C. Cheung

Patterns of Aortic Dilatation in Bicuspid Aortic Valve-Associated Aortopathy

BACKGROUND Bicuspid aortic valves (BAVs) are associated with aortopathy. Recent studies suggest that aortic dilatation is more likely to be seen with left-right coronary cusp fusion (type I) compared with right-noncoronary cusp fusion (type II). The aim of this study was to investigate the association between BAV morphology and patterns of aortopathy. METHODS Aortic dimensions and BAV morphology were obtained retrospectively from archived cine loops of 581 consecutive patients with BAVs and 277 matched normal controls from the Vancouver General Hospital echocardiography database. Patient demographics and other echocardiographic parameters were extracted from the database. RESULTS The study population was composed of 71% type I BAVs (415 patients) and 26% type II BAVs (149 patients). Aortic dilatation was present in 30% of the population. Type I BAV was associated with increased dimensions indexed to body surface area at the sinus of Valsalva compared with type II BAV. No difference in proximal ascending aortic dimension was seen between different BAV morphologies. The pattern of dilatation with type I BAV was more likely to be at the level of the annulus or sinus of Valsalva compared with type II BAV (62% vs 33%, P= .002). Type I BAV was an independent predictor of proximal aortic dilatation (odds ratio, 3.42; 95% confidence interval, 1.07-10.9). CONCLUSIONS Type I BAV is associated with a greater likelihood of dilatation at the annulus and sinus of Valsalva. There is relative sparing of this region of the aorta in patients with type II BAVs. Individuals with different BAV morphologies may require different strategies of aortopathy surveillance.

Outcome of Apparently Unexplained Cardiac Arrest: Results From Investigation and Follow-Up of the Prospective Cardiac Arrest Survivors With Preserved Ejection Fraction Registry

Background—The Cardiac Arrest Survivors with Preserved Ejection Fraction Registry (CASPER) enrolls patients with apparently unexplained cardiac arrest and no evident cardiac disease to identify the pathogenesis of cardiac arrest through systematic clinical testing. Exercise testing, drug provocation, advanced cardiac imaging, and genetic testing may be useful when a cause is not apparent. Methods and Results—The first 200 survivors of unexplained cardiac arrest from 14 centers across Canada were evaluated to determine the results of investigation and follow-up (age, 48.6±14.7 years, 41% female). Patients were free of evidence of coronary artery disease, left ventricular dysfunction, or evident repolarization syndromes. Advanced testing determined a diagnosis in 34% of patients at baseline, with a diagnosis emerging during follow-up in 7% of patients. Of those who were diagnosed, 28 (35%) had an underlying structural condition and 53 (65%) had a primary electric disease. During a mean follow-up of 3.15±2.34 years, 23% of patients had either a shock or an appropriate antitachycardia pacing from their implantable cardioverter defibrillator, or both. The implantable cardioverter defibrillator appropriate intervention rate was 8.4% at 1 year and 18.1% at 3 years, with no clear difference between diagnosed and undiagnosed subjects, or between those diagnosed with a primary electric versus structural pathogenesis. Conclusions—Obtaining a diagnosis in previously unexplained cardiac arrest patients requires systematic clinical testing and regular follow-up to unmask the cause. Nearly half of apparently unexplained cardiac arrest patients ultimately received a diagnosis, allowing for improved treatment and family screening. A substantial proportion of patients received appropriate implantable cardioverter defibrillator therapy during medium-term follow-up. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00292032.

Exercise and Inherited Arrhythmias

Sudden cardiac death (SCD) in an apparently healthy individual is a tragedy that prompts a series of investigations to identify the cause of death and to prevent SCD in potentially at-risk family members. Several inherited channelopathies and cardiomyopathies, including long QT syndrome (LQTS), catecholaminergic polymorphic ventricular cardiomyopathy (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC) are associated with exercise-related SCD. Exercise restriction has been a historical mainstay of therapy for these conditions. Syncope and cardiac arrest occur during exercise in LQTS and CPVT because of ventricular arrhythmias, which are managed with β-blockade and exercise restriction. Exercise may provoke hemodynamic or ischemic changes in HCM, leading to ventricular arrhythmias. ARVC is a disease of the desmosome, whose underlying disease process is accelerated by exercise. On this basis, expert consensus has erred on the side of caution, recommending rigorous exercise restriction for all inherited arrhythmias. With time, as familiarity with inherited arrhythmia conditions has increased and patients with milder forms of disease are diagnosed, practitioners have questioned the historical rigorous restrictions advocated for all. This change has been driven by the fact that these are often children and young adults who wish to lead active lives. Recent evidence suggests a lower risk of exercise-related arrhythmias in treated patients than was previously assumed, including those with previous symptoms managed with an implantable cardioverter-defibrillator. In this review, we emphasize shared decision making, monitored medical therapy, individual and team awareness of precautions and emergency response measures, and a more permissive approach to recreational and competitive exercise.

Comparing 14-day adhesive patch with 24-h Holter monitoring.

Barrett PM, Komatireddy R, Haaser S et al. Comparison of 24-hour Holter monitoring with 14-day novel adhesive patch electrocardiographic monitoring. Am. J. Med. 127(1), 95.e11–95.e17 (2014). The investigation of cardiac arrhythmias in the outpatient ambulatory setting has traditionally been initiated with the Holter monitor. Using the continuous recording over 24 or 48 h, the Holter monitor permits the detection of baseline rhythm, dysrhythmia and conduction abnormalities, including heart block and changes in the ST segment that may indicate myocardial ischemia. However, apart from the bulkiness and inconvenience of the device itself, the lack of extended monitoring results in a diagnostic yield of typically less than 20%. In this study by Barrett et al., 146 patients referred for the evaluation of cardiac arrhythmia were prospectively enrolled to wear both the 24-h Holter monitor and 14-day adhesive patch monitor (Zio Patch) simultaneously. The primary outcome was the detection of any one of six arrhythmias: supraventricular tachycardia, atrial fibrillation/flutter, pause >3 s, atrioventricular block, ventricular tachycardia, or polymorphic ventricular tachycardia/fibrillation. The adhesive patch monitor detected more arrhythmia events compared with the Holter monitor over the total wear time (96 vs. 61 events; p < 0.001), although the Holter monitor detected more events during the initial 24-h monitoring period (61 vs. 52 events; p = 0.013). Novel, single-lead, intermediate-duration, user-friendly adhesive patch monitoring devices, such as the Zio Patch, represent the changing face of ambulatory ECG monitoring. However, the loss of quality, automated rhythm analysis and inability to detect myocardial ischemia continue to remain important issues that will need to be addressed prior to the implementation of these new devices.

The importance of a comprehensive evaluation of survivors of cardiac arrest

In the absence of structural heart disease, an apparently unexplained cardiac arrest includes an eclectic compilation of latent causes, including long QT syndrome, Brugada syndrome, early repolarization syndrome, and several structural causes. After comprehensive assessment, about half of patients with unexplained cardiac arrest will have a specific aetiology identified, with the remaining indeterminate cases labelled ‘idiopathic ventricular fibrillation’ (IVF). In this issue of the journal, Waldmann et al. report the medical evaluation and outcomes among a Parisian cohort of 717 cardiac arrest survivors, focusing on those patients who remained undiagnosed after diagnostic testing. Among patients labeled IVF (49 patients), only 16% received a comprehensive assessment, defined as cardiac magnetic resonance (CMR), ergonovine challenge, and pharmacological testing. Although most patients underwent CMR (82%), genetic testing was performed in less than one-fifth and exercise testing in less than one-tenth of individuals. Importantly, family screening occurred in less than a quarter of patients. The authors’ findings highlight the importance of a comprehensive systematic evaluation of cardiac arrest survivors, and gaps in the current delivery of guideline-directed unexplained cardiac arrest assessment.

Perceptions of interprofessionalism in health professional students participating in a novel community service initiative

ABSTRACT Interprofessional collaboration is integral to effective patient care in today’s healthcare system. Early exposure to other professions in a hands-on manner during education can be helpful for future practice. However, opportunities for interprofessional education are typically faculty driven and remain limited. Thirty-eight students from different health professions at the University of British Columbia worked collaboratively to promote cardiovascular risk reduction in Vancouver’s Downtown Eastside. Student attitudes toward interprofessionalism were assessed using the Interdisciplinary Education Perception Scale (IEPS). While 38 participants (55%) completed the survey prior to participation in this initiative, only 21 individuals completed the follow-up survey After participation, there were significant improvements in the competency and autonomy (p = 0.02) and perception of actual cooperation (p = 0.04). Students did not report any difference in their perceived need for cooperation after participation in the initiative. These results suggest that student-led community service initiatives can be an effective method for interprofessional education amongst health professional students.

Response to Letter Regarding Article, “Outcome of Apparently Unexplained Cardiac Arrest: Results From Investigation and Follow-Up of the Prospective Cardiac Arrest Survivors With Preserved Ejection Fraction Registry”

We would like to thank Professors Jaimez and Sanchez for their letter of response commenting on our recent summary of evaluation and outcome of our first 200 unexplained cardiac arrest probands.1 We would first like to point out that we excluded patients with a manifest diagnosis, so none of these patients had overt evidence of an ion channelopathy or cardiomyopathy that are typically both readily diagnosed and treated. This is reflected in our empirical strength of diagnosis framework, which is necessary when a classic diagnosis is not forthcoming.2 In addition, registries do not mandate care but rather capture it, and reflect the reality of practice with the vagaries of contextual clinical decision making. In response to the concerns about the incidence of shocks and the inefficacy of medical therapy, it is important to point out the difference between efficacy and effectiveness. Without …

The Emerging Role of Wearable Technologies in Detection of Arrhythmia

Over the past decade, there has been an explosion of consumer devices for the purposes of health and fitness tracking. The wearable technology market, composed of devices that monitor physiological parameters, such as heart rate and sleep pattern, is anticipated to grow to 929 million connected devices in 2021. These devices encompass wristbands, glasses, in-ear monitors, or electronic shirts, with varying capacity to monitor heart rate, heart rhythm, blood pressure, physical activity, respiratory rate, blood glucose, and sleep patterns. For heart-rate monitoring, most wearable devices use photoplethysmography (PPG) technology, meaning they are inherently less accurate than conventional electrocardiography monitoring techniques (reference standard). However, a growing body of evidence suggests that these technologies can be harnessed to facilitate arrhythmia detection in the appropriate context. Studies evaluating PPG-based wearables in conjunction with machine-learning algorithms have shown promise in detection of such arrhythmias, as atrial fibrillation. Limitations of wearable technologies include their accuracy and accessibility and the clinical implications of wearable-detected arrhythmias. Despite this, wearable technologies represent an important frontier in health evaluation. Future wearables will benefit from improved reliability and accuracy, collect additional health and fitness parameters, support management of chronic disease, and provide real-time connectivity and feedback that may supplant conventional medical monitoring. Wearables have the potential to become truly disruptive in our health care sector, with large segments of the population soon to have readily available health data that the physician must interpret.

Remote Monitoring of Cardiac Implantable Electronic Devices

Over the past decade, technological advancements have transformed the delivery of care for arrhythmia patients. From early transtelephonic monitoring to new devices capable of wireless and cellular transmission, remote monitoring has revolutionized device care. In this article, we review the current evolution and evidence for remote monitoring in patients with cardiac implantable electronic devices. From passive transmission of device diagnostics, to active transmission of patient- and device-triggered alerts, remote monitoring can shorten the time to diagnosis and treatment. Studies have shown that remote monitoring can reduce hospitalization and emergency room visits, and improve survival. Remote monitoring can also reduce the health care costs, while providing increased access to patients living in rural or marginalized communities. Unfortunately, as many as two-thirds of patients with remote monitoring-capable devices do not use, or are not offered, this feature. Current guidelines recommend remote monitoring and interrogation, combined with annual in-person evaluation in all cardiac device patients. Remote monitoring should be considered in all eligible device patients and should be considered standard of care.

Eosinophilic Myocarditis: A Concise Review for Clinicians

ABSTRACT Persistent eosinophilia can cause cardiac tissue damage, typically in the form of eosinophilic myocarditis, whether the underlying cause is reactive, a clonal myeloid disorder, or idiopathic hypereosinophilic syndrome (HES). Eosinophilic myocarditis ranges from mild localized disease to multifocal widespread infiltrates associated with myocardial necrosis, thrombotic complications and endomyocardial fibrosis. Systemic treatment varies widely depending on the underlying cause, so thorough investigation and precise diagnosis are essential. Evaluation includes assessment for reactive causes of eosinophilia (vasculitis such as eosinophilic granulomatosis and polyangiitis or Churg‐Strauss, parasitic infection, autoimmune disease, immunoglobulinG4‐related disease, medications and other causes), genetic lesions characteristic of clonal myeloid disorders (platelet‐derived growth factor receptor‐&agr;, platelet‐derived growth factor receptor‐&bgr; and fibroblast growth factor receptor 1) and flow cytometry and molecular studies for the aberrant T cells characteristic of lymphocyte‐variant HES. Patients with reactive eosinophilia require treatment for the underlying cause, such as antiparasitic therapy for helminthic infection or immunosuppression for eosinophilic granulomatosis and polyangiitis or Churg‐Strauss. Those with a myeloid clone often benefit from the tyrosine kinase inhibitor imatinib. Steroids are the first‐line treatment for idiopathic HES and lymphocyte‐variant HES, and hydroxyurea or (pegylated) interferon‐&agr; may be used for relapsed or refractory disease. Mepolizumab, an anti‐interleukin‐5 monoclonal antibody, is an effective steroid‐sparing agent in HES but is not widely available for this indication.