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BACKGROUND - Ictal asystole is a rare, serious, and often treatable cause of syncope. There are currently limited data to guide management. Characterization of ictal syncope predictors may aid in the selection of high-risk patients for treatments such as pacemakers.
METHODS AND RESULTS - We searched our epilepsy monitoring unit database from October 2003 to July 2013 for all patients with ictal asystole events. Clinical, electroencephalogram, and ECG data for each of their seizures were examined for their relationships with ictal syncope events. In 10 patients with ictal asystole, we observed 76 clinical seizures with 26 ictal asystole episodes, 15 of which led to syncope. No seizure with asystole duration≤6 s led to syncope, whereas 94% (15/16) of seizures with asystole duration>6 s led to syncope (P=0.02). During ictal asystole events, 4 patients had left temporal seizure onset, 4 patients had right temporal seizure onset, and 2 patients had both. Syncope was more common with left temporal (40%) than with right temporal seizures (10%; P=0.002). Treatment options included antiepileptic drug changes, epilepsy surgery, and pacemaker implantation. Eight patients received pacemakers. During follow-up of 72±95 months, all patients remained syncope free.
CONCLUSIONS - Ictal asystole>6 s is strongly associated with ictal syncope. Ictal syncope is more common in left than in right temporal seizures. A permanent pacemaker should be considered in patients with ictal syncope if they are not considered good candidates for epilepsy surgery.
© 2014 American Heart Association, Inc.
BACKGROUND - The use of cardiac implantable electronic devices (CIEDs) has expanded dramatically over the past decade, but net clinical benefit has been curtailed by increasing infectious complications. In particular, CIED-related infectious endocarditis (IE) is a serious condition with significant morbidity and mortality.
METHODS - We performed a single-center, retrospective study between July 2006 and February 2011 with CIED-related IE, defined by either lead vegetations detected on echocardiography or by fulfilling Duke criteria for definite endocarditis. Clinical parameters and outcomes were detailed by electronic medical record review and vital status was confirmed by the Social Security Death Index.
RESULTS - Eighty patients (median age 67, interquartile range 56-75, 58 M/22 F) were diagnosed with CIED-related IE. Overall mortality was 36% with a median time to death of 95 days from presentation. Over half (52%) of the deaths were infection related with a median time to death of 29 days. Multivariate analysis showed methicillin-resistant Staphylococcus aureus (MRSA) infection (odds ratio [OR] 0.158; 95% confidence interval [CI], 0.047-0.534; P = .003) and concomitant valve endocarditis (OR 0.141, CI 0.041-0.491, P = .002) independently predicted mortality.
CONCLUSION - In this contemporary series, all-cause mortality in patients with CIED-related IE was high with a short time to death from onset of infection. MRSA and concomitant valve infection were the most powerful independent predictors of mortality.
©2014 Wiley Periodicals, Inc.
BACKGROUND/AIMS - Rehabilitation of the bilaterally paralyzed human larynx remains a complex clinical problem. Conventional treatment generally involves surgical enlargement of the compromised airway, but often with resultant dysphonia and risk of aspiration. In this retrospective study, we compared one such treatment, posterior cordotomy, with unilateral laryngeal pacing: reanimation of vocal fold opening by functional electrical stimulation of the posterior cricoarytenoid muscle.
METHODS - Postoperative peak inspiratory flow (PIF) values and overall voice grade ratings were compared between the two surgical groups, and pre- and postoperative PIF were compared within the pacing group.
RESULTS - There were 5 patients in the unilateral pacing group and 12 patients in the unilateral cordotomy group. Within the pacing group, postoperative PIF values were significantly improved from preoperative PIF values (p = 0.04) without a significant effect on voice (grade; p = 0.62). Within the pacing group, the mean postoperative PIF value was significantly higher than that in the cordotomy group (p = 0.05). Also, the mean postoperative overall voice grade values in the pacing group were significantly lower (better) than those of the cordotomy group (p = 0.03).
CONCLUSION - Unilateral pacing appears to be an effective treatment superior to posterior cordotomy with respect to postoperative ventilation and voice outcome measures.
Copyright © 2013 S. Karger AG, Basel.
INTRODUCTION - The incidence of cardiac implantable electronic device (CIED) infections has risen rapidly since 2004. A commercially available minocycline and rifampin impregnated antibacterial envelope has been associated with a low CIED infection rate. We performed a retrospective cohort study analyzing CIED infection rates in patients receiving an antibacterial envelope.
METHODS - Prospectively applied criteria for use of the antibacterial envelope included ≥2 of the following: diabetes, renal insufficiency, anticoagulation, chronic corticosteroid use, fever or leukocytosis at the time of implantation, prior CIED infection, ≥3 leads (cardiac resynchronization therapy or abandoned leads), pacemaker dependence, or early pocket reentry. CIED infection rate was compared to a cohort of patients with matched risk factors and a CIED implanted prior to use of the antibacterial envelope.
RESULTS - A total of 260 antibacterial envelopes were implanted from November 1, 2009 to April 30, 2012. The mean number of CIED infection risk factors was 2.8 ± 1.2. The control cohort (N = 639) was matched for mean number of CIED infection risk factors (2.8 ± 1.2), though individual risk factors differed. After a minimum of 90 days of follow-up, there was one CIED infection among patients who received an antibacterial envelope (0.4%), compared to 19 (3%) in controls (odds ratio [95% confidence interval] 0.13 [0.02-0.95], P = 0.04). This difference persisted after adjustment for covariates (0.09 [0.01-0.73], P = 0.02) and propensity score matching (0.11 [0.01-0.85], P = 0.04).
CONCLUSIONS - In patients prospectively identified at high risk for CIED infection, use of a commercially available antibacterial envelope was associated with a marked reduction in CIED infections when compared to a matched control cohort.
©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.
Symptomatic bradycardia may complicate atrial fibrillation (AF) and necessitate a permanent pacemaker. Identifying patients at increased risk for symptomatic bradycardia may reduce associated morbidities and health care costs. The aim of this study was to investigate predictors for developing bradycardia requiring a permanent pacemaker in patients with AF. The records of all patients treated for AF or atrial flutter in an academic hospital's emergency department from August 1, 2005, to July 31, 2008, were reviewed. Survival and the presence of a pacemaker as of November 1, 2011, were determined. Cases were defined as patients with pacemakers placed for bradycardia after their AF diagnoses. Patients without pacemakers who were followed constituted the control group. Variables for the logistic regression analysis were identified a priori. A post hoc model was fit adjusting for AF type and atrioventricular nodal blocker use. Of the 362 patients in the cohort, 119 cases had permanent pacemakers implanted for bradycardia after AF diagnosis, and 243 controls were alive without pacemakers. The median follow-up time was 4.5 years (interquartile range 3.8 to 5.4). Odds ratios were determined for age at the time of AF diagnosis (1.02, 95% confidence interval [CI] 1 to 1.04), female gender (1.58, 95% CI 0.95 to 2.63), previous heart failure (2.72, 95% CI 1.47 to 5.01), and African American race (0.33, 95% CI 0.12 to 0.94). The post hoc model identified permanent AF (odds ratio 2.99, 95% CI 1.61 to 5.57) and atrioventricular nodal blocker use (odds ratio 1.43, 95% CI 0.85 to 2.4). In conclusion, in patients with AF, heart failure and permanent AF each nearly triple the odds of developing bradycardia requiring a permanent pacemaker; although not statistically significant, our results suggest that women are more likely and African Americans less likely to develop bradycardia requiring pacemaker implantation.
Copyright © 2012 Elsevier Inc. All rights reserved.
In the setting of acute myocardial infarction, prolongation of the QRS interval on electrocardiography identifies patients at risk for needing permanent pacemaker implantation. However, the implications of prolonged QRS intervals in healthy subjects are unclear, especially given that the QRS prolongation encountered in this setting is typically mild. The aim of this study was to assess the relation between QRS duration and incident pacemaker implantation in a community-based cohort of 8,311 subjects (mean age 54 years, 55% women) who attended 17,731 routine examinations with resting 12-lead electrocardiography. QRS duration was analyzed as a continuous and a categorical variable (<100, 100 to <120, and > or =120 ms). During up to 35 years of follow-up, 157 participants (56 women) developed need for permanent pacemakers. In multivariable Cox regression models adjusting for cardiovascular risk factors and previous myocardial infarction or heart failure, mild QRS prolongation was associated with a threefold risk for pacemaker implantation (adjusted hazard ratio 2.90, 95% confidence interval 1.81 to 4.66, p <0.0001), and bundle branch block was associated with a fourfold risk for pacemaker implantation (hazard ratio 4.43, 95% confidence interval 2.94 to 6.68, p <0.0001). Each standard deviation increment in QRS duration (11 ms) was associated with an adjusted hazard ratio of 1.14 (95% confidence interval 1.11 to 1.18, p <0.0001) for pacemaker placement. This association remained significant after excluding subjects with QRS durations > or =120 ms. In conclusion, subjects with prolonged QRS durations, even without bundle branch block, are at increased risk for future pacemaker implantation. Such individuals may warrant monitoring for progressive conduction disease.
2010 Elsevier Inc. All rights reserved.
CONTEXT - Prolongation of the electrocardiographic PR interval, known as first-degree atrioventricular block when the PR interval exceeds 200 milliseconds, is frequently encountered in clinical practice.
OBJECTIVE - To determine the clinical significance of PR prolongation in ambulatory individuals.
DESIGN, SETTING, AND PARTICIPANTS - Prospective, community-based cohort including 7575 individuals from the Framingham Heart Study (mean age, 47 years; 54% women) who underwent routine 12-lead electrocardiography. The study cohort underwent prospective follow-up through 2007 from baseline examinations in 1968-1974. Multivariable-adjusted Cox proportional hazards models were used to examine the associations of PR interval with the incidence of arrhythmic events and death.
MAIN OUTCOME MEASURES - Incident atrial fibrillation (AF), pacemaker implantation, and all-cause mortality.
RESULTS - During follow-up, 481 participants developed AF, 124 required pacemaker implantation, and 1739 died. At the baseline examination, 124 individuals had PR intervals longer than 200 milliseconds. For those with PR intervals longer than 200 milliseconds compared with those with PR intervals of 200 milliseconds or shorter, incidence rates per 10 000 person-years were 140 (95% confidence interval [CI], 95-208) vs 36 (95% CI, 32-39) for AF, 59 (95% CI, 40-87) vs 6 (95% CI, 5-7) for pacemaker implantation, and 334 (95% CI, 260-428) vs 129 (95% CI, 123-135) for all-cause mortality. Corresponding absolute risk increases were 1.04% (AF), 0.53% (pacemaker implantation), and 2.05% (all-cause mortality) per year. In multivariable analyses, each 20-millisecond increment in PR was associated with an adjusted hazard ratio (HR) of 1.11 (95% CI, 1.02-1.22; P = .02) for AF, 1.22 (95% CI, 1.14-1.30; P < .001) for pacemaker implantation, and 1.08 (95% CI, 1.02-1.13; P = .005) for all-cause mortality. Individuals with first-degree atrioventricular block had a 2-fold adjusted risk of AF (HR, 2.06; 95% CI, 1.36-3.12; P < .001), 3-fold adjusted risk of pacemaker implantation (HR, 2.89; 95% CI, 1.83-4.57; P < .001), and 1.4-fold adjusted risk of all-cause mortality (HR, 1.44, 95% CI, 1.09-1.91; P = .01).
CONCLUSION - Prolongation of the PR interval is associated with increased risks of AF, pacemaker implantation, and all-cause mortality.
Wavefront propagation in cardiac tissue is affected greatly by the geometry of the wavefront. We describe a computer-controlled stimulator system that creates reproducible wavefronts of a predetermined shape and orientation for the investigation of the effects of wavefront geometry. We conducted demonstration experiments on isolated perfused rabbit hearts, which were stained with the voltage-sensitive dye, di-4-ANEPPS. The wavefronts were imaged using a laser and a charge-coupled device (CCD) camera. The stimulator and imaging systems have been used to characterize the relationship between wavefront velocity and fiber orientation. This approach has potential applications in investigating curvature effects, testing numerical models of cardiac tissue, and creating complex wavefronts using one-, two-, or three-dimensional electrode arrays.