Adult ; Brugada Syndrome ; Defibrillators, Implantable ; adverse effects ; Electrocardiography ; Humans ; Male

PURPOSE: In some patients with an implantable cardioverter defibrillator (ICD), multiple episodes of electrical storm (ES) can occur. We assessed the prevalence, features, and predictors of ES in patients with ICD. MATERIALS AND METHODS: Eighty-five patients with an ICD were analyzed. ES was defined as the occurrence of two or more ventricular tachyarrhythmias within 24 hours. RESULTS: Twenty-six patients experienced at least one ES episode, and 16 patients experienced two or more ES episodes. The first ES occurred 209 +/- 277 days after ICD implantation. In most ES cases, the index arrhythmia was ventricular tachycardia (65%). There were no obvious etiologic factors at the onset of most ES episodes (57%). More patients with a structurally normal heart (p = 0.043) or ventricular fibrillation (VF) as the index arrhythmia (p = 0.017) were in the ES-free group. Kaplan-Meier estimates and a log-rank test showed that patients with nonischemic dilated cardiomyopathy (DCMP) (log-rank test, p = 0.016) or with left ventricular ejection fraction < 35% (p = 0.032) were more likely to experience ES, and that patients with VF (p = 0.047) were less affected by ES. Cox proportional hazard regression analysis showed that nonischemic DCMP correlated with a greater probability of ES (hazard ratio, 3.71; 95% confidence interval, 1.16-11.85; p = 0.027). CONCLUSION: ES is a common and recurrent event in patients with an ICD. Nonischemic DCMP is an independent predictor of ES. Patients with VF or with a structurally normal heart are less likely to experience ES.
Adult ; Aged ; Defibrillators, Implantable/*adverse effects ; Female ; Humans ; Male ; Middle Aged ; Tachycardia, Ventricular/*diagnosis/etiology ; Ventricular Fibrillation/*diagnosis/etiology

BACKGROUNDImplantable cardioverter defibrillator (ICD) is the only effective therapy in patients with life threatening ventricular arrhythmias. Inappropriate detection and therapy by ICDs are the most common causes of side effects that affect the quality of life in ICD recipients. This study evaluated the incidence and causes of inappropriate detection and therapy by ICDs in patients in our hospital.

METHODSFrom January 2000 to December 2005, fifty patients who received ICD implantation for ventricular arrhythmias for prevention of sudden cardiac death were evaluated in this study. Each ICD was programmed using clinical arrhythmic and cardiac data of the patient before discharge. Patients were followed up by standard schedule after implantation and all data retrieved from each device were collected and saved for further analysis.

RESULTSNo arrhythmic event was detected in 12/50 (24%) patients during the period of follow-up. Among the remaining patients, 11 (22%) experienced inappropriate detections and therapies during follow-up in this study. ICD detected 383 ventricular tachyarrhythmia (VT) and 108 ventricular fibrillation (VF) episodes and delivered 678 therapies. In VT group, ICD delivered 413 antitachycardiac pacings (ATPs) and 118 shocks, among which 78 ATPs and 9 shocks were initiated by 55/383 (14.3%) inappropriate detections. In VF group ICD delivered 147 shocks, among which 56 shocks were initiated by 28/108 (26.9%) inappropriate detections. Overall, more than 50% of these episodes were caused by atrial fibrillation (AF) with rapid ventricular response, followed by electromagnetic or myopotential interference. In addition, most inappropriate therapies occurred within one year after ICD implantation.

CONCLUSIONSAbout one fifth of patients experienced ICD inappropriate detection and therapy after implantation. The main cause was AF with rapid ventricular response, followed by electromagnetic or myopotential interference.

Adult ; Aged ; Defibrillators, Implantable ; adverse effects ; Electrocardiography ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Tachycardia, Ventricular ; physiopathology ; therapy

Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complications subsequent to pacemaker implantation are demonstrated herein.
Aged ; Aged, 80 and over ; Cardiac Pacing, Artificial ; *Defibrillators, Implantable/adverse effects ; Female ; Humans ; Male ; Middle Aged ; *Pacemaker, Artificial/adverse effects ; *Radiography, Thoracic ; *Tomography, X-Ray Computed

OBJECTIVEWidely pacemaker/implantable cardioverter defibrillator (ICD) implantation is also related to an increasing need for transvenous lead extraction. Understanding the location and extent of pathological changes, including adhesions and fibrous tissue formation along the course of chronic pacemaker/ICD leads, are essential for operators performing lead extraction operations in order to reduce the potential life threatening complications.

METHODSThree parts are included in the research, pathological examination on 83 extracted pacemaker/ICD leads using excimer laser technique from March 2008 to March 2011, autopsy examination of one died patient during lead extraction for lead-related infective endocarditis, and anatomical analysis on pacemaker/ICD leads from 10 patients died of other non-cardiac causes.

RESULTSExtensive encapsulated fibrous tissue around the leads and extensive adhesion/fibrosis along the course of the leads from venous entry site to the lead/myocardial interface could be detected on transvenous pacemaker/ICD leads. Since the tissue at the junction between superior vena cava (SVC) and right atrium (RA) is very thin, free of pericardium, thus, this is a common place for extensive adhesion/fibrosis and myocardial perforation/tear during lead extraction, which accounted for one death during extraction in our cohort. Extensive adhesion and fibrosis were also observed at the tricuspid valve and subvalvular structures. Leads implanted to the right ventricular apex were close to the epicardial surface and prone to perforation through myocardium. It is common to observe thrombus on the leads or at the interface between leads and myocardial tissue, especially at right atrial appendage (RAA) at the site of lead insertion.

CONCLUSIONExtensive adhesions and fibrosis can be commonly seen along the course of pacemaker/ICD leads, and at SVC to RA junction, the tricuspid valve/subvalvular structures, and RA/RV lead interface. The tissue at SVC to RA junction is very thin, making it vulnerable for myocardial perforation/tear during lead extraction. Thrombus is commonly seen along the leads or at the lead-tissue interface.

Defibrillators, Implantable ; adverse effects ; Device Removal ; Fibrosis ; Heart Atria ; pathology ; Heart Ventricles ; pathology ; Humans ; Lasers, Excimer ; Myocardium ; pathology ; Pacemaker, Artificial ; adverse effects ; Thrombosis ; pathology ; Vena Cava, Superior ; pathology

BACKGROUNDThe conventional venous access for cardiovascular implantable electronic device (CIED) is the subclavian vein, which is often accompanied by high complication rate. The aim of this study was to assess the efficacy and safety of optimized axillary vein technique.

METHODSA total of 247 patients undergoing CIED implantation were included and assigned to the axillary vein group or the subclavian vein group randomly. Success rate of puncture and complications in the perioperative period and follow-ups were recorded.

RESULTSThe overall success rate (95.7% vs. 96.0%) and one-time success rate (68.4% vs. 66.1%) of punctures were similar between the two groups. In the subclavian vein group, pneumothorax occurred in three patients. The subclavian gaps of three patients were too tight to allow operation of the electrode lead. In contrast, there were no puncture-associated complications in the axillary vein group. In the patient follow-ups, two patients in the subclavian vein group had subclavian crush syndrome and both of them received lead replacement. The incidence of complications during the perioperative period and follow-ups of the axillary vein group and the subclavian vein group was 1.6% (2/125) and 8.2% (10/122), respectively (χ2 = 5.813, P = 0.016).

CONCLUSIONOptimized axillary vein technique may be superior to the conventional subclavian vein technique for CIED lead placement.

TRIAL REGISTRATIONwww.clinicaltrials.gov, NCT02358551; https://clinicaltrials.gov/ct2/show/NCT02358551?term=NCT02358551& rank=1.

Aged ; Axillary Vein ; Defibrillators, Implantable ; adverse effects ; Electrodes, Implanted ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Pacemaker, Artificial ; adverse effects ; Perioperative Care ; Pneumothorax ; diagnosis ; etiology ; Postoperative Complications ; Prosthesis Implantation ; adverse effects ; Subclavian Vein

BACKGROUNDAn implantable cardioverter-defibrillator (ICD) has been suggested for heart failure patients for primary prevention of sudden cardiac death. However, few data have been reported on the application of ICD as primary prevention of sudden cardiac death in China. We evaluated the value of primary prevention ICD therapy in Chinese patients with heart failure.

METHODSThirty-four patients at an average age of (60.2 +/- 13.7) years seen in Peking Union Medical College Hospital were treated with ICD implantation for primary prevention of sudden cardiac death from November 2005 to July 2009. Single-chamber ICDs were implanted in 16 (47.0%) cases, and dual-chamber or cardiac resynchronization therapy defibrillators in 18 (53.0%) cases. The patients had an average left ventricular ejection fraction of (26.9 +/- 5.5)% (11% to 35%), of which 18 (53.0%) patients had ischemic cardiomyopathy and 16 (47.0%) patients had non-ischemic cardiomyopathy. All patients were followed up at three months after the implantation and every six months thereafter or when prompted by an ICD event.

RESULTSThere were five (14.7%) deaths, including two of heart failure and three with a non-cardiac course, during an average follow-up of (15.0 +/- 11.9) months. Forty-one ICD therapy events were recorded, including 19 (46.3%) appropriate ICD therapies in six patients and 22 (53.7%) inappropriate ICD therapies in four patients with single chamber leads. Inappropriate ICD therapies were mainly due to supraventricular tachyarrhythmias, especially atrial fibrillation. Patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy did not differ in the incidence of either appropriate or inappropriate therapy.

CONCLUSIONSICD for primary prevention of sudden cardiac death in China prevents patients from arrhythmia death. Relatively high incidence of inappropriate therapies highlights the importance of an atrial lead.

Aged ; Death, Sudden, Cardiac ; prevention & control ; Defibrillators, Implantable ; adverse effects ; Female ; Heart Failure ; mortality ; therapy ; Humans ; Male ; Middle Aged ; Treatment Outcome

OBJECTIVETo evaluate the acute and long-term effects of catheter radiofrequency ablation for the treatment of ventricular arrhythmia storm (VAS) post implantable cardioverter-defibrillators (ICD) implantation.

METHODSAcute and long-term effects of catheter radiofrequency ablation for the treatment of VAS post ICD implantation were retrospectively assessed in 11 patients from September 2008 to August 2011.

RESULTSA total of 15 ablation procedures were performed in 11 patients. Six ablation procedures were performed through epicardial approach. In 9 patients, 20 types of ventricular tachycardia (VT) (including 20% hemodynamically unstable VT) were induced during the procedures [mean cycle length (384 ± 141) ms] and polymorphic ventricular tachycardia were induced in 7 patients. The average X-ray fluoroscopy time and procedural time were (26 ± 17) min and (189 ± 60) min, respectively. Complete success, partial success, and failure rates immediately post catheter radiofrequency ablation were 46.7% (7/15), 26.7% (4/15) and 26.7% (4/15), respectively. All patients are alive at follow-up[(2.45 ± 9.6) months after the last catheter ablation] and the complete success, partial success, and failure rates during follow-up were 72.7% (8/11), 9.1% (1/11) and 18.2% (2/11), respectively.

CONCLUSIONVAS can be effectively treated by catheter radiofrequency ablation in patients post ICD implantation.

Adult ; Aged ; Catheter Ablation ; Defibrillators, Implantable ; adverse effects ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Tachycardia, Ventricular ; etiology ; surgery ; Treatment Outcome

BACKGROUNDPrevious clinical studies have suggested that patients with congestive heart failure and intraventricular conduction delay could benefit from cardiac resynchronization therapy (CRT). Implantation of left ventricular lead is a complex procedure with some potential for complications. This study was conducted to analyse the complications of CRT in patients with congestive heart failure.

METHODSTotally 117 patients, 86 males and 31 females, mean age of 53 years, with congestive heart failure and intraventricular conduction delay were enrolled in this study. Venography was performed on all patients. Different types of coronary sinus leads were used to pace the left ventricle.

RESULTSLeft ventricular lead was attempted to implant through coronary sinus for all the 117 patients and was successfully implanted in 111 patients. The success rate was 94.9%. Main complications rate was 6.8%, including coronary sinus dissection in 4 patients, phrenic nerve stimulation required lead repositioning in 2 patients and lead dislodgement in 2 patients.

CONCLUSIONSIt is feasible and safe to pace left ventricle through coronary sinus. However, there are some procedural complications.

Angioplasty, Balloon, Coronary ; Cardiac Pacing, Artificial ; adverse effects ; Defibrillators, Implantable ; Female ; Heart Failure ; complications ; therapy ; Heart Ventricles ; Humans ; Male ; Middle Aged

OBJECTIVE: To evaluate the efficacy and safety of implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy-defibrillators (CRT-D) avoiding defibrillation threshold (DFT) testing when treating ventricular tachycardia (VT) or ventricular fibrillation (VF). METHODS: We analyzed a continuous database of the 21 patients who had avoided DFT during ICD implantation from Oct. 1999 to Aug. 2008. Follow-up data were completed and analyzed in the 21 patients with ICD implantation. RESULTS: ICDs were implanted successfully in 17 patients with VT or VF, and CRT-D were implanted successfully in 4 myocardiopathy patients with severe heart failure who avoided DFT during ICD or CRT-D implantation. Eight patients accepted DFT 1 week later, VT or VF was not induced in 3 patients (37.5%). During the mean follow-up of 1 approximately 7 (4.2+/-1.9) years, malignant ventricular arrythmia was recorded in 16 patients. Among them, 89 episodes were successfully terminated by defbrillation (100%), 120 VT events were terminated by the first run of antitachycardia pacing (51.1%) and 22 by low energy cardioversion (59.2%). All patients took antiarrhycardia drugs after ICD or CRT-D implantation. No patient died from malignant ventricular arrythmia during the follow-up. CONCLUSION No application of routine DFT may avoid complications associated with DFT during ICD or CRT-D implantation. ICD or CRT-D implantation may effectively treat fatal ventricular tachyarrhythmias and prevent sudden cardiac death.
Adolescent ; Adult ; Aged ; Arrhythmias, Cardiac ; therapy ; Defibrillators, Implantable ; adverse effects ; standards ; Electric Countershock ; adverse effects ; standards ; Equipment Safety ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Sensory Thresholds ; Unnecessary Procedures ; Ventricular Fibrillation ; etiology ; prevention & control ; Young Adult