HRS White Paper on Clinical Utilization of Digital Health Technology.

This collaborative statement from the Digital Health Committee of the Heart Rhythm Society provides everyday clinical scenarios in which wearables may be utilized by patients for cardiovascular health and arrhythmia management. We describe herein the spectrum of wearables that are commercially available for patients, and their benefits, shortcomings and areas for technological improvement. Although wearables for rhythm diagnosis and management have not been examined in large randomized clinical trials, undoubtedly the usage of wearables has quickly escalated in clinical practice. This document is the first of a planned series in which we will update information on wearables as they are revised and released to consumers.

Miniaturized Robotic End-Effector with Piezoelectric Actuation and Fiber Optic Sensing for Minimally Invasive Cardiac Procedures.

Each year 35,000 cardiac ablation procedures are performed to treat atrial fibrillation through the use of catheter systems. The success rate of this treatment is highly dependent on the force which the catheter applies on the heart wall. If the magnitude of the applied force is much higher than a certain threshold the tissue perforates, whereas if the force is lower than this threshold the lesion size may be too large and is inconsistent. Furthermore, studies have shown large variability in the applied force from trained physicians during treatment, suggesting that physicians are unable to manually regulate the levels of the force at the site of treatment. Current catheter systems do not provide the physicians with active means for contact force control and are only at most aided by visual feedback of the forces measured in situ. This paper discusses a novel design of a robotic end-effector that integrates mechanisms of sensing and actively controlling of the applied forces into a miniaturized compact form. The required specifications for design and integration were derived from the current application under investigation. An off-the-shelf miniature piezoelectric motor was chosen for actuation, and a force sensing solution was developed to meet the specifications. Experimental characterization of the actuator and the force sensor within the integrated setup show compliance with the specifications and pave the way for future experimentation where closed-loop control of the system can be implemented according to the contact force control strategies for the application.

Mechano-electric finite element model of the left atrium.

Mechanical stretch plays a major role in modulating atrial function, being responsible for beat-by-beat responses to changes in chamber preload, enabling a prompt regulation of cardiac function. Mechano-electric coupling (MEC) operates through many mechanisms and has many targets, making it experimentally difficult to isolate causes and effects especially under sinus conditions where effects are more transient and subtle. Therefore, modelling is a powerful tool to help understand the role of MEC with respect to the atrial electromechanical interaction. We propose a cellular-based computational model of the left atrium that includes a strongly coupled MEC component and mitral flow component to account for correct pressure generation in the atrial chamber as a consequence of blood volume and contraction. The method was applied to a healthy porcine left atrium. Results of the strongly coupled simulation show that strains are higher in the areas adjacent to the mitral annulus, the rim of the appendage, around the pulmonary venous trunks and at the location of the Bachmann's bundle, approximately between the mitral annulus and the region where the venous tissue transitions into atrial. These are regions where arrhythmias are likely to originate. The role of stretch-activated channels was very small for sinus rhythm for the single cardiac beat simulation, although tension development was very sensitive to stretch. The method could be applied to investigate potential therapeutic interventions acting on the mechano-electrical properties of the left atrium.

Design of a Coupled Thermoresponsive Hydrogel and Robotic System for Postinfarct Biomaterial Injection Therapy.

BACKGROUND: In preclinical testing, ventricular wall injection of hydrogels has been shown to be effective in modulating ventricular remodeling and preserving cardiac function. For some approaches, early-stage clinical trials are under way. The hydrogel delivery method varies, with minimally invasive approaches being preferred. Endocardial injections carry a risk of hydrogel regurgitation into the circulation, and precise injection patterning is a challenge. An epicardial approach with a thermally gelling hydrogel through the subxiphoid pathway overcomes these disadvantages. METHODS: A relatively stiff, thermally responsive, injectable hydrogel based on N-isopropylacrylamide and N-vinylpyrrolidone (VP gel) was synthesized and characterized. VP gel thermal behavior was tuned to couple with a transepicardial injection robot, incorporating a cooling feature to achieve injectability. Ventricular wall injections of the optimized VP gel have been performed ex vivo and on beating porcine hearts. RESULTS: Thermal transition temperature, viscosity, and gelling time for the VP gel were manipulated by altering N-vinylpyrrolidone content. The target parameters for cooling in the robotic system were chosen by thermal modeling to support smooth, repeated injections on an ex vivo heart. Injections at predefined locations and depth were confirmed in an infarcted porcine model. CONCLUSIONS: A coupled thermoresponsive hydrogel and robotic injection system incorporating a temperature-controlled injectate line was capable of targeted injections and amenable to use with a subxiphoid transepicardial approach for hydrogel injection after myocardial infarction. The confirmation of precise location and depth injections would facilitate a patient-specific planning strategy to optimize injection patterning to maximize the mechanical benefits of hydrogel placement.

Relaxin suppresses atrial fibrillation in aged rats by reversing fibrosis and upregulating Na+ channels.

BACKGROUND: Atrial fibrillation (AF) contributes significantly to morbidity and mortality in elderly patients and has been correlated with enhanced age-dependent atrial fibrosis. Reversal of atrial fibrosis has been proposed as therapeutic strategy to suppress AF. OBJECTIVE: To test the ability of relaxin to reverse age-dependent atrial fibrosis and suppress AF. METHODS: Aged F-344 rats (24 months old) were treated with subcutaneous infusion of vehicle or relaxin (0.4 mg/kg/day) for 2 weeks. Rat hearts were excised, perfused on a Langendorff apparatus, and stained with voltage and Ca(2+) indicator dyes. Optical mapping and programmed electrical stimulation was used to test arrhythmia vulnerability and changes in electrophysiological characteristics. Changes in protein expression and Na(+) current density (INa) were measured by tissue immunofluorescence and whole-cell patch clamp technique. RESULTS: In aged rats, sustained AF was readily induced with a premature pulse (n = 7/8) and relaxin treatment suppressed sustained AF by a premature impulse or burst pacing (n = 1/6) (P < .01). Relaxin significantly increased atrial action potential conduction velocity and decreased atrial fibrosis. Relaxin treatment increased Nav1.5 expression (n = 6; 36% ± 10%) and decreased total collagen and collagen I (n = 5-6; 55%-66% ± 15%) in aged atria (P < .05) and decreased collagen I and III and TGF-ß1 mRNA (P < .05). Voltage-clamp experiments demonstrated that relaxin treatment (100 nM for 2 days) increased atrial INa by 46% ± 4% (n = 12-13/group, P < .02). CONCLUSION: Relaxin suppresses AF through an increase in atrial conduction velocity by decreasing atrial fibrosis and increasing INa. These data provide compelling evidence that relaxin may serve as an effective therapy to manage AF in geriatric patients by reversing fibrosis and modulating cardiac ionic currents.

Myocardial extracellular volume fraction quantified by cardiovascular magnetic resonance is increased in diabetes and associated with mortality and incident heart failure admission.

AIMS: Diabetes may promote myocardial extracellular matrix (ECM) expansion that increases vulnerability. We hypothesized that: (i) type 2 diabetes would be associated with quantitative cardiovascular magnetic resonance (CMR) measures of myocardial ECM expansion, i.e. extracellular volume fraction (ECV); (ii) medications blocking the renin-angiotensin-aldosterone system (RAAS) would be associated with lower ECV; and (iii) ECV in diabetic individuals would be associated with mortality and/or incident hospitalization for heart failure. METHODS AND RESULTS: We enrolled 1176 consecutive patients referred for CMR without amyloidosis and computed ECV from measures of the haematocrit and myocardial and blood T1 pre- and post-contrast. Linear regression modelled ECV; Cox regression modelled mortality and/or hospitalization for heart failure. Diabetic individuals (n = 231) had higher median ECV than those without diabetes (n = 945): 30.2% (IQR: 26.9-32.7) vs. 28.1% (IQR: 25.9-31.0), respectively, P < 0.001). Diabetes remained associated with higher ECV in models adjusting for demographics, comorbidities, and medications (P < 0.001). Renin-angiotensin-aldosterone system blockade was associated with lower ECV (P = 0.028) in multivariable linear models. Over a median of 1.3 years (IQR: 0.8-1.9), 38 diabetic individuals had events (21 incident hospitalizations for heart failure; 24 deaths), and ECV was associated with these events (HR: 1.52, 95% CI: 1.21-1.89 per 3% ECV increase) in multivariable Cox regression models. CONCLUSION: Diabetes is associated with increased ECV. Extracellular volume fraction detects amelioration of ECM expansion associated with RAAS blockade, and is associated with mortality and/or incident hospitalization for heart failure in diabetic individuals. Extracellular matrix expansion may be an important intermediate phenotype in diabetic individuals that is detectable and treatable.

Effectiveness of late gadolinium enhancement to improve outcomes prediction in patients referred for cardiovascular magnetic resonance after echocardiography.

BACKGROUND: Echocardiography (echo) is a first line test to assess cardiac structure and function. It is not known if cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) ordered during routine clinical practice in selected patients can add additional prognostic information after routine echo. We assessed whether CMR improves outcomes prediction after contemporaneous echo, which may have implications for efforts to optimize processes of care, assess effectiveness, and allocate limited health care resources. METHODS AND RESULTS: We prospectively enrolled 1044 consecutive patients referred for CMR. There were 38 deaths and 3 cardiac transplants over a median follow-up of 1.0 years (IQR 0.4-1.5). We first reproduced previous survival curve strata (presence of LGE and ejection fraction (EF) < 50%) for transplant free survival, to support generalizability of any findings. Then, in a subset (n = 444) with contemporaneous echo (median 3 days apart, IQR 1-9), EF by echo (assessed visually) or CMR were modestly correlated (R(2) = 0.66, p < 0.001), and 30 deaths and 3 transplants occurred over a median follow-up of 0.83 years (IQR 0.29-1.40). CMR EF predicted mortality better than echo EF in univariable Cox models (Integrated Discrimination Improvement (IDI) 0.018, 95% CI 0.008-0.034; Net Reclassification Improvement (NRI) 0.51, 95% CI 0.11-0.85). Finally, LGE further improved prediction beyond EF as determined by hazard ratios, NRI, and IDI in all Cox models predicting mortality or transplant free survival, adjusting for age, gender, wall motion, and EF. CONCLUSIONS: Among those referred for CMR after echocardiography, CMR with LGE further improves risk stratification of individuals at risk for death or death/cardiac transplant.

Association between extracellular matrix expansion quantified by cardiovascular magnetic resonance and short-term mortality.

BACKGROUND: Extracellular matrix expansion may be a fundamental feature of adverse myocardial remodeling, it appears to be treatable, and its measurement may improve risk stratification. Yet, the relationship between mortality and extracellular matrix is not clear because of difficulties with its measurement. To assess its relationship with outcomes, we used novel, validated cardiovascular magnetic resonance techniques to quantify the full spectrum of extracellular matrix expansion not readily detectable by conventional cardiovascular magnetic resonance. METHODS AND RESULTS: We recruited 793 consecutive patients at the time of cardiovascular magnetic resonance without amyloidosis or hypertrophic cardiomyopathy as well as 9 healthy volunteers (ages 20-50 years). We measured the extracellular volume fraction (ECV) to quantify the extracellular matrix expansion in myocardium without myocardial infarction. ECV uses gadolinium contrast as an extracellular space marker based on T1 measures of blood and myocardium pre- and post-gadolinium contrast and hematocrit measurement. In volunteers, ECV ranged from 21.7% to 26.2%, but in patients it ranged from 21.0% to 45.8%, indicating considerable burden. There were 39 deaths over a median follow-up of 0.8 years (interquartile range 0.5-1.2 years), and 43 individuals who experienced the composite end point of death/cardiac transplant/left ventricular assist device implantation. In Cox regression models, ECV related to all-cause mortality and the composite end point (hazard ratio, 1.55; 95% confidence interval, 1.27-1.88 and hazard ratio, 1.48; 95% confidence interval, 1.23-1.78, respectively, for every 3% increase in ECV), adjusting for age, left ventricular ejection fraction, and myocardial infarction size. CONCLUSIONS: ECV measures of extracellular matrix expansion may predict mortality as well as other composite end points (death/cardiac transplant/left ventricular assist device implantation).

Minimally invasive surgery using bipolar radiofrequency energy is effective treatment for refractory atrial fibrillation.

BACKGROUND: A web-based registry was used to prospectively study patients after minimally invasive surgery with monitoring to determine freedom from atrial fibrillation (AF) (clinicaltrials.gov/ct2/show/NCT00747838). This is a report showing the utility and feasibility of the registry. METHODS: All patients had symptomatic AF refractory to medical treatment. Surgical ablation was performed using bipolar radiofrequency (RF) energy with a clamp around pulmonary veins and additional RF was delivered to ablate ganglionic plexi and create linear lesions. After a 3-month blanking period, prolonged electrocardiogram monitoring was done at 6 months, 1 year, and 2 years. Success was defined as no episodes of AF and atrial tachyarrhythmias greater than 30 seconds by monitoring. RESULTS: A total of 118 patients were studied from 4 institutions from June 2006 to February 2011. Seventy-two patients were male (61%). The mean age was 64±9 years. CHADS2 (Congestive heart failure, Hypertension, age greater than 75, Diabetes and Stroke score for risk of thromboembolic events in patients with atrial fibrillation) was 1.3. Warfarin was used in 92 (78%), antiarrhythmic medications in 108 (92%), and 35 (30%) had previous catheter ablation. Paroxysmal AF was present in 80 (68%), persistent AF present in 35 (30%), and long-standing persistent present in 3 (2%). The mean left atrial size was 4.4 cm. The surgical approach was bilateral minithoracotomy in 69 (58%) and totally thoracoscopic in 49 (42%). The left atrial appendage was excluded or excised in 112 (95%) patients. There were no deaths related to the procedure. Only 5 (4%) patients required ventilation greater than 24 hours; permanent pacemaker was needed in 3 (2%) patients. Mean length of hospital stay was 5 days. At a mean follow-up of 16.5 months, 80% of patients were free of AF off antiarrhythmic medications with long-term monitoring. Quality of life data showed significant improvement at 6 and 12 months. CONCLUSIONS: The STAR (stable angina in practice) registry is an effective web-based tool for long-term follow-up of patients after surgery for AF. Minimally invasive surgery with lesions created by bipolar RF energy is an effective treatment for AF in carefully selected patients.

In vivo porcine left atrial wall stress: Effect of ventricular tachypacing on spatial and temporal stress distribution.

Animal models of ventricular tachypacing (VTP) have been successfully used to reproduce the relevant features observed in patients with atrial fibrillation, such as increased atrial pressure and volume, ion-channel alterations and fibrosis. After performing VTP on a healthy Yorkshire pig, we measured an increase in volume of 60%, a two-fold rise in pressure, and a complex pattern of local mechanical, histological and biochemical changes, including a generalized stiffening of the wall. A protocol recently developed was employed to generate computational models of the porcine left atrium mechanics in healthy conditions and after VTP. Comparison of the stress distribution in the healthy vs. VTP case provided a map of how pressure overload affects and modifies left atrium mechanics. Overall, a positive increase in stress was computed after the VTP treatment. Regions of large increase in the stresses post-VTP were the appendage boundaries, the area around the lower pulmonary vein and the area in the front of the atrium towards the appendage. Due to the elevated stress, the back of the atrium mainly modified its mechanical response, while the appendage remodeled both its shape and its mechanical properties. Large changes in the shape of the mitral valve annulus could be observed as a consequence of the remodeling in the front of the atrium. The relation between local mechanical stress and remodeling that emerges from the results is in agreement with our hypothesis that the structural changes in the atrium are a consequence of a stress-mediated mechanism.

In vivo porcine left atrial wall stress: Computational model.

Most computational models of the heart have so far concentrated on the study of the left ventricle, mainly using simplified geometries. The same approach cannot be adopted to model the left atrium, whose irregular shape does not allow morphological simplifications. In addition, the deformation of the left atrium during the cardiac cycle strongly depends on the interaction with its surrounding structures. We present a procedure to generate a comprehensive computational model of the left atrium, including physiological loads (blood pressure), boundary conditions (pericardium, pulmonary veins and mitral valve annulus movement) and mechanical properties based on planar biaxial experiments. The model was able to accurately reproduce the in vivo dynamics of the left atrium during the passive portion of the cardiac cycle. A shift in time between the peak pressure and the maximum displacement of the mitral valve annulus allows the appendage to inflate and bend towards the ventricle before the pulling effect associated with the ventricle contraction takes place. The ventricular systole creates room for further expansion of the appendage, which gets in close contact with the pericardium. The temporal evolution of the volume in the atrial cavity as predicted by the finite element simulation matches the volume changes obtained from CT scans. The stress field computed at each time point shows remarkable spatial heterogeneity. In particular, high stress concentration occurs along the appendage rim and in the region surrounding the pulmonary veins.

Severe functional mitral regurgitation arising from isolated annular dilatation.

Functional mitral regurgitation or functional tricuspid regurgitation most commonly result from maladaptive remodeling due to ischemic heart disease or idiopathic dilatative cardiomyopathy. We report a case of significant functional mitral regurgitation and functional tricuspid regurgitation arising from isolated annular dilatation secondary to atrial fibrillation and associated atrial remodeling. The patient underwent successful mitral and tricuspid valve repair and a bi-atrial Maze procedure.

Intramural dyssynchrony from acute right ventricular apical pacing in human subjects with normal left ventricular function.

Ventricular pacing causes early myocardial shortening at the pacing site and pre-stretch at the opposing ventricular wall. This contraction pattern is energetically inefficient and may lead to decreased cardiac function. This study was designed to describe the acute effects of right ventricular apical (RV(a)) pacing on dyssynchrony and systolic function in human subjects with normal left ventricular (LV) function and compare these effects to pacing from alternate ventricular sites. Patients (n = 26) undergoing an electrophysiology evaluation were studied during atrial pacing (AAI) and dual chamber pacing from the RV(a), left ventricular free wall (LV(fw)), and the combination of RV(a) and LV(fw) (BiV). Tissue Doppler imaging was used to measure intramural dyssynchrony by utilizing an integrated cross-correlation synchrony index (CCSI) from the apical 4-chamber view. RV(a) and BiV pacing significantly reduced systolic function as measured by longitudinal systolic contraction amplitude (SCA(long)) (p < 0.05) and LV velocity time integral (VTI) (p < 0.05) compared to AAI and LV(fw) pacing. RV(a) (and to a lesser extent BiV) pacing resulted in septal and lateral intramural dyssynchrony as indicated by significantly (p < 0.05) lower CCSI values as compared to AAI. CCSI was significantly (p < 0.05) worse during RV(a) than LV(fw) pacing. In patients with normal LV function, acute ventricular pacing in the RV(a) alone, or in conjunction with LV(fw) pacing (BiV), results in impaired regional and global LV systolic function and intramural dyssynchrony as compared to LV(fw) pacing alone.

Decreasing pain and anxiety associated with patient-activated atrial shock: a placebo-controlled study of adjunctive sedation with oral triazolam.

INTRODUCTION: Implantable atrial defibrillators (IADs) have proved to be safe and effective in the management of atrial fibrillation. A potential limitation of self-activated IAD therapy is patient-reported pain and anxiety. The main objective of the present study was to determine whether triazolam improved patient perception of the shock experience or altered patient memory of shock discomfort relative to placebo. METHODS AND RESULTS: A total of 15 men and women (mean age: 59 +/- 6 years) were enrolled in this double-blind, placebo-controlled, crossover study of triazolam. Randomized study medication was administered orally 75 minutes prior to scheduled atrial shock delivery. Patient perception of the shock experience was assessed along with sedation, memory, anxiety, and mood. Triazolam reduced mean pre-shock anxiety (t= 2.98, df = 14, P = 0.01) and shock-related pain (t= 2.74, df = 13, P = 0.01) and intensity (t= 2.64, df = 13, P = 0.018) relative to placebo. Similarly, participants recalled less discomfort the morning after shock with triazolam than with placebo (t= 2.82, df = 11, P = 0.017). CONCLUSIONS: This study was the first to investigate the use of an oral benzodiazepine administered prior to patient-activated shock delivery with an IAD. Our data indicate that oral triazolam is beneficial in decreasing pain and anxiety associated with self-activated atrial defibrillation. If triazolam provides a similar benefit in the community to that which has been reported here, this medication could be offered to patients as an adjunct to intermittent IAD therapy.

Understanding atrial symptom reports: objective versus subjective predictors.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with a variety of symptoms such as dizziness, palpitations, shortness of breath, and other signs of heart failure, which in turn impact quality of life (QOL). Implantable cardioverter defibrillators with atrial therapies (ICDs-ATs) have been shown to reduce AF symptoms and improve QOL in select AF samples. METHOD: This study examined the strength of relationships between objective (device-detected AF events) versus subjective (emotional symptoms) data and AF symptoms (number) reported as part of the Patient Atrial Shock Survey of Acceptance and Tolerance Study (N = 96, 72% men, M age = 65, SD = 12). Depression and anxiety were assessed via the Center for Epidemiological Studies--Depression Scale and the-State Trait Anxiety Inventory. AF disease burden was measured via a number of device-detected AF episodes and the Atrial Tachyarrhythmia Symptom Severity Scale. RESULTS: Hierarchical multiple regression analysis indicated that negative emotions accounted for a significant 13.2% of unique variance in AF symptom score (F change (1, 54) = 9.625, P = 0.003). On the other hand, the number of device-detected AF episodes accounted for non-significant 8.2% of unique variance in the AF symptom score (P = 0.167). The full model explained 25.7% of the variance in AF symptom score (F(6, 54) = 3.110, P = 0.011). Specifically, greater number of treated AF episodes (beta= 0.251, P = 0.043) and higher levels of negative emotions (beta= 0.369, P = 0.003) predicted greater number of reported AF symptoms. CONCLUSION: Therefore, psychological distress may be a significant confounding factor affecting patient's report of AF symptoms rather than the actual experience of recurrent AF episodes.

Do patients accept implantable atrial defibrillation therapy? Results from the Patient Atrial Shock Survey of Acceptance and Tolerance (PASSAT) Study.

INTRODUCTION: The Medtronic Jewel AF 7250 is an implantable cardioverter defibrillator with atrial and ventricular therapies (ICD-AT). The ICD-AT is effective in managing atrial tachyarrhythmias (atrial fibrillation [AF]), but patient acceptance remains an issue. This aim of this study was to measure ICD-AT acceptance. METHODS AND RESULTS: ICD-AT acceptance was evaluated in 96 patients enrolled in the "Jewel AF-AF-Only Study" for > or =3 months of follow-up (mean 19 months). Patients were mostly men (72%; age 65 +/- 12 years). Clinical data and a written survey (75% response rate) were used to quantify demographics, AF frequency and symptoms, atrial defibrillation therapy, quality of life (QOL), psychosocial distress, and ICD-AT therapy acceptance. From implant to survey, AF symptom and severity scores decreased by 18% (P < or = 0.05), and QOL (SF-36) scores increased by 15% to 50% (P < or = 0.05). ICD-AT therapy acceptance was high, with 71.3% of patients scoring in the 75th percentile on the Florida Patient Acceptance Survey. ICD-AT acceptance was correlated with the Physical Component Scale and Mental Health Component Scale scores of the SF-36 (r = 0.28 and 0.35, respectively). ICD-AT acceptance was negatively correlated with depressive symptomatology (r =-0.59), trait anxiety (r =-0.48), illness intrusiveness (r =-0.55), and AF symptom and severity scores (r =-0.26). ICD-AT acceptance did not correlate with preimplant cardioversions, number of atrial shocks, AF episodes detected by the device, or device implant duration. CONCLUSION: Most patients accepted ICD-AT therapy. Patients were more likely to accept ICD-AT if they had less psychosocial distress, greater QOL, and lower AF symptom burden.

Sleep quality among patients treated with implantable atrial defibrillation therapy: effect of nocturnal shock delivery and psychological distress.

INTRODUCTION: The Medtronic ICD-AT has atrial/ventricular therapies, which can be programmed to deliver atrial defibrillation during sleep, intended to potentially decrease shock anxiety/pain and lifestyle disruption. However, these shocks may diminish sleep quality. This study examined atrial shock characteristics (i.e., mode, frequency), AF symptoms, and psychological factors as determinants of sleep quality. METHODS AND RESULTS: The 96 ICD-AT patients were mostly men (72%; M age 65 +/- 12 years) and implanted for 1.6 years (SD = 0.8 years). Patients were divided into shock groups based on the proportion of mode (> or =90%) of total atrial shocks received. Patients were grouped into either automatic-nocturnal shock group (8 P.M.-8 A.M.; n = 35) or manual-awake shock group (n = 42). Psychological measures included Pittsburgh Sleep Quality Index (PSQI), Center for Epidemiology Studies-Depression Scale, State-Trait Anxiety Inventory, and Illness Intrusiveness Rating Scale. Atrial fibrillation disease burden was assessed via atrial symptom score and atrial shock use. PSQI global scores were similar between manual (7.67 +/- 2.53) and automatic shock (8.20 +/- 2.93) groups. A multiple hierarchical regression analysis indicated that no atrial shock variables were predictive of sleep quality; yet, both AF symptom (B = 0.226, P = 0.040) and depression (B = 0.392, P = 0.034) scores predicted diminished sleep quality, accounting for 42% of the variance in global sleep quality (P < 0.001). CONCLUSION: These results suggest that atrial defibrillation therapy does not have a deleterious impact on sleep. However, the significance of AF symptoms and depression indicate that comprehensive care of both physical and psychological symptomatology may improve sleep quality in ICD-AT patients.

Effect of an implantable cardioverter defibrillator with atrial detection and shock therapies on patient-perceived, health-related quality of life.

BACKGROUND: This study used a device (DDD implantable cardioverter defibrillator [ICD]) capable of delivering pacing and shock therapies to restore normal sinus rhythm in patients with atrial tachycardias or atrial fibrillation (AF). The purpose of this study was to assess the effect of the device on patient-perceived, health-related quality of life (QOL). METHODS: The DDD ICD was implanted in 267 patients with drug refractory, symptomatic AF from 45 centers across Europe, the United States, and Canada. Patients completed self-reported, validated QOL assessments at baseline and at 3- and 6-month follow-up visits (The Medical Outcomes Short Form 36 [SF-36] and the Symptom Checklist [SCL]). RESULTS: The mean age of the study group was 62 +/- 12 years, and 73% of the patients were male. A total of 150 patients completed SF-36 assessments, and 138 patients completed SCL assessments at all 3 times. Baseline scores were more impaired (P <.05) on most SF-36 scales compared with norms for a general population, but were similar to a comparison group of patients with AF who were referred to tertiary care centers. The role-physical, physical functioning, vitality, mental health, and social functioning scales all improved significantly with time (all P <.04). Similarly, symptom frequency and severity (SCL) also improved significantly from baseline to 6 months (both P <.01). Shock therapy was delivered in 86 of the 150 patients (57%) with complete SF-36 evaluations. There was no evidence that receiving shocks decreased the relative improvement in QOL associated with implantation of the device. CONCLUSIONS: In a 6-month period, QOL improves after implantation of a DDD ICD with atrial shock and pacing therapies. These improvements were not attenuated by receipt of shocks.