3D-speckle-tracking echocardiography correlates with cardiovascular magnetic resonance imaging diagnosis of acute myocarditis - An observational study.

Background: The diagnostic importance of three-dimensional (3D) speckle-tracking strain-imaging echocardiography in patients with acute myocarditis remains unclear. The aim of this study was to test the diagnostic performance of 3D-speckle-tracking echocardiography compared to CMR (cardiovascular magnetic resonance imaging) for the diagnosis of acute myocarditis. Methods and results: 45 patients with clinically suspected myocarditis were enrolled in our study (29% female, mean age: 43.9 ± 16.3 years, peak troponin I level: 1.38 ± 3.51 ng/ml). 3D full-volume echocardiographic images were obtained and offline 2D as well as 3D speckle-tracking analysis of regional and global LV deformation was performed. All patients received CMR scans and myocarditis was diagnosed in 29 subjects based on original Lake-Louise criteria. The 16 patients, in whom myocarditis was excluded by CMR, served as controls. Regional changes in myocardial texture (diagnosed by CMR) were significantly associated with regional impairment of circumferential, longitudinal, and radial strain, as well as regional 3D displacement and total 3D strain. Interestingly, the 2D and 3D global longitudinal strain (GLS) showed higher diagnostic performance than well-known parameters associated with myocarditis, such as LVEF (as obtained by echocardiography and CMR) and LVEDV (as obtained by CMR). Conclusions: In this study, we examined the use of 3D-speckle-tracking echocardiography in patients with acute myocarditis. Global longitudinal strain was significantly impaired in patients with acute myocarditis and correlated with CMR findings. Therefore, 3D echocardiography could become a useful diagnostic tool in the primary diagnosis of myocarditis.

Influence of smoking dosage and chronic obstructive lung disease on the incidence of appropriate therapies and mortality in patients with structural heart disease and an implantable cardioverter defibrillator.

BACKGROUND: Smoking is known as a relevant risk factor for severe cardiac morbidities and mortality. This study was initiated to explore the influence of smoking dosage and presence of chronic obstructive lung disease (COPD) on the incidence of appropriate implantable cardioverter defibrillator (ICD) interventions and on mortality. METHODS: Prior studies on patients equipped with an ICD suggested that nicotine consumption increases the risk of experiencing an appropriate ICD therapy. There is no substantial data regarding the influence of cigarette smoking dosage on overall mortality in such endangered patients. A total of 349 patients with structural heart disease, either coronary artery disease or nonischemic cardiomyopathy equipped with an ICD, were included. Every patient answered a questionnaire regarding his smoking status and performed a spirometry and body plethysmography. RESULTS: A total of 104 patients (30%) suffered from COPD. Fifty-eight patients (17%) were "current smokers," 196 patients (56%) were revealed as "former smokers," while 93 (27%) patients were registered as "never smokers." A total of 163 patients (47%) received at least one appropriate ICD intervention during follow-up (median 48 ± 8 months). Twenty-three patients died during this study (6.6%). There was no association of COPD with the incidence of appropriate ICD therapies or mortality. Smoking dosage revealed as a significant risk factor for both appropriate ICD interventions (hazard ratio [HR] 1.5 for 60 pack years [PY] P = 0.04) and mortality (HR 2.3 for 60 PY P = 0.02). CONCLUSION: This study demonstrates a dose-related increased risk of smokers for appropriate ICD interventions and mortality. The results of this trail urge a strict nicotine abstinence, especially in patients with a structural heart disease undergoing ICD 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.

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.

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.

Usefulness of sleep-disordered breathing to predict occurrence of appropriate and inappropriate implantable-cardioverter defibrillator therapy in patients with implantable cardioverter-defibrillator for primary prevention of sudden cardiac death.

Advanced heart failure (HF) is associated with severe sleep-disordered breathing (SDB). In addition, most patients with HF are treated with an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death. The incidence of ICD therapy in such a patient cohort with SDB has never been investigated. The present study sought to determine the effect of SDB on the incidence of appropriate and inappropriate ICD therapy in patients with a categorical primary prevention ICD indication. A total of 133 consecutive ICD patients with New York Heart Association class II-III HF and depressed left ventricular function (≤35%) with no history of ventricular arrhythmia underwent a sleep study before ICD implantation and were followed for 24 ± 8 months, prospectively. A relevant SDB was defined as an apnea-hypopnea index of ≥10 events/hour. Of these 133 patients, 82 (62%) had SDB. Overweight (body mass index >29.1 vs 24.7 kg/m(2); p <0.001) was identified as the only independent risk factor for SDB. Appropriate ICD therapy intervention was significantly greater among patients with SDB than among patients without SDB (54% vs 34%, p = 0.03). Inappropriate ICD therapy intervention was documented more often in patients with SDB (n = 24 [29%] vs 7 [14%]; p = 0.04). An apnea-hypopnea index >10 events/hour was an independent predictor of appropriate ICD therapy on multivariate analysis (odds ratio 2.5, 95% confidence interval 1.8 to 4.04; p = 0.01). In conclusion, the present study is the first trial exploring the effect of SDB on the incidence of appropriate and inappropriate ICD therapy in patients with HF with a primary prevention indication. These results indicate that a preimplantation sleep study will identify patients with HF prone to receive appropriate and inappropriate ICD therapy.

Pulmonary arterial hypertension in patients with sarcoidosis: the Pulsar single center experience.

Sarcoidosis is a systemic granulomatous disease with unknown etiology. Lungs and lymph nodes are commonly affected. Also, cases of pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) are described. However, the exact prevalence of PAH in patients with sarcoidosis is unclear. A 111 patients with proven sarcoidosis were recruited from January 2010 to October 2010. All patients were studied prospectively by transthoracic echocardiography (TTE) for the presence of PH. In assumed PH, a right heart catheterization (RHC) followed if there were no other reasons for PH. In 23 of the 111 patients (21%) PH was assumed in TTE. Three patients presented with severe mitral insufficiency III° and IV°, in eight patients PH was supposed to be caused by chronic heart failure or relevant diastolic dysfunction > II°, two patients declined undergoing RHC. Of the ten patients investigated with RHC, four showed a precapillary pulmonary arterial hypertension and in one patient a postcapillary hypertension was diagnosed. All four patients with precapillary PH had a radiologic stage III and IV. In three of the four patients a significantly reduced transfer factor for carbon monoxide (TLCO) <50% was found. All patients with precapillary PH had a chronic course of sarcoidosis lasting ≥13 years. This is the first study which prospectively investigated a large cohort of patients with sarcoidosis for the prevalence of PH and PAH. The prevalence of precapillary PH was found to be at least 3.6% (4/111) and therefore exceeds the prevalence of PAH in the normal population by far. A chronic and progressive lung involvement due to sarcoidosis seems to be the most evident risk factor for developing a sarcoidosis PH.

Real-world data on the lifespan of implantable cardioverter-defibrillators depending on manufacturers and the amount of ventricular pacing.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) longevity is crucial for both patients and public health systems because it determines the number of surgical ICD replacements, which can generally be considered an additional risk factor for complications, and the cost-effectiveness of ICD therapy. Our objective was to obtain insight into the "real-world" longevities of implantable cardioverter-defibrillators, which quite often differ from those stated in the manufacturers' declarations. METHODS AND RESULTS: On the basis of a prospective database, we analyzed all ICD implantations performed in our hospital from June 1988 to June 2009. We studied 980 patients (follow-up 58 ± 51 months) with 1,502 ICDs and all respective data until August 2010. We compared the percentage of still operating ICDs at different points in time in relation to manufacturers, types of device (single chamber 623, dual chamber 588, cardiac resynchronization therapy ICDs [CRT-D] 291), and amount of right ventricular pacing (VP). We found distinct differences between the mean lifespans of ICDs of different manufacturers (Biotronik 4.3 years, Sorin 4.5 years, Guidant/Boston Scientific 4.7 years, St. Jude Medical 5 years, Medtronic 5.8 years). CRT-D devices (hazard ratio [HR] 1.778, P = 0.0005) were associated with an elevated annual relative risk for device replacement while a decrease in the proportion of VP (HR 0.934 for each 10% decrease in VP, P < 0.0001) and Medtronic ICDs were associated with a reduced risk of device replacement (HR 0.544, P < 0.0001). CONCLUSION: CRT-Ds and an elevated percentage of VP are associated with a significantly elevated risk for device replacement, while Medtronic ICDs showed the longest lifespans.

Kidney dysfunction and deterioration of ejection fraction pose independent risk factors for mortality in implantable cardioverter-defibrillator recipients for primary prevention.

BACKGROUND: A growing number of patients with advanced heart failure fulfill a primary-prevention indication for an implantable cardioverter-defibrillator (ICD). This study seeks to identify new predictors of overall mortality in a Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)-like collective to enhance risk stratification. HYPOTHESIS: An impaired renal function and severely depressed left ventricular ejection fraction pose relevant risk factors for mortality in primary prevention ICD recipients. METHODS: Ninety-four consecutive ICD patients with New York Heart Association class II-III heart failure and depressed left ventricular function (left ventricular ejection fraction [LVEF] ≤ 35%) with no history of malignant ventricular arrhythmias were followed for 34 ± 20 months. RESULTS: During this period, 30 patients died (32%). Deceased patients revealed a significantly worse renal function before ICD implantation (1.55 ± 0.7 mg/dL vs 1.1 ± 0.4 mg/dL; P = 0.007), suffered more often from coronary artery disease (53 vs 29; P = 0.006), and were older (69.5 ± 8 y vs 67 ± 12 y; P = 0.0002) than surviving patients. Furthermore, increased serum creatinine at baseline (2 mg/dL vs 1 mg/dL; odds ratio [OR]: 3.96, 95% confidence interval [CI]: 1.2-13.04, P = 0.02), presence of coronary artery disease (OR: 8.6, 95% CI: 1.1-65, P = 0.036), and low LVEF (OR per 5% baseline LVEF deterioration: 1.4, 95% CI: 1-1.8, P = 0.034) represented strong and independent predictors for overall mortality. CONCLUSIONS: Impaired renal function, the presence of coronary artery disease, and reduced LVEF before implantation represent independent predictors for mortality in a cohort of patients with advanced systolic heart failure. These conditions still bear a high mortality risk, even if ICD implantation effectively prevents sudden arrhythmic death. Indeed, in patients suffering from several of the identified "high-risk" comorbidities, primary-prevention ICD implantation might have a limited survival benefit. The possible adverse effects of these comorbidities should be openly discussed with the potential ICD recipient and his or her close relatives.

Independent predictors of mortality in patients with advanced heart failure treated by cardiac resynchronization therapy.

AIMS: The current study includes all consecutive patients with advanced heart failure and cardiac resynchronization therapy (CRT) with an implantable cardioverter defibrillator (ICD) over a 10-year period in a tertiary referral centre. It aims at identifying independent risk factors for mortality during CRT-defibrillator (CRT-D) treatment. METHODS AND RESULTS: This study includes 239 consecutive patients who had undergone implantation of a CRT-D system (ejection fraction 25.9 ± 8%; 139 patients with ischaemic, 100 patients with non-ischaemic cardiomyopathy). Enrolment took place between 2001 and 2010, resulting in a median follow-up of 43 ± 30 months. During follow-up, 59 patients (25%) died. An impaired baseline kidney function [hazard ratio (HR) 1.98; 95% confidence interval (CI) 1.7-3; P< 0.0001], appropriate ICD therapy during follow-up (HR 2.1; CI 1.1-3.4; P= 0.001), lack of beta-blocker therapy (HR 2.3; CI 1.6-3.8; P= 0.004), and intake of amiodarone (HR 2; CI 1.8-4.1; P< 0.0001) were identified as predictors of overall mortality. CONCLUSION: This study demonstrates the benefit of beta-blocker therapy also in patients on long-term CRT-D treatment. It confirms the prognostic significance of impaired renal function and the occurrence of appropriate ICD therapies also in CRT-D patients. It argues for an intensified follow-up regimen and adjustment of heart failure treatment whenever these prognostic markers are identified in a patient treated with CRT-D.

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.

Safety, feasibility, and diagnostic value of cardiac magnetic resonance imaging in patients with cardiac pacemakers and implantable cardioverters/defibrillators at 1.5 T.

BACKGROUND: Recent studies suggest that magnetic resonance (MR) imaging of the brain and spine may safely be performed in patients with pacemakers (PMs) and implantable cardioverter/defibrillators (ICDs), when taking adequate precautions. The aim of this study was to investigate safety, feasibility, and diagnostic value (DV) of MR imaging in cardiac applications (cardiac MR [CMR]) in patients with PMs and ICDs for the first time. METHODS: Thirty-two PM/ICD patients with a clinical need for CMR were examined. The specific absorption rate was limited to 1.5 W/kg. Devices were reprogrammed pre-CMR to minimize interference with the electromagnetic fields. Devices were interrogated pre-CMR and post-CMR and after 3 months. Troponin I levels were measured pre-CMR and post-CMR; image quality (IQ) and DV of CMR were assessed. RESULTS: All devices could be reprogrammed normally post-CMR. No significant changes of pacing capture threshold, lead impedance, and troponin I were observed. Image quality in patients with right-sided devices (RSD) was better compared with that in patients with left-sided devices (LSD) (P < .05), and less myocardial segments were affected by device-related artefacts (P < .05). Diagnostic value was rated as sufficiently high, allowing for diagnosis, or better in 12 (100%) of 12 patients with RSD, and only in 7 (35%) of 20 patients with LSD. CONCLUSIONS: Cardiac MR may be performed safely when limiting specific absorption rate, appropriately monitoring patients, and following device reprogramming. Cardiac MR delivers good IQ and DV in patients with RSD. Cardiac MR in patients with RSD may therefore be performed with an acceptable risk/benefit ratio, whereas the risk/benefit ratio is rather unfavorable in patients with LSD.

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.

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.

T-wave variability detects abnormalities in ventricular repolarization: a prospective study comparing healthy persons and Olympic athletes.

BACKGROUND: Sudden cardiac death in athletes is more common than in the general population. Routine screening procedures are performed to identify competitors at risk. A new Holter-based parameter analyzes variation of the ventricular repolarization (TVar). The aim of this study was to evaluate differences in electrocardiogram (ECG), Echo, and Holter (H) in competitive athletes compared to a healthy control group consisting of medical students (MS). METHODS: A total of 40 athletes (19 females, Olympic team, Luxembourg) and 40 MS (22 females) were examined by means of a resting ECG, treadmill exercise (TE), echocardiogram (Echo), as well as H recordings during a routine screening visit. To analyze TVar, a 20-minute H recording at rest (sampling rate 1000 per second) was performed. Moreover, heart rate variability (HRV) as well as HR turbulence (HRT) was computed. RESULTS: No differences in demographic variables were detected. Quantification of HRV detected a significant increase in the vagal component of autonomic cardiac modulation. In contrast, no differences for HRT were found. Echo parameter demonstrated a thicker septal wall without differences of the posterior wall. TVar values were normal in range, but did differ significantly between the two groups. No correlation between TVar and echo as well as Holter parameters was detected. CONCLUSIONS: TVar was able to demonstrate significant differences in terms of alterations of ventricular activation. This might indicate an early change of myocardial repolarization representing a substrate for life-threatening arrhythmia. Larger studies on the predictive value of TVar including follow-up are necessary to confirm this preliminary finding.

Evaluation of fractal-coated temporary pacing leads in the early postoperative course.

BACKGROUND: The performance of temporary pacing wires is still limited by capture and sensing problems. Fractal coating can enhance electrical properties and reliability. We therefore investigated fractal-laminated wires in comparison with conventional wires. METHODS: In 21 patients two unipolar, fractal-coated pacing wires (fe) and one conventional bipolar electrode (se) were implanted in ventricular position. Afterward pacing threshold (V), R-wave sensing (mV), lead impedance (ohm), and slew-rate (mV/s) were measured. Loss of capture or sensing and dislocation was documented. fe wires were examined with energy dispersive x-ray diffraction (EDX)-analysis and scanning electrode microscopy (SEM). RESULTS: Failure in pacing was less frequent in fe wires. Also fe leads had lower pacing thresholds at implantation (0.76 +/- 0.15 V vs 1.51 +/- 0.95 V, P< 0.0001) and afterward. Furthermore fe wires showed lower increase of pacing threshold/time (0.25 V/day vs 0.42 V/day). R-wave sensing and slew-rate values in the fe group on day of operation (5.81 +/- 4.80 mV; 0.63 +/- 0.71 V/s) were lower than in the se group (10.37 +/- 6.89 mV; 1.85 +/- 1.71 V/s P< 0.0001) and afterward. Nevertheless, decrease of amplitude/time was lower in fe wires (0.17mV/day vs 0.46 mV/day). fe wires always had lower impedance values. CONCLUSIONS: Lower pacing threshold and increase of threshold/time in fe wires indicate more reliable function. Initial lower sensitivity values are still not understandable and must be investigated. However, fe wires, constancy of sensing and impedance values was more stable, so fe epicardial wires can be recommended for safe and feasible use.