Dong-In Shin

Implantation and follow-up of totally subcutaneous versus conventional implantable cardioverter-defibrillators: A multicenter case-control study

BACKGROUNDnThe approval of an entirely subcutaneous implantable-cardioverter defibrillator (ICD) system (S-ICD) has raised attention about this promising technology. It was developed to overcome lead failure and infection problems of conventional transvenous ICD systems. Nevertheless, lead migration of the initial design and inappropriate shock rates have raised concerns regarding its reliability and safety.nnnOBJECTIVEnThe purpose of this study was to report the largest multicenter series to date of patients with the new device in comparison with a matched conventional transvenous ICD collective with focus on perioperative complications, conversion of induced ventricular fibrillation (VF), and short-term follow-up.nnnMETHODS/RESULTSnSixty-nine patients (50 male and 19 female; mean age 45.7 ± 15.7 years) received an S-ICD in three German centers and were randomly assigned to 69 sex- and age-matched conventional ICD patients. The indication was primary prevention in 41 patients (59.4%) without difference between groups (34 control patients; P = .268). The predominant underlying heart disease was ischemic cardiomyopathy in 11 (15.9%), dilated cardiomyopathy in 25 (36.2%), and hypertrophic cardiomyopathy in 10 (14.5%) in the S-ICD group. Mean implantation time was 70.8 ± 27.9 minutes (P = .398). Conversion rates of induced VF were 89.5% for 65 J (15-J safety margin) and 95.5% including reversed shock polarity (15-J safety margin) in the study group. Termination of induced VF was successful in 90.8% (10-J safety margin, device dependent) of the control patients (P = .815). Procedural complications were similar between the 2 groups. Mean follow-up was 217 ± 138 days. During follow-up, 3 patients with S-ICD were appropriately treated for ventricular arrhythmias. Three inappropriate episodes (5.2%) occurred in 3 S-ICD patients due to T-wave oversensing, whereas atrial fibrillation with rapid conduction was the predominant reason for inappropriate therapy in conventional devices (P = .745).nnnCONCLUSIONnThe novel S-ICD system can be implanted safely with similar perioperative adverse events compared with standard transvenous devices. Our case-control study demonstrates a 10.4% failure of conversion of induced VF with the S-ICD set to standard polarity and 15-J safety margin and comparable inappropriate shock rates during short-term follow-up.

Initial results of using a novel irrigated multielectrode mapping and ablation catheter for pulmonary vein isolation

BACKGROUNDnPulmonary vein isolation (PVI) as a cornerstone for catheter ablation of atrial fibrillation (AF) remains a complex and time-consuming procedure.nnnOBJECTIVEnTo assess feasibility, safety, and acute efficacy of a novel irrigated multielectrode ablation catheter guided by an electroanatomic mapping system for PVI in patients with paroxysmal AF.nnnMETHODSnTwenty-five consecutive patients (60 ± 10 years) with paroxysmal AF underwent PVI by using a novel decapolar mapping and ablation catheter (nMARQ catheter, Biosense Webster Inc, Diamond Bar, CA). Ablation was guided by electroanatomic mapping allowing radiofrequency (RF) energy delivery in the antral region of pulmonary veins (PVs) from 10 irrigated electrodes simultaneously. The day after ablation, cardiac magnetic resonance imaging was performed routinely in order to assess for potential acute PV stenosis.nnnRESULTSnOverall, 97 of 97 (100%) targeted PVs could be isolated with a mean of 27 ± 11 RF applications and a mean total burning time of 15 ± 6 minutes per patient. The total procedure time from femoral vein access to catheter withdrawal was 110 ± 31 minutes, including a mean total fluoroscopy time of 23 ± 9 minutes. On average, 6 ± 3 RF impulses with a maximum of 25 W were applied per vein. After a short learning curve, procedure, fluoroscopy, and total burning times decreased to 94 ± 16, 16 ± 3, and 9 ± 2 minutes, respectively (P < .05). Entrance and exit blocks could be verified by placing the ablation catheter into 90 of 97 (93%) PVs in 18 of 25 (72%) patients. No procedure-related complications were observed, especially no acute PV stenosis could be detected.nnnCONCLUSIONSnThe use of a novel irrigated multielectrode ablation system for PVI is feasible and safe, resulting in acute isolation of all targeted PVs with no complications and short procedure times. Sustainability of these initial results has to be confirmed in long-term efficacy and follow-up trials.

Left atrial appendage morphology is closely associated with specific echocardiographic flow pattern in patients with atrial fibrillation.

AIMSnTo assess the relation between left atrial appendage (LAA) morphology and echocardiographic flow pattern of the LAA by means of two- and three-dimensional transoesophageal echocardiography (3D-TEE).nnnMETHODS AND RESULTSnIn a total of 131 patients with atrial fibrillation, LAA morphology was analyzed by 3D-TEE and classified into four types (Chicken Wing, Windsock, Cactus, Cauliflower). Left atrial appendage flow pattern as maximal LAA emptying flow velocity and spontaneous echo contrast (SEC) were retrieved from 2D-TEE imaging in all patients. In patients with atrial fibrillation (AF), Chicken Wing morphology was associated with a higher LAA emptying flow velocity (difference of means = -11.7, 95% CI 4.6-19.3, P = 0.003) and a reduced prevalence of SEC (OR 3.2, 95% CI 1.1-9.3, P = 0.025) compared with all other LAA types (so-called Non-Chicken Wing LAA). These alterations were irrespective of the underlying type of AF.nnnCONCLUSIONnNon-Chicken Wing LAA morphologies are associated with a specific echocardiographic flow pattern in patients with AF. Since evidence exists that LAA flow pattern are indicative of an enhanced risk of thrombus formation, 3D-TEE might be a valuable tool warranting future studies to test whether these morphological and functional characteristics permit risk stratification in AF.

Neurofilament light chain as an early and sensitive predictor of long-term neurological outcome in patients after cardiac arrest

BACKGROUNDnNeurofilament light chain (NF-L) is the major intermediate filament specifically expressed in neurons and their axons. No data are available concerning serum levels of NF-L after global cerebral ischemia due to cardiac arrest. To find a specific neuronal marker of long-term neurological outcome, we examined serum levels of NF-L in patients after cardiac arrest.nnnMETHODSnA prospective observational cohort study was conducted. Blood samples for the measurement of NF-L were analyzed from 85 patients within 2h after admission, as well as on 2nd, 3rd, 5th, and 7th day. Neurological outcome was assessed 6 months after cardiac arrest by employing the Modified Glasgow Outcome Score (MGOS).nnnRESULTSnThe serum course of NF-L in patients with poor neurological outcome (MGOS 1+2) was significantly augmented compared to patients with good neurological outcome (MGOS 3+4+5) (on admission (pg/ml): good: 125 ± 11.7 vs. poor: 884.4 ± 86.2 pg/ml; 3rd day: good: 153.1 ± 13.2 vs. poor: 854.4 ± 119.1; 7th day: good: 112.5 ± 10.4 vs. poor: 1011.8 ± 100.8; P<0.001). Intermediate NF-L serum values were found in patients with MGOS 0, which represents a mixture of patients who died with and without certified brain damage (on admission (pg/dl): 433.7 ± 49.8; 3rd day: 598.3 ± 86.6; 7th day: 474 ± 77.4). A prediction power of 0.93 (c-statistic, 95%-CI 0.87-0.99) on 1st, 0.85 (0.81-0.95) on 2nd, 0.92 (0.85-0.99) on 3rd, 0.97 (0.92-1) on 5th and 0.99 (0.98-1) on 7th day was achieved for NF-L predicting poor neurological outcome.nnnCONCLUSIONSnThe present data suggest that within 7 days after cardiac arrest serum NF-L is a valuable marker of long-term neurological outcome.

Improvement of Left Ventricular Function under Cardiac Resynchronization Therapy Goes along with a Reduced Incidence of Ventricular Arrhythmia

Objectives The beneficial effects of cardiac resynchronization therapy (CRT) are thought to result from favorable left ventricular (LV) reverse remodeling, however CRT is only successful in about 70% of patients. Whether response to CRT is associated with a decrease in ventricular arrhythmias (VA) is still discussed controversially. Therefore, we investigated the incidence of VA in CRT responders in comparison with non-responders. Methods In this nonrandomized, two-center, observational study patients with moderate-to-severe heart failure, LV ejection fraction (LVEF) ≤35%, and QRS duration >120 ms undergoing CRT were included. After 6 months patients were classified as CRT responders or non-responders. Incidence of VA was compared between both groups by Kaplan-Meier analysis and Cox regression analysis. ROC analysis was performed to determine the aptitude of LVEF cut-off values to predict VA. Results In total 126 consecutive patients (64±11years; 67%male) were included, 74 were classified as responders and 52 as non-responders. While the mean LVEF at baseline was comparable in both groups (25±7% vs. 24±8%; Pu200a=u200a0.4583) only the responder group showed an improvement of LVEF (36±6% vs. 24±7; p<0.0001) under CRT. In total in 56 patients VA were observed during a mean follow-up of 28±14 months, with CRT responders experiencing fewer VA than non-responders (35% vs. 58%, p<0.0061). Secondary preventive CRT implantation was associated with a higher likelihood of VA. As determined by ROC analysis an increase of LVEF by >7% was found to be a predictor of a significantly lower incidence of VA (AUCu200a=u200a0.606). Conclusions Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.

Intermuscular technique for implantation of the subcutaneous implantable cardioverter defibrillator: long-term performance and complications

AimsnThe subcutaneous cardioverter defibrillator was designed to overcome electrode complications of transvenous defibrillation systems. While largely achieved, pocket complications have increased. Subcutaneous implantation of the pulse generator leaves it prone to erosion, extrusion, discomfort, and poor cosmesis.nnnMethods and resultsnWe use a demonstration electrode and pulse generator with fluoroscopy, prior to prepping and draping, to maximize the left ventricular mass between them. We adapted a submuscular abdominal ICD technique to implant the S-ICD intermuscularly between the anterior surface of serratus anterior and the posterior surface of latissimus dorsi. Surgery in our patients beyond the subcutaneous tissue was bloodless, as muscle layers were carefully separated but not incised, which also protected the long thoracic nerve. Two layers of muscle protect the pulse generator. We have implanted 82 consecutive patients with this technique, taking ∼65 min. All patients were converted with 65 J standard polarity shock during induced arrhythmia conversion testing, with six (7.3%) patients requiring a repositioning of the pulse generator prior to successful conversion. Seven spontaneous episodes of ventricular fibrillation were detected in three (3.6%) patients, all successfully converted back to sinus rhythm. Long-term patient outcomes have been good with low complication rates over the mean ± standard deviation 3.6 ± 1.2 years.nnnConclusionnOur intermuscular technique and implant methodology is successful for placement of the subcutaneous defibrillator pulse generator. Our technique leads to an excellent cosmetic result and high levels of patient satisfaction. Rates of first shock conversion during defibrillation testing, inappropriate shocks, and complications during follow-up compare favourably with previous published case series. There were no left arm movement limitations post-operatively.

Subcutaneous implantable cardioverter-defibrillators and sternal wires: a cautionary tale.

We commenced implanting the subcutaneous implantable cardioverter-defibrillators (S-ICD) in July 2010, and a surgeon (J.W.) has implanted 86 systems to date without surgical complications until this case study.nnThis patient was a man, aged 71 years, 1.68 m, 79 kg with left ventricular ejection fraction of 30% with previous myocardial infarctions, atrial fibrillation, mechanical aortic valve, and single coronary artery bypass graft via median sternotomy in 1999, renal insufficiency since 2003 with hemodialysis via a catheter in the right internal jugular vein, and bare metal stents in 2013. The patient fulfilled Multi center Automatic Defibrillator Implantation Trial (MADIT) II criteria for primary ICD implantation. Surgery under general anesthesia was uneventful. The S-ICD has 3 sensing vectors, described in Figure 1. The chosen sensing vector at implant was secondary with 1.8-mV amplitude after automatic assessment of QRS:T wave ratio. Ventricular fibrillation conversion …

Total atrial conduction time to predict occult atrial fibrillation after cryptogenic stroke

BackgroundInsertable cardiac monitor (ICM) increases the detection rate of occult atrial fibrillation (AF) after cryptogenic stroke. The aim of this study was to evaluate the prognostic significance of total atrial conduction time (TACT) assessed by tissue Doppler imaging (PA-TDI interval) to predict AF presence in patients with cryptogenic stroke.MethodsNinety patients (57.7xa0±xa012.3xa0years, 48xa0% women) after acute cryptogenic stroke and ICM implantation were prospective recruited at four centers for continuous rhythm monitoring. In all patients, TACT was measured by PA-TDI interval via echocardiography. Patients were followed up (331xa0±xa0186xa0days) for detection of AF (defined by episode lasting ≥30xa0s).ResultsAF was detected in 16 patients (18xa0%) during follow-up (331xa0±xa0186xa0days). The median period to AF detection was 30xa0days (q1–q3; 16–62xa0days). Patients who exhibited occult AF were characterized by significantly longer PA-TDI intervals (154.7xa0±xa012.6 vs. 133.9xa0±xa09.5xa0ms, pxa0<xa00.0001). The cut-off value of PA-TDI interval at 145xa0ms demonstrated sensitivity and specificity for AF detection of 93.8 and 90.5xa0%, respectively. In multivariate analysis, CHA2DS2–VASc score (HR 1.96 per 1 point, pxa0<xa00.01) and longer PA-TDI interval (HR 4.05 per 10xa0ms, pxa0<xa00.0001) were independent predictors of occult AF.ConclusionOur data suggest that measurement of TACT could help to predict future AF detection in patients with cryptogenic stroke. The clinical importance of prolonged rhythm monitoring or indication of direct anticoagulation therapy after cryptogenic stroke based on TACT should be further investigated.

Value of 3D TEE for LAA Morphology.

The left atrial appendage (LAA) is one of the major sites of cardiac thrombus formation. Recently, a large retrospective study found a relationship between specific types of LAA morphology and earlier thromboembolic events by means of computed tomography (CT) and cardiac magnetic resonance (CMR). In

AV-Knoten-Reentrytachykardie

ZusammenfassungDie AV-Knoten-Reentrytachykardie (AVNRT) ist eine der häufigsten supraventrikulären Herzrhythmusstörungen im klinischen Alltag. Diese ist u.xa0a. durch eine regelmäßige Herzfrequenz sowie ein On-off-Phänomen gekennzeichnet. Die Beschwerden reichen von Palpitationen und Angstgefühlen bis hin zur Polyurie und Dyspnoe. Typischerweise kann sie bei vielen Patienten durch vagale Manöver unterbrochen werden. Die Therapie der Wahl bei der symptomatischen AVNRT ist die Ablationsbehandlung. Dieser Artikel beschreibt die Charakteristik und Differentialdiagnose der AVNRT sowie die Technik der Ablationsbehandlung im EPU-Labor (elektrophysiologische Untersuchung). Er ist der zweite Teil einer Serie von Manuskripten, welche die Weiterbildung im Fachgebiet Rhythmologie erleichtern soll.AbstractThe AV nodal reentrant tachycardia (AVNRT) is one of the most common arrhythmias encountered in clinical practice. It is characterized by a constant heart rate and an on/off phenomenon. The clinical symptoms may include palpitations, anxiety, polyuria, and dyspnea. Typically, tachycardia may be disrupted by vagal maneuvers in many patients. First-line treatment of symptomatic AVNRT is radiofrequency ablation. The present article deals with the characteristics, differential diagnosis and treatment of AVNRT in the EP lab. It is the second part of a series of manuscripts which may facilitate further education in the specific field of electrophysiology.The AV nodal reentrant tachycardia (AVNRT) is one of the most common arrhythmias encountered in clinical practice. It is characterized by a constant heart rate and an on/off phenomenon. The clinical symptoms may include palpitations, anxiety, polyuria, and dyspnea. Typically, tachycardia may be disrupted by vagal maneuvers in many patients. First-line treatment of symptomatic AVNRT is radiofrequency ablation. The present article deals with the characteristics, differential diagnosis and treatment of AVNRT in the EP lab. It is the second part of a series of manuscripts which may facilitate further education in the specific field of electrophysiology.