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The article present a case study of 73-year-old woman with syncope due to 2/1 atrioventricular (AV) block, QT prolongation, and paroxysmal polymorphic ventricular tachycardia. It discusses that patient had a dual-chamber pacemaker with an Auto-PVARP algorithm, which failed to adapt to a rapid increase in sinus rhythm, leading to functional undersensing and 2/1 AV block; and also mentions about reprogramming the pacemaker or considering an implantable cardioverter-defibrillator (ICD).

The article presents a case study related to 65-year-old man with severe ischemic cardiomyopathy and narrow QRS underwent prophylactic single-chamber internal cardioverter-defibrillator implant with the VDD active-fixation single-coil dedicated bipolar ventricular lead in a right ventricular mid septal position. Topics icnlude the significant decrease in R-wave amplitude has noticed during a routine remote monitoring session, and the chest X-ray has excluded lead dislocation or damage.

A 76‐year‐old woman with permanent atrial fibrillation and a mechanical aortic valve came to our attention. Echocardiography showed a 50‐55% ejection fraction (EF) with good prosthesis performance. For symptomatic bradyarrhythmia, she received a VVI pacemaker (Proponent MRI L2010 model; Boston Scientific.). During follow‐up, frequent symptomatic (presyncopal) episodes of nonsustained episodes of ventricular tachycardia (VT) were detected. Amiodarone proved unsuccessful; she was then offered an upgrade to an implantable cardioverter defibrillator (ICD) and a subcutaneous ICD (S‐ICD) was chosen by the patient. A few weeks later, two sustained VT were detected and effectively treated with 80‐J shock delivery. In both cases, device interrogation revealed a VT rate around 163 bpm (370 ms cycle length), below the lowest device detection cutoff. The report is a case‐based review. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Infection remains a dreaded complication after cardiac implanted electronic device (CIED) placement. The prognostic value of the preoperative white blood cell (WBC) count, in the absence of other signs of infection, at time of CIED placement as a predictor of postoperative infection, has not been previously examined. Methods: The study population included 1,247 consecutive device implantations over a 4‐year period that met inclusion criteria. The association between preoperative WBC count and resultant infection postoperatively was examined. Early infection was defined as definite infection of the pocket or lead system or development of systemic infection identified <60 days after implantation. Preoperative WBC counts were obtained within 48 hours of the procedure. Results: Baseline characteristics of the population studied were mean age of 65 years, 66% men, and 72% Caucasian. Pacemakers, implantable cardioverter defibrillators (ICDs), and biventricular ICDs were implanted in 41%, 44%, and 15%, respectively. Average procedure time was 174 minutes ± 80. Of 1,247 device implantations, there were 10 infections (0.8%). Mean preprocedure WBC count in those diagnosed with infection was 8.1 × 103/uL (range 5–11.7) and in those without infection was 7.8 × 10^3/uL (range 2.3–29) (P = 0.73). Cases resulting in infection demonstrated minimal change in WBC count (mean +5.5 ± 26.5%). There was no statistically significant difference in preprocedure WBC count between the two groups (P = 0.7). Regardless of preprocedural WBC, no patients had other signs and symptoms of infection at time of device implantation. Conclusion: As an isolated finding, an elevated preprocedure WBC should not delay the implantation of an indicated device. [ABSTRACT FROM AUTHOR]

The article offers tips and considerations to ensure whether the implanted implantable cardioverter defibrillator capable of resynchronization therapy (ICD/CRT) functions normally. It discusses the medical case of a 52-year-old man with nonischemic cardiomyopathy, heart failure and left bundle branch block who received an ICD/CRT-D, with information on plugging lead connectors with connector cavity, active electrode poles, and prevention of lead connector switch.

Transvenous leads are a known source of iatrogenic tricuspid regurgitation. It is commonly held that extraction of chronic pacing and defibrillator leads will not reduce this, due to the inevitable trauma to the valve associated with the procedure. We demonstrate three cases of clinically significant reductions in tricuspid regurgitation after extraction of leads that were looped across the tricuspid valve. [ABSTRACT FROM AUTHOR]

A case study of a 71-year-old woman who underwent uncomplicated routine generator change and a history of myocardial infarction and ventricular tachycardia is presented. A high voltage (HV) lead integrity testing has been administered following the diagnosis of single out-of-range low-voltage shock coil read alert. The display of alerts on re-interrogation were found to be manifestations of pulse generator failure.

Background Recently, there has been an increasing number of internal medicine-trained electrophysiologists who choose not to test for acute defibrillation efficacy during implantable cardioverter defibrillator (ICD) implantation. It is not known whether this same trend is seen in pediatric electrophysiologists, who care primarily for patients with congenital heart disease or primary electrical problems. Methods Through a 14-question survey created on Survey Monkey, we asked the members of the Pediatric and Adult Congenital Electrophysiology Society (PACES) for their approach to ICD implantation. In particular, respondents were asked for their individual practice preferences on testing for acute defibrillation efficacy, including methods used for testing. Results There were 108 survey respondents. Thirty-nine percent test acute defibrillation efficacy at all implants, while 46% test in most patients, barring any clinical concerns. Another 14% routinely test during initial ICD system implants but not during generator changes with existing leads. Less than 1% of respondents do not routinely test acute defibrillation efficacy. Conclusions The practice preferences of pediatric electrophysiologists in evaluating for acute defibrillation efficacy during ICD implants are in contrast to the recent trend in their internal medicine-trained counterparts. More studies are needed to determine if practice changes should be considered in the pediatric and adult congenital patient population. [ABSTRACT FROM AUTHOR]

Background Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection. Methods We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA). Results Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%). Conclusions In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort. [ABSTRACT FROM AUTHOR]

Diaphragmatic myopotential oversensing (DMO) causes inhibition of pacing and inappropriate detection of ventricular fibrillation in implantable cardioverter defibrillators (ICDs). It occurs almost exclusively with integrated bipolar leads and is extremely rare with dedicated bipolar leads. If DMO cannot be corrected by reducing programmed sensitivity, ventricular lead revision is often required. The new Low Frequency Attenuation (LFA) filter in St. Jude Medical ICDs (St. Jude Medical, Sylmar, CA, USA) alters the sensing bandpass to reduce T-wave oversensing. This paper aims to present the LFA filter as a reversible cause of DMO. Unnecessary lead revision can be avoided by the simple programming solution of deactivating this LFA filter. [ABSTRACT FROM AUTHOR]

Background Interrogation/interpretation of cardiac implantable electronic devices (CIEDs) is frequently required in the emergency department (ED) or perioperative areas (OR) where resources to do this are often not available. CareLink Express (CLE; Medtronic, plc, Mounds View, MN, USA) is a technician-supported real-time remote interrogation system for Medtronic CIEDs. Using data from 136 US locations, this retrospective study was designed to assess CLE efficiency compared to traditional device management, and examine its findings. Methods All 7,044 US CLE transmissions from the ED and OR (January 2012-October 2014) were compared to 217 traditional requests where CIED interrogations/interpretations were performed by calling industry representatives to these sites. Results CLE reduced the time to device interrogation/interpretation by 78%: 100 ± 140-22 ± 14 minutes, P < 0.0001, improving response time and consistency; ED: 82 ± 103-23 ± 18 minutes, P, ≤ 0.01; OR: 127 ± 181-17 ± 10 minutes, P < 0.0001. Actionable events (AE) (arrhythmia, device/lead abnormalities) were infrequent: 9.1% overall (ED: 9.9%; OR: 4.1%). Only 6.5% of patients with syncope/presyncope and 13.6% with a perceived shock had AE. AEs were more common in those with suspected device problems (30.4%) or audible alerts (52.6%). They were more likely in patients not enrolled in long-term remote monitoring (23.9% vs 8.2%, P < 0.0001) and in those with older CIED systems (7.4% in year 1 vs 31.0% after 10 years). Conclusions The many patients with CIEDs, and the ability to quickly identify the minority with high-risk AE from the no/low-risk majority, strongly support CLE use in the ED and OR, sites which are expensive and prioritize efficiency. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 52-year-old man with myocardial infarction and severe ischemic cardiomyopathy w ho has received dual-chamber implantable cardioverter defibrillator (ICD) after resuscitated cardiac arrest from ventricular fibrillation (VF). The article discusses the T-wave oversensing (TWOS) which is the cause of inappropriate ICD therapies to patients with integrated tip-to-coil sensing.

Abstract: Background: Many patients with severe heart failure (HF) have an indication for baroreflex activation therapy (BAT) and an implantable cardioverter‐defibrillator (ICD). Concerns about device‐device interactions were addressed in a study with small sample size that concluded combined BAT and ICD therapy is safe. There are no published data, however, concerning device‐device interactions between BAT and a subcutaneous ICD (S‐ICD). Since BAT frequently interferes with surface electrocardiogram recordings, there are doubts about compatibility of BAT and S‐ICD devices. Case Description: A 54‐year‐old male patient with dilated cardiomyopathy and severely reduced left ventricular ejection fraction received an S‐ICD after recurrent systemic infections due to a diabetic foot syndrome, ultimately associated with infective endocarditis. Since medical HF therapy could not be further optimized and the patient presented with persistent cardiac decompensations, he was evaluated for BAT. Preoperatively, the barostim was epicutaneously placed on the patient's thorax with conductive gel in order to evaluate a possible interference with the S‐ICD. Positioning of the barostim in loco typico did not affect the S‐ICD's sensing in any vector. Only positioning of the carotis sinus lead directly upon the S‐ICD lead, which is beyond clinical relevance, lead to missensing. Subsequently, BAT was implanted with successful perioperative testing of the S‐ICD: there was accurate detection of ventricular fibrillation and immediate termination via first shock delivery under maximum barostim output. Conclusions: To our knowledge, there are no other reports in which a barostim was safely implanted in a patient with a preexisting S‐ICD. Until data with large patient numbers are available, individual perioperative testing is highly recommended. [ABSTRACT FROM AUTHOR]

Background Both implantable cardioverter defibrillators (ICDs) and left ventricular assist devices (LVADs) have a positive impact on survival in the heart failure population. We sought to determine whether these positive effects on survival are additive or whether LVAD therapy supersedes ICD therapy. Method We analyzed survival data of patients implanted with nonpulsatile LVADs between October 2004 and March 2013. Survival in patients with ICDs (n = 64) was compared to those without ICDs (n = 36). Patients exited the study at the time of heart transplantation or death. Results A total of 100 patients underwent LVAD implantation during this time. Patients had a mean follow-up time of 364 ± 295 days. Death occurred in 15 (38%) patients in the no ICD group versus 18 (30%) in the ICD group. Univariate analysis demonstrated a marginal early survival benefit at up to 1 year post-LVAD implant in the ICD cohort; however, at time points greater than 1 year there was no statistically significant benefit in ICD therapy in LVAD patients (P = 0.56). Multivariate analysis did not show any significant predictor of survival. There were no patients who died of sudden cardiac death. There was no significant difference in the time to heart transplantation (443 days ± 251 no ICD vs 372 days ± 277 ICD, P = 0.37). Conclusion The benefit of ICD therapy in the setting of continuous flow LVAD therapy is uncertain. Although prolonged ventricular arrhythmias (VAs) may potentially impact on patient survival, LVAD therapy is beneficial in prevention of sudden cardiac death due to VAs. [ABSTRACT FROM AUTHOR]

Background Management of patients treated with oral anticoagulation (OAC) requiring a cardiovascular implantable electronic device (CIED) surgery is a challenge that requires balancing the risk of bleeding complications with the risk of thromboembolic events. Recently the approach of performing these procedures while the patient remains with a therapeutic international normalized ratio has gained interest due to several publications showing its relative safety. Objectives To evaluate the safety and effectiveness of continuous use of OAC compared with heparin bridging in the perioperative setting of CIED surgery using a meta-analysis. Methods A systematic review of PubMed/MEDLINE, Ovid, and Elsevier databases was performed. Eligible randomized controlled trials and cohort studies were included. The outcomes studied were risk of clinically significant bleeding and of thromboembolic events. Our analysis was restricted to OAC with vitamin K antagonists. Results Of 560 manuscripts initially considered relevant, seven were included in the meta-analysis, totaling 2,191 patients. Data are reported as odds ratios (ORs) with confidence interval (CI) of 95%. Maintenance of OAC was associated with a significantly lower risk of postoperative bleeding compared with heparin bridge (OR = 0.25, 95% CI 0.17-0.36, P < 0.00001). There was no difference noted in the risk of thromboembolic events between the two strategies (OR = 1.86, 95% CI 0.29-12.17, P = 0.57). Conclusions Uninterrupted use of OAC in the perioperative of CIED surgery was associated with a reduced risk of bleeding. This strategy should be considered the preferred one in patients at moderate-to-high risk of thromboembolic events. [ABSTRACT FROM AUTHOR]

The article presents a case study of 31-year old women with a background of adult congenital heart disease suffering from staphylococcal septicemia and acute pulmonary valve stenosis. It notes that the heart rate of the patient was not normal even after cardiopulmonary resuscitation. The article discusses the diagnosis of tachycardia and the problems related to the use of subcutaneous implantable cardioverter defibrillator.

Background Insulation defects resulting in conductor externalization (CE) have been reported in the Riata family of implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA, USA). The aim of this study was to identify, prospectively, the rate of CE and outcomes following this, within a group of patients with a Riata ICD lead. Methods Patients with a Riata ICD lead attended for fluoroscopic screening and electrical assessment of the lead at yearly intervals between 2010 and 2012. Results One hundred and forty patients had no or borderline evidence of CE on initial assessment in 2010. These patients were prospectively followed for 3 years (304.6 patient-years). During this time, 11 patients developed definite CE, equating to an event rate of 3.6 (95% confidence intervals: 1.8-6.5) per 100 patient-years of follow-up. Of those patients developing definite CE, one patient had the ICD lead explanted (for reasons unrelated to CE) and no patients died. CE was not associated with any electrical abnormalities of the ICD lead. Conclusions CE was observed at a rate of 3.6 per 100 patient-years of follow-up, in 140 individuals with a Riata ICD lead and no definite evidence of CE at baseline. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 65 year old male patient with an implantable cardioverter defibrillator who presented to physicians with new onset episodes of pacemaker-mediated tachycardia (PMT) and automatic mode switching (AMS). A discussion of the factors which could have caused the patient's automatic mode switching and tachycardia is presented.

Background: There are insufficient data to guide perioperative implantable cardioverter-defibrillator (ICD) management for patients undergoing surgical procedures using electrocautery. Methods: We conducted a multicenter randomized controlled trial of patients with ICDs undergoing surgery with monopolar electrocautery. Subjects were randomized to an "Off" group (ICD therapy programmed off, then postoperatively programmed on) or a "Magnet" group (ICD therapy suspended with a magnet and no immediate postoperative ICD interrogation). Also, a registry was maintained of ICD patients with procedures within 6 inches of the ICD (all programmed off). The primary endpoint was ICD off time with secondary endpoints being caregiver handoffs and incidence of electromagnetic interference (EMI). Results: All patients (n= 80) had pectoral ICDs. Subject demographics were well matched in each group, and duration of electrocautery was similar (80 minutes vs 64 minutes, P = 0.58). The mean "excess" ICD off time (ICD off time - electrocautery time) was significantly higher in the Off group than the Magnet group (115 minutes vs 28 minutes, P < 0.001). Mean number of caregiver handoffs were higher in the Off group (6.6 vs 5.5, P < 0.001). There was no EMI in any lower abdominal or lower extremity procedures. Neither group had arrhythmic events or device reset. Conclusion: A magnet protocol simplifies perioperative ICD management for procedures using electrocautery more than 6 inches from the ICD. This protocol results in significantly shorter time with ICD therapy off, fewer provider handoffs, no risk of inadvertently discharging patients home with ICD therapies off, and no device reset. [ABSTRACT FROM AUTHOR]

Background Patients who develop a cardiovascular implantable electronic device (CIED) infection requiring extraction may have risk factors that make them prone to developing another infection of the reimplanted CIED. However, the rate of a second infection requiring repeat extraction in such patients is unknown and may have important clinical implications. Methods We retrospectively reviewed all patients at our institution from January 2001 to October 2012 who underwent a CIED extraction for an infection and then required reimplantation. We then reviewed the incidence of a repeat extraction due to a second infection. Clinical and device parameters at the time of the second infection were retrieved. Results There were 168 patients who underwent a CIED extraction because of infection and were subsequently reimplanted. The median time to reimplantation was 3 [1st quartile: 1, 3rd quartile: 10] days. After a mean follow-up of 4.4 ± 2.7 years, nine (5.4%) patients underwent a repeat CIED extraction due to a second infection. Six repeat extractions (67%) occurred in the first year, leading to an event rate of 3.9% within 1 year of reimplantation. Patients with a second infection requiring a repeat CIED extraction were younger (57 ± 20 vs 68 ± 16, P = 0.046). Pocket infection was the most common presentation of a second infection, occurring in eight of the nine patients. Conclusion The rate of a second infection leading to a CIED repeat extraction is elevated within the first year after reimplantation. To determine predictors of recurring infection, analysis of a larger multicenter series is warranted. [ABSTRACT FROM AUTHOR]

Background The complex relationship between heart failure and atrial tachyarrhythmias (AT/atrial fibrillation [AF]) is not well understood. We examined the temporal association between changes in intrathoracic impedance, suggesting thoracic fluid accumulation, and AT/AF occurrence in cardiac resynchronization therapy-defibrillator and implantable cardioverter defibrillator (ICD) patients. Methods A retrospective analysis was conducted on stored implantable device data to identify patients with automatic monitoring of daily AT/AF burden and intrathoracic impedance. Daily population trends in AT/AF burden before and after a fluid index threshold crossing (FIC) were determined. Results A total of 73,018 patients (68 ± 12 years, 51% ICD, 75% male) were evaluated over 18.6 ± 11.5 months. Kaplan-Meier analysis indicated a significantly higher probability of FIC events in the first month following the onset of persistent AT/AF when compared to a matched group without persistent AT/AF (hazard ratio [HR] 1.65, 95% confidence interval [CI] [1.58, 1.72], P < 0.001). Conversely, patients were significantly more likely to experience an episode of persistent AF in the first month after the FIC event (HR 1.32, 95% CI [1.08, 1.63], P = 0.008). The probability of a fluid index crossing within 30 days of the onset of persistent AT/AF was significantly lower in a subgroup of patients with adequate rate control (35.8% [34.3-37.4%] vs 42.0% [39.6-44.6%]; HR 1.24 [1.13-1.36]). Conclusion Thoracic fluid accumulation, as indicated by decreasing intrathoracic impedance, was more likely to occur immediately after the onset of persistent AT/AF, especially in the presence of inadequate rate control. Likewise, the onset of persistent AT/AF was more likely following a decrease in intrathoracic impedance. [ABSTRACT FROM AUTHOR]

Introduction Prior studies have suggested that pacemaker reuse may be a reasonable alternative to provide device therapy in the low- and middle-income countries. We studied explant indications and remaining battery life of cardiac implantable electronic devices (CIEDs) at a tertiary medical center. Methods and Results We conducted a retrospective review of all CIEDs extracted at the University of Michigan between 2007 and 2011. Devices were considered reusable if battery longevity was ≥48 months or >75% battery life was remaining; there was no evidence of electrical malfunction, and they were not under advisory or recall. Eight hundred and one CIEDs were explanted: Medtronic (MDT [Medtronic Inc., Minneapolis, MN, USA]; 454), Boston Scientific (BS [Boston Scientific Corp., Natick, MA, USA])/Guidant (GDT; 255 [Guidant Corp., St. Paul, MN, USA]), St. Jude Medical (SJM; 73 [St. Paul, MN, USA]), and Biotronik (BTK; 15 [Biotronik GmBH, Berlin, Germany]). After eliminating devices explanted for elective replacement indicator (ERI, 541), 51.9% of pacemakers (41/79), 54.2% of implantable cardioverter-defibrillators (ICDs) (64/118), and 47.6% of cardiac resynchronization therapy and defibrillation (CRT-D) devices (30/63) had sufficient battery life and no evidence of electrical malfunction to be considered for reuse. A logistic regression analysis found that the indications for device removal independently predicted reusability: upgrade to an ICD (odds ratio [OR] 162.8, P < 0.001) or CRT-D (OR 63.8, P < 0.001), infection (OR 110.7, P < 0.001), heart transplantation or left ventricular assist device placement (OR 56.6, P < 0.001), and device removal at patient's request (OR 115.4, P < 0.001). Conclusion The majority of explanted CIEDs for reasons other than ERI have an adequate battery life and, if proven safe, may conceivably be reutilized for basic pacing in underserved nations where access to this life-saving therapy is limited. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 67 year old man with a history of coronary artery disease, atrial fibrillation, left ventricular dysfunction, congestive heart failure, and a dual chamber implantable cardioverter defibrillator (ICD) who presented to physicians after receiving two ICD shocks. A discussion of tachycardia which was diagnosed in the patient, and of factors which could have led to the tachycardia, is presented.

Background Most patients with left ventricular assist devices (LVADs) have concomitant cardiovascular implantable electronic devices (CIEDs). However, clinical presentation and outcome of CIED infection in the setting of LVAD has not been previously described. Methods We retrospectively reviewed 247 patients who underwent LVAD implantation at Mayo Clinic campuses in Minnesota, Arizona, and Florida, from January 2005 to December 2011. Demographic and clinical data of patients who met criteria for CIED infection were extracted. Results Of 247 patients with LVADs, 215 (87%) had CIED at the time of LVAD implantation and six (2.8%) subsequently developed CIED infections. Three patients developed CIED lead-related endocarditis and the other three had pocket infection. All three instances of CIED pocket infection were preceded by device generator exchange, whereas all three patients with CIED lead-related endocarditis had prior LVAD-related infections. Causative pathogens included Pseudomonas aeruginos (1), coagulase-negative staphylococci (2), methicillin-resistant Staphylococcus aureus (1), a gram-positive bacillus (1), and culture negative (2). All patients underwent complete CIED removal along with antimicrobial therapy. The three patients with CIED lead-related endocarditis and prior LVAD infections received chronic suppressive antibiotic therapy, and one patient had LVAD exchange. All but one remained alive at the last follow-up with a median duration of 15 months (7-46 months) from the time of CIED infection. Conclusion Patients who are receiving LVAD therapy and develop CIED infection should be managed with complete CIED removal. Chronic suppressive antibiotic therapy is warranted in cases that have concomitant LVAD infection. [ABSTRACT FROM AUTHOR]

Objectives Pacemaker (PM) and implantable cardioverter defibrillator (ICD) leads become encapsulated intravascularly and in the generator pocket by fibrotic adhesions that accumulate over time. These adhesions are responsible for the difficulty and risk of lead extraction procedures. We developed a classification scheme for pocket adhesions, classified all of the patients in the cohort, and examined the relationship between pocket adhesions and the outcome of the procedure. Methods The classification of adhesions with respect to the intraoperative adhesion coverage was as followed: class 0 = adhesion free; class 1 ≤ 30% of adhesion coverage; class 2 = 30-60% of adhesion coverage; and class 3 ≥ 60% coverage. Patient data between December 2010 and March 2012 were collected. A total of 100 leads were extracted from 58 patients (1.7 ± 0.8 leads/patient); the mean lead implant duration was 78.5 ± 66.7 months, and the percentage of PM/ICD leads was 68% (n = 68)/32% (n = 32). Results Distribution of the leads among classes: 0 = 10; 1 = 17; 2 = 25; and 3 = 48. Average implant times (months) according to the adhesion classes: 0 = 1.2 ± 0.4; 1 = 19.8 ± 19.2; 2 = 79.3 ± 46.6; and 3 = 115.1 ± 106.0 (correlation-coefficient 0.71; P ≤ 0.05). Average numbers of extraction tools used according to the adhesions: 0 = none; 1 = 0.4 ± 0.7; 2 = 1.6 ± 1.0; and 3 = 2.3 ± 1.2 (correlation coefficient = 0.67; P ≤ 0.05). Complete removal was achieved in 100% of the patients in classes 0 and 1; 96% in class 2 (n = 24); and 75% in class 3 (n = 36) (P ≤ 0.05). Mortality = 0. Conclusions Extensive adhesions in the generator pocket predict the need for a higher number of extraction tools. High-grade pocket adhesions predict lower success rates with regard to complete lead extraction. Both findings suggest that the degree of pocket adhesions predicts the degree of intravascular adhesions. [ABSTRACT FROM AUTHOR]

Background The utility of cardiac device-based intrathoracic monitoring (OptiVol, Medtronic Inc., Minneapolis, MN, USA) for congestive heart failure (CHF) exacerbation has not been evaluated in pediatric or congenital heart disease patients. Methods This was a retrospective study of all patients at a single center with an endocardial OptiVol capable device. OptiVol index values were collected in 2-week bins from January 2007 to December 2010. The clinical outcomes were CHF exacerbation defined as hospitalization or medication change for CHF and device-treated ventricular arrhythmia based on remote or in-office device interrogation. Clinical and OptiVol data were collected by separate investigators blinded to the other parameter. OptiVol data were correlated to the clinical outcomes to determine sensitivity and predictability for multiple threshold values in the entire cohort and pediatric and congenital subgroups. Results Forty-seven patients were included. A total of 1,106 months of OptiVol data were collected. Median age of the cohort was 18 years (range 6-58 years). There were 23 pediatric, median age 13 years (range 6-16), at device implant, and 18 patients, median age 31 years (range 13-58), considered at risk for heart failure at implant. There were three heart failure exacerbations and 17 treated ventricular arrhythmias. The study population-specific positive predictive value (PPV) of OptiVol was low (sensitivity 33% and PPV ≤4.4%) for both CHF exacerbation and arrhythmias in all analyzed groups. Conclusions The sensitivity and positive predictive value of intrathoracic impedance monitoring was low in this population of adult congenital and pediatric patients. Recent improvements to the OptiVol algorithm may decrease these deficiencies. [ABSTRACT FROM AUTHOR]

Background The prevalence, predictors, and survival for the development of pacemaker dependence (PD) in patients implanted with an implantable cardioverter defibrillator (ICD) are unknown. Methods This was a retrospective analysis of 1,550 consecutive patients with ICD implantation at a single center from 1996 to 2008 with a mean of 4.2 ± 3.4 years. Patients with implant intrinsic heart rates less than 40 beats/min (n = 48) and cardiac resynchronization therapy (n = 444) were excluded leaving 1,058 patients in this study. PD was defined as an intrinsic rhythm <40 beats/min after inhibiting the pacemaker, <50 beats/min with transient symptoms of dizziness relieved by resumption of pacing and right ventricle pacing despite algorithms to promote intrinsic conduction at the 3 monthly follow-up ICD clinic visits. Multivariate regression and Cox proportional hazard models were used for analysis. Results The mean age was 64 ± 13 years; 79% were male with a primary indication for the ICD in 57%. PD occurred in 142 (13.4%) of patients, with a mean time to PD of 2.6 ± 1.9 years. PD was associated with a 48% increased odds for mortality versus non-PD ICD patients during the mean follow-up time of 4.2 ± 3.4 years (adjusted odds ratio = 1.48 [95% confidence interval 1.080-2.042]; P = 0.015). Older age, a history of atrial fibrillation, amiodarone use, and secondary prevention were the strongest predictors for the development of PD. Conclusions In this single-center ICD cohort, the development of PD was not uncommon and was associated with decreased survival. [ABSTRACT FROM AUTHOR]

Background Octogenarians (>80 years) have been underrepresented in clinical trials of cardiac resynchronization therapy (CRT). Objective To determine the benefit of CRT with or without a defibrillator in older elderly patients. Methods We retrospectively studied consecutive patients who received CRT at our institution from 2002 through 2008. New York Heart Association (NYHA) class and echocardiographic parameters were assessed before and after CRT. Thirty-day complications after device implant were collected. Survival data were obtained from the national death and location database. Data were compared between those 80 years and younger and those older than 80 years. Results Of 728 patients identified, 90 (12.4%) were older than 80 years. After CRT, older and younger patients had similar improvements in NHYA class (P = 0.41), ejection fraction (P = 0.48), and mitral valve regurgitation (MR) severity (P = 0.42). In the older patients, defibrillator implantation was associated with comparable improvement in NYHA class, ejection fraction, and MR grade severity (P > 0.05), as in those without a defibrillator. Overall survival was worse in octogenarians than in the younger patients by Kaplan-Meier estimates (P = 0.001). Multivariate analysis showed similar survival between the younger and older subjects (hazard ratio, 1.23; 95% confidence interval, 0.83-1.84; P = 0.31). The observed complication rate in all study subjects was 12.2%, with no difference between the two age groups. Conclusion Octogenarian patients who received CRT with or without a defibrillator for advanced heart failure had similar clinical benefits as younger patients. CRT should not be withheld from octogenarians meeting current selection guidelines. [ABSTRACT FROM AUTHOR]

Background Cardiac resynchronization therapy (CRT) reduces mortality and morbidity in patients with heart failure, diminished left ventricular function, and prolonged QRS duration. We investigated adherence to the CRT guidelines and screened for unidentified CRT candidates. Methods Every unique patient visiting the outpatient clinic during three months was analyzed. In patients with QRS duration ≥120 ms or a paced QRS duration ≥200 ms on the electrocardiogram (ECG), left ventricular ejection fraction (LVEF), and New York Heart Association functional class were retrieved from hospital records and compared with the institutional implantable cardioverter defibrillator/pacemaker implantation database. The appropriateness of CRT indication was studied in patients who previously received CRT. Results QRS duration was <120 ms in 2,609 out of 3,053 patients screened. LVEF was ≤35% in 28 out of 282 patients with a QRS duration ≥120 ms or a paced QRS duration ≥200 ms. Of those, 11 patients were potential CRT candidates. During follow-up, three patients received a CRT device, two patients died, one patient improved, and one refused implantation, leaving four potential CRT candidates. Forty-six patients previously implanted with a CRT device visited the outpatient clinic, of whom 42 (91.3%) fulfilled the guideline criteria. Hence, 45 out of 49 patients (91.8%) qualifying for CRT had received CRT or were implanted during follow-up, and four (8.2%) CRT candidates were unidentified. Conclusion In a large, tertiary academic hospital, >91% of patients fulfilling guideline criteria received CRT, and 8.2% of patients were unidentified. Systematic ECG screening of every patient may prove a simple tool to detect CRT candidates who were otherwise unrecognized. (PACE 2013; 36:69-75) [ABSTRACT FROM AUTHOR]

Background Ventricular fibrillation (VF) can be abolished by targeting triggering ventricular ectopy, most often originating in the Purkinje network or right ventricular outflow tract (RVOT). This strategy relies upon the induction of premature ventricular complex (PVC) and/or VF. We sought to evaluate a VF ablation strategy that utilizes analysis of stored implantable cardioverter defibrillator (ICD) electrograms. Methods Eleven consecutive patients experiencing frequent VF episodes (≥three episodes in prior month) underwent electrophysiology study and ablation of VF triggers. PVC and VF induction was intentionally avoided or not possible in all of these patients. Pacemapping at likely sites for PVC triggers of VF using an analysis of the morphology and relative timing of the stored far- and near-field ICD electrograms of VF triggers was used to identify potential culprit locations. Radiofrequency energy was applied to these sites for ablation of the identified VF trigger. Results Areas targeted for ablation included the left posterior fascicle (six), left anterior fascicle (three), RVOT (three) and left ventricular outflow tract (one); two patients had two separate triggers. Ablation was completed successfully without any complications. With a mean follow-up of 288 days (range 45-649), 10 patients are free of VF. Conclusion Ablation of VF triggers can be performed successfully with good short-term outcomes in patients with and without underlying heart disease. Use of stored ICD electrograms with a focus on likely target areas permit ablation without the need for PVC or VF induction. This can be useful when ectopy is not present for mapping and to avoid potentially dangerous initiation of multiple episodes of VF. (PACE 2013; 36:76-85) [ABSTRACT FROM AUTHOR]

Background: Cardiac resynchronization therapy (CRT) device and coronary sinus (CS) lead extraction is required due to the occurrence of system infection, malfunction, or upgrade. Published series of CS lead extraction are limited by small sample sizes. We present a 10-year experience of CRT device and CS lead extraction. Methods: All lead extractions between 2000 and 2010 were entered into a computer database. From these, a cohort of 71 cases involving a CRT device or CS lead was analyzed for procedural method, success, and complications. Results: Sixty coronary sinus leads were extracted in 71 cases (median age 71 years; 90% male) by manual traction/locking stylets (n = 54) or using a laser sheath (n = 6). Procedural success was achieved in 98% of CS leads. A total of 143 non-CS leads were extracted, with laser required in 46% of cases. The mean duration of lead implantation was 35.8 months (range 1-116 months) and 2.86 ± 1.07 leads were extracted per case. CRT extraction case load increased significantly over time. Minor complications occurred in four (5.6%) cases and major complications in one (1.4%) case. There were no intraprocedural deaths, but two deaths occurred within 30 days of extraction. Conclusions: Our 10-year experience confirms that percutaneous removal of CS leads can be achieved with high procedural success. Our recorded complication rates are no higher than those of non-CS lead extraction series, and should be taken in the context of the frail nature of CRT patients. Ongoing audit of procedure success and complications will be required to further guide best practice in CS lead extraction. (PACE 2011; 34:1209-1216) [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the potential cross-talk between implantable cardioverter defibrillator device (ICD) and implantable neuromodulation device (IND) during the implantation procedure and the ventricular fibrillation induction test and in daily life. We present two cases of patients with an IND who underwent ICD implantation and one case of a patient implanted with a biventricular ICD who received an IND 6 months later. Two of these patients had a spinal cord stimulator (SCS), while the other had a sacral neuromodulator. No cross-talk was recorded in the patient with the sacral neuromodulator and the ICD. Temporary damage to one of the SCSs was observed after multiple ICD shocks. When implanted contemporarily with sacral or spinal neurostimulators, cardiac devices appear to be safe, as confirmed by the appropriate detection and interruption of arrhythmic episodes. On the other hand, neuromodulation devices could be temporarily or permanently damaged by multiple ICD discharges. It is recommended that the neurostimulator be interrogated after an ICD shock, in order to check the state of the device. (PACE 2011; 1-4) [ABSTRACT FROM AUTHOR]

Cardiovascular implantable electronic device (CIED) infection rates are increasing faster than implantation rates. More effective antimicrobial prophylaxis may help reduce CIED infections and improve clinical outcomes. The AIGIS antibacterial envelope is a polymer mesh implanted in the generator pocket with the CIED. After implantation it releases two antibiotics, minocycline and rifampin, that have been shown to reduce infections associated with other medical devices. The purpose of this retrospective cohort study is to determine the rate of CIED implantation success and CIED infection in procedures utilizing the antibacterial envelope. This study enrolled consecutive CIED procedures utilizing the antibacterial envelope at 10 US academic, community, and Veterans Affairs medical centers. Procedures following an explantation for a prior CIED infection or off-label use of the antibacterial envelope were excluded. The 624 eligible procedures (age 70 ± 13 years, 68.1% men, 27.2% renal insufficiency, 35.4% oral anticoagulant use, 67.8% replacement/revision procedures) utilized pacemakers (35%), implantable cardioverter-defibrillators (ICD)(29%), and cardiac resynchronization therapy with defibrillator devices (CRT-D)(36%). Nearly half of the patients (49%) had at least three predefined risk factors for CIED infection. CIED implantation was successful in 621 procedures (99.5%[95% confidence interval (CI) 98.8-99.9]). There were three major infections (0.48%[95%CI 0.17-1.40]) after 1.9 ± 2.4 months follow-up. The infections followed one ICD revision and two CRT-D replacements. There were seven deaths; none was a result of the antibacterial envelope or the CIED procedure. CIED procedures that utilized an antibacterial envelope had a high rate of CIED implantation success (>99%). Although the follow-up to date is short, there was also a low rate of infection (<0.50%) in this population at high risk for CIED infection. (PACE 2011; 34:133-142) [ABSTRACT FROM AUTHOR]

The article presents a case study of a 63-year-old man who underwent surgery for an implantable cardioverter defibrillator due to ischemic cardiomyopathy. Following implantation, the patient experienced double counting episodes. Four years following surgery, the patient developed heart failure symptoms and cardiac resynchronization therapy revision was performed.

Background: In adults, transvenous implantable cardioverter defibrillator (ICD) lead failure rates are significant, and their occurrence increases with time from implant. There are limited data in children. The goal of this study was to assess lead survival in young patients undergoing ICD implantation at a single center. Methods: Records of patients under 21 years old with transvenous ICD leads implanted at our center from June 1997 to August 2007 were retrospectively reviewed. Age, weight, height, diagnosis, lead and generator model, venous access technique, generator position, pacing thresholds, lead impedance, and R wave size were recorded. “Lead failure” was defined as any lead problem requiring surgical intervention to restore proper function to the ICD system. Results: Seventy-one transvenous leads were included (70 patients). Average age at implant was 14.8 years (range 5.7–19.5). All the devices were implanted by a single operator (HMS). Venous access was obtained via cephalic cutdown in 66/71. Mean follow-up time was 2.8 years (range 0.2–7.8 years, median 2.3 years). There were no infections requiring explantation. There were four lead failures. Three were lead fractures, occurring 12, 13, and 19 months after implant. The fourth lead failed when an arrhythmia was not appropriately detected, and a second dedicated rate-sensing lead was thus implanted. Univariate analysis did not identify any variable to be a significant predictor of lead failure. Kaplan–Meier survival analysis demonstrated 5-year lead survival at 89.6%. Conclusions: ICD lead survival in children, when performed by an experienced operator, is similar to that found in adults. (PACE 2010; 33:186–191) [ABSTRACT FROM AUTHOR]

The article describes the case of a 73-year-old man with coronary artery disease s/p coronary artery bypass grafting, class four congestive heart failure on palliative intravenous milrinone and prior cardiac resynchronization therapy defibrillator implantation. Episode electrograms indicated a slow ventricular tachycardia (VT) found in the VT-1 zone. His implantable cardioverter-defibrillator (ICD) was reprogrammed and he was evaluated for palliative therapies.

The article describes the case of a male patient with dextro-transposition of great arteries previously treated with palliative Mustard procedure and underwent transvenous implantation of dual-chamber pacemaker (PM). A subcutaneous cardioverter defibrillator was implanted to prevent sudden death in accordance with the current guidelines. He was admitted to the hospital in August 2014 after five shocks delivered during a treadmill workout and a diagnosis of inappropriate therapies was made.

The article describes the case of a 72 year old man with ischemic cardiomyopathy and sinus node dysfunction implanted with a dual-chamber implantable cardioverter defibrillator for secondary prevention. It describes a proarrhythmic effect of the ventricular intrinsic preference (VIP) algorithm generating atrial fibrillation (AF) in a patient without history of atrial arrhythmias. Reprogramming a shorter VIP extension was found to be enough to avoid retrograde VA conduction.

A 53-year-old female patient with hypertrophic obstructive cardiomyopathy (HOCM) was admitted for alcohol septal ablation (ASA). A subcutaneous internal cardioverter defibrillator (S-ICD) was implanted for primary prevention. After ASA, the patient developed a right bundle branch block, and the S-ICD delivered a total of five inappropriate shocks due to T-wave oversensing (TWOS). TWOS is a relatively frequent cause of inappropriate shocks in S-ICD patients. After invasive treatment for HOCM, there is a risk of developing intraventricular conduction delay and subsequent changes in QRS and T-wave morphology. This should be taken into consideration when ICD indication is evaluated in HOCM patients. [ABSTRACT FROM AUTHOR]

The article presents a case of an 11-year-old boy with two episodes of syncope. The baseline electrocardiogram (ECG) showed sinus rhythm with frequent premature ventricular contractions (PVCs). The ECG showed the bigeminal PVC couplet which resulted in the false detection of ventricular fibrillation (VF) and an inappropriate shock. The EGC was sent to St. Jude Medical Inc. for further clarification.

A 51-year-old woman presented with an episode of syncope. Upon further review she was found to have a typical Brugada type pattern on her electrocardiogram. She did not have evidence for structural heart disease. At electrophysiological testing she was found to have marked infrahisian conduction disease and had easily inducible polymorphic ventricular tachycardia. She underwent implantation of a dual-chamber implantable cardioverter defibrillator (ICD) and family screening was recommended. Genetic analysis revealed a novel nonsense mutation in the gene encoding for the sodium channel (SCN5A). Five months after ICD implantation the patient had an episode of ventricular fibrillation documented on ICD interrogation. This case is unique as it is consistent with an overlap syndrome, namely both Brugada Syndrome and distal atrioventricular (AV) conduction disease secondary to a novel SCN5A mutation in a young female. This finding highlights the phenotypic heterogeneity of novel SCN5A mutations. [ABSTRACT FROM AUTHOR]

We present a case of Twiddler syndrome in a patient with a subcutaneous implantable cardioverter defibrillator (S-ICD). The patient presented herself to the outpatient clinic with pain in the left chest. Chest x-ray confirmed Twiddler syndrome and ICD read-out revealed lead failure resulting in absent heart rhythm sensing in one vector. The lead and pulse generator were extracted and a new S-ICD system was reimplanted submuscular underneath the serratus anterior muscle to prevent reoccurrence. Lead investigation revealed an insulation defect caused by excessive mechanical stress. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 40-year-old woman with implantable cardioverter-defibrillator (ICD) for her ventricular fibrillation caused by a sudden cardiac arrest due to revascularized ischemic heart disease, normal ejection fraction, and end-stage renal disease. The patient suffered from infection and the device was removed. She received three shock episodes of subcutaneous ICD.

The article presents a case study of a 77-year-old man with an implanted Medtronic Viva Quad XT Cardiac Resynchronization Therapy Defibrillator (CRT-D) device. The patient underwent an actual device interrogation which showed a Power-on-Reset (PoR) activity leading to an electrical reset of the device. An aberrant behavior of the battery life indicator on Meditronic devices can be caused by PoR.

The author reflects on the role that catheter ablation of ventricular tachycardia (VT) plays in reducing ventricular tachycardia episodes in patients with implantable cardioverter defibrillators (ICDs). The author suggests that improved techniques for addressing recurrent episodes of VT in patients with ICDs and recurrent shocks are needed. The author argues that additional research is needed on strategies which could improve the success of patients with scar-related VT who are undergoing catheter ablation.

The article presents a case report of a 79-year-old man with an ischemic cardiomyopathy, congestive heart failure, permanent atrial fibrillation, and prior atrioventricular junction (AVJ) ablation. The patient underwent implantation of a left pectoral biventricular implantable-cardioverter defibrillator. The device interrogation showed multiple elevated pacing and high voltage lead impedances.

The article presents a case study of a 53-year-old man with history of anterior myocardial infarction and undergone a secondary prevention dual-chamber implantable cardioverter defibrillator (ICD; with an apical right ventricular lead). The ICD was programmed with a paced atrioventricular (AV) delay of 190 milliseconds (MS) and sensed AV delay of 170 ms. He developed worsening dyspnea over the next few days and an electrocardiogram (ECG) was performed.

The article reports on the case of a 52 year old male patient who underwent routine device interrogation six months following uncomplicated insertion of a biventricular (Bi-V), implantable cardioverter defibrillator. A discussion of an electrocardiogram which was conducted on the patient and revealed that his device was functioning improperly is presented.

Intracardiac lead fracture or free-wall perforation is a rare complication of implantable defibrillators. Complete disconnection of the fractured electrode has not been reported yet. Here, we report a case of lead fracture/disconnection and free-wall perforation, which occurred consecutively in a patient. (PACE 2012; 35:e167-e169) [ABSTRACT FROM AUTHOR]