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.

Comparison of 'anatomically designed' and 'point-by-point' catheter ablations for human atrial fibrillation in terms of procedure timing and costs in German hospitals.

AIMS: The purpose of the FAST-PVI study was to compare 'traditional' ablation tools based on 'point-by-point' technology with the new 'anatomically designed' technologies in terms of procedure times and related costs for the treatment of paroxysmal atrial fibrillation. METHODS AND RESULTS: Four hundred and fifty-two consecutive ablation procedures (222 'anatomically designed', 136 Arctic Front® and 86 PVAC®) and 230 'point-by-point' ablations (100 CARTO XP and 130 NavX navigation systems) performed by nine university centres across Germany from 2006 to 2010 were evaluated retrospectively. Staffing and resources times for each procedure were documented together with patient morbidities, complications, and pulmonary veins isolations. On the basis of DRG data from 2006 to 2010, human resources use and equipment maintenance costs were assigned to ablation procedure and calendar year. All procedural times were significantly higher in 'point-by-point' technologies compared with 'anatomically designed' ablations [average lab occupancy time 185.30 vs. 280.28 min; physician time 152.21 vs. 238.04 min; support time 183.43 vs. 278.34 min and fluoroscopy time 29.11 vs. 40.72 min; P < 0.001 (95% confidence interval, CI)]. For each ablation procedure human resource use per operating minute resulted in lower costs for 'anatomically designed' ablations [€744.24 per patient; P < 0.001 (95% CI)]. Savings due to reduced duration in 'anatomically designed' technologies accrued to 20% lower human resource costs. Sensitivity analyses did not lead to any significant variations on the outcomes parameter cost per minute. CONCLUSION: FAST-PVI showed reductions in ablation procedural time may lead to increased hospital capacity and non-device-related cost-savings, while maintaining quality.

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.

Impact of pulmonary vein isolation on obstructive sleep apnea in patients with atrial fibrillation.

BACKGROUND: Obstructive sleep apnea (OSA) has been identified as associated with the onset and propagation of atrial fibrillation (AF) and predicts recurrences of AF after pulmonary vein isolation (PVI). Vice versa, it has never been investigated whether PVI influences OSA. However, it has been controversial whether a restored atrial function can affect the course of OSA. There-fore, we have assessed whether PVI procedure modulates the prevalence and severity of OSA. METHODS AND RESULTS: We included 23 individuals with AF that were assigned to undergo PVI into this study. Patients were 65 ± 7 years old, obese (BMI 29.9 ± 5.4 kg/m²), white (100%) and had a normal left ventricular function (LVEF 64 ± 9%). Polygraphic assessment was carried out before and 6 months after PVI. The prevalence of OSA, defined as an apnea-hypopnea index (AHI) ≥ 5 per hour of sleep, was 74% before PVI compared to 70% 6 months after the procedure (p > 0.05). Severity of OSA did not differ (AHI before vs. after: 18 ± 18/h vs. 15 ± 17/h, p > 0.05) as well as further polygraphic parameters did not differ before and after the procedure. CONCLUSIONS: Prevalence and severity of OSA are not affected by PVI in patients suffering from AF.

The Connexin40A96S mutation from a patient with atrial fibrillation causes decreased atrial conduction velocities and sustained episodes of induced atrial fibrillation in mice.

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and a major cause of stroke. In the mammalian heart the gap junction proteins connexin40 (Cx40) and connexin43 (Cx43) are strongly expressed in the atrial myocardium mediating effective propagation of electrical impulses. Different heterozygous mutations in the coding region for Cx40 were identified in patients with AF. We have generated transgenic Cx40A96S mice harboring one of these mutations, the loss-of-function Cx40A96S mutation, as a model for atrial fibrillation. Cx40A96S mice were characterized by immunochemical and electrophysiological analyses. Significantly reduced atrial conduction velocities and strongly prolonged episodes of atrial fibrillation were found after induction in Cx40A96S mice. Analyses of the gating properties of Cx40A96S channels in cultured HeLa cells also revealed significantly lower junctional conductance and enhanced sensitivity voltage gating of Cx40A96S in comparison to Cx40 wild-type gap junctions. This is caused by reduced open probabilities of Cx40A96S gap junction channels, while single channel conductance remained the same. Similar to the corresponding patient, heterozygous Cx40A96S mice revealed normal expression levels and localization of the Cx40 protein. We conclude that heterozygous Cx40A96S mice exhibit prolonged episodes of induced atrial fibrillation and severely reduced atrial conduction velocities similar to the corresponding human patient.

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.

Differences in clinical and echocardiographic parameters between paroxysmal and persistent atrial flutter in the AURUM 8 study: targets for prevention of persistent arrhythmia?

PURPOSE: Cavotricuspid isthmus-dependent atrial flutter (AFL) can occur in a paroxysmal or persistent pattern. The aim of this study was to identify clinical, echocardiographic, and electrophysiological risk factors independently associated with persistence of AFL. METHODS: Patients of the recently published AURUM 8 study with paroxysmal versus persistent AFL were compared with respect to clinical and echocardiographic baseline characteristics as well as procedural parameters. The AURUM 8 study is a randomized, multicenter clinical trial comparing the efficacy and safety of gold versus platinum-iridium 8-mm-tip ablation. AFL was paroxysmal in 218 patients and persistent in 210 patients. RESULTS: Univariate analysis revealed that patients with persistent AFL had higher New York Heart Association class (P = 0.002), shorter time since 1st AFL episode (median 0.18 vs 0.34, P = 0.037), a higher prevalence of previous coronary artery bypass grafting surgery (17% vs 9%, P = 0.02), left ventricular hypertrophy (17% vs 8%, P = 0.005), dyspnea during AFL (P < 0.001), mitral regurgitation (P = 0.002), tricuspid regurgitation (P = 0.049), and pulmonary hypertension (P = 0.01). Palpitations during AFL were less frequent in patients with persistent AFL (P = 0.001). Multivariate analysis revealed that age, weight, AFL diagnosis after initiation of class IC or III antiarrhythmic drugs for atrial fibrillation, history of left ventricular hypertrophy, dyspnea during AFL and mitral regurgitation on echocardiography were significant independent variables associated with persistent AFL. A history of atrial fibrillation and palpitations during AFL were independently associated with paroxysmal AFL. CONCLUSIONS: We were able to identify clinical and echocardiographic risk factors associated with persistence of typical AFL. Treatment of these risk factors can potentially not only prevent the transition from paroxysmal to persistent AFL, but maybe also the development or initiation of AFL in general.

Total beta-adrenoceptor knockout slows conduction and reduces inducible arrhythmias in the mouse heart.

INTRODUCTION: Beta-adrenoceptors (ß-AR) play an important role in the neurohumoral regulation of cardiac function. Three ß-AR subtypes (ß(1), ß(2), ß(3)) have been described so far. Total deficiency of these adrenoceptors (TKO) results in cardiac hypotrophy and negative inotropy. TKO represents a unique mouse model mimicking total unselective medical ß-blocker therapy in men. Electrophysiological characteristics of TKO have not yet been investigated in an animal model. METHODS: In vivo electrophysiological studies using right heart catheterisation were performed in 10 TKO mice and 10 129SV wild type control mice (WT) at the age of 15 weeks. Standard surface ECG, intracardiac and electrophysiological parameters, and arrhythmia inducibility were analyzed. RESULTS: The surface ECG of TKO mice revealed a reduced heart rate (359.2±20.9 bpm vs. 461.1±33.3 bpm; p<0.001), prolonged P wave (17.5±3.0 ms vs. 15.1±1.2 ms; p = 0.019) and PQ time (40.8±2.4 ms vs. 37.3±3.0 ms; p = 0.013) compared to WT. Intracardiac ECG showed a significantly prolonged infra-Hisian conductance (HV-interval: 12.9±1.4 ms vs. 6.8±1.0 ms; p<0.001). Functional testing showed prolonged atrial and ventricular refractory periods in TKO (40.5±15.5 ms vs. 21.3±5.8 ms; p = 0.004; and 41.0±9.7 ms vs. 28.3±6.6 ms; p = 0.004, respectively). In TKO both the probability of induction of atrial fibrillation (12% vs. 24%; p<0.001) and of ventricular tachycardias (0% vs. 26%; p<0.001) were significantly reduced. CONCLUSION: TKO results in significant prolongations of cardiac conduction times and refractory periods. This was accompanied by a highly significant reduction of atrial and ventricular arrhythmias. Our finding confirms the importance of ß-AR in arrhythmogenesis and the potential role of unspecific beta-receptor-blockade as therapeutic target.

Cardiomyocyte-specific deletion of survivin causes global cardiac conduction defects.

Survivin (Surv) belongs to the inhibitor of apoptosis protein family. Its cardiac-specific deletion results in reduced cardiomyocyte number, increased cardiomyocyte size and ploidy, and development of heart failure. Its impact on cardiac electrophysiology is unknown. In vivo transvenous electrophysiological studies were carried out in adult male mice with a cardiac-specific deletion of survivin (Surv(-/-); n = 12) and wild-type controls (Surv(+/+); n = 12). Epicardial activation mapping (EAM) was performed in Langendorff-perfused hearts of 16 Surv(-/-) and 6 Surv(+/+) mice. Surface-ECG showed lower heart rates in Surv(-/-) mice (326 ± 66 bpm vs. 440.6 ± 39 ms; P = 0.0001), accompanied by significantly prolonged P waves (20.3 ± 5.8 vs. 14.6 ± 2.0 ms; P = 0.009), PQ-(47.4 ± 8.6 vs. 41.1 ± 3.7 ms; P = 0.043), QRS- (19.5 ± 4.8 vs. 14.0 ± 1.0 ms; P = 0.002) and QT-intervals (41.6 ± 4.4 vs. 36.2 ± 3.4 ms; P = 0.003). The HV-interval was prolonged in Surv(-/-) mice (12.1 ± 2.4 vs. 9.3 ± 1.4 ms; P = 0.0045). We found impaired sinus-nodal function (sinus node recovery times: 310.2 ± 76.6 vs. 207.8 ± 68.6 ms; P = 0.003) and AV-nodal conduction (Wenckebach-periodicity: 105.9 ± 15.9 vs. 79.6 ± 8.1 ms; P = 0.0002). EAM showed significant slowing and heterogeneity of conduction in the myocardium of Surv(-/-) mice. All Surv(-/-) mice showed spontaneous supraventricular and ventricular ectopic beats (P < 0.0001 vs. wildtype). Quantitative immunofluorescence staining for connexin43 (Cx43) revealed a decrease in both per cardiomyocyte and single gap junction. Surv(-/-) mice exhibit severe global conduction attenuations in atrial and ventricular myocardium as well as the specific conduction system, accompanied by lower connexin43 levels. Lack of susceptibility to AF and VT suggests that reduced cardiomyocyte number and increased size constitute determinants of electrical stableness in the heart and counteract potentially proarrhythmogenic connexin43 loss in Surv(-/-).

Left phrenic nerve injury during cryoballoon ablation of the left superior pulmonary vein.

Transcatheter ablation of the pulmonary veins (PVs) has been established as a therapeutic option for patients with symptomatic atrial fibrillation. Cryothermal energy is an alternative energy source that has been developed to overcome some of the disadvantages of radiofrequency ablation. The major complication of the cryoballoon technique seems to be right-sided phrenic nerve injury (PNI) following ablation of the right superior PV. This case report describes a left-sided PNI after cryoballoon ablation of the left superior PV.

Atrioesophageal fistula after cryoballoon pulmonary vein isolation.

The risk of atrioesophageal fistula after cryoballoon pulmonary vein isolation is thought to be much lower than after radiofrequency ablation, seeing that no data exist on this complication so far. We report for the first time on the occurrence of an atrioesophageal fistula 4 weeks after cryoballoon ablation at the site of the left inferior pulmonary vein. We suggest that even when using cryothermal ablation technique, an imaging modality to assess the proximity of esophagus and left atrium should be routinely performed to avoid this fatal complication.

Superiority of gold versus platinum irrigated tip catheter ablation of the pulmonary veins and the cavotricuspid isthmus: a randomized study comparing tip temperatures and cooling flow requirements.

INTRODUCTION: In order to optimize power delivery into the myocardium during radiofrequency ablation (RFA) without overheating the electrode tip, active cooling of the tip electrode as well as electrode tips made of gold have evolved. Recently, an externally irrigated gold tip electrode ablation catheter has been developed to combine the advantages of these 2 technologies. We sought to investigate the procedural parameters tip temperature, delivered power and cooling flow requirements of the irrigated gold tip catheter in comparison to the conventional irrigated platinum iridium (Pt) tip catheter in pulmonary vein isolation (PVI) and cavotricuspid isthmus (CTI) ablation. METHODS AND RESULTS: Sixty patients referred for first PVI were randomized into ablation with irrigated gold tip catheter versus irrigated Pt tip catheter. Forty-nine patients received ablation of CTI following PVI. Mean and standard deviation from all measurements were calculated for each patient. During RFA of pulmonary veins, mean catheter tip temperature was significantly lower in the gold group (35.4 ± 0.9 °C vs 38.2 ± 0.8 °C, P < 0.001), and total amount of delivered energy was higher (1303.1 ± 81.1 W vs 1223.7 ± 115.6 W, P = 0.004). During CTI ablation, necessary saline flow was almost 2.5-fold lower in the gold group (22.5 ± 5.9 mL/min vs 52.5 ± 9.7 mL/min, P < 0.001), accompanied by significantly lower tip temperature (39.1 ± 0.6 °C vs 40.5 ± 1.4 °C, P < 0.001). CONCLUSION: The irrigated gold tip electrode allows to deliver significantly more energy at a lower electrode tip temperature in RFA of PV and CTI in comparison to the irrigated Pt tip electrode. The required saline flow during CTI ablation is much lower than in Pt.

"Largest amplitude ablation" is the optimal approach for typical atrial flutter ablation: a subanalysis from the AURUM 8 study.

INTRODUCTION: The recently proposed "maximum voltage-guided" (MVG) technique for radiofrequency catheter ablation of atrial flutter targets high-voltage electrograms along cavotricuspid isthmus (CTI) to ablate the functionally important anatomic muscle bundles alone, without drawing a complete anatomic line across the CTI. This innovative approach may shorten ablation time and procedure duration. METHODS AND RESULTS: Within the multicenter AURUM 8 study, which compared 8-mm gold- and Pt-Ir-tip catheters in atrial flutter ablation, we made a post hoc comparison of procedural data from 72 patients treated with MVG technique with data from 281 patients undergoing anatomic CTI ablation (unmatched) and with data from 72 patients selected from among those 281 patients such that they were matched with the MVG group with respect to selected baseline parameters and catheter type (matched). The MVG technique markedly reduced (P < 0.001) ablation time (mean 6.9 minutes vs 10.9/9.7 minutes [unmatched/matched]), number of lesions (8.3 vs 13.7/12.9), fluoroscopy time (9.5 minutes vs 20.6/17.9 minutes), procedure duration (59 minutes vs 93/86 minutes), and energy delivered (19 kJ vs 34/30 kJ) compared with anatomic CTI ablation. The incidence of charring was higher for MVG than for anatomic ablation technique (31.9% vs 18.5/15.3%, P < 0.05), where Pt-Ir tip catheters were 6-fold more susceptible to charring than gold-tip catheters (P < 0.001), likely because of a lower thermal conductivity of the Pt-Ir material. The acute success rate was slightly better for MVG than for anatomic ablation technique (97.2% vs 92.2/91.7%, P = n.s.). CONCLUSION: Major procedural parameters are remarkably improved with MVG technique. Gold-tip catheters are substantially less susceptible to charring and may therefore be preferred over Pt-Ir-tip catheters for MVG ablation technique.

Left atrial deformation imaging with ultrasound based two-dimensional speckle-tracking predicts the rate of recurrence of paroxysmal and persistent atrial fibrillation after successful ablation procedures.

OBJECTIVE: Since predictors of recurrence of atrial fibrillation (AF) after ablation procedures are poorly defined, this prospective study was conducted to assess the value of left atrial (LA) deformation imaging with two-dimensional speckle-tracking (2D-ST) to predict AF recurrences after successful ablation procedures. METHODS AND RESULTS: One hundred and three consecutive patients (age 58.1 ± 16.6 years, 72.8% male) with AF (76 paroxysmal, 27 persistent) and 30 matched controls underwent transthoracic echocardiography and 2D-ST-LA-deformation analysis with assessment of LA-radial and LA-longitudinal strain (Sr, Sl), and velocities derived from the apical 4- and 2-chamber views (4CV, 2CV). AF recurrence was assessed during 6 months of follow-up. For determination of AF-related LA changes, AF patients were compared to controls and patients with AF recurrences after ablation procedures (n = 30, 29.1%) were compared with patients who maintained sinus rhythm (n = 73, 70.9%). Atrial deformation capabilities were significantly reduced (P < 0.0005) in patients with AF (4CVSl 17.8 ± 13.5%; 4CVSr 22.3 ± 14.9%; 4CV-velocities 2.53 ± 0.97 seconds) when compared with controls (4CVSl 31.3 ± 12.4%; 4CVSr 30.3 ± 9.1%; 4CV-velocities 3.48 ± 1.01 cm/s). Independent predictors for AF recurrence after ablation procedures were 2CV-LA-global-strain (Sr, P = 0.03; Sl, P = 0.003), 4CV-LA-gobal-strain (Sr, P = 0.03; Sl, P = 0.02), and regional LA-septal wall-Sl (P = 0.008). LA-global-strain parameters were superior to regional LA function analysis for the prediction of AF recurrences, with cutoff values (cov), hazard ratios (HR), positive and negative predictive values (PPV, NPV) were: 4CVSl cov, 10.79% (HR 27.8, P < 0.0005; PPV 78.8%, NPV 93.9%), 4CVSr cov, -16.65% (HR 24.8, P < 0.0005; PPV 69.4%, NPV 96.6%), 2CVSl cov, 12.31% (HR 22.7, P < 0.0005; PPV 75.8%, NPV 95.3%), and 2CVSr cov, -14.9% (HR 12.9, P < 0.0005; PPV 64.3%, NPV 93.2%). CONCLUSION: Compared with controls, AF itself seems to decrease LA deformation capabilities. The assessment of global LA strain with 2D-ST identifies patients with high risk for AF recurrence after ablation procedures. This imaging technique may help to improve therapeutic guiding for patients with AF.

An impaired renal function: a predictor of ventricular arrhythmias and mortality in patients with nonischemic cardiomyopathy and heart failure.

BACKGROUND: This study investigated the overall mortality and the incidence of ventricular tachyarrhythmia (VT) in 99 patients with nonischemic cardiomyopathy (NICM) and with an implantable cardioverter defibrillator (ICD) suffering from heart failure. METHODS: We performed a stepwise regression model to identify independent risk factors for the occurrence of ventricular arrhythmias. Using a Cox regression model, independent risk factors for total mortality were evaluated and, subsequently, a Kaplan-Meier analysis was applied. The primary endpoint of this study was the identification of independent predictors of overall mortality and the incidence of malignant arrhythmias. RESULTS: One hundred twenty-five VT (≥310 ms), 51 fast VT (between 310 ms and 240 ms), and 48 episodes of ventricular fibrillation (≤240 ms) were documented in 32 patients. Independent predictors of arrhythmias detected and treated by the ICD included female gender (odds ratio [OR] 3.4), lack of statin therapy (OR 3.5), and increased serum creatinine (OR 3.7). The Kaplan-Meier analysis showed no difference in survival between participants with or without VT. Total mortality was predicted by increased age (OR 2.3) and an impaired renal function (OR 1.9), independently. CONCLUSIONS: In this cohort of NICM patients with heart failure, female gender, lack of statin therapy, and increased creatinine represented independent risk factors for the incidence of malignant arrhythmias. Furthermore, renal insufficiency and age favored total mortality. Considering these results, impaired renal function might represent a valuable noninvasive tool to identify NICM patients who, despite ICD implantation, have the highest risk of mortality and therefore require a particularly thorough follow-up.

Prevalence of asymptomatic upper extremity venous obstruction in 302 patients undergoing first implantation of cardioverter defibrillator.

BACKGROUND: Little is known about the prevalence of upper extremity vein obstruction or anomalies in patients before first implantation of implantable cardioverter defibrillator (ICD). It remains unclear in which patients contrast venography is warranted before implantation procedure. METHODS: Results of clinical data and contrast venography of 302 consecutive patients scheduled for first ICD implantation were analyzed. RESULTS: Prevalence of upper vein obstruction was 6.6% (20/302 patients) in a typical patient population undergoing first ICD implantation. Age, left ventricular ejection fraction, underlying heart disease, prior open-heart surgery, or cardiopulmonary resuscitation were not predictors of obstruction. Patients with previous cardiac pacemaker implantation had a higher rate of obstruction, though this was not statistically significant (20% vs 15.7%, P = 0.54). Persistent left vena cava was found in 0.7%. CONCLUSION: There is no clinical parameter sufficient enough to predict upper extremity venous obstruction. Contrast venography may be considered in patients with previous pacemaker placement but should not be a routine diagnostic tool in unselected patients prior to first ICD-implantation procedure.

Gold vs. platinum-iridium tip catheter for cavotricuspid isthmus ablation: the AURUM 8 study.

AIMS: Gold electrodes have the theoretical advantage of creating bigger lesions than platinum-iridium (Pt-Ir) electrodes. We performed a prospective randomized study to compare the clinical efficacy of standard 8 mm Pt-Ir tip catheter (control) and 8 mm gold-tip catheters in the ablation of the cavotricuspid isthmus (CTI)-dependent atrial flutter. METHODS AND RESULTS: A total of 463 patients undergoing CTI ablation in 19 clinical centres were randomized to receive the treatment by gold-tip or control catheter. The primary endpoint was cumulative radiofrequency (RF) application duration until achieving bidirectional CTI block. It did not differ significantly for the two catheters. The gold-tip catheter was, however, associated with a higher ablation success rate (94.3 vs. 89.0%, P = 0.042) and a substantially lower incidence of char and coagulum formation (4.8 vs. 37.9%, P < 0.001), which required exchange of 1 gold-tip (0.4%) and 10 control catheters (4.6%, P = 0.005). The gold-tip catheter delivered more mean power (52 ± 12 W) than the control catheter (48 ± 13 W, P < 0.001). Both mean and maximum temperatures measured by the thermocouple integrated in the catheter tip were statistically significantly lower in the gold (mean: 53.2 ± 4.7°C, max: 68.7 ± 6.6°C) than in the control catheter (54.3 ± 5.2 and 70.2 ± 7.0°C, respectively, P < 0.05). Fluoroscopy time, procedure duration, procedural-related complications, and arrhythmia recurrence during 6 months of follow-up did not differ between the two catheters. CONCLUSION: Owing to a higher primary ablation success rate and reduced incidence of char/coagulum formation, gold may be preferred over Pt-Ir as electrode material for 8 mm tip catheters for CTI ablation. ClinicalTrials.gov: NCT00326001 (http://clinicaltrials.gov/ct2/show/NCT00326001).

An impaired renal function and advanced heart failure represent independent predictors of the incidence of malignant ventricular arrhythmias in patients with an implantable cardioverter/defibrillator for primary prevention.

AIMS: Malignant ventricular arrhythmias and inappropriate therapies represent unsolved problems in patients with implantable cardioverter/defibrillator (ICD) for primary prevention. This study focuses on the incidence of such therapies and thereby seeks to identify new predictors of adverse events to enhance risk stratification. METHODS AND RESULTS: Ninety-four consecutive patients with mild-to-moderate heart failure (NYHA II-III) and depressed left ventricular function (≤35%) were followed for 34 ± 20 months. Two hundred and ninety-one malignant ventricular arrhythmias were documented in 51 patients (54%). Eighteen patients (19%) received inappropriate ICD therapies (e.g. atrial fibrillation, sinus tachycardia, etc.). Patients with malignant arrhythmia (1.34 ± 0.44 vs. 1.16 ± 0.4 mg/dL, P = 0.017) and patients suffering from inappropriate ICD therapies (1.54 ± 0.48 vs. 1.2 ± 0.38 mg/dL; P = 0.007) revealed a significantly worse renal function before ICD implantation than participants without any therapy. An increased serum creatinine at baseline (2 vs. 1 mg/dL; odds ratio (OR) 3.96; P = 0.02; 95% CI: 1.2-13.04) and NHYA class III compared with II (OR: 2.96; P = 0.02; 95% CI: 1.16-7.48) represent strong and independent predictors for the occurrence of ventricular arrhythmias. Moreover, an impaired renal function is identified as an independent risk factor for inappropriate therapies (OR: 5.6; P = 0.004; 95% CI: 1.72-18.22). CONCLUSION: An impaired renal function and advanced heart failure before ICD implantation for primary prevention are identified as independent predictors for the incidence of appropriate ICD interventions. With regard to current guidelines and economical aspects, patients suffering from an impaired renal function or advanced heart failure seem to benefit most from ICD therapy.

High prevalence of obstructive sleep apnea in patients with resistant paroxysmal atrial fibrillation after pulmonary vein isolation.

OBJECTIVES: To address the question whether obstructive sleep apnea (OSA) is associated with the recurrence of paroxysmal atrial fibrillation (AF) in patients treated with ≥2 pulmonary vein isolation procedures. PATIENTS AND METHODS: In this study, we included adults with therapy-resistant symptomatic paroxysmal AF, defined as AF recurring after ≥2 PV-isolation procedures (n = 23). For comparison, we selected another cohort of patients being successfully treated by one PV isolation without AF recurrence within 6 months (n = 23). PV isolation was performed by radiofrequency with an open irrigated tip catheter. Each of the 46 participants completed an overnight polygraphic study. The two groups were matched for age, gender, and ejection fraction. Patients were late middle-aged (65 ± 7 vs 63 ± 10 years, P = 0.23), white (100%), and overweight (BMI 27.3 ± 3.6 vs. 27.2 ± 4.6 kg/m(2), P = 0.97). RESULTS: The prevalence of sleep apnea, defined as an apnea-hypopnea index (AHI) of >5 per hour of sleep, was 87% in patients with therapy-resistant AF compared to 48% in the control cohort (P = 0.005). In addition, OSA was more severe in the resistant AF group indicated by a significantly higher AHI (27 ± 22 vs 12 ± 16, P = 0.01). CONCLUSION: The extraordinarily high prevalence of sleep apnea in patients with recurrent paroxysmal AF supports its presumable role in the pathogenesis of AF and demands further controlled prospective trials. Moreover, OSA should inherently be considered in patients with therapy-resistant AF.

Detailed electrical analysis of lead failures in a small-scaled right ventricular defibrillator lead: reality of Sprint Fidelis medical device recalls.

INTRODUCTION: This paper illustrates our experience with the Sprint Fidelis lead (SF, single coil model 6931). We investigated lead failure incidence, analysed for possible predictive factors and examined the efficacy of integrated early ICD warning systems. METHODS: We analysed 181 consecutive patients with SF (follow up: 406 +/- 250 days). Left ventricular ejection fraction, age, gender, follow up, ICD indication, type of device, duration of implantation, and target vein used for implantation were evaluated as potential predictive factors of lead failure. Additionally, the predictive value of recommended impedance alert adaptations, the potential effects of the sensing integrity counter (SIC), and of the new lead integrity alert (LIA)(R) were studied. RESULTS: Nine lead failures were identified. Lead failure occurred significantly more often in patients with single- and dual-chamber devices. None of the patients under cardiac resynchronisation therapy (CRT) had a lead failure (p=0.04). Seven failures (78%) became apparent through inappropriate shock interventions. Impedance alert adaptations did not prevent any inappropriate shock intervention, but the SIC and the activation of the LIA might have prevented inappropriate interventions. A fractured pace/sense ring conductor was identified as the most vulnerable part of the SF lead (in 7 failures, 78%). CONCLUSION: We verified an increased failure rate in patients with the SF lead. Only patients with CRT devices were free from lead failure, suggesting a correlation with increased physical activity. The impedance alert reprogramming did not predict any inadequate shock interventions but LIA may become a new valuable tool for the early detection of lead failure signs.