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

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

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

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

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

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

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

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

Long QT syndrome (LQTs) is an uncommon genetic disease causing sudden cardiac death with Torsade de Pointes (TdP). The first line drug treatment has been known to be beta-blocker. We encountered a 15-year-old female student with LQTs who had prolonged QTc and multiple episodes of syncope or agonal respiration during sleep. Although her T wave morphology in surface electrocardiography resembled LQTs type 1, her clinical presentation was unusual. During the epinephrine test, TdP was aggravated during beta-blocker medication, but alleviated by sodium channel blocker (mexiletine). Therefore, she underwent implantable cardioverter defibrillator implantation.
Adolescent ; Adrenergic beta-Antagonists/*adverse effects/therapeutic use ; Defibrillators, Implantable ; Diagnosis, Differential ; Diagnostic Techniques, Cardiovascular ; Epinephrine/*diagnostic use ; Female ; Humans ; Long QT Syndrome/classification/*diagnosis/genetics/therapy ; Mexiletine/*therapeutic use ; Pedigree ; *Syncope

Limited data are available on inappropriate shocks in Korean patients implanted with an implantable cardioverter-defibrillator (ICD). We investigated the impact of inappropriate shocks on clinical outcomes. This retrospective, single-center study included 148 patients treated between October 1999 and June 2011. The primary outcome was a composite event of all-cause mortality or hospitalization for any cardiac reason. The median follow-up duration was 29 months (interquartile range: 8 to 53). One or more inappropriate shocks occurred in 34 (23.0%) patients. A history of atrial fibrillation was the only independent predictor of inappropriate shock (hazard ratio [HR]: 4.16, 95% confidence interval [CI]: 1.89-9.15, P < 0.001). Atrial fibrillation was the most common cause of inappropriate shock (67.7%), followed by supraventricular tachycardia (23.5%), and abnormal sensing (8.8%). A composite event of all-cause mortality or hospitalizations for any cardiac reason during follow-up was not significantly different between patients with or without inappropriate shock (inappropriate shock vs no inappropriate shock: 35.3% vs 35.4%, adjusted HR: 1.06, 95% CI: 0.49-2.29, P = 0.877). Inappropriate shocks do not affect clinical outcomes in patients implanted with an ICD, although the incidence of inappropriate shocks is high.
Adult ; Aged ; Atrial Fibrillation/complications ; Defibrillators, Implantable/*adverse effects ; Equipment Failure ; Female ; Hospitalization ; Humans ; Kaplan-Meier Estimate ; Male ; Middle Aged ; *Predictive Value of Tests ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Shock/*etiology/mortality ; Tachycardia, Supraventricular/complications