between QT dispersion and the extent of myocardial ischemia in patients with three-vessel coronary artery disease.

The aim of the study was to examine the relation between the extent of myocardial ischemia and changes in QT interval dispersion in patients with obstructive coronary artery disease and in patients with normal coronary arteries. QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies showed QT interval dispersion changes during episodes of myocardial ischemia in patients with coronary artery disease, but no data on the relation between extent of myocardial ischemia and degree of QT interval dispersion changes are available. To assess the effects of myocardial ischemia on myocardial repolarization by analyzing the change in QT dispersion during incremental atrial pacing, we studied 33 patients (7 women and 26 men, mean age 60.1 +/- 5.1 years, 18 patients with normal coronary arteries, 15 patients with coronary 3-vessel disease). QT dispersion was measured at baseline, after each pacing period, within 30 seconds after cessation of pacing ("peak ischemic stress"), and at 1-minute intervals for up to 5 minutes. Paired blood samples for determination of serum lactate were withdrawn from the coronary sinus and radial artery to determine the cardiac lactate extraction ratio at each point of electrocardiographic registration. In patients with coronary artery disease, QT dispersion increased from a baseline value of 39 +/- 7 ms to a peak ischemic stress value of 63 +/- 10 ms (p <0.0001). Patients with normal coronary arteries showed almost unchanged values of QT dispersion (41 +/- 9 vs 42 +/- 7 ms). There was a significant relation between the pacing-induced change in QT dispersion and the induced change in myocardial lactate extraction ratio (r = 0.76, p <0.0001). The change in QT dispersion (baseline vs peak pacing stress) was related to the extent of the cardiac lactate extraction ratio (r = -0.79, p <0.0001). These data indicate that the severity or extent of induced myocardial ischemia was related to the degree of induced changes of the variability in the timing of the ventricular recovery pattern.

Cardiomyopathic lentiginosis/LEOPARD syndrome presenting as sudden cardiac arrest.

A 26-year-old apparently healthy man with numerous pigmented skin lesions collapsed during an evening party and was resuscitated from ventricular fibrillation. Hypertrophic cardiomyopathy and subaortic tunnel were disclosed by angiocardiography. A diagnosis of cardiomyopathic lentiginosis/lentigines (multiple), electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of the genitalia, retardation of growth, and deafness (sensorineural) syndrome was made. The patient then underwent treatment with an implantable pacer-cardioverter-defibrillator device. Further evaluation revealed several well-established features of the disorder. This is the first reported case of survival from ventricular fibrillation associated with this rare and little known multifaceted syndrome. Disseminated lentiginosis must prompt clinicians to evaluate such cases further since underlying disorders may be associated with considerable morbidity and, apparently, sudden death.

Clinical profile and management of heart failure: rural community hospital vs. metropolitan heart center.

BACKGROUND: Knowledge on clinical characteristics and prognosis of patients with heart failure originates from studies of selected populations in clinical trials or from epidemiological observations. Reports on the large numbers of patients with heart failure treated in community hospitals are sparse. OBJECTIVE: Are there differences in patient characteristics and heart failure management between a metropolitan heart center (HC) and a rural community hospital (RCH)? PATIENTS AND METHODS: Retrospective analysis of medical charts from all patients admitted for heart failure (ICD 428.x, NYHA II-IV, EF<45%) between May 1997 and April 1998 and discharged alive from a rural community hospital. A similar, but prospective registry was available at the HC. Follow-up information was obtained by request at registration authorities. RESULTS: Patient groups comprised 120 in RCH and 146 in HC. Mean age was 75+/-11 and 66+/-11 years, respectively (P<0.001); 48% (RCH) vs. 74% (HC) of patients were male (P<0.001). On admission the proportion of functional class IV was 69% (RCH) vs. 17% (HC) (P<0.001). At discharge, the rate of ACE-inhibitors was 74% (RCH) vs. 98% (HC); 11% (RCH) vs. 43% (HC) of patients received beta-blocker therapy. Ninety-six percent of patients in HC underwent and 22% in RCH had undergone invasive diagnostics. One-year mortality rate of patients discharged alive was 26% in RCH and 19% in HC (P=n.s. after adjustment for age and gender). CONCLUSION: Heart failure management according to current guidelines, using beta-blockers and ACE inhibitors, and invasive cardiac examination was significantly less performed in the rural community hospital than in the metropolitan heart center. Therefore, strategies to improve heart failure management according to guidelines are urgently needed.

Differential effects of defibrillation on systemic and cardiac sympathetic activity.

OBJECTIVE: To assess the effect of defibrillation shocks on cardiac and circulating catecholamines. DESIGN: Prospective examination of myocardial catecholamine balance during dc shock by simultaneous determination of arterial and coronary sinus plasma concentrations. Internal countershocks (10-34 J) were applied in 30 patients after initiation of ventricular fibrillation for a routine implantable cardioverter defibrillator test. Another 10 patients were externally cardioverted (50-360 J) for atrial fibrillation. MAIN OUTCOME MEASURES: Transcardiac noradrenaline, adrenaline, and lactate gradients immediately after the shock. RESULTS: After internal shock, arterial noradrenaline increased from a mean (SD) of 263 (128) pg/ml at baseline to 370 (148) pg/ml (p = 0.001), while coronary sinus noradrenaline fell from 448 (292) to 363 (216) pg/ml (p = 0.01), reflecting a shift from cardiac net release to net uptake. After external shock delivery, there was a similar increase in arterial noradrenaline, from 260 (112) to 459 (200) pg/ml (p = 0.03), while coronary sinus noradrenaline remained unchanged. Systemic adrenaline increased 11-fold after external shock (p = 0.01), outlasting the threefold rise following internal shock (p = 0.001). In both groups, a negative transmyocardial adrenaline gradient at baseline decreased further, indicating enhanced myocardial uptake. Cardiac lactate production occurred after ventricular fibrillation and internal shock, but not after external cardioversion, so the neurohumoral changes resulted from the defibrillation process and not from alterations in oxidative metabolism. CONCLUSIONS: A dc shock induces marked systemic sympathoadrenal and sympathoneuronal activation, but attenuates cardiac sympathetic activity. This might promote the transient myocardial depression observed after electrical discharge to the heart.

Impact of early accelerated dose tissue plasminogen activator on in-hospital patency of the infarcted vessel in patients with acute right ventricular infarction.

OBJECTIVE: To assess the efficacy of early accelerated dose tissue plasminogen activator on in-hospital patency of the infarct related artery in patients with inferior myocardial infarction with and without right ventricular involvement. DESIGN: Single centre prospective assessment before discharge of infarct related vessel patency after early thrombolysis. SETTING: Tertiary cardiac referral centre at a university hospital. PATIENTS AND METHODS: 90 consecutive unselected patients with acute myocardial infarction, of whom 35 (39%) had electro-cardiographic evidence of right ventricular involvement (ST segment elevation greater than 0.1 mV in right precordial lead V4R), were studied. All patients received accelerated dose tissue plasminogen activator 100 mg within six hours from the onset of symptoms and had control angiography before discharge. MAIN OUTCOME MEASURES: Infarct related coronary artery patency using the Thrombolysis in Myocardial Infarction (TIMI) grading system before discharge. Incidence of prolonged systemic hypotension, sinus bradycardia, complete atrioventricular block, and ventricular tachyarrhythmia during early hospitalisation. RESULTS: Despite aspirin and bolus heparinisation before thrombolysis and high dose heparinisation thereafter for at least 48 hours the infarct related artery was more likely to be occluded (TIMI 0 or 1 flow) in patients with right ventricular involvement than in those without (69 v 29%, P < 0.001), as shown by control angiography performed a mean of 12.8 days after thrombolysis. These findings may be explained, at least in part, by predominant involvement of the proximal right coronary artery (66 v 31%, P < 0.05) and a low cardiac output syndrome, being indirectly reflected by a high incidence of prolonged hypotension (26 v 7%, P = 0.02), bradycardia (34 v 14%, P = 0.03), and complete atrioventricular block (37 v 5%, P = 0.0001). CONCLUSION: Primary angioplasty should be considered as the treatment of choice in patients with acute inferior infarction with right ventricular involvement because of the high failure rate of thrombolysis.

Development of sinus node disease in patients with AV block: implications for single lead VDD pacing.

OBJECTIVE: To investigate the incidence of sinus node disease after pacemaker implantation for exclusive atrioventricular (AV) block. DESIGN: 441 patients were followed after VDD (n = 219) or DDD pacemaker (n = 222) implantation for AV block over a mean period of 37 months. Sinus node disease and atrial arrhythmias had been excluded by Holter monitoring and treadmill exercise preoperatively in 286 patients (group A). In 155 patients with complete AV block, a sinus rate above 70 beats/min was required for inclusion in the study (group B). Holter monitoring and treadmill exercise were performed two weeks, three months, and every six months after implantation. Sinus bradycardia below 40 beats/min, sinoatrial block, sinus arrest, or subnormal increase of heart rate during treadmill exercise were defined as sinus node dysfunction. RESULTS: Cumulative incidence of sinus node disease was 0.65% per year without differences between groups. Clinical indicators of sinus node dysfunction were sinus bradycardia below 40 beats/min in six patients (1.4%), intermittent sinoatrial block in two (0.5%), and chronotropic incompetence in five patients (1.1%). Only one of these patients (0.2%) was symptomatic. Cumulative incidence of atrial fibrillation was 2.0% per year, independent of the method used for the assessment of sinus node function and of the implanted device. CONCLUSIONS: In patients undergoing pacemaker implantation for isolated AV block, sinus node syndrome rarely occurs during follow up. Thus single lead VDD pacing can safely be performed in these patients.

Myocardial ischemia in generalized coronary artery-left ventricular microfistulae.

Generalized (multiple) arterio-systemic fistulae are fistulae arising from all three major coronary arteries and drain into the left ventricle are rare and the clinical and hemodynamic sequelae are incompletely understood. This communication is based on the clinical and hemodynamic data of a series of patients (eight cases out of 7262 consecutive patients) incidentally identified at coronary angiography combined with data from cases previously reported in literature. The aim was to assess the role of generalized coronary artery fistulae as a non-atherosclerotic cause of myocardial ischemia by means of a coronary sinus lactate study. Coronary sinus lactate study demonstrated myocardial ischemia in 6/7 patients. Mean arterio-coronary venous lactate difference decreased from 0.31+/-0.18 mmol/l (lactate extraction ratio, LER, 29.4+/-13.9%) at rest to 0.04+/-0.13 mmol/l (LER -4.0+/-13.3%) at peak exercise. Five minutes after cessation of pacing, lactate difference increased to 0.22+/-0.21 mmol/l (LER -20.7+/- 13.2%). At peak pacing stress, 4/7 patients showed frank lactate production, and two patients presented with a reduced cardiac lactate extraction rate also indicating myocardial ischemia metabolically. In the present study, we demonstrated a possible role of a coronary steal mechanism due to microfistulae pathways in the pathogenesis of myocardial ischemia in patients with generalized coronary artery-left ventricular microfistulae.

Priming of neutrophils after elective percutaneous transluminal coronary angioplasty is unrelated to accompanying brief myocardial ischemia.

OBJECTIVE: The purpose of this study was to investigate the effect of brief myocardial ischemia and vascular trauma induced by elective percutaneous transluminal coronary angioplasty on in vivo 'priming' and activation of neutrophils. PATIENTS AND METHODS: We studied 16 patients undergoing elective coronary angioplasty for symptomatic coronary artery disease and a control group of seven patients undergoing diagnostic cardiac catheterization. Free radical production from purified neutrophils (Ficoll-Hypaque density gradient method) was measured indirectly by the chemiluminescence method. Myocardial ischemia during balloon inflation was assessed by serial lactate determinations from coronary sinus and arterial blood. The degree of transient angioplasty-related myocardial ischemia was related to the oxidative response of activated neutrophils. RESULTS: Mean (+/-S.E.M.) oxidative response, i.e. the lucigenin- and luminol-enhanced-chemiluminescence (counts per minute) of neutrophils sampled from the coronary sinus increased significantly after percutaneous transluminal coronary angioplasty (Lucigenin-chemiluminescence: pre-angioplasty 3.69+/-0.64x10(5) vs. post-angioplasty 7.08+/-1.2x10(5), P<0.01; Luminol-chemiluminescence: pre-angioplasty 2.81+/-0.67x10(6) vs. post-angioplasty 5.2+/-0.92x10(6), P<0.01). Twelve of 16 patients developed transient cardiac lactate production (mean coronary sinus lactate excess: +0.12 mmol/l) and three disclosed a lactate extraction ratio <10%, both suggestive of myocardial ischemia. However, there was no correlation between the cardiac lactate production and the increased oxidative response after coronary angioplasty (r2 (Lucigenin-chemiluminescence)=0.02, n.s.; r2 (Luminol-chemiluminescence)=0.06, n.s.). CONCLUSION: 'Priming' of neutrophils, as reflected by increased oxidative response, is likely to occur after coronary angioplasty, but not after the angiographic procedure itself. However, 'priming' seems to be unrelated to the transient brief period of myocardial ischemia and rather depends on an alternative mechanism.

[Recent aspects of cardiologic therapy in advanced age]. / Neuere Aspekte der kardiologischen Therapie im höheren Lebensalter.

The aging heart differs in several aspects from the heart in younger people: Cardiac muscle mass, systolic and diastolic wall stress increase, the velocity of electrical conduction decreases in different anatomical structures. Supraventricular and ventricular arrhythmias appear more frequently than in younger people. Heart rate and cardiac index tend to diminish, especially under work load. Work capacity is reduced. In the treatment of coronary heart disease drugs are preferred which lead to a reduction of preload. Nitrates and molsidomine are followed by calcium channel blockers and--afterwards--by beta-blockers. Bypass surgery is performed in elderly patients more often for therapeutical than for prognostic reasons, similarly in the case of valvular surgery. Typical tachyarrhythmias are treated only in case of hemodynamic relevance, whereas pacemaker therapy is not limited by greater age. The choice of the most suitable pacemaker model, however, has to be based upon the overall circumstances in each individual case. For the treatment of congestive heart failure, vasodilators, especially angiotensin-converting enzyme inhibitors, seem to be superior, in elderly patients, to diuretics and digitalis glycosides.

[Doppler echocardiographic demonstration of ventricular septum rupture in acute myocardial infarct in an intensive care unit]. / Dopplerechokardiographischer Nachweis der Ventrikelseptumruptur bei akutem Myokardinfarkt auf der Intensivstation.

Rupture of the ventricular septum after acute transmural myocardial infarction occurred in four patients aged between 53 and 79 years. The rupture was verified by means of right-side cardiac catheterization. Only in two cases did two-dimensional echocardiography reveal the rupture; in both cases the rupture site located by echocardiography was confirmed at autopsy. In each of the four patients the left-to-right shunt could be identified by means of pulsed Doppler echocardiography which showed a turbulence in the right ventricle. Furthermore, the combination of two-dimensional echocardiography and Doppler echocardiography allowed a correct localization of the turbulent left-to-right flow in all cases. In view of these findings, the combination of Doppler echocardiography and two-dimensional echocardiography may be regarded as a suitable method for a readily available, non-invasive diagnosis of ventricular septum rupture in patients with acute myocardial infarction in an intensive care unit.

[Right ventricular intracardial recordings of late potentials in patients with acute myocardial infarction and recurrent ventricular tachycardias]. / Rechtsventrikuläre intrakardiale Aufzeichnung von Spätpotentialen bei Patienten mit akutem Herzinfarkt und rezidivierenden Kammertachykardien.

The role of delayed potentials in ventricular arrhythmias occurring in connection with acute myocardial infarction has been of increasing interest in recent years. In order to obtain further information about delayed electrical activity, we studied a group of 51 patients in the acute phase of myocardial infarction, and intracardiac recordings were made using bipolar electrodes. In 31 of the 51 patients we recorded delayed potentials 150-200 ms after the beginning of QRS. 14 patients showed delayed electrical activity in diastole even after the T wave. The same potentials as those obtained by intracardiac recording techniques were also recorded from the body surface using a signal-averaging technique. In several cases we were able to show that these delayed potentials initiated premature ventricular beats. In 1 patient a sustained ventricular tachycardia induced by delayed potentials was recorded. We found that delayed potentials could be abolished by antiarrhythmic drugs. There thus appears to be an important relationship between delayed electrical activity and the occurrence of ventricular arrhythmias.

Inhibition of ventricular stimulation in patients with dual chamber pacemakers and prolonged AV conduction.

Episodes of repetitive P wave undersensing have been described in dual chamber pacemakers due to automatic extension of the postventricular atrial refractory period (PVARP). Pacemaker stimulation was completely inhibited despite the presence of adequate P waves. This study sought to determine whether cycles of repetitive P wave undersensing occur even in the absence of PVARP extension. Two-hundred fifty-five patients were investigated after DDD or VDD pacemaker implantation for intermittent atrioventricular (AV) block. Forty-six episodes of repetitive atrial undersensing were found during 24-hour Holter ECG in nine patients. Pacemaker syndrome-like symptoms occurred. Episodes were elicited by atrial or ventricular premature contractions when (1) native AV conduction was present but considerably prolonged, (2) intrinsic sinus rate exceeded pacemaker intervention rate, and (3) native AV interval plus PVARP exceeded sinus cycle length. Programming of a particularly short AV interval and PVARP helped to reduce the incidence of repetitive P wave undersensing. Patients with dual chamber devices and prolonged native AV conduction are prone to develop episodes of output inhibition. Standard timing cycles may be inappropriate in these patients.

[Radiation-induced cardiac disease]. / Strahlenschaden des Herzens.

Radiation-induced effects may damage various cardiac structures chronically and cause heart valve dysfunction as well as occlusive lesions of coronary and other arteries exposed to radiation. A 72-year-old woman with a history of radiation treatment after breast cancer was admitted 25 years later with symptoms of tachycardia and acute dyspnea. We found valvular thickening, medium to severe valvular dysfunction and high grade occlusive coronary artery disease in proximal portions. The left subclavian artery also was affected. Surgical treatment was required immediately. Long-term follow-up cardiac evaluation even in asymptomatic patients is mandatory to uncover cardiac injuries by radiation. To lower the risk and maximize the benefit, early intervention by valvular replacement and myocardial revascularization is indicated. Restrictive myopathy and chronic pericarditis increase risk and have to be clarified. Diagnosis in these radiation exposed patients can be made by typical findings. Echocardiography is of eminent relevancy.

[Bilateral coronary-pulmonary artery fistula and accessory vascular connection of the thoracic aorta to the right lower pulmonary artery]. / Bilaterale koronar-pulmonalarterielle Fisteln und akzessorische Gefässverbindung der thorakalen Aorta zur rechten unteren Pulmonalarterie.

A 41-year-old man presenting with atypical chest pain was admitted to hospital with suspected pericarditis after a common cold disease. A complex risk profile for arteriosclerotic coronary artery disease was taken into account in differential diagnosis. Cardiac catheterization revealed large bilateral coronary artery-pulmonary artery fistulas as well as an accessory vessel with origin of the thoracic aorta both draining into the lower right pulmonary artery. The vessel anomalies showed a remarkable plexus-like morphology before entering into the pulmonary artery. Arteriosclerotic coronary artery disease was not found. No evidence of myocardial ischemia was found in the furthermore asymptomatic patient, therefore surgical correction of the vessel anomalies was not performed. To our knowledge the present case report represents the first case with bilateral coronary artery-pulmonary artery fistulas and an accessory communication of the thoracic aorta to the pulmonary artery vasculature.

Adverse pacemaker hemodynamics evaluated by pulmonary venous flow monitoring.

The pacemaker syndrome refers to symptoms and signs in the pacemaker patient caused by an inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in a decreased cardiac output and venous cannon A waves. The objective of this study was to define the left atrial and pulmonary venous flow response to ventricular pacing in a group of 14 unselected consecutive patients with total heart block and sinus rhythm. Pulmonary venous flow was assessed by transesophageal pulsed Doppler echocardiography in the VVI and DDD pacing modes. An inappropriate atrial timing caused a marked augmentation of the normally small pulmonary venous z wave in all patients ("negative atrial kick," peak z wave in DDD pacing 14.5 +/- 4.6 cm/s, VVI pacing 51.8 +/- 15.0 cm/s). Restoration of AV synchrony (DDD pacing, AV interval 100 ms) abolished these "cannon z waves" in all patients, and a normal pattern of pulmonary venous flow was achieved. Abnormal pulmonary venous flow characteristics were observed in 2 of 14 patients during DDD pacing with short AV intervals (100 ms). The Doppler pattern was similar to the findings seen in VVI pacing. Assessment of pulmonary venous flow by transesophageal pulsed Doppler echocardiography may provide a simple, sensitive, and relatively noninvasive technique to evaluate patients with suspected pacing induced adverse hemodynamics.

[Atrial sensing and atrioventricular synchrony in single lead VDD pacemakers. Can the appearance of atrial undersensing be predicted?]. / Atriale Wahrnehmung und AV-Synchronität bei "Single-Lead"-VDD-Schrittmachern. Ist das Auftreten von atrialem Undersensing vorhersabar?

Single-lead VDD-pacing is an alternative to DDD-systems in patients with AV-block and normal sinus node function. Atrial sensing plays a central role in these pacemakers. AV-synchrony, incidence of atrial arrhythmias and the occurrence of sinus node disease were investigated in 108 patients with VDD-pacemakers followed over a mean period of 24.8 months after implantation. Determinants influencing the occurrence of atrial undersensing were especially focused on. Mean atrial potential and sensing threshold were reduced within the first 2 weeks after implantation (p < 0.01). Intermittent atrial undersensing occurred in 25.9% of patients and was observed in 82.1% of these patients within the first 2 weeks after implantation. Positioning the atrial dipole in the low right atrium showed a significantly higher incidence of atrial undersensing (42% in comparison to 24% in the other positions). In a multivariate analysis including intra- and postoperative measurements as well as characteristics of the pacemakers and leads, it was the only parameter significantly (p < 0.02) correlated to the occurrence of atrial undersensing. Atrial fibrillation was observed in 4.6% of patients, a sinus node disease became evident in 2.7% of patients; 92.6% of patients remained in the AV-synchronous mode. Intermittent atrial undersensing is common in single-lead VDD-pacemakers and difficult to provide during implantation. The atrial dipole should not be positioned in the low right atrium and highest atrial sensitivity should generally be programmed. Nevertheless, VDD-pacing achieves an AV-synchrony comparable to DDD-pacemakers.

Electrophysiological characteristics of bipolar membrane carbon leads with and without steroid elution compared with a conventional carbon and a steroid-eluting platinum lead.

In a controlled study, the following four bipolar leads with passive fixation were implanted in 46 patients with the Siemens-Multilog-VVI or Sensolog-VVIR-pacemakers: membrane covered activated porous carbon with steroid elution (Siemens 1402 T, 11 patients) and without (Siemens 1403 T, 15 patients); activated carbon (Siemens 1010 T, 10 patients); and platinum with steroid elution (Medtronic Cap-Sure 5026, 10 patients). Stimulation threshold (STH) (assessed by a vario-test), impedance (IMP), and the intracardial R wave potential (IRW) (both gauged by a telemetric method) were measured 1, 5, and 10 days as well as 3 and 6 months after implantation during unipolar and bipolar stimulation, chronaxie rheobase product (CRP) and energy consumption (EC) were systematically determined. Differing insignificantly at the first day after implantation, STH is significantly lower for the 1402 T and CapSure 5026 leads at the tenth day. However, the 1402 T lead shows a significant increase of STH in the follow-up, in contrast to the other leads. The lowest chronic STH was found in the CapSure 5026 lead (CRP is significantly lower in all other leads, too). IMP is significantly lower in the CapSure 5026 lead compared to 1010 T lead. EC does not differ significantly during chronic stimulation in spite of the best possible programming of pulse amplitude and duration. No significant changes of IRW were observed. Unipolar versus bipolar stimulation shows significantly lower STH, CRP, and IMP, differences of EC and IRW were insignificant. In conclusion, the addition of steroid in membrane covered carbon leads protracts the increase of STH, but does not prevent it. The CapSure 5026 lead shows advantageous stimulation characteristics, but energy consumption is not significantly reduced because of low impedance and impossibility of programming an appropriate low output in Multilog pacemakers.