Biomedical subjects

Claus Schmitt

Publications and source records attributed to Claus Schmitt.

At least 19 recordsLinked to original sources

PubMed2006

Effects of circumferential or segmental pulmonary vein ablation for paroxysmal atrial fibrillation on cardiac autonomic function.

BACKGROUND: Circumferential and segmental pulmonary vein ablations are two established treatment strategies for ablation of atrial fibrillation. Both techniques require the application of radiofrequency current at anatomical sites that are close to autonomic ganglia. However, the effects of current pulmonary vein ablation techniques on cardiac autonomic function are unknown. OBJECTIVE: The purpose of this study was to analyze the short- and long-term effects of circumferential and segmental pulmonary vein ablation on cardiac autonomic function. METHODS: One hundred patients with highly symptomatic atrial fibrillation were randomly assigned to undergo either circumferential or segmental pulmonary vein ablation. Holter recordings were recorded at baseline and at regular intervals for up to 1 year after ablation. Autonomic function was assessed by deceleration capacity and acceleration capacity of heart rate as well as by standard measures of heart rate variability. RESULTS: In the circumferential pulmonary vein ablation group, deceleration capacity and acceleration capacity decreased highly significantly from 5.7 +/- 2.1 ms and -8.0 +/- 1.9 ms at baseline to 3.3 +/- 1.8 ms and -5.5 +/- 2.3 ms directly after ablation, respectively (P<.00001). Impairment of deceleration capacity and acceleration capacity was present up to 1 year after ablation. In the segmental pulmonary vein ablation group, deceleration capacity and acceleration capacity decreased from 5.8 +/- 2.0 ms and -7.8 +/- 1.6 ms at baseline to 3.4 +/- 1.2 ms and -6.0 +/- 2.4 ms directly after ablation (P<.00001), respectively. However, deceleration capacity and acceleration capacity returned to baseline values within 1 month. CONCLUSIONS: Circumferential and segmental pulmonary vein ablations induce an immediate decrease of autonomic function. However, while this decrease is only transient with segmental pulmonary vein ablation, it persists with circumferential pulmonary vein ablation for at least 1 year.

Aged↗

PubMed2006

Near-fatal incident on routine induction of ventricular fibrillation at the replacement of an implantable cardioverter defibrillator.

The case of a 54-year-old patient with severe coronary artery disease and storms of ventricular tachyarrhythmias is presented. On the replacement of an implantable cardioverter defibrillator due to battery depletion, he suffered life-threatening complications associated with arrhythmia induction. Performing a routine induction of ventricular arrhythmias on the occasion of pulse generator replacement may be reconsidered in selected patients.

Defibrillators, Implantable↗

PubMed2006

Electrical isolation of pulmonary veins in patients with atrial fibrillation: reduction of fluoroscopy exposure and procedure duration by the use of a non-fluoroscopic navigation system (NavX).

AIMS: The aim of the study was to investigate the feasibility of performing segmental pulmonary vein (PV) isolation guided by the NavX (Endocardial Solutions, St Jude Medical, Inc., St Paul, MN, USA) system without the three-dimensional (3D) geometric reconstruction option and whether the use of NavX system will reduce the radiation exposure and procedure duration. METHODS AND RESULTS: The study included 64 patients with symptomatic paroxysmal or permanent atrial fibrillation, in whom PV isolation was performed using fluoroscopic guidance (n=32) or the NavX system (n=32). Pulmonary vein mapping with a circular mapping catheter allowed the identification and localization of myocardial connections between the PV and the left atrium. PV isolation was performed by radiofrequency ablation of these connections at the atrial aspect of the PV ostium. Primary success rate for isolated PVs did not differ significantly in patients ablated under fluoroscopic guidance vs. those ablated under guidance of NavX system [100/107 PVs (93.5%) vs. 120/124 PV (96.8%; P=n.s.)]. Compared with fluoroscopy guided procedures, NavX-guided procedures showed a significant reduction in the fluoroscopy time (75.8+/-24.5 vs. 38.9+/-19.3 min, P<0.05), total X-ray exposure (93.2+/-51.6 vs. 56.6+/-37.9 Gy cm(2), P=0.03), and total procedural time (237.7+/-65.4 vs. 188.6+/-62.7 min, P=0.01). The mean follow-up was 9.5+/-3.0 months. One patient in each group was lost to follow-up. Seven-day Holter monitoring showed that 23 of 31 patients (74.2%) in the NavX-guided group and 21 of 31 patients (67.7%) in the fluoroscopy-guided group were in sinus rhythm (P=0.57). CONCLUSION: The 3D visualization of the catheters by NavX system allows a rapid and precise visualization of the mapping and ablation catheters at the PV ostia and markedly reduces fluoroscopy time, total X-ray exposure, and procedural duration during PV isolation compared with ablation performed under fluoroscopy guidance.

Aged↗

PubMed2006

Phrenic nerve injury after catheter ablation: should we worry about this complication?

INTRODUCTION: Phrenic nerve injury (PNI) is a complication that can occur with catheter ablation. METHODS: Data from 17 patients with PNI following different catheter ablation techniques were reviewed. PNI was defined as decreased motility (transient) or paralysis (persistent) of the hemi-diaphragm on fluoroscopy or chest X-ray. Patient's recovery was monitored. Normalization of chest images and sniff test would be considered as complete clinical recovery. RESULTS: Out of the 17 PNI patients (16 right, 1 left), 13 (11 persistent, 2 transient) occurred after pulmonary veins isolation with or without superior vena cava ablation. Three patients had persistent PNI after sinus node modification and one other patient experienced PNI after epicardial ventricular tachycardia ablation. Ablation was performed with different energy source including radiofrequency (n = 13), cryothermal (n = 1), ultrasound (n = 2) and laser (n = 1). Patient's symptoms varied broadly from asymptomatic to dyspnea, and even to respiratory insufficiency that required temporary mechanical ventilation support. Two patients with transient PNI resolved immediately after the procedure and the other 15 persistent PNI patients resolved within a mean time of 8.3 +/- 6.6 months. CONCLUSIONS: PNI caused by catheter ablation appears to functionally recover over time regardless of the energy sources used for the procedure.

Adult↗

PubMed2006

Stem cell mobilization by granulocyte colony-stimulating factor in patients with acute myocardial infarction: a randomized controlled trial.

CONTEXT: Experimental studies and early phase clinical trials suggest that transplantation of blood-derived or bone marrow-derived stem cells may improve cardiac regeneration and neovascularization after acute myocardial infarction. Granulocyte colony-stimulating factor (G-CSF) induces mobilization of bone marrow stem cells. OBJECTIVE: To assess the value of stem cell mobilization by G-CSF therapy in patients with acute myocardial infarction. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind, placebo-controlled trial of patients diagnosed with ST-segment elevation acute myocardial infarction who had successful reperfusion by percutaneous coronary intervention within 12 hours after onset of symptoms in Germany between February 24, 2004, and February 2, 2005. INTERVENTIONS: Patients were randomly assigned to receive subcutaneously either a daily dose of 10 microg/kg of G-CSF or placebo for 5 days. MAIN OUTCOME MEASURES: The primary end point was reduction of left ventricular infarct size according to technetium Tc 99m sestamibi scintigraphy performed at baseline and at 4 to 6 months after randomization. Secondary end points included improvement of left ventricular ejection fraction measured by magnetic resonance imaging and the incidence of angiographic restenosis. RESULTS: Of the 114 patients, 56 were assigned to receive treatment with G-CSF and 58 were assigned to receive placebo. Treatment with G-CSF produced a significant mobilization of stem cells. Between baseline and follow-up, left ventricular infarct size according to scintigraphy was reduced by a mean (SD) of 6.2% (9.1%) in the G-CSF group and 4.9% (8.9%) in the placebo group (P = .56) and left ventricular ejection fraction was improved by 0.5% (3.8%) in the G-CSF group and 2.0% (4.9%) in the placebo group (P = .14). Angiographic restenosis occurred in 19 (35.2%) of 54 patients in the G-CSF group and in 17 (30.9%) of 55 patients in the placebo group (P = .79). The most common adverse event among patients assigned to G-CSF was mild to moderate bone pain and muscle discomfort. CONCLUSION: Stem cell mobilization by G-CSF therapy in patients with acute myocardial infarction and successful mechanical reperfusion has no influence on infarct size, left ventricular function, or coronary restenosis. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00126100.

Aged↗

PubMed2006

Transient ST-segment-elevation during pulmonary vein ablation using circumferential coiled microelectrodes in a prospective multi-centre study.

AIMS: Paroxysmal atrial fibrillation (PAF) is predominantly triggered by focal ectopies located within the pulmonary veins (PV). The BITMAP Study (Breakthrough and Isolation Trial: Mapping and Ablation of Pulmonary Veins) investigated prospectively the safety and efficacy of a catheter design with circumferential mapping and ablation electrodes. We report the phenomenon of ST-segment-elevation during catheter placement in the left atrium (LA) and superior PVs in this multi-centre study. METHODS AND RESULTS: Forty-three patients (57+/-10 years) with PAF were included in this study. Radiofrequency catheter (RFC) ablation supported by the 4F REVELATION Helix microcatheter (Cardima Inc., Freemont, CA, USA) with eight distal-coiled microelectrodes for bipolar mapping and ablation. RFC was applied at the ostial region of PV (30 W, 45-50 degrees C) with a maximum of four RFC applications per electrode. In four of the 43 patients from three centres, we recorded the occurrence of ST-segment-elevation greater than 0.2 mV and accompanying left thoracic discomfort. The ECG changes and the symptoms started abruptly and lasted for 4.2+/-2.2 min. Pericardial effusion could instantaneously be excluded by echocardiography in all cases. Coronary angiograms were performed in three patients with the longest episodes; no thrombotic material or air emboli were present. The symptoms and the ECG changes resolved completely in all patients. CONCLUSION: The phenomenon of ST-segment-elevation during LA- and PV-mapping in patients with PAF may be a common occurrence. In this prospective multi-centre trial, we demonstrated the reversibility of this phenomenon; no cardiovascular or cerebral damage was reported during both the procedure and the follow-up. Although the mechanism is still unclear, vasospasm may contribute to this phenomenon because of autonomic dysregulation.

Adult↗

PubMed2006

Left atrial tachycardia after circumferential pulmonary vein ablation for atrial fibrillation: incidence, electrophysiological characteristics, and results of radiofrequency ablation.

AIMS: To investigate the incidence, electrophysiological properties, and ablation results for left atrial (LA) tachycardia as a sequel to the circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF). METHODS AND RESULTS: Sixty-seven patients with AF underwent CPVA. Sustained LA tachycardia developed in 21/67 (31%) patients and in 16/21 symptomatic patients 55 LA tachycardias (3.4+/-2.4 per patient) were mapped: 18 (33%) tachycardias were related to macro-re-entry around the mitral valve (7) or pulmonary vein(s) (11). In 20 tachycardias (36%), a 'small-loop' LA re-entrant tachycardia (LART) was identified; gaps in prior ablation lines (7 LART) or an area of extremely slow conduction adjacent to the CPVA lesions (13 LART) were crucial for these re-entries. Seventeen tachycardias (31%) were too unstable for complete mapping. Ablation was a primary success in 34 of 38 (89%) mapped LART, but in eight of 21 procedures, cardioversion was necessary to achieve sinus rhythm. CONCLUSION: LART develops in a high percentage of patients after CPVA. Small-loop re-entry, which is difficult to map, may arise and patients suffer from several and/or unstable variants of LART. Thus, mapping and ablation of these LART is challenging and the overall success is yet not satisfactory.

Aged↗

PubMed2006

Atresia of the coronary sinus in patients with supraventricular tachycardia.

BACKGROUND: Atresia of the coronary sinus (CS) ostium with retrograde drainage of the cardiac veins via the persistent left superior vena cava (PLSVC) is a rare abnormality and only a few case reports in association with electrophysiological studies have been reported. METHODS: During standard electrophysiological study in three patients with a focal left atrial tachycardia, atrial fibrillation and common type right atrial flutter, the CS could not be cannulated despite several attempts. Assuming an occluded CS ostium we advanced a multipurpose catheter via the right atrium and the right superior vena cava in a PLSVC and performed CS angiography. RESULTS: CS angiography showed that the CS was occluded in all 3 patients and the PLSVC was used as a drainage route to the superior vena cava. After retrograde placement of a 2.5 Fr nonsteerable diagnostic catheter via the PLSVC in the CS, the intracardiac CS electrogram was recorded. Successful ablation could be performed in all three cases. CONCLUSIONS: The cases highlight the possibility that failure to access the CS during electrophysiological studies may be related to this anomaly and that retrograde cannulation via PLSVC enables the CS access and acquisition of its electrograms.

Aged↗

PubMed2006

Long-term follow-up of patients supplied with single-chamber or dual-chamber cardioverter defibrillators.

INTRODUCTION: In patients who have an indication for an implantable cardioverter defibrillator (ICD) a dual-chamber device is indicated in the case of concomitant significant sinus node disease or atrioventricular block. It is a matter of debate whether dual-chamber ICD may be beneficial for patients with preserved sinus and atrioventricular nodal function as data from prospective randomized trials are limited. Mid- or long-term follow-up data are unavailable. METHODS AND RESULTS: One hundred patients (age 60+/-12 years, 11 women) with the indication for the implantation of an ICD and without antibradycardia pacing indication were randomly assigned to either receive a dual-chamber ICD (n=52) or a single-chamber ICD (n=48). Patients were followed-up for a mean of 52+/-14 months. Mortality and arrhythmogenic morbidity were assessed. All-cause mortality was 21% for single-chamber and 31% for dual-chamber ICD recipients, respectively (P=0.26). Cardiovascular mortality was 13% for single-chamber ICD recipients versus 21% in the dual-chamber group (P=0.25). Subgroup analysis using 35% of ventricular paced beats as cutoff value in the dual-chamber ICD group revealed a 42% mortality rate for the patients with frequent ventricular pacing compared to 10% of patients with a low rate of ventricular pacing (P=0.05, relative risk 4.21, 95% confidence interval: 0.9-19.8). As for arrhythmogenic morbidity, the difference in the ventricular tachyarrhythmia load was not different in both groups (single chamber: 23+/-74 VT episodes, dual chamber: 54+/-134 VT episodes, P=0.17). CONCLUSION: In ICD recipients without conventional indication for dual-chamber pacing, dual chamber compared to single-chamber ICD has no advantage concerning mortality and arrhythmogenic morbidity in a long-term follow-up. In these patients the implantation of a single-chamber device is sufficient.

Arrhythmias, Cardiac↗

PubMed2006

Cardiac pacing in a patient with diaphragm pacing for congenital central hypoventilation syndrome (Ondine's curse).

Mechanical ventilation support and diaphragm pacing has improved the prognosis of patients with idiopathic congenital central hypoventilation syndrome (CCHS; Ondine's curse). However, severe bradyarrhythmias may occur. This report is about a patient who was supplied with a bilateral diaphragm pacing system at early childhood. At the age of 17 years, he experienced multiple syncopes due to sinus nodal arrest, which was successfully treated by the implantation of a dual chamber pacemaker.

Adolescent↗

PubMed2006

Management of far-field R wave sensing for the avoidance of inappropriate mode switch in dual chamber pacemakers: results of the FFS-test study.

BACKGROUND AND OBJECTIVE: Far-field R wave sensing (FFS) in the atrial channel of dual chamber pacemakers is a relevant source for inappropriate mode switch from the DDD mode to the DDI or VDI mode. Inappropriate loss of atrioventricular synchrony due to false positive mode switch is hemodynamically disadvantageous, may induce atrial tachyarrhythmias, can lead to pacemaker syndrome, and impairs the reliability of pacemaker Holter data. The aim of the study was to determine whether individual adjustment of the postventricular atrial blanking period (PVAB) based on an additional test is effective in avoiding inappropriate mode switch due to FFS when compared with standard programming of the PVAB. METHODS: A total of 207 patients were supplied with a St. Jude Medical Identity DR or Identity ADx DR dual chamber pacemaker for sinus nodal disease (n = 84), atrioventricular block (n = 79), binodal disease (n = 35), or other indications (n = 9). At hospital discharge, they were randomized to an individually optimized PVAB (n = 100) or to a control group with the PVAB left at the nominal of 100 msec (n = 107). Primary endpoint was the occurrence of inappropriate mode switch due to FFS within 3 months after pacemaker implantation assessed by stored electrograms of the pacemaker. RESULTS: At the 3-month follow-up, 28/107 (26%) patients with the standard programming of the PVAB showed at least one episode of inappropriate mode switch due to FFS versus 10/100 (10%) patients with optimized PVAB (P < 0.01). The optimized PVAB was shorter than the nominal PVAB in about one-third of patients and longer in about two-third of patients. Different atrial lead localizations were not associated with the occurrence of inappropriate mode switch. CONCLUSIONS: Individual adjustment of the PVAB significantly reduces the incidence of inappropriate mode switch due to FFS.

Aged↗

PubMed2005

Mechanical reperfusion in patients with acute myocardial infarction presenting more than 12 hours from symptom onset: a randomized controlled trial.

CONTEXT: No specifically designed studies have addressed the role of primary percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction (STEMI) presenting more than 12 hours after symptom onset. Current guidelines do not recommend reperfusion treatment in these patients. OBJECTIVE: To assess whether an immediate invasive treatment strategy is associated with a reduction of infarct size in patients with acute STEMI, presenting between 12 and 48 hours after symptom onset, vs a conventional conservative strategy. DESIGN, SETTING, AND PATIENTS: International, multicenter, open-label, randomized controlled trial conducted from May 23, 2001, to December 15, 2004, of 365 patients aged 18 to 80 years without persistent symptoms admitted with the diagnosis of acute STEMI between 12 and 48 hours after symptom onset. INTERVENTIONS: Random assignment to either an invasive strategy (n=182) based predominantly on coronary stenting with abciximab or a conventional conservative treatment strategy (n=183). MAIN OUTCOME MEASURES: The primary end point was final left ventricular infarct size according to single-photon emission computed tomography study with technetium Tc 99m sestamibi performed between 5 and 10 days after randomization in 347 patients (95.1%). Secondary end points included composite of death, recurrent MI, or stroke at 30 days. RESULTS: The final left ventricular infarct size was significantly smaller in patients assigned to the invasive group (median, 8.0%; interquartile range [IQR], 2.0%-15.8%) vs those assigned to the conservative group (median, 13.0%; IQR, 3.0%-27.0%; P<.001). The mean difference in final left ventricular infarct size between the invasive and conservative groups was -6.8% (95% confidence interval [CI], -10.2% to -3.5%). The secondary end points of death, recurrent MI, or stroke at 30 days occurred in 8 patients in the invasive group (4.4%) and 12 patients in the conservative group (6.6%) (relative risk, 0.67; 95% CI, 0.27-1.62; P = .37). CONCLUSION: An invasive strategy based on coronary stenting with adjunctive use of abciximab reduces infarct size in patients with acute STEMI without persistent symptoms presenting 12 to 48 hours after symptom onset.

Abciximab↗

PubMed2005

Freedom from atrial tachyarrhythmias after catheter ablation of atrial fibrillation: a randomized comparison between 2 current ablation strategies.

BACKGROUND: Data on the comparative value of the circumferential pulmonary vein and the segmental pulmonary vein ablation for interventional treatment of atrial fibrillation are limited. We hypothesized that the circumferential pulmonary vein ablation approach was superior to the segmental pulmonary vein ablation approach. METHODS AND RESULTS: One hundred patients with highly symptomatic atrial fibrillation were randomly assigned to undergo either circumferential (n=50) or segmental pulmonary vein ablation (n=50). Freedom from atrial tachyarrhythmias in a 7-day Holter monitoring at 6 months was the primary end point. Secondary end points were freedom of arrhythmia-related symptoms and a composite of pericardial tamponade, thromboembolic complications, and pulmonary vein stenosis (safety end point). On the basis of the results of the 7-day Holter monitoring at 6 months, 21 patients (42%) after circumferential pulmonary vein ablation and 33 patients (66%) after segmental pulmonary vein ablation (P=0.02) were free of atrial tachyarrhythmia episodes. During the 6-month follow-up period, 27 patients (54%) after circumferential pulmonary vein ablation and 41 patients (82%) after segmental pulmonary vein ablation remained free of arrhythmia-related symptoms (P<0.01). No significant difference was found in the safety end point (6 versus 7 events; P=0.77) in the circumferential versus segmental pulmonary vein ablation group, respectively. CONCLUSIONS: This study demonstrates no superiority of the circumferential pulmonary vein ablation over segmental pulmonary vein ablation for treatment of atrial fibrillation in terms of efficacy and safety.

Aged↗

PubMed2005

One year outcomes with abciximab vs. placebo during percutaneous coronary intervention after pre-treatment with clopidogrel.

AIMS: In the Intracoronary Stenting and Antithrombotic Regimen-Rapid Early Action for Coronary Treatment Trial, the use of abciximab in patients undergoing percutaneous coronary intervention (PCI) after pretreatment with 600 mg clopidogrel for >2 h was associated with no clinically measurable benefit at 30 days. We assessed whether there was any clinical benefit from abciximab at 1 year follow-up. METHODS AND RESULTS: After pre-treatment with 600 mg clopidogrel, a total of 2159 patients undergoing PCI for stable or unstable angina without marked ST-segment shifts or positive biomarkers were randomly assigned to receive abciximab or placebo. The occurrence of the composite endpoint of death, myocardial infarction, or target vessel revascularization was assessed at 1 year after randomization. At 1 year, the composite endpoint occurred in 23.8% of the patients in each group [relative risk (RR), 1.01; 95% confidence interval (CI), 0.85-1.20; P=0.92]. The combined incidence of death and myocardial infarction was 6.0% in the abciximab group and 6.4% in the placebo group (RR, 0.94; 95% CI, 0.67-1.32; P=0.73). The mortality rate was 2.1% in the abciximab group and 2.4% in the placebo group (RR, 0.88; 95% CI, 0.50-1.54; P=0.66). No trend towards clinical benefit was observed with abciximab at 1 year in any subgroup analysed. CONCLUSION: In patients with a low-to-intermediate risk profile undergoing PCI after pre-treatment with a 600 mg clopidogrel for at least 2 h, the use of abciximab offers no additional clinical benefit at 1 year.

Abciximab↗

PubMed2005

Sirolimus-eluting stent or paclitaxel-eluting stent vs balloon angioplasty for prevention of recurrences in patients with coronary in-stent restenosis: a randomized controlled trial.

CONTEXT: In patients with de novo coronary lesions, drug-eluting stents have drastically reduced restenosis risk compared with bare metal stents and conventional balloon angioplasty. It is less clear whether drug-eluting stents are superior to conventional balloon angioplasty for the treatment of patients with in-stent restenosis. OBJECTIVES: To assess if drug-eluting stents are a more effective treatment of in-stent restenosis than conventional balloon angioplasty, and to assess the relative merits of 2 drug-eluting stents, a sirolimus-eluting stent and a paclitaxel-eluting stent. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label, active-controlled trial conducted among 300 patients with angiographically significant in-stent restenosis in 2 tertiary German centers from June 1, 2003, to October 20, 2003. INTERVENTIONS: After pretreatment with 600 mg of clopidogrel for at least 2 hours before intervention, all patients were randomly assigned to 1 of 3 treatment groups: sirolimus stent, paclitaxel stent, or balloon angioplasty (100 patients in each group). MAIN OUTCOME MEASURES: Primary end point: angiographic restenosis (diameter stenosis > or =50%) at 6-month follow-up angiography based on "in-segment" analysis. Primary analysis was comparison between stent groups and balloon angioplasty groups; a secondary analysis compared sirolimus and paclitaxel stents. RESULTS: Follow-up angiography was performed in 275 (92%) of 300 patients. The incidence of angiographic restenosis was 44.6% (41/92) in the balloon angioplasty group, 14.3% (13/91) in the sirolimus stent group (P<.001 vs balloon angioplasty), and 21.7% (20/92) in the paclitaxel stent group (P = .001 vs balloon angioplasty). When compared with balloon angioplasty, receiving a sirolimus stent had a relative risk (RR) of angiographic restenosis of 0.32 (95% confidence interval [CI], 0.18-0.56); a paclitaxel stent had an RR of 0.49 (95% CI, 0.31-0.76). The incidence of target vessel revascularization was 33.0% (33/100) in the balloon angioplasty group, 8.0% (8/100) in the sirolimus stent group (P<.001 vs balloon angioplasty), and 19.0% (19/100) in the paclitaxel stent group (P = .02 vs balloon angioplasty). The secondary analysis showed a trend toward a lower rate of angiographic restenosis (P = .19) and a significantly lower rate of target vessel revascularization (P = .02) among sirolimus stent patients compared with paclitaxel stent patients. CONCLUSIONS: In patients with in-stent restenosis, a strategy based on sirolimus- or paclitaxel-eluting stents is superior to conventional balloon angioplasty for the prevention of recurrent restenosis. Sirolimus-eluting stents may be superior to paclitaxel-eluting stents for treatment of this disorder.

Aged↗

PubMed2005

Rescue ablation of electrical storm in patients with ischemic cardiomyopathy: a potential-guided ablation approach by modifying substrate of intractable, unmappable ventricular tachycardias.

OBJECTIVES: The purpose of this study was to evaluate a substrate-modifying, primarily potential-guided catheter ablation approach as a bailout therapy in patients with complex myocardial infarction and electrical storms due to ventricular tachycardias (VTs). BACKGROUND: Management of electrical storm is a domain of medical treatment. A definite trigger or delineated scar has been characterized as a requirement for substrate-orientated ablation of intractable unmappable ventricular tachyarrhythmias but can be absent, as shown in the presented cases. METHODS: Five patients who presented with ischemic cardiomyopathy and severe reduced left ventricular ejection fraction also suffered from multiple types of unstable VTs that deteriorated into drug-refractory electrical storm. Patients had 96 to 580 VT episodes requiring therapy with an implantable cardioverter-defibrillator (ICD) and received 3 to 310 shock deliveries prior to ablation. Treatment with beta-blockers, amiodarone, class IB antiarrhythmic drugs, deep sedation, and overdrive pacing and/or cardioversion of incessant VTs failed to stabilize the electrical storm but enabled left ventricular electroanatomic voltage mapping. A simplified substrate modification was performed by ablation of delayed fractionated potentials in areas identified by pace mapping, matching three to eight documented types of VTs per patient in complex scar areas. RESULTS: All patients could be stabilized after ablation. During 12 to 30 months of follow-up, three patients remained free of any VT episode requiring ICD treatment, and two patients had <1 VT episode per month. CONCLUSIONS: The cases presented demonstrate that rescue VT ablation of drug-refractory electrical storm is possible by a substrate-orientated ablation approach even in patients with complex chronic infarction and various VTs.

Aged↗

PubMed2005

Catheter ablation of left atrial focal tachycardia guided by electroanatomic mapping and new insights into interatrial electrical conduction.

BACKGROUND: Experience in catheter ablation of left atrial (LA) focal tachycardia and information about interatrial electrical connections during LA focal tachycardia are limited. OBJECTIVES: The purpose of this study was to describe our experience in electroanatomic mapping-guided catheter ablation of LA focal tachycardia and to investigate interatrial electrical connections during LA focal tachycardias. METHODS: Thirty-three patients undergoing catheter ablation for LA focal tachycardia guided by electroanatomic mapping were reported. Interatrial electrical connections were analyzed in LA focal tachycardias with biatrial electroanatomic maps. RESULTS: Of the 35 LA focal tachycardias (cycle length 309 +/- 100 ms) mapped, 19 (54%) originated from the pulmonary veins (PVs), 6 (17%) from the mitral annulus, 3 (8.6%) from LA roof, 3 (8.6%) from LA posterior wall, 2 (5.7%) from LA appendage, and 2 (5.7%) from LA septum. Fourteen of the 19 PV tachycardias (74%) were located in proximity to PV ostia. In 14 (7 PV, 7 non-PV) LA focal tachycardias with biatrial electroanatomic maps, posterior right atrium breakthrough sites at the intercaval area were identified in 7 PV tachycardias and 1 non-PV tachycardia. Five of the 7 PV tachycardias used only the posterior breakthrough for interatrial propagation. Procedural success was achieved in 33 of 35 LA focal tachycardias (94%) in 31 patients. During 23 +/- 19 months of follow-up, 2 patients (6%) had recurrence of ablated tachycardia, and 3 (10%) developed new LA focal tachycardias. CONCLUSIONS: The PVs and the mitral annulus were the main sources of LA focal tachycardias. The majority of PV tachycardias originated from PV ostia. A posterior interatrial connection appeared to play a major role in interatrial electrical propagation during PV tachycardias. Electroanatomic mapping facilitated precise localization of LA focal tachycardias and achievement of a high rate of ablation success.

Adult↗

PubMed2005

Successful pacemaker lead implantation via the subclavian vein despite of high degree stenosis of the vein.

This case reports on an 81-year-old man with implanted dual-chamber pacemaker for binodal disease who required ventricular lead revision due to loss of ventricular capture. Successful placement of a new lead via the subclavian vein despite of high degree stenosis of the medial part of the vein is described using a very thin bipolar ventricular pacing lead. Currently available pacing electrodes for this purpose are reviewed.

Aged↗