Expression of platelet-bound stromal cell-derived factor-1 in patients with non-valvular atrial fibrillation and ischemic heart disease.

AIMS: Blood cell infiltration and inflammation are involved in atrial remodelling during atrial fibrillation (AF) although the exact mechanisms of inflammatory cell recruitment remain poorly understood. Platelet-bound stromal cell-derived factor-1 (SDF-1) is increased in cases of ischemic myocardium and regulates recruitment of CXCR4(+) cells on the vascular wall. Whether platelet-bound SDF-1 expression is differentially influenced by non-valvular paroxysmal or permanent atrial fibrillation (AF) in patients with stable angina pectoris (SAP) or acute coronary syndrome (ACS) has not been reported so far. METHODS AND RESULTS: A total of 1291 consecutive patients with coronary artery disease (CAD) undergoing coronary angiography were recruited. Among the patients with SAP, platelet-bound-SDF-1 is increased in patients with paroxysmal AF compared with SR or to persistent/permanent AF (P < 0.05 for both). Platelet-bound SDF-1 correlated with plasma SDF-1 (r = 0.488, P = 0.013) in patients with AF and ACS, which was more pronounced among patients with persistent AF (r = 0.842, P = 0.009). Plasma SDF-1 was increased in persistent/permanent AF compared with SR. Patients with ACS presented with enhanced platelet-bound-SDF-1 compared with SAP. Interestingly, among patients with ACS, patients with paroxysmal or persistent/permanent AF presented with an impaired platelet-bound SDF-1 expression compared with patients with SR. CONCLUSIONS: Differential expression of platelet-bound and plasma SDF-1 was observed in patients with AF compared with SR which may be involved in progenitor cell mobilization and inflammatory cell recruitment in patients with AF and ischemic heart disease. Further in vivo studies are required to elucidate the role of SDF-1 in atrial remodeling and the atrial fibrillation course.

[Catheter ablation of paroxysmal atrial fibrillation: extended recommendations considering safety improvements of pulmonary vein isolation with a cryoballoon--Case 11/2011]. / Katheterablation von paroxysmalem Vorhofflimmern: großzügigere Indikationsstellung durch verbesserte Sicherheit der Pulmonalvenenisolation mittels Cryoballon - Fall 11/2011.

HISTORY AND ADMISSION FINDINGS: A 71-year-old, male patient was referred to our clinic for paroxysmal palpitations with dyspnoe and fatigue since four years despite pharmacological treatment with flecainide and bisoprolol. INVESTIGATIONS: A paroxysmal atrial fibrillation was documented in a 24-hour Holter recording. A bicycle ergometry showed a hypertensive reaction during exercise without any sign of coronary insufficiency. Intracardiac thrombi could by excluded by transesophageal echocardiography. DIAGNOSIS, TREATMENT AND COURSE: The diagnosos of a drug-refractory paroxysmal atrial fibrillation was made and cryoballoon pulmonary vein isolation was performed. A follow-up 3 months after the ablation disclosed a freedom from atrial fibrillation documented in 7-day Holter recording. CONCLUSIONS: Compared to pharmacological rhythm control, interventional treatment has been established as more effective therapy for paroxysmal atrial fibrillation. However, patients should be referred to the ablation early enough to avoid structural atrial remodeling and thus transition into persistent or permanent atrial fibrillation. New technical developments e.g. cryoballoon catheter-system simplifies the procedure and has been reported to be effective and safe to use for circumferential pulmonary vein isolation. Should the very promising preclinical data on efficacy and safety of cryothermal energy ablation be confirmed by results of ongoing, controlled trials, the catheter ablation may become the fist-line treatment for all patients with paroxysmal atrial fibrillation.

[Contact force control - the key to safe zero-fluoroscopy catheter ablation of atrioventricular nodal reentrant tachycardia]. / Die Anpresskraftkontrolle als Schlüssel zur sicheren strahlenfreien Katheterablation der AV-Knoten-Reentrytachykardie.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is a frequent supraventricular tachycardia in children and young adults. Despite favourable success rates of catheter ablation, conventional fluoroscopic catheter guidance is associated with risks of low-dose ionizing radiation for the patient and the personnel. Here we describe a technique for zero-fluoroscopy catheter ablation using contact force technology. PATIENTS AND METHODS: Zero-fluoroscopy catheter ablation was attempted in 12 patients with AVNRT (median age 20 years; range 11-75 years). An ablation catheter with integrated contact force sensor and a nonfluoroscopic electroanatomical mapping system was used for visualization of cardiovascular structures. Mean contact forces during mapping and ablation were restricted to an upper limit of 50 g to avoid cardiovascular injuries. RESULTS: Zero-fluoroscopy catheter ablation was performed successfully and uneventfully in all patients. There were no arrhythmia recurrences during a median follow-up of 6.2 months (range 2.7-12.8). CONCLUSION: Zero-fluoroscopy catheter ablation of AVNRT is possible and appears simple yet safe, when a nonfluoroscopic electroanatomical mapping system is used in combination with an ablation catheter with integrated contact force sensor. The presented technique could thus be easily employed in most electrophysiological laboratories.

Transient outward potassium current in rabbit atrium is depressed after short-time rapid atrial pacing but recovers after a longer pacing period.

In rabbit, after short-time rapid atrial pacing (RAP), atrial ion currents are reduced similarly as in human chronic atrial fibrillation (AF). Using the rabbit model, time-course of transient outward potassium current (I(to)) remodeling due to RAP was studied. RAP (600 bpm) was applied via an atrial lead for 0 (control), 24 and 120 h, n = 4 animals/group. Using patch clamp technique in whole-cell mode, current densities and biophysical properties were measured in isolated atrial myocytes. After 24 h of RAP, a reduction of peak I(to) (mean +/- SEM, test potential +50 mV, +37 degrees C) was observed (60.3 +/- 5.4 pA/pF (control, n = 20) vs. 28.0 +/- 2.5 pA/pF (24 h, n = 21)). Inactivation of I(to) was slower after 24 h, other biophysical properties were unaltered. However, I(to) recovered after 120 h: 51.7 +/- 4.5 pA/pF (n = 26, p = n.s. vs. control). Inactivation tended to also recover to initial values but was still different to control. Early I(to) remodeling due to RAP in rabbits seems to be more complex than previously thought: a time course of I(to) remodeling with swayings has to be considered when using the rabbit model of RAP in order to study early remodeling or rather its therapeutic manipulation.

[Cardiac resynchronization therapy in non-ischemic cardiomyopathy]. / Resynchronisationstherapie bei nicht-ischämischer Kardiomyopathie.

Cardiac resynchronization therapy is recommended in patients with advanced heart failure (usually NYHA class III or IV) despite optimal pharmacologic therapy, severe systolic dysfunction (eg, left ventricular ejection fraction < 35 percent) and intraventricular conduction delay or echocardiographic indices of dyssynchrony and wide QRS complex (eg, QRS > or = 120 ms). Viral infection is the most common cause of myocarditis and has been implicated in the development of non-ischemic cardiomyopathy. We report on a patient who developed progressive congestive heart failure caused by non-ischemic cardiomyopathy after liver transplantation and reactivation of the underlying hepatitis C. Due to an insufficient response to optimized pharmacological therapy, the patient was successfully treated using cardiac resynchronization therapy.

[Efficiency potential in the pacemaker/implantable cardioverter defibrillator outpatient clinic]. / Effizienzpotential in der Nachsorge von Schrittmachern und implantierbaren Kardioverter Defibrillatoren.

The aim of the present study was to elucidate whether the duration of a technical follow-up (FU) of a pacemaker (PM)/implantable cardioverter defibrillator (ICD) has an impact on cost-effectiveness in the outpatient clinic. We determined the time required for a complete FU of devices from three different manufacturers. In 130 patients (70 VVI/DDD-PM, 60 VVI/DDD-ICD) with either a PM (Phylos, Chorum/Talent, Kappa, EnPulse) or an ICD (Belos, Alto or GEM) the time was recorded for a complete FU including determination of lead impedance, sensing and pacing threshold. The time for activation of individual menue buttons was excluded. On the basis of time required for FU, cost-units (CU) were calculated for 2000 FU/year and for a presumed device longevity (PM 7 years, ICD 5 years). For VVI-PM, the duration of FU was almost identical for devices from different manufacturers (105+/-11 s to 125+/-8 s; p=n.s.). However, analysis of DDD-PM revealed marked differences (140+/-25 s vs 282+/-23 s, p<0.05). Time for FU of ICDs varied between 108+/-5 s and 207+/-21 s (p<0.05) in VVI-ICDs and between 129+/-8 ms and 225+/-23 s (p<0.05) in DDD-ICDs. The total savings could be 55 000 CU in VVI- and 53 333 CU in DDD-ICDs. For full automatic DDD-pacemakers (EnPulse) time for FU could be reduced to 58+/-3 s (p<0.05). Differences in FU times were caused by problems with telemetry, delay during booting of the programmer, interrogation at the beginning and at the end of FU and for sensing tests. Improving not only programmers and devices but also test automaticity could significantly increase cost-efficiency in the outpatient clinic.

Far-field R wave oversensing in a dual chamber arrhythmia management device: predisposing factors and practical implications.

Initial experience with the Medtronic Jewel 7250, the ICD designed to detect and treat ventricular and supraventricular tachyarrhythmias, is very promising. Its effectiveness, however, depends on sensing performance, which has not yet been systematically examined. The aim of the study was to determine the incidence of, predisposing factors for, and practical implications of far-field R wave oversensing (FFRWOS) in this dual chamber ICD. During a total follow-up of 797 months in 48 patients who had the Jewel 7250, follow-up strip charts, 12-channel Holter recordings and, in particular cases, Holter recordings with intracardiac markers were analyzed for the presence of FFRWOS. FFRWOS was documented in ten (21.3%) patients. Compared to other lead locations, the right atrial appendage lead position was most frequently associated with FFRWOS (7/27 vs 3/21, P < 0.05). Patients with FFRWOS had significantly more treated and nontreated atrial episodes, many of which were judged to have been detected inappropriately. In one case, inappropriate atrial antitachycardia pacing due to R wave oversensing triggered sustained ventricular tachycardia, terminated eventually with a high energy shock. In dual chamber ICDs, FFRWOS may represent a frequent phenomenon possibly leading to serious consequences. For atrial leads, a lateral atrial wall position seems to be preferable. In most cases, FFRWOS can be eliminated by optimization of atrial sensing parameters. Given the possibility of ventricular proarrhythmia with atrial pacing therapy, the capability of ventricular backup defibrillation in respective devices is at least reassuring.