Gregory Webster

Efficacy of implantable cardioverter defibrillators in young patients with catecholaminergic polymorphic ventricular tachycardia: Success depends on substrate

Background—The effectiveness of implantable cardioverter-defibrillator (ICD) therapy for the management of catecholaminergic polymorphic ventricular tachycardia (VT) in young patients is not known. ICD discharges are not always effective and inappropriate discharges are common, both resulting in morbidity and mortality. Methods and Results—This is a multicenter, retrospective review of young patients with catecholaminergic polymorphic VT and ICDs from 5 centers. ICD discharges were evaluated to determine arrhythmia mechanism, appropriateness, efficacy of therapy, and complications. A total of 24 patients were included. Median (interquartile range) ages at onset of catecholaminergic polymorphic VT symptoms and ICD implant were 10.6 (5.0–13.8) years and 13.7 (10.7–16.3) years, respectively. Fourteen patients received 140 shocks. Ten patients (42%) experienced 75 appropriate shocks and 11 patients (46%) received 65 inappropriate shocks. On actuarial analysis, freedom from appropriate shock at 1 year after ICD implant was 75%. Of appropriate shocks, only 43 (57%) demonstrated successful primary termination. All successful appropriate ICD discharges were for ventricular fibrillation. No episodes of polymorphic VT or bidirectional VT demonstrated successful primary termination. The adjusted mean (95% confidence interval) cycle length of successful discharges was significantly shorter than unsuccessful discharges (168 [152–184] ms versus 245 [229–262] ms; adjusted P=0.002). Electrical storm occurred in 29% (4/14) and induction of more malignant ventricular arrhythmias in 36% (5/14). There were no deaths. Conclusions—ICD efficacy in catecholaminergic polymorphic VT depends on arrhythmia mechanism. Episodes of ventricular fibrillation were uniformly successfully treated, whereas polymorphic and bidirectional VT did not demonstrate successful primary termination. Inappropriate shocks, electrical storm, and ICD complications were common.

Shock-related anxiety and sexual function in adults with congenital heart disease and implantable cardioverter-defibrillators

BACKGROUND An increasing number of adults with congenital heart disease (CHD) require implantable cardioverter-defibrillators (ICDs), yet little is known about their impact on psychological well-being and sexual function. OBJECTIVE To assess shock-related anxiety in adults with CHD and its association with depression and sexual function. METHODS A prospective, multicenter, cross-sectional study was conducted on adult patients with CHD with (ICD(+)) and without (ICD(-)) ICDs. The Florida Shock Anxiety Scale was administered to patients with ICD(+) and the Beck Depression Inventory-II to all patients. Men completed the Sexual Health Inventory for Men, and women completed the Female Sexual Function Index. RESULTS A total of 180 adults with CHD (ICD(+): n = 70; ICD(-): n = 110; median age 32 years [interquartile range 27-40 years]; 44% women) were enrolled. The complexity of CHD was classified as mild in 32 (18%), moderate in 93 (52%), and severe in 54 (30%) subjects. In ICD recipients, a high level of shock-related anxiety was identified (Florida Shock Anxiety Scale score 16; interquartile range 12-23.5), which was slightly higher than the median score for ICD recipients in the general population (P = .057). A higher level of shock-related anxiety was associated with poorer sexual function scores in both men (Spearmans ρ =-.480; P<.001) and women (Spearmans ρ =-.512; P<.01). It was also associated with self-reported depressive symptomatology (Spearmans ρ = .536; P< .001). CONCLUSIONS Adults with CHD and ICDs demonstrate a high level of shock-related anxiety, which is associated with lower sexual functioning scores in men and women. These results underscore the need for increased clinical attention related to ICD-related shock anxiety and impaired sexual function in this population.

An Update on Channelopathies From Mechanisms to Management

The basic science of membrane channels has set in motion striking clinical results, especially in cardiology. The clinical phenotype of cardiac channelopathies is conspicuous; sudden death or cardiac arrest may be the initial presentation. The last 2 decades have changed the face of diagnosis and treatment of inherited channelopathies for families who have a high, and often unrecognized, likelihood of sudden death. The simple paradigm of one gene, one mutation, one disease remains true in some channelopathy diseases, but as we look deeper, the relationships increase in complexity as channel biology interrelates with membrane, intercellular, and extracellular biology. No protein acts in isolation. Genetic testing ideally identifies patients at risk, offers a window into optimal therapy, and aids in identifying those patients who are not carriers and therefore assign them to a low-risk group. However, the best-case scenario is not always the clinical scenario. The task of the clinical practitioner is to digest the flood of basic science information and use it to best serve patients. As the prevalence of genetic testing has increased, the limitations become more important to the practicing physician. Testing may reveal a change in the patient’s genome from the typical sequence, but certifying a mutation as the clinical cause of a patient’s disease remains a challenge. Along with the difficult task of learning the names and nuances of the genetic products (eg, the LQT1 genotype stems from mutations in KCNQ1 , previously known as KVLQT1 , on chromosome 11p15.5, encoding Kv7.1, which conducts an IKs current), the practitioner must learn a new genetic vocabulary to convert a cardiac genetic test report into an informed clinical decision. The aim of this review is to summarize the scope of arrhythmia genetics and relate those mechanisms to clinical management strategies. When Keating et al1 made the …

Congenital Long-QT Syndromes: A Clinical and Genetic Update From Infancy Through Adulthood

Long-QT syndromes (LQTSs) have been described in all ages and are a significant cause of cardiovascular mortality, especially in structurally normal hearts. Abnormalities in transmembrane ion conduction channels and structural proteins produce these clinical syndromes, labeled LQT1-LQT12; however, genotype-positive patients still represent only about 70% of LQTSs. Future research will determine the etiology of the remaining cases, further risk-stratify the known genetic defects, improve current treatment options for these syndromes, and uncover novel therapies.

Psychiatric functioning and quality of life in young patients with cardiac rhythm devices

BACKGROUND: Less is known about depression, anxiety and quality of life (QoL) in children and adolescents with pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) than is known in adults with these devices. METHODS: A standardized psychiatric interview diagnosed anxiety/depressive disorders in a cross-sectional study. Self-report measures of anxiety, depression and post-traumatic stress disorder were obtained. Medical disease severity, family functioning and QoL data were collected. A total of 166 patients were enrolled (52 ICD, 114 PM; median age 15 years). RESULTS: Prevalence of current and lifetime psychiatric disorders was higher in patients with ICDs than PMs (Current: 27% vs. 11%, P = .02; Lifetime: 52% ICD vs. 34% PM, P = .01). Patients with ICDs had more anxiety than a healthy population (25% vs. 7%, P < .01). Patients with ICDs and PMs had similar levels of depression as a healthy population (ICD 10%, PM 4%, reference 4%, P = .29). In multivariate analysis including a medical disease score, demographics, exposure to beta-blockers, activity limitations, hospitalizations, shocks and procedures, the type of device (PM versus ICD) did not predict psychiatric diagnoses when age at implantation and the severity of medical disease were controlled for. Patients with ICDs and PMs had lower physical QoL scores (ICD 45, PM 47.5, Norm 53, P ≤ .03), but similar psychosocial functioning scores (ICD 49, PM 51, Norm 51, P ≥ .16) versus a normal reference population. CONCLUSIONS: Anxiety is highly prevalent in young patients with ICDs, but the higher rates can be attributed to medical disease severity and age at implantation instead of type of device.

Intermediate-Term Outcome of 140 Consecutive Fontan Conversions With Arrhythmia Operations.

BACKGROUND Atrial arrhythmias and progressive circulatory failure frequently develop in patients with a Fontan circulation. Improvement of flow dynamics and revision of the arrhythmia substrate may improve outcomes in selected patients. We sought to determine intermediate-term outcomes after Fontan conversion with arrhythmia operations and identify characteristics associated with decreased transplant-free survival. METHODS The first 140 Fontan conversions with arrhythmia operations at a single institution were analyzed for predictors of cardiac death or transplant and incidence of arrhythmia recurrence. RESULTS The median age at the Fontan conversion operation was 23.2 years (range, 2.6 to 47.3 years). Preoperative arrhythmias were present in 136 patients: right atrial tachycardia in 48 patients, left atrial tachycardia in 21, and atrial fibrillation in 67. Freedom from cardiac death or transplant was 90% at 5 years, 84% at 10 years, and 66% at 15 years. The median age at the last follow-up among survivors was 32 years (range, 15 to 61 years). By multivariable analysis, risk factors for cardiac death or heart transplantation were a right or indeterminate ventricular morphology, cardiopulmonary bypass time exceeding 240 minutes, ascites, protein-losing enteropathy, or a biatrial arrhythmia operation at the time of conversion. Freedom from recurrence of atrial tachycardia was 77% at 10 years. Among 67 patients with atrial fibrillation undergoing biatrial arrhythmia operations, none had recurrent atrial fibrillation. CONCLUSIONS Freedom from cardiac death or transplant for patients undergoing Fontan conversion with an arrhythmia operation is 84% at 10 years. The effects of atrial arrhythmia operations are durable in most patients. These outcomes may serve as useful benchmarks for alternative management strategies.

Digital music players cause interference with interrogation telemetry for pacemakers and implantable cardioverter-defibrillators without affecting device function

BACKGROUND Concern exists regarding the potential electromagnetic interaction between pacemakers, implantable cardioverter-defibrillators (ICDs) and digital music players (DMPs). A preliminary study reported interference in 50% of patients whose devices were interrogated near Apple iPods. OBJECTIVE Given the high prevalence of DMP use among young patients, we sought to define the nature of interference from iPods and evaluate other DMPs. METHODS Four DMPs (Apple Nano, Apple Video, SanDisk Sansa and Microsoft Zune) were evaluated against pacemakers and ICDs (PM/ICD). Along with continuous monitoring, we recorded a baseline ECG strip, sensing parameters and lead impedance at baseline and for each device. RESULTS Among 51 patients evaluated (age 6 to 60 years, median 22), there was no interference with intrinsic device function. Interference with the programmer occurred in 41% of the patients. All four DMPs caused programmer interference, including disabled communication between the PM/ICD and programmer, noise in the ECG channel, and lost marker channel indicators. Sensing parameters and lead impedances exhibited no more than baseline variability. When the DMPs were removed six inches, there were no further programmer telemetry interactions. CONCLUSIONS Contrary to a prior report, we did not identify any evidence for electromagnetic interference between a selection of DMPs and intrinsic function of PM/ICDs. The DMPs did sometimes interfere with device-programmer communication, but not in a way that compromised device function. Therefore, we recommend that DMPs not be used during device interrogation, but suggest that there is reassuring counterevidence to mitigate the current high level of concern for interactions between DMPs and implantable cardiac rhythm devices.

Recommendations for Advanced Fellowship Training in Clinical Pediatric and Congenital Electrophysiology: A Report from the Training and Credentialing Committee of the Pediatric and Congenital Electrophysiology Society

A Report from the Training and Credentialing Committee of the Pediatric and CongenitalElectrophysiology SocietyEndorsed by the Heart Rhythm SocietyCOMMITTEE MEMBERSEdward P. Walsh, MD, FHRS, ChairYaniv Bar-Cohen, MDAnjan S. Batra, MD, FHRS*Macdonald Dick II, MD, FHRSChristopher Erickson, MDFrank Fish, MDRobert M. Hamilton, MD

The multicenter pediatric and adult congenital EP quality (MAP-IT) initiative-rationale and design: Report from the pediatric and congenital electrophysiology society's MAP-IT taskforce

Multicenter clinical registries are increasingly recognized as valuable tools for establishing benchmarks, facilitating patient-centered quality improvement and research. In 2010, the Pediatric and Congenital Electrophysiology Society convened a taskforce of its members to design, construct, and implement a clinical registry known as the Multicenter Pediatric and Adult Congenital EP Quality (MAP-IT) Initiative. The present aim of the MAP-IT Initiative is to create an infrastructure by which we can measurably improve patient-centered outcomes and reduce complications associated with electrophysiology studies and catheter ablation in pediatric and congenital heart disease patients. The purpose of this writing is to report the progress to date from three of the four subcommittees of the MAP-IT taskforce. Specifically, we present our initial set of key data elements and definitions, recommended database table structure, and considerations regarding wide-scale implementation of the registry. Development of a risk/complexity score for use in the MAP-IT registry is presented in a separate companion manuscript. It is our intent that these manuscripts will serve to introduce the electrophysiology and pediatric cardiology community to the MAP-IT initiative and provide a rationale for its design and recommended implementation strategy.

Jarisch-Herxheimer reaction associated with ciprofloxacin administration for tick-borne relapsing fever.

A 14-year-old girl was seen at a community clinic with a chief complaint of abdominal pain and fevers and was treated with oral ciprofloxacin for presumed pyelonephritis. She became tachycardic and hypotensive after her first dose of antibiotic, and she developed disseminated intravascular coagulation. She was admitted to our hospital for presumed sepsis. Her outpatient peripheral blood smear was reviewed, revealing spirochetes consistent with Borrelia sp. To our knowledge this is the first reported case of the Jarisch-Herxheimer reaction to ciprofloxacin.