Increased mortality and ICD therapies in ischemic versus non-ischemic dilated cardiomyopathy patients with cardiac resynchronization having survived until first device replacement.

INTRODUCTION: Cardiac resynchronization therapy combined with an implantable cardioverter defibrillator (CRT-D) is widely applied in heart failure patients. Sufficient data on arrhythmia and defibrillator therapies during long-term follow-up of more than 4 years are lacking and data on mortality are conflicting. We aimed to characterize the occurrence of ventricular arrhythmia, respective defibrillator therapies and mortality for several years following CRT-D implantation or upgrade. MATERIAL AND METHODS: Eighty-eight patients with ischemic (ICM) or non-ischemic dilated cardiomyopathy (DCM) and at least one CRT-D replacement were included in this study and analyzed for incidence of non-sustained ventricular tachycardia (NSVT), defibrillator shocks, anti-tachycardia pacing (ATP) and mortality. RESULTS: ICM was the underlying disease in 59%, DCM in 41% of patients. During a mean follow-up of 76.4 ±24.8 months the incidence of appropriate defibrillator therapies (shock or ATP) was 46.6% and was elevated in ICM compared to DCM patients (57.7% vs. 30.6%, respectively; p = 0.017). Kaplan-Meier analysis revealed significantly higher ICD therapy-free survival rates in DCM patients (p = 0.031). Left ventricular ejection fraction, NSVT per year and ICM (vs. DCM) were independent predictors of device intervention. The ICM patients showed increased mortality compared to DCM patients, with cumulative all-cause mortality at 9 years of follow-up of 45.4% and 10.6%, respectively. Chronic renal failure, peripheral artery disease and chronic obstructive pulmonary disease were independent predictors of mortality. CONCLUSIONS: The clinical course of patients with ICM and DCM treated with CRT-D differs significantly during long-term follow-up, with increased mortality and incidence of ICD therapies in ICM patients.

Treatment with mononuclear cell populations improves post-infarction cardiac function but does not reduce arrhythmia susceptibility.

BACKGROUND: Clinical and experimental data give evidence that transplantation of stem and progenitor cells in myocardial infarction could be beneficial, although the underlying mechanism has remained elusive. Ventricular tachyarrhythmia is the most frequent and potentially lethal complication of myocardial infarction, but the impact of mono nuclear cells on the incidence of ventricular arrhythmia is still not clear. OBJECTIVE: We aimed to characterize the influence of splenic mononuclear cell populations on ventricular arrhythmia after myocardial infarction. METHODS: We assessed electrical vulnerability in vivo in mice with left ventricular cryoinfarction 14 days after injury and intramyocardial injection of specific subpopulations of mononuclear cells (MNCs) (CD11b-positive cells, Sca-1-positive cells, early endothelial progenitor cells (eEPCs)). As positive control group we used embryonic cardiomyocytes (eCMs). Epicardial mapping was performed for analysing conduction velocities in the border zone. Left ventricular function was quantified by echocardiography and left heart catheterization. RESULTS: In vivo pacing protocols induced ventricular tachycardia (VT) in 30% of non-infarcted mice. In contrast, monomorphic or polymorphic VT could be evoked in 94% of infarcted and vehicle-injected mice (p<0.01). Only transplantation of eCMs prevented post-infarction VT and improved conduction velocities in the border zone in accordance to increased expression of connexin 43. Cryoinfarction resulted in a broad aggravation of left ventricular function. All transplanted cell types augmented left ventricular function to a similar extent. CONCLUSIONS: Transplantation of different MNC populations after myocardial infarction improves left ventricular function similar to effects of eCMs. Prevention of inducible ventricular arrhythmia is only seen after transplantation of eCMs.

Cardiac magnetic resonance using late gadolinium enhancement and atrial T1 mapping predicts poor outcome in patients with atrial fibrillation after catheter ablation therapy.

To determine the pre-procedural value of different fibrotic biomarkers and comprehensive cardiac magnetic resonance (CMR) for the prediction of poor response to ablation therapy in patients with atrial fibrillation (AF). Left atrial (LA) late gadolinium enhancement (LGE) and native LA T1 relaxation times were assessed using CMR. Plasma levels of relaxin, myeloperoxidase and serum levels of matrix metalloproteinase (MMP)-mediated cardiac specific titin fragmentation and MMP-mediated type IV collagen degradation were obtained. Poor outcome was defined by the recurrence of AF during 1-year follow-up. 61 patients were included in final analysis. Twenty (32.8%) patients had recurrence of AF. Patients with a recurrence of AF had a higher percentage of LA LGE (26.7 ± 12.5% vs. 17.0 ± 7.7%; P < 0.001), higher LA T1 relaxation times (856.7 ± 112.2 ms vs. 746.8 ± 91.0 ms; P < 0.001) and higher plasma levels of relaxin (0.69 ± 1.34 pg/ml vs. 0.37 ± 0.88 pg/ml; P = 0.035). In the multivariate Cox regression analysis, poor ablation outcome was best predicted by advanced LGE stage (hazard ratio (HR):5.487; P = 0.001) and T1 relaxation times (HR:1.007; P = 0.001). Pre-procedural CMR is a valuable tool for prediction of poor response to catheter ablation therapy in patients with AF. It offers various imaging techniques for outcome prediction and might be valuable for a better patient selection prior to ablation therapy.

High rate of persistent iatrogenic atrial septal defect after single transseptal puncture for cryoballoon pulmonary vein isolation.

PURPOSE: Congenital atrial septal defect (ASD) is associated with increased morbidity, whereas little is known about the rate of spontaneous closure, associated clinical and echocardiographic parameters, or complications of iatrogenic atrial septal defect (iASD) beyond 1 year of follow-up. Persistent iASD after transseptal puncture for PVI has been described in up to 38% of small cohorts of patients in short-term follow-up after transseptal puncture. We sought to investigate the course of iASD after single transseptal puncture for first pulmonary vein isolation (PVI) with cryoballoon, along with possible risk factors for persistent iASD. METHODS: After a first PVI with cryoballoon, 102 patients (64 ± 10 years, 64% male) underwent long-term clinical follow-up and comprehensive transthoracic and transesophageal echocardiographic study. RESULTS: Prevalence of iASD after PVI was 37% after 2.9 (1.6-4.9) years. No clinical complications or deterioration of echocardiographic parameters were associated with iASD. Lower left atrial appendage flow velocity was associated with higher risk of persistence of iASD (3.5% for every 1 cm/s decrease, p = 0.002). CONCLUSIONS: Despite a high rate of iASD after cryoballoon PVI in long-term follow-up, this was not associated with increased clinical complications. Lower LAA velocity was associated with higher risk of persistent iASD. Repeated routine echocardiographic follow-up may not be necessary in these patients.

Chronic lower-dose relaxin administration protects from arrhythmia in experimental myocardial infarction due to anti-inflammatory and anti-fibrotic properties.

BACKGROUND: The peptide hormone relaxin-2 (RLX) exerts beneficial effects during myocardial ischemia, but functional data on lower-dose RLX in myocardial infarction (MI) is lacking. Therefore, we investigated the impact of 75µg/kg/d RLX treatment on electrical vulnerability and left ventricular function in a mouse model of MI. METHODS AND RESULTS: Standardized cryoinfarction of the left anterior ventricular wall was performed in mice. A two week treatment period with vehicle or RLX via subcutaneously implanted osmotic minipumps was started immediately after MI. The relaxin receptor RXFP1 was expressed on ventricular/atrial cardiomyocytes, myofibroblasts, macrophages and endothelial but not vascular smooth muscle cells of small coronary vessels. RLX treatment resulted in a significant reduction of ventricular tachycardia inducibility (vehicle: 91%, RLX: 18%, p<0.0001) and increased epicardial conduction velocity in the left ventricle and borderzone. Furthermore, left ventricular function following MI was improved in RLX treated mice (left ventricular ejection fraction; vehicle: 41.1±1.9%, RLX: 50.5±3.5%, p=0.04). Interestingly, scar formation was attenuated by RLX with decreased transcript expression of connective tissue growth factor. Transcript levels of the pro-inflammatory cytokines interleukin-6 and interleukin-1ß were upregulated in hearts of vehicle treated animals compared to mice without MI. Application of RLX attenuated this inflammatory response. In addition, macrophage infiltration was reduced in the borderzone of RLX treated mice. CONCLUSION: Treatment with lower-dose RLX in mice prevents post-infarction ventricular tachycardia due to attenuation of scar formation and cardiac inflammation. Therefore, RLX could be evaluated as new therapeutic option in the treatment of MI.

Outcome in patients with left common pulmonary vein after cryoablation with second-generation cryoballoon.

BACKGROUND: Pulmonary vein isolation (PVI) has become a widely accepted therapy in patients suffering from symptomatic atrial fibrillation (AF). HYPOTHESIS: AF-free survival differs in patients with left common pulmonary vein (LCPV) after PVI with second-generation cryoballoon. METHODS: We included patients scheduled for first PVI for paroxysmal or persistent AF. Symptomatic and/or documented arrhythmia episodes (>30 seconds) were defined as AF recurrence, excluding a 3-month blanking period. RESULTS: We observed a LCPV in 37 of 270 consecutive patients (13.7%). Analyses were performed in a 1:1 propensity score matched cohort of 68 patients. During a median follow-up of 77.0 weeks, 37 patients (54.4%) had recurrent AF. The prevalence of LCPV was numerically higher in patients with AF recurrence (62.2% vs 35.5%, P  =  0.051) and Kaplan-Meier analysis showed lower AF-free survival in patients with existence of a LCPV (P  =  0.028). At 1-year follow-up, 70.6% of patients without versus 55.1% of patients with LCPV were free of AF. Multivariate Cox regression analysis revealed presence of a LCPV (hazard ratio [HR]: 2.996), chronic heart failure (HR: 3.423), and mitral regurgitation > I° (HR: 2.571) as predictors of AF recurrence. CONCLUSION: Patients with LCPV had significantly reduced AF-free survival after ablation with the second-generation cryoballoon, despite similar acutely successful PVIs.

Laboratory markers of cardiac and metabolic complications after generalized tonic-clonic seizures.

BACKGROUND: Generalized tonic-clonic seizures (GTCS) frequently lead to emergency inpatient referrals. Laboratory blood values are routinely performed on admission to detect underlying causes and metabolic or cardiac complications. Our goal was to assess the nature and frequency of complications occurring in association with GTCS. METHODS: We retrospectively extracted data from emergency protocols and discharge letters of adult patients admitted to the Department of Epileptology between 01/2010 and 06/2015. Inclusion criteria were diagnosis of GTCS and admission via emergency services. Exclusion criteria were status epilepticus prior to admission to hospital and non-generalized seizures. RESULTS: A total of 223 patients (of 986 screened cases) were included. Overall, 1.8% required intubation while 1.3% had less severe respiratory problems. In 5.6% of patients, a transient hypoxemia was measured. Hypertensive urgencies affected 7.8% of the patients, sinus tachycardia occurred in 41.2%. Troponin I (cTNI) was determined in 75 patients and was increased in 12% of these cases. Occurrence of elevated cTNI levels was significantly correlated with patient's age. Four patients were diagnosed with NSTEMI and one patient with STEMI. Creatine kinase (CK) was increased in 59.4% of the patients, with <5-fold increases in 47%, <10-fold in 5.8% and >10-fold increases in 4.3%. Rhabdomyolysis with an >50 fold increase in CK was detected in 1.9% of patients. Prolonged disturbances of consciousness affected 5% of cases while agitation, delirium, and psychotic episodes occurred in 6.3%. Minor traumatic injuries affected 45.7% of patients. CONCLUSIONS: Troponin elevations in association with GTCS are one of the more common complications after emergency admissions especially in older patients. In our selected patient population, serious complications such as intracranial hemorrhage, myocardial infarction and acute renal failure occurred in <1% of GTCS only.

Aging-related mitochondrial dysfunction facilitates the occurrence of serious arrhythmia after myocardial infarction.

BACKGROUND: During aging a mosaic of normal cells and cells with mitochondrial deficiency develops in various tissues including the heart. Whether this contributes to higher susceptibility for arrhythmia following myocardial infarction (MI) is unknown. METHODS AND RESULTS: Myocardial cryoinfarction was performed in 12-month-old transgenic mice with accelerated accumulation of deletions in mitochondrial DNA. Occurrence and pathogenesis of arrhythmia was investigated after two weeks. Holter-ECG recordings revealed higher rates of premature ventricular complexes (incidence > 10/24 h: 100% vs. 20%; p = 0.048) and more severe spontaneous arrhythmia during stress test in mutant mice with MI as compared to control mice with MI. Mice with mitochondrial dysfunction exhibited longer spontaneous AV-blocks (467 ± 26 ms vs. 377 ± 24 ms; p = 0.013), an increased probability for induction of ventricular tachycardia during in vivo electrophysiological investigation (22% vs. 9%; p = 0.044), and a reduced conduction velocity in the infarct borderzone (38.5 ± 0.5 cm/s vs. 55.3 ± 0.9 cm/s; p = 0.001). Furthermore, mutant mice exhibited a significant reduction of the phospho-Cx43/Cx43 ratio in right (0.59 ± 0.04 vs. 0.85 ± 0.01; p = 0.027) and left ventricular myocardium (0.72 ± 0.01 vs. 0.86 ± 0.02; p = 0.023). CONCLUSIONS: Aging-related cardiac mosaic respiratory chain dysfunction facilitates the occurrence of spontaneous and inducible cardiac arrhythmia after myocardial infarction and is associated with slowing of electrical impulse propagation in the infarct borderzone.

Relaxin reduces susceptibility to post-infarct atrial fibrillation in mice due to anti-fibrotic and anti-inflammatory properties.

BACKGROUND: Relaxin-2 (RLX) is a peptide hormone that exerts beneficial anti-fibrotic and anti-inflammatory effects in diverse models of cardiovascular disease. The goal of this study was to determine the effects of RLX treatment on the susceptibility to atrial fibrillation (AF) after myocardial infarction (MI). METHODS: Mice with cryoinfarction of the left anterior ventricular wall were treated for two weeks with either RLX (75 µg/kg/d) or vehicle (sodium acetate) delivered via subcutaneously implanted osmotic minipumps. RESULTS: RLX treatment significantly attenuated the increase in AF-inducibility following cryoinfarction and reduced the mean duration of AF episodes. Furthermore, epicardial mapping of both atria revealed an increase in conduction velocity. In addition to an attenuation of atrial hypertrophy, chronic application of RLX reduced atrial fibrosis, which was linked to a significant reduction in atrial mRNA expression of connective tissue growth factor. Transcript levels of the pro-inflammatory cytokines interleukin-6 and interleukin-1ß were reduced in RLX treated mice, but macrophage infiltration into atrial myocardium was similar in the vehicle and RLX treated groups. CONCLUSION: Treatment with RLX in mice after MI reduces susceptibility to AF due to anti-inflammatory and anti-fibrotic properties. Because to these favorable actions, RLX may become a new therapeutic option in the treatment of AF, even when complicating MI.

A real world wearable cardioverter defibrillator experience - Very high appropriate shock rate in ischemic cardiomyopathy patients at a European single-center.

BACKGROUND: The wearable cardioverter defibrillator (WCD) has emerged as a valuable tool to protect patients with increased risk of sudden cardiac death (SCD). We sought to characterize WCD patients and to analyze predictors of ventricular arrhythmia (VA) occurrence and WCD shock delivery. METHODS AND RESULTS: One hundred fourteen patients with WCD use were included in the study. Indications were mainly ischemic cardiomyopathy (ICM; 31.6%), non-ICM (45.6%) and explantation of implantable cardioverter defibrillator due to device infection (11.4%). We observed sustained VA in 9.6% of the study population and 6.1% received an appropriate shock. VA occurred in 16.7% of ICM, 3.8% of non-ICM and 15.4% of patients with device infection. CONCLUSIONS: Our data demonstrate a very high rate of sustained VA in patients at risk for SCD during WCD use. ICM patients, including those with recent MI, bore the highest risk.

Risk for life-threatening arrhythmia in newly diagnosed peripartum cardiomyopathy with low ejection fraction: a German multi-centre analysis.

INTRODUCTION: Peripartum cardiomyopathy (PPCM) is a rare cardiomyopathy characterized by an acute reduction in left ventricular ejection fraction (LVEF). Sudden deaths during the course of PPCM are reported to be elevated, the underlying mechanisms remains unknown. The aim of the present multi-centre study was to evaluate the arrhythmia burden in a multi-centre approach in patients with PPCM using a wearable cardioverter/defibrillator (WCD). METHODS AND RESULTS: Forty-nine patients from 16 German centres with newly diagnosed PPCM and LVEF ≤35% receiving a WCD were included in this retrospective analysis. Mean follow-up was 15 ± 10 months. At diagnosis, mean age was 33 ± 5 years, parity was 2.1 ± 1.6, LVEF was 21 ± 7%, NYHA functional class was 3.4 ± 0.7. Mean wear time was 120 ± 106 days, mean wear time per day was 21.4 ± 3.3 h. Six (12%) patients presented eight ventricular tachyarrhythmias during WCD period: five episodes of VF, two sustained ventricular tachycardia (VT) and one non-sustained VT occurred. CONCLUSION: This multicentre study underpins the elevated risk for ventricular tachyarrhythmias in patients with newly diagnosed PPCM and reduced LVEF. A WCD should be considered for 3-6 months in these patients to prevent sudden cardiac death from ventricular tachyarrhythmias.

Laserballoon and Cryoballoon Pulmonary Vein Isolation in Persistent and Longstanding Persistent Atrial Fibrillation.

BACKGROUND: Visually guided laserballoon (LB) ablation has recently been introduced for pulmonary vein (PV) isolation (PVI). We analyzed efficacy and safety results of the newly introduced LB ablation technique in patients with persistent and longstanding persistent atrial fibrillation (AF), and compared this with an established standard method using the cryoballoon (CB). METHODS: A total of 35 patients with symptomatic persistent AF underwent LB ablation and were followed-up for 1 year. Results were compared to 35 patients who underwent CB ablation at the same institution and case matched for age, sex, CHA2 DS2 -VASc score, and left atrial volume. RESULTS: Complete isolation of all PVs was achieved in 68.6% in the LB and 97.1% in the CB group (P < 0.01). No significant differences were found for AF-free survival after 12 months in the complete cohort of all patients (LB: 53.3% vs CB: 70.4%; P = n.s.) and after excluding patients without complete PVI (LB: 57.8% vs CB: 72.5%; P = n.s.). LB ablation resulted in longer procedure (158.5 ± 37.9 minutes vs 110.9 ± 26.5 minutes; P < 0.01) and fluoroscopy durations (28.4 ± 11.1 minutes vs 23.5 ± 9.4 minutes; P = 0.04.), and a trend toward more major complications (14.3% vs 2.9%; P = n.s.). Procedure durations and complications declined over time and were level with CB-treated patients when reaching the last quartile of the LB patients. CONCLUSION: PVI in patients with persistent AF using the LB or the CB resulted in comparable success rates. Initial prolongations in procedure and safety parameters as a result of a learning curve effect for the LB have to be considered before starting to use this technique.

Anti-atherosclerotic effects of serelaxin in apolipoprotein E-deficient mice.

BACKGROUND AND AIMS: Serelaxin (SLX) is a recombinant form of human relaxin-2, a naturally occurring peptide that regulates maternal cardiovascular adaptations to pregnancy. It is unclear whether SLX has a therapeutic effect on atherosclerosis. Therefore, we investigated direct vascular effects of SLX in a mouse model of atherosclerosis. METHODS: 6-8 week-old female apolipoprotein E-deficient mice were fed a high-fat, cholesterol-rich diet for 6 weeks and additionally received a continuous treatment with vehicle or SLX (0.05 or 0.1 µg/h), during the last 4 weeks, via subcutaneously implanted osmotic mini-pumps. Vascular oxidative stress, vasorelaxation and atherosclerotic plaque development were assessed. RESULTS: Vascular oxidative stress was reduced in SLX-treated mice (vehicle: 322.67 RLU/s, SLX 0.05 µg/h: 119.76 RLU/s (p < 0.001 vs. vehicle), SLX 0.1 µg/h: 109.33 RLU/s (p < 0.001 vs. vehicle; p = 0.967 vs. 0.05 µg/h SLX)). Further SLX improved endothelium-dependent vasodilatation without influencing endothelium-independent vasorelaxation. Atherosclerotic plaque development was significantly reduced by SLX (vehicle: 0.38 ± 0.02 mm(2), 0.05 µg/h SLX: 0.32 ± 0.02 mm(2) (p = 0.047 vs. vehicle), 0.1 µg/h SLX: 0.29 ± 0.02 mm(2) (p = 0.002 vs. vehicle; p = 0.490 vs. 0.05 µg/h SLX)). Neither vascular macrophage, T-cell or neutrophil infiltration, nor collagen/vascular smooth muscle cell content differed between the groups. We observed a significant down-regulation of the angiotensin II type 1a receptor and a decrease in IL-6 and an increase in IL-10 plasma concentrations. CONCLUSIONS: Our data demonstrates novel pleiotropic effects of SLX on vascular oxidative stress, endothelial dysfunction and atherosclerotic plaque burden. Therefore, SLX could serve as a new drug for the treatment of atherosclerosis-related diseases.

Neutrophil-derived myeloperoxidase promotes atherogenesis and neointima formation in mice.

BACKGROUND: Myeloperoxidase (MPO), expressed mainly in neutrophils, is an enzyme linked to inflammation and oxidative stress. MPO is an independent prognostic marker in healthy individuals as well as in patients with coronary artery disease. In this present study we analyze the role of MPO in experimental atherogenesis and neointima formation after vascular injury in mice. METHODS AND RESULTS: 6-8 weeks old apolipoprotein E-deficient (ApoE(-/-)) mice were fed a high-cholesterol diet for 8 weeks with concomitant treatment with two different doses (10 µg/mg bw vs. 20 µg/mg bw) of 4-ABAH (MPO inhibitor). Application at lower dosage did not affect oxidative stress, endothelial function and atherosclerotic plaque development. 4-ABAH in higher dosage decreased inflammatory markers and vascular oxidative stress, consecutively improved endothelial function and reduced significantly atherosclerotic plaque development. To assess the role of circulating intracellular MPO, irradiated ApoE(-/-) mice were repopulated with bone marrow-derived cells from MPO(-/-) mice and were fed a high-cholesterol diet for 8 weeks. This MPO deficiency resulted in alleviated inflammation, reduced oxidative stress and improved endothelial function with a significant impact on plaque formation. To understand the possible role of MPO in vascular remodeling, we tested its effects on neointima formation following vascular injury in mice. MPO inhibition by 4-ABAH reduced significantly neointima formation. It was significantly reduced in MPO deficient mice, whereas transfer of spleen-derived neutrophils from WT mice enhanced it. CONCLUSION: Our data suggests a central role of MPO in the pathogenesis of atherogenesis and prefers pharmacological MPO inhibition as a therapeutic strategy for prevention and therapy of atherosclerosis and restenosis.

Usefulness of the wearable cardioverter defibrillator in patients in the early post-myocardial infarction phase with high risk of sudden cardiac death: A single-center European experience.

BACKGROUND: The effectiveness of the wearable cardioverter defibrillator (WCD) therapy in early post-myocardial infarction (MI) patients remains uncertain. METHODS: We analyzed the characteristics and outcomes of patients who received a WCD in the early post-MI phase. RESULTS: Twenty-four patients were followed-up for 8 months (range, 4-16 months). Two patients (8.3%) received appropriate shocks. Left ventricular ejection fraction improved after the WCD therapy (P<0.01). Fourteen patients (58%) received an implantable cardioverter defibrillator at the end of the follow-up period. CONCLUSION: Early post-MI patients at high risk of sudden cardiac death may benefit from WCD therapy.

Fluoroscopy of spontaneous breathing is more sensitive than phrenic nerve stimulation for detection of right phrenic nerve injury during cryoballoon ablation of atrial fibrillation.

INTRODUCTION: Right phrenic nerve palsy (PNP) is a typical complication of cryoballoon ablation of the right-sided pulmonary veins (PVs). Phrenic nerve function can be monitored by palpating the abdomen during phrenic nerve pacing from the superior vena cava (SVC pacing) or by fluoroscopy of spontaneous breathing. We sought to compare the sensitivity of these 2 techniques during cryoballoon ablation for detection of PNP. METHODS AND RESULTS: A total of 133 patients undergoing cryoballoon ablation were monitored with both SVC pacing and fluoroscopy of spontaneous breathing during ablation of the right superior PV. PNP occurred in 27/133 patients (20.0%). Most patients (89%) had spontaneous recovery of phrenic nerve function at the end of the procedure or on the following day. Three patients were discharged with persistent PNP. All PNP were detected first by fluoroscopic observation of diaphragm movement during spontaneous breathing, while diaphragm could still be stimulated by SVC pacing. In patients with no recovery until discharge, PNP occurred at a significantly earlier time (86 ± 34 seconds vs. 296 ± 159 seconds, P < 0.001). No recovery occurred in 2/4 patients who were ablated with a 23 mm cryoballoon as opposed to 1/23 patients with a 28 mm cryoballoon (P = 0.049). CONCLUSION: Fluoroscopic assessment of diaphragm movement during spontaneous breathing is more sensitive for detection PNP as compared to SVC pacing. PNP as assessed by fluoroscopy is frequent (20.0%) and carries a high rate of recovery (89%) until discharge. Early onset of PNP and use of 23 mm cryoballoon are associated with PNP persisting beyond hospital discharge.

Induction of atrial fibrillation by neutrophils critically depends on CD11b/CD18 integrins.

BACKGROUND: Recent observational clinical and ex-vivo studies suggest that inflammation and in particular leukocyte activation predisposes to atrial fibrillation (AF). However, whether local binding and extravasation of leukocytes into atrial myocardium is an essential prerequisite for the initiation and propagation of AF remains elusive. Here we investigated the role of atrial CD11b/CD18 mediated infiltration of polymorphonuclear neutrophils (PMN) for the susceptibility to AF. METHODS AND RESULTS: C57bl/6J wildtype (WT) and CD11b/CD18 knock-out (CD11b(-/-)) mice were treated for 14 days with subcutaneous infusion of angiotensin II (Ang II), a known stimulus for PMN activation. Atria of Ang II-treated WT mice were characterized by increased PMN infiltration assessed in immunohistochemically stained sections. In contrast, atrial sections of CD11b(-/-) mice lacked a significant increase in PMN infiltration upon Ang II infusion. PMN infiltration was accompanied by profoundly enhanced atrial fibrosis in Ang II treated WT as compared to CD11b(-/-) mice. Upon in-vivo electrophysiological investigation, Ang II treatment significantly elevated the susceptibility for AF in WT mice if compared to vehicle treated animals given an increased number and increased duration of AF episodes. In contrast, animals deficient of CD11b/CD18 were entirely protected from AF induction. Likewise, epicardial activation mapping revealed decreased electrical conduction velocity in atria of Ang II treated WT mice, which was preserved in CD11b(-/-) mice. In addition, atrial PMN infiltration was enhanced in atrial appendage sections of patients with persistent AF as compared to patients without AF. CONCLUSIONS: The current data critically link CD11b-integrin mediated atrial PMN infiltration to the formation of fibrosis, which promotes the initiation and propagation of AF. These findings not only reveal a mechanistic role of leukocytes in AF but also point towards a potential novel avenue of treatment in AF.

Left atrial pressure as predictor for recurrence of atrial fibrillation after pulmonary vein isolation.

PURPOSE: Identification of reliable risk factors for recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) has important implications. Left atrial (LA) pressure is a largely observator-independent parameter that can easily be determined after transseptal puncture. The purpose of this study was to investigate the predictive value of LA pressure for AF recurrence after PVI. METHODS: Two hundred five consecutive patients with paroxysmal or persistent AF scheduled for first PVI were included. Baseline clinical data were collected. During PVI, LA pressure was determined invasively after transseptal puncture. PVI was performed with radiofrequency or cryoenergy, and patients were followed for 25 ± 7 months. RESULTS: One hundred five (51 %) patients had AF recurrence. Patients with persistent AF prior to ablation had significantly more recurrences than patients with paroxysmal AF (70.1 vs. 42.0 %, p < 0.001). Mean LA pressure was significantly higher in patients with recurrence of AF (13.4 ± 7.1 vs. 11.0 ± 5.2 mmHg, p = 0.007), as was mean LA volume index (40.1 ± 18.5 vs. 33.0 ± 11.2 mL/m(2), p < 0.001). In the multivariate analysis, mean LA pressure was predictive in patients with normal or mildly enlarged LA, while AF type was not predictive. For each 1-mmHg increase in LA pressure, the risk of AF recurrence increased by 11 % in this subgroup. In patients with moderately or severely enlarged LA, AF type was predictive whereas LA pressure was not. CONCLUSION: LA pressure, AF type, and LA volume index are independent predictors for recurrence of AF after PVI. LA pressure may be helpful especially in patients with small atria, where AF type is not predictive.