AIMS:Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease. Insertable cardiac monitors (ICMs) are increasingly used in this population to provide closer monitoring, with the potential for notification systems. However, little is known regarding the psychological impact this information may have on patients. The Abbott Confirm Rx™ ICM has the capability of connecting to the patient's smartphone to enable active participation in their care, as well as two-way communication between the patient and their care providers. This study aimed to explore individuals' experiences of having a smartphone-enabled ICM to monitor for arrhythmias in HCM. METHODS AND RESULTS:Semi-structured interviews were conducted with 10 participants. Utilizing a grounded theory approach, the interview guide was modified based on emerging themes throughout the study. Reflexive thematic analysis was applied to categorize interview data into codes and overacting themes, with each interview independently coded by two study members. Analysis revealed three key themes: (i) psychological impact, (ii) educational needs, and (iii) technology expectations. Participants reported that receiving feedback from ICM transmissions resulted in improved symptom clarity, providing reassurance, and aiding implantable cardioverter defibrillator decision-making. Some participants reported uncertainty regarding when to send manual transmissions. Lastly, participants reported the app interface did not meet expectations with regard to the amount of data available for patients. CONCLUSION:Overall, utilizing a smartphone app to facilitate two-way communication of ICM transmissions was well accepted. Future directions include addressing gaps in educational needs and improvements in the patient interface with increased access to data.

Background:Sudden cardiac death (SCD) risk stratification in hypertrophic cardiomyopathy (HCM) currently relies on arrhythmic burden quantification by 24 or 48-hour Holter monitoring. Whether this approach adequately captures arrhythmic burden, compared with longer-term continuous monitoring, is unclear. We sought to assess the long-term incidence of nonsustained ventricular tachycardia (NSVT) in HCM patients at low or moderate SCD risk, using implantable cardiac monitors (ICMs) paired with a novel Bluetooth-enabled 2-way communication platform.Methods:This prospective, single-arm, observational study enrolled 33 HCM patients. Patients were implanted with an Abbott (Chicago, IL) Confirm Rx ICM and monitored using a protocolized care pathway.Results:A total of 20 patients (60.6%) had ≥ 1 episode of NSVT recorded on the ICM, the majority of whom had previous Holter monitors that did not identify NSVT (60%, n = 12). A total of 71 episodes of NSVT were detected. Median time to first NSVT detection was 76.5 days (range: 0-553 days). A total of 19 patients underwent primary prevention implantable cardioverter defibrillator implantation during an average follow-up of 544 days (range: 42-925 days). A total of 172,112 automatic transmissions were received, and 65 (0.04%) required clinical follow-up. A total of 325 manual transmissions were received and managed. A total of 14 manual transmissions (4.3%) required follow-up, whereas 311 (95.7%) were managed solely with a text message.Conclusions:Surveillance and reporting systems utilizing 2-way communication enabled by novel ICMs are feasible and allow remote management of patients with HCM. Prolonged monitoring with ICMs identified more patients with nonsustained arrythmias than did standard Holter monitoring. In many cases, this information impacted both SCD risk stratification and patient management.

Hypertrophic cardiomyopathy (HCM) is considered the most common inherited heart disease affecting 1 in 500 individuals. Those with HCM are at increased risk of non-sustained ventricular tachycardia (NSVT) and sudden cardiac death. Guidelines recommend HCM patients undergo arrhythmia monitoring every 1-2 years to determine candidacy for primary prevention implantable cardioverter defibrillators (ICD). A variety of implantable cardiac monitors (ICMs) are currently approved for use with varying technology and interface platforms.

LIA and LinoxIntroductionMedtronic's Lead Integrity Alert (LIA) software algorithm is useful for detecting abnormal parameters across various ICD-lead families. However, its utility in the assessment of the Biotronik Linox family of high-voltage (HV) leads is unknown.MethodsWe conducted a retrospective cohort study to assess the performance of the LIA algorithm to detect abnormalities and lead failure in Linox ICD-leads. All LIA-enabled Medtronic devices connected to an active Linox lead were included. The alerts were adjudicated by 2 blinded electrophysiologists and correlated with clinical data.ResultsBetween 2008 and 2012, data from 208 patients with 564 patient-years of follow-up were available for analysis. The median follow-up duration was 32 (IQR 21-41 months). Twenty-one LIA triggers were noted in 20 different patients. The median delay until a positive LIA was 32 months (IQR 21-41 months) postimplant with a 5-year lead survival free from LIA of 76%. Ninety-five percent (19/20) LIA alerts were true lead failures. The most common LIA triggers were short V-V intervals (85%) and nonsustained ventricular tachycardia (85%). Abrupt changes of the ICD-lead impedance occurred in 5/20 triggers. Inappropriate ICD-shocks were strongly associated with a positive LIA (30% vs. 7.4%; P = 0.006). Of the explanted Linox leads 53% had visible abnormalities. The sensitivity, specificity, and positive predictive value for lead failure in the presence of a LIA trigger were 87%, 99.5%, and 95.2%, respectively.ConclusionsA positive LIA trigger in Biotronik Linox ICD-leads is highly predictive of lead failure. LIA is useful in ongoing surveillance of lead performance.

AIMS:In the era of increasing implantable cardioverter defibrillator (ICD) complexity, the ICD patient alert is deemed to be an important feature in the early detection of ICD system malfunction and is either an audible or a vibratory alert. We sought to evaluate the patient's ability to detect these ICD alerts in the device clinic setting as a surrogate endpoint of clinical utility.METHODS AND RESULTS:From 1 November 2006 to 31 March 2008, 563 patients with an ICD equipped with either an audible patient alert (APA, Medtronic and Guidant; n = 485) or a vibratory monitoring alert ([VMA, St Jude Medical; n = 78) had their alarm demonstrated in the quiet clinic setting. The ability to recognize the alert was analysed and then stratified by gender, age, manufacturer, type of alert, and pocket location. The average patient age was 63.3 (± 13.6) years and 82.8% of patients were male. Implantable cardioverter defibrillator manufacturers were Medtronic (n = 464), Boston Scientific (n = 21), and SJM (n = 78). The APA was heard in 86.0% of patients. This was less likely in patients who were older, male, and where the device was placed in the submuscular position. Every patient with a VMA sensed their alert.CONCLUSION:In the current ICD alert technology, the ability to sense the ICD alert in the device clinic appears to be higher for the VMA than for the APA. In particular, older patients and male patients are less likely to sense the APA.