John Paul Mounsey

Epidemiology, management, and outcomes of sustained ventricular arrhythmias after continuous-flow left ventricular assist device implantation.

BACKGROUND Left ventricular assist devices (LVADs) are pivotal treatment options for patients with end-stage heart failure. Despite robust left ventricular unloading, the right ventricle remains unsupported and susceptible to hemodynamic perturbations from ventricular arrhythmias (VAs). Little is known about the epidemiology, management, resource use, and outcomes of sustained VAs in continuous-flow LVAD patients. METHODS We reviewed data from all consecutive patients receiving a continuous-flow LVAD at the University of North Carolina from January 2006 to February 2011. Patient demographics, pharmacotherapies, resource use, and outcomes were recorded. Descriptive statistics were generated, and multivariable logistic regression was used to assess the independent association of clinical variables on the development of postimplantation VAs. RESULTS Of 61 patients, 26 (43%) had sustained VAs after LVAD. Most were male (65%), had history of hypertension (65%), and had nonischemic cardiomyopathy (62%). Patients with VAs after LVAD more often had preimplant VAs (62% vs 14%, P < .01), prior implantable cardioverter-defibrillator (92% vs 71%, P = .04), and history of implantable cardioverter-defibrillator discharge (38% vs 11%, P < .01). Although length of stay was similar, those with postimplant VAs had greater rehospitalization rates, greater antiarrhythmic drug use, and frequently required external defibrillation. Using multivariable logistic regression, only history of prior VA was associated with postimplant arrhythmias (odds ratio 13.7, P < .001). CONCLUSIONS Ventricular arrhythmias in LVAD patients are common, often refractory to conservative therapy, and associated with frequent rehospitalization. Post-LVAD VAs, however, did not significantly impact survival or transplantation rates. Arrhythmia burden should be considered before LVAD placement, and future study should focus on the impact of VAs on quality of life.

The Effect of Anxiety and Depression on Symptoms Attributed to Atrial Fibrillation

Symptoms attributed to atrial fibrillation (AF) are nonspecific, and it remains unclear what influences perception of symptoms. Anxiety or depression may be important in modulating perception of AF symptoms. However, few longitudinal studies have addressed this effect.

Effect of Body Mass Index, Physical Activity, Depression, and Educational Attainment on High-Sensitivity C-Reactive Protein in Patients With Atrial Fibrillation

Atherosclerosis development is a complex process, with inflammation, indicated by elevated high-sensitivity C-reactive protein (hs-CRP), as a potential mediator. Obesity, physical activity, and depression have all been reported to affect hs-CRP. However, these factors are interconnected, and their relative individual importance remains unclear. From a separate prospective cohort study, 289 patients were selected for the present substudy. We assessed the relation of a variety of potential predictors and hs-CRP. Obesity, physical activity, and depression, in addition to several other potential factors, were analyzed in bivariate and multivariate linear regression models, adjusting for potential confounders. In unadjusted analyses, mild-to-moderate and severe depression were associated with increased hs-CRP compared to no or minimal depression. Vigorous physical activity was associated with decreased hs-CRP compared to no physical activity. All classes of obesity were associated with increased hs-CRP. In addition, attaining a college or graduate degree was associated with decreased hs-CRP compared to high school or less educational attainment. On multivariate analysis, depression was no longer associated with increased hs-CRP. Physical activity remained associated with decreased hs-CRP but only at vigorous levels. Educational attainment also remained associated but only at the collegiate or professional education level. Ultimately, obesity remained the greatest absolute predictor of elevated hs-CRP. In conclusion, in analyses of multiple factors potentially predictive of elevated hs-CRP in a large population of patients with subclinical coronary heart disease, we found the most important predictor to be obesity.

Accuracy of patient perception of their prevailing rhythm: a comparative analysis of monitor data and questionnaire responses in patients with atrial fibrillation.

BACKGROUND Atrial fibrillation (AF) guidelines recommend that symptom relief be a primary goal in management. However, patient perception of their prevailing rhythm is often inaccurate, complicating symptom-targeted treatment. OBJECTIVE The purpose of this study was to evaluate the accuracy of patient perception of their prevailing rhythm and identify factors that predict inaccuracies. METHODS Demographic and health status data were captured by questionnaires for 458 outpatients with documented AF. AF burden (%) was captured by 1-week continuous heart monitors. Patients estimated the length and frequency of their AF episodes by completing the AF Symptom Severity questionnaire. Patient reports were compared to AF burden, and outliers were identified and broken into 2 groups: patients with AF burden <10% who indicated near-continuous AF (overestimators) and patients with AF burden >90% who estimated little to no AF (underestimators). Multinomial logistic regression was used to identify predictors of inaccuracies (over- or underestimators). RESULTS By continuous monitor, 15% of patients were found to be over- or underestimators. Persistent AF, female sex, older age, anxiety, and depression were predictive of inaccurate patient perception. Persistent AF, female sex, and older age were predictive of underestimating, while mood disorders (anxiety and depression) were predictive of overestimating. The prevalence of underestimators was nearly twice that of overestimators. CONCLUSION Sex, age, and mood disorders are among factors that lead to inaccurate patient perception of their prevailing rhythm in patients with AF. Such modulating factors should be considered when evaluating treatment strategies. Consideration should be given to more liberal use of heart monitors in these patient populations to better target therapy.

Relation of Atrial Fibrillation Burden and N-Terminal Pro-Brain Natriuretic Peptide

Previous studies have noted a correlation between the presence of atrial fibrillation (AF) and elevated brain natriuretic peptide hormone level, although the exact nature of this association is unclear. Understanding the relation between AF and brain natriuretic peptide may enhance care for this patient population. The aim of this study was to establish the relationship between AF burden and N-terminal pro-brain natriuretic peptide (NT-proBNP) level. One hundred eighty-four patients who presented to the University of North Carolina electrophysiology clinic with AF underwent baseline questionnaires, laboratory testing (including NT-proBNP), echocardiography, and 1-week ambulatory rhythm monitoring. Multivariate linear regression was used to determine the association between AF burden and NT-proBNP level. Increased AF burden was associated with increased NT-proBNP level, and this association remained significant after adjusting for possible confounders. Compared with a 0% AF burden, those with an AF burden of 1% to 25% had a nearly 1.5-fold increase (p = 0.102), those with an AF burden of 26% to 99% had a nearly fourfold increase (p <0.001), and those with an AF burden of 100% had a nearly 4.5-fold increase (p <0.001). In conclusion, AF burden as assessed by continuous 1-week ambulatory rhythm monitoring is directly associated with NT-proBNP level. NT-proBNP may act as a useful surrogate for assessing AF burden.

Sudden Unexpected Death in North Carolina (SUDDEN): methodology review and screening results.

Objectives This paper describes the methodology for a prospective, community-based study of sudden unexpected death in Wake County, North Carolina. Methods From 1 March to 29 June 2013, data of presumed cardiac arrest cases were captured from Wake County Emergency Medical Services. Participants were screened into the presumed sudden unexpected death group based on specific and sequential screening criteria, and medical and public records were collected for each participant in this group. A committee of independent cardiologists reviewed all data to determine final inclusion/exclusion of each participant into registry. Results We received 398 presumed cardiac arrest referrals. Of these, 105 participants, age 18–65 years old, were identified as presumed sudden unexpected deaths. The primary reason for exclusion was survival to hospital (38%). Ninety-five per cent of participants in the presumed sudden unexpected death group experienced an unwitnessed death. Hypertension was present in almost 50%, while dyslipidaemia and diabetes mellitus were present in almost 25% of the same group. In addition, the presumed sudden unexpected death group includes 67.6% males (95% CI 58 to 76) whereas the control group only included 58.9% (95% CI 46 to 55) males. Conclusions Participant identification and data collection processes identify presumed sudden unexpected death cases and secure medical and public data for screening and final adjudication. The study infrastructure developed in Wake County will allow its expansion to other counties in North Carolina. Preliminary data indicate the study presently focuses on a population demographically representative of North Carolina.

Effectiveness of atrial fibrillation monitor characteristics to predict severity of symptoms of atrial fibrillation.

The goal of treatment for atrial fibrillation (AF) is often to control symptoms. It remains unclear whether targets for treatment such as AF rate or AF burden are correlated with AF symptom severity. Two hundred eighty-six patients completed a questionnaire of their general health and well-being, including a detailed AF symptom assessment immediately followed by a 7-day continuous monitor. AF characteristics assessed from the monitor included AF burden, AF rate, sinus rhythm rate, frequency and severity of pauses, and premature atrial contraction or premature ventricular contraction burden. Characteristics were analyzed separately for patients with paroxysmal or persistent AF. Symptom severity was assessed using the University of Toronto Atrial Fibrillation Severity Scale. Monitor characteristics were compared with AF symptom severity. The mean age of the cohort was 61.8 years and the majority of subjects were male (65.4%). Co-morbidities included hypertension (64.5%), sleep apnea (38.4%), congestive heart failure (19.6%), and diabetes (16.4%). In those with persistent or paroxysmal AF, there were no significant predictors of AF symptom severity. Specifically, heart rate in AF or sinus rhythm, AF burden, or premature atrial contraction or premature ventricular contraction burden was not predictive of AF symptom severity. After adjusting for potential cofounders (including age, gender, and co-morbidities), these findings persisted. In conclusion, there is no value in using AF monitor characteristics to predict symptoms in patients with AF.

Atrial Fibrillation Ablation Using a Closed Irrigation Radiofrequency Ablation Catheter

Background: Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open‐irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed‐irrigated RF catheters create equivalent lesions, but clinical outcomes are limited.

Prominent R wave in ECG lead V1 predicts improvement of left ventricular ejection fraction after cardiac resynchronization therapy in patients with or without left bundle branch block.

BACKGROUND QRS morphology on postprocedural ECG indicating posterolateral left ventricular pacing may be predictive of response to cardiac resynchronization therapy (CRT). OBJECTIVE The purpose of this study was to assess whether a positive vector in V1 and/or negative vector in lead I on the first postprocedural ECG, suggesting posterolateral capture from CRT, correlates with improvement in left ventricular ejection fraction (LVEF). METHODS A retrospective chart review was conducted on all patients who underwent CRT implantation at our institution between April 2008 and December 2011. Biventricular (BiV) paced QRS morphology was defined as R/S ≥1 in V1 and/or R/S ≤ 1 in lead I. The primary outcome was improvement of LVEF ≥7.5%. The χ(2) and t tests were used for analysis. RESULTS Of 68 patients, 49 (72%) met our BiV paced QRS morphology criteria. Thirty-four of these 49 patients (69%) had improvement in LVEF. Of the 19 patients who did not meet our criteria, 17 (89%) did not have an improvement in LVEF (sensitivity 94%, specificity 53%, χ(2) = 19.04, P < .0001). The average LVEF improvement in patients who met our BiV paced QRS morphology criteria was significantly greater than in those who did not (14.27% vs 2.63%, P = .0001). Preprocedural left bundle branch block was not a predictor of echocardiographic response. CONCLUSION Our results highlight the importance of periprocedural ECG analysis to optimize response to CRT. Moreover, patients without left bundle branch block still benefited from CRT if they met our BiV paced morphology criteria. This suggests that postprocedural left ventricular activation as reflected on the ECG may supersede the baseline conduction delay.

Early recurrences are not always benign after catheter ablation of atrial fibrillation:do we need to reassess the need for a blanking period?

Radiofrequency catheter ablation has become a wellaccepted management strategy for atrial fibrillation (AF). However, failure is not uncommon and only two-thirds or less of the patients are free of atrial fibrillation on long-term follow-up.1,2 It has been recognized that early recurrence of atrial tachyarrhythmia (ERAT), usually defined as arrhythmia recurrence in the first 3 months following ablation, may not always predict recurrent arrhythmia later, although retrospective studies have shown that ERAT is frequently associated with late recurrence (LR) of atrial tachyarrhythmia.3,4 In a study published in this issue of the Journal, Andrade et al. have addressed the question of the relationship of early and late recurrence in a prospectively designed study.5 ERAT is common, occurring in as many as 16–65% of patients, with pooled estimate of 38%.3-7 Almost half of the patients experiencing ERAT remain arrhythmia free on long-term follow-up.3,4 ERAT may be mechanistically different from LR and may be related to potentially reversible mechanisms of arrhythmia related to the ablation procedure. Acute myocardial injury and the subsequent inflammatory response, as well as modifications of the cardiac autonomic nervous system provide an early (and potentially reversible) proarrhythmic substrate because of altered atrial myocardial conduction and refractoriness. Unlike early recurrences, late recurrences are more likely attributable to reconnections and reactivation of proarrhythmic substrates. Others are reentrant arrhythmias developing from gaps in linear ablation lesions. Although it is recognized that ERAT does not always lead to LR, occurrence of ERAT certainly increases the risk of later recurrences.3,4,7 Patients with ERAT are heterogeneous with a definite increase in the risk for LR if the ERAT occurs in the later part of the 3-month window used to define it. A few studies have clearly documented that the later the ERAT in the 3-month window, the higher the risk of late recurrence.3 Predictors of ERAT include not only markers of acute inflammation (including body temperature, CRP levels, and anatomic changes on magnetic resonance imaging),8-11 but