ICD therapy in the elderly: a retrospective single-center analysis of mortality.

BACKGROUND: Current implantable cardioverter-defibrillator (ICD) guidelines do not impose age limitations for ICD implantation (IMPL) and generator exchange (GE); however, patients (pts) should be expected to survive for 1 year. With higher age, comorbidity and mortality due to non-sudden cardiac death increase. Thus, the benefit of ICD therapy in elderly pts remains unclear. Mortality after ICD IMPL or GE in pts ≥ 75 years was assessed. METHODS: Consecutive pts aged ≥ 75 years with ICD IMPL or GE at the University Hospital Cologne, Germany, between 01/2013 and 12/2017 were included in this retrospective analysis. RESULTS: Of 418 pts, 82 (20%) fulfilled the inclusion criteria; in 70 (55 = IMPL, 79%, 15 = GE, 21%) follow-up (FU) was available. The median FU was 3.1 years. During FU, 40 pts (57%) died (29/55 [53%] IMPL; 11/15 [73%] GE). Mean survival after surgery was 561 ± 462 days. The 1­year mortality rate was 19/70 (27%) overall, 9/52 (17%) in pts ≥ 75 and 10/18 (56%) in pts ≥ 80 years. Deceased pts were more likely to suffer from chronic renal failure (85% vs. 53%, p = 0.004) and peripheral artery disease (18% vs. 0%, p = 0.02). During FU, seven pts experienced ICD shocks (four appropriate, three inappropriate). In primary prevention (n = 35) mortality was 46% and four pts experienced ICD therapies (two adequate); in secondary prevention (n = 35) mortality was 69% (p = 0.053) with three ICD therapies (two adequate). CONCLUSION: Mortality in ICD pts aged ≥ 80 years was 56% at 1 and 72% at 2 years in this retrospective analysis. The decision to implant an ICD in elderly pts should be made carefully and individually.

Hydrochlorothiazide therapy: impact on early recurrence of atrial fibrillation after catheter ablation?

BACKGROUND: Hypokalemia has been linked to electrocardiogram changes and afterdepolarization-mediated arrhythmias. However, the association between hypokalemia and atrial fibrillation (AF) has not been well studied. Hydrochlorothiazide (HCT) diuretic therapy was shown to be associated with hypokalemia in multiple studies. We aimed to determine whether HCT therapy is associated with early recurrence of AF after radiofrequency (RF) catheter ablation during a 3-month follow-up. METHODS: We performed a retrospective registry analysis of our internal AF ablation registry, containing 807 consecutive patients that underwent RF ablation for symptomatic AF. Propensity score matching was used to match 156 patients on HCT therapy with 156 controls. Furthermore, we performed propensity score matching between the first and the fourth quartile of baseline serum potassium (K) concentrations in the initial population (N.=807). RESULTS: We observed a small but statistically significant difference in baseline mean potassium levels between the HCT group and the control group (4.03 mmol/L vs. 4.19 mmol/L respectively, P=0.001). There was no difference in short term recurrence of atrial fibrillation in the HCT group compared to the propensity score matched control group (41.0% [N.=64] vs. 45.5% [N.=71], P=0.424). In the comparison between the first and the fourth quartile of baseline serum potassium values, no difference in AF recurrence (38.2% [N.=63] vs. 37.0% [N.=61], P=0.820) during a 3-month follow-up after ablation was observed between both groups. CONCLUSIONS: Patients on HCT therapy showed no difference in short term recurrence of AF after ablation compared to propensity matched controls.

First transcatheter leadless pacemaker implantation in a pediatric patient with a genetic disease.

A pediatric patient suffering from Marden-Walker syndrome, a rare genetic disease, was referred to the authors' hospital for syncope due to bradycardia. Since this disease is associated with severe joint contractures, a transcatheter leadless pacing system (TPS) was chosen. Despite the small body size and complex anatomy, TPS implantation was feasible, demonstrating that it is a safe alternative in difficult venous access compared to a conventional pacemaker with increased risk of lead complications in these patients.

Porous tip contact force-sensing catheters for pulmonary vein isolation: performance in a clinical routine setting.

PURPOSE: In catheter ablation of atrial fibrillation (AF), contact force (CF)-sensing catheters with an irrigated tip are used to deliver radiofrequency (RF) energy to the tissue. The ThermoCool® Smarttouch™ Surroundflow catheter (STSF) integrates CF-sensing technology and a new porous tip for advanced external cooling. The aim was to evaluate the performance and safety of STSF in a clinical setting of pulmonary vein isolation (PVI) in comparison with standard contact force-sensing catheter (ST). METHODS: We assigned consecutive patients (n = 80, prospectively, open-label, non-randomized) with symptomatic AF to either PVI with STSF (n = 60) or ST (n = 20). RESULTS: Total ablation time to achieve PVI was significantly shorter in STSF compared to that in ST (STSF, 1556 ± 435 s vs. ST, 1922 ± 961 s; p = 0.045). Ablation time to achieve loss of pace capture of left pulmonary veins was shorter using STSF (left veins, 155 ± 140 s vs. 291 ± 188 s; p = 0.01; right veins, 208 ± 196 s vs. 369 ± 306 s; p = 0.09). Furthermore, administered irrigation fluid was significantly reduced in STSF (241.4 ± 79.6 ml vs. 540.3 ± 229.5 ml; p < 0.01). CF was lower during ablation of left pulmonary veins. One steam pop occurred in STSF, which did not lead to pericardial effusion (vs. no steam pop in ST). The Kaplan-Meier estimate 12-month AF recurrence was 34.3% and 37.7% (p = 0.8). CONCLUSIONS: Integrating CF technology and the porous tip technology enables effective energy transfer to the tissue resulting in shorter ablation time and less irrigation fluid administration. In our cohort, PVI using the STSF was not associated with an increased complication rate or AF recurrence rate after 12-month follow-up when compared with the ST.

Pulmonary vein isolation in a patient with congenital pulmonary atresia: a case report.

BACKGROUND: Tetralogy of Fallot is a congenital heart defect characterized by pulmonary valve stenosis, ventricular septal defect (VSD), overriding aorta, and right ventricular hypertrophy. In its' extreme form, the pulmonary valve orifice does not develop during organogenesis, resulting in pulmonary atresia. We report a case of catheter ablation of symptomatic atrial fibrillation (AF) in a 37-year-old patient with congenital pulmonary atresia. CASE SUMMARY: The young man described paroxysmal tachycardia correlating to AF episodes in the previously implanted event recorder. Computed tomography scan described the complex anatomy with congenital pulmonary atresia, VSD, and major aortopulmonary collateral arteries. Electroanatomical mapping revealed typical pulmonary vein electrograms in a hypotrophic left atrium. Modified pulmonary vein isolation was successfully performed and non-excitability of the ablation line was reached. The patient recovered uneventfully and event recorder interrogation showed no AF recurrence after 3 months. DISCUSSION: Incidence of pulmonary atresia is low. Untreated survival rate is 50% after 1 year and 8% after 10 years. Tachycardia is a major cause of increased morbidity and mortality in patients with cyanotic congenital heart defects and pulmonary vein foci are described as driver for AF. Considerations preceding catheter ablation included pathophysiological mechanism, complex anatomy, atypical left atrium access, and reduced pulmonary perfusion resulting in a hypotrophic left atrium. Pulmonary veins showed typical electrograms, and isolation of pulmonary veins was feasible without adverse events.

Predictors of freedom from atrial arrhythmia recurrence after cryoballoon ablation for persistent atrial fibrillation: A multicenter study.

AIMS: We sought to assess (1) clinical outcomes of second-generation cryoballoon (CB) ablation for persistent atrial fibrillation (AF), and (2) the association of baseline and procedural covariates with atrial arrhythmia recurrence (AAR) after ablation. METHODS: A total of 135 patients (63 ± 11 years, 96 men [71%]) with persistent AF underwent CB ablation at three experienced electrophysiology centers. Freedom from AAR was estimated with the Kaplan-Meier method. A Cox proportional-hazards model was used to estimate the effects of baseline and procedural covariates on the likelihood of AAR. RESULTS: Freedom from AAR at 6, 12, and 18 months was estimated at 91% (95% confidence interval [CI] 86%-96%), 75% (95% CI, 67%-83%), and 53% (95% CI, 43%-65%), respectively. The presence of an implantable cardiac device (Hazard ratio [HR] 3.09; 95% CI, 1.37-7.00; P = .007), a left atrial (LA) diameter > 50 mm (HR 1.69; 95% CI, 1.02-2.79; P = .043), and absence of antiarrhythmic drug (AAD) therapy before the ablation procedure (HR 3.12; 95% CI, 1.72-5.64; P < .001) were associated with AAR. A trend toward an increased risk of AAR was revealed for women (HR 1.73; 95% CI, 0.96-3.11; P = .069). CONCLUSIONS: CB ablation for persistent AF resulted in freedom from AAR about that reported for RF ablation. The presence of an implantable cardiac device, LA size, and absence of AAD therapy at baseline were associated with the risk of AAR.

Incidence of myopotential induction in subcutaneous implantable cardioverter-defibrillator patients: Is the oversensing issue really solved?

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has established its role in the prevention of sudden cardiac death in a defined population. Inappropriate shocks and device malfunction in S-ICD therapy may be caused by myopotential (MP) oversensing. OBJECTIVE: The purpose of this study was to systematically evaluate a cohort of consecutive S-ICD patients for MP inducibility. METHODS: After S-ICD implantation, all vectors (primary [PrimV], secondary [SecV], alternative [AltV]) were analyzed during isometric chest press (ICP), lifting and holding a 20-kg weight, and side plank exercise (SPE), supporting the body weight on the left arm. When MPs were induced, signal classification was assessed: adequate noise detection, induced undersensing (R waves classified as noise), and oversensing (noise annotated as R waves). In case of noise induction in the current vector, device reprogramming to a noise-free vector was done. RESULTS: We systematically assessed 41 patients. In nearly all patients (90.2%), MPs were inducible. ICP was the most potent inductor of MPs. Whereas SecV (70.7%) and AltV (75.6%) were most vulnerable during ICP, PrimV was most affected during SPE (51.2%). In only a few cases did the S-ICD software distinguish correctly between MPs and QRS. MPs predominantly led to undersensing (up to 65.9%), but in up to 22% of patients MP-induced oversensing occurred but did not lead to tachycardia detection. No relation was seen between S-ICD lead and generator position and MP inducibility. CONCLUSION: Induction of MPs during physical exercise was observed frequently. Although in most cases MP noise led to undersensing, oversensing events were commonly observed.

The use of a high-resolution mapping system may facilitate standard clinical practice in VE and VT ablation.

BACKGROUND: First experiences using a 64-electrode mini-basket catheter (BC) paired with an automatic mapping system (Rhythmia™) for catheter ablation (CA) of ventricular ectopy (VE) and ventricular tachycardia (VT) have been reported. OBJECTIVES: We aimed to evaluate (1) differences in ventricular access for the BC and (2) benefit of this technology in the setting of standard clinical practice. METHODS: Patients (pts) undergoing CA for VE or VT using the Intellamap Orion™ paired with the Rhythmia™ automated-mapping system were included in this study. For LV access, transseptal and retrograde access were compared. RESULTS: All 32 pts (29 men, age 63 ± 15 years) underwent CA for VE (17 pts) or VT (15 pts). For mapping of VE originating from the left ventricle (LV) in 10 out of 13 pts, a transaortic access was feasible. The predominant access for CA of VT was transaortic (5/7). Feasibility and safety seem to be equal. The total procedure time was 179.1 ± 21.2 min for VE ablation and 212.0 ± 71.7 min for VT ablation (p = 0.177). For VE, an acquisition of 1602 ± 1672 map points and annotation of 140 ± 98 automated mapping points sufficed to abolish VE in all pts. During a 6-month follow-up (FU) after CA for VE, a VE burden reduction from 18.5 ± 2.1% to 2.8 ± 2.2% (p = 0.019) was achieved. In VT pts, one patient showed recurrence of sustained VT episodes during FU. CONCLUSION: Use of a high-resolution mapping system for VE/VT CA potentially facilitates revelation of VE origin and VT circuits in the setting of standard clinical practice. Feasibility and safety of a venous, transaortic, transseptal, or a combined approach seem to be equal.

Efficacy and safety of cryoballoon ablation in the elderly: A multicenter study.

BACKGROUND: The prevalence of atrial fibrillation (AF) increases with age. Second-generation cryoballoon (CB2)-based PVI has demonstrated encouraging clinical results in the treatment of paroxysmal (PAF) and persistent atrial fibrillation (PersAF). The objective of this study was to assess data on safety, efficacy and long-term clinical success of CB2-based pulmonary vein isolation (PVI) in patients ≥75 years of age. METHODS: CB2-based PVI was performed in 104 patients ≥75 years of age (elderly group) and symptomatic AF (PersAF: n = 44, 42.3%) in three highly experienced German EP centers. The data was compared to propensity score matched patients with age <75 years (n = 104, control group; PersAF: n = 45, 43.3%, p = 0.956). RESULTS: The median age of the elderly group was 77.5 [75, 80] years while it was 63 [52, 70] years of control group patients (p = 0.0001). The median procedure time was 92.5 [75, 120] minutes (elderly group) and 100 [75, 120] (control group), p = 0.124. Major complications were registered in 7/104 (6.7%) elderly patients and 7/104 (6.7%) control group patients (p = 0.999). Clinical success in terms of freedom from AF recurrence after one-year follow-up was 80% (95% CI: 72-88) and 82% (95% CI: 75-90) and after three-year follow-up 59% (95% CI: 47-74) and 49% (95% CI: 37 64) for the elderly group and the control group, respectively (p = 0.7). CONCLUSIONS: CB2-based PVI in patients ≥75 years of age appears safe, is associated with low procedure times and shows promising clinical success rates equal to patients of the younger population.

Effects of propofol sedation on pacing thresholds : Results from an observational cohort study.

BACKGROUND: Propofol is one of the most commonly used intravenous anaesthetic drugs for surgical procedures. The use of propofol for sedation is also common practice during endoscopic procedures, electrophysiology studies, and ablation procedures, as well as pacemaker and defibrillator implantation. It was found that propofol alters the electrophysiologic properties of the heart and its conduction system. The effects of propofol on pacing thresholds are unknown and could have implications for pacemaker (PM) and defibrillator (ICD) implantation procedures, as well as sedation and anaesthesia in PM and ICD patients in general. OBJECTIVES: We sought to investigate the effects of propofol sedation on atrial and right ventricular pacing thresholds in PM and ICD patients. MATERIALS AND METHODS: A total of 50 patients with PM, ICD, or cardiac resynchronization therapy (CRT) undergoing propofol sedation for electrophysiology (EP) investigation, transesophageal echocardiography (TEE), electrocardioversion (ECV), or bronchoscopy were included prospectively. Pacing thresholds, impedance, and sensing were assessed by device interrogation immediately prior to sedation and after the desired sedation depth was achieved by the administration of propofol. RESULTS: Mean atrial (0.68 V vs 0.77 V, p = 0.136) and mean right ventricular thresholds (0.90 V vs 0.93 V, p = 0.274) remained unchanged. Impedances and sensing remained unaffected in all patients. CONCLUSIONS: Propofol sedation did not affect pacing thresholds of atrial and right ventricular leads in this cohort of PM and ICD patients.

[3-D mapping of ventricular tachycardia in patients with dilative cardiomyopathy]. / 3-D-Mapping ventrikulärer Tachyarrhythmien bei dilatativer Kardiomyopathie.

Catheter ablation of ventricular tachycardia (VT) is gaining in importance. The current guidelines suggest considering catheter ablation for VT even in patients with a single sustained and documented episode. This is also underlined by recent data indicating that absence of VT predicts lower mortality and longer transplant-free survival. The majority of patients with VTs have a history of prior myocardial infarction; in a smaller proportion, patients present with dilated cardiomyopathy. The latter has a less structured scar pattern which makes it more complicated to apply efficient ablation strategies. Data have shown that the probability of VT recurrence after catheter ablation is higher and an epicardial access more frequently required. Algorithms and strategies to improve catheter ablation results have been developed and evaluated especially on patients with dilated cardiomyopathy (DCM) to further improve outcomes. The present article will strive to acquaint the reader with the current strategies and state of knowledge.

Intramyocardially Transplanted Neonatal Cardiomyocytes (NCMs) Show Structural and Electrophysiological Maturation and Integration and Dose-Dependently Stabilize Function of Infarcted Rat Hearts.

Cardiac cell replacement therapy is a promising therapy to improve cardiac function in heart failure. Persistence, structural and functional maturation, and integration of transplanted cardiomyocytes into recipients' hearts are crucial for a safe and efficient replacement of lost cells. We studied histology, electrophysiology, and quantity of intramyocardially transplanted rat neonatal cardiomyocytes (NCMs) and performed a detailed functional study with repeated invasive (pressure-volume catheter) and noninvasive (echocardiography) analyses of infarcted female rat hearts including pharmacological stress before and 3 weeks after intramyocardial injection of 5 × 106 (low NCM) or 25 × 106 (high NCM) syngeneic male NCMs or medium as placebo (Ctrl). Quantitative real-time polymerase chain reaction (PCR) for Y-chromosome confirmed a fivefold higher persisting male cell number in high NCM versus low NCM after 3 weeks. Sharp electrode measurements within viable slices of recipient hearts demonstrated that transplanted NCMs integrate into host myocardium and mature to an almost adult phenotype, which might be facilitated through gap junctions between host myocardium and transplanted NCMs as indicated by connexin43 in histology. Ejection fraction of recipient hearts was severely impaired after ligation of left anterior descending (LAD; pressure-volume catheter: 39.2 ± 3.6%, echocardiography: 39.9 ± 1.4%). Repeated analyses revealed a significant further decline within 3 weeks in Ctrl and a dose-dependent stabilization in cell-treated groups. Consistently, stabilized cardiac function/morphology in cell-treated groups was seen in stroke volume, cardiac output, ventricle length, and wall thickness. Our findings confirm that cardiac cell replacement is a promising therapy for ischemic heart disease since immature cardiomyocytes persist, integrate, and mature after intramyocardial transplantation, and they dose-dependently stabilize cardiac function after myocardial infarction.