Left atrial booster pump function is an independent predictor of subsequent life-threatening ventricular arrhythmias in non-ischaemic cardiomyopathy.

AIMS: Left atrial (LA) function helps to preserve cardiac output and to control pulmonary capillary wedge pressure in the setting of left ventricular (LV) impairment, but little is known about the contribution of the LA function to ventricular arrhythmia. We sought whether LA booster pump function was associated with arrhythmias in patients undergoing primary prevention implantable cardioverter-defibrillator (ICD) implantation for non-ischaemic dilated cardiomyopathy (NICM), independent of global longitudinal strain (GLS) and mechanical dispersion (MD). METHODS AND RESULTS: We identified 124 NICM patients (56 ± 13, 67 male) who underwent echocardiography pre-ICD implantation for primary prevention. The main outcome measure was appropriate ICD therapy (anti-tachycardia pacing or shock). The mitral A-wave was used as an LA functional marker. MD was defined as standard deviation of time to peak strain of each segment. Over a median follow-up of 3.8 ± 2.2 years, 36 patients had appropriate ICD therapy, including 23 shocks. Patients with appropriate ICD therapy had lower A-wave velocity (P < 0.001), larger LA volume (P < 0.001), and impaired circumferential MD (P = 0.006), but similar ejection fraction (EF) (P = 0.40) and GLS (P = 0.11). In sequential Cox proportional hazards models, A-wave, E/A ratio, and GLS were significantly associated with outcomes, independent of age, sex, and cardiac resynchronization therapy defibrillator or left bundle branch block. In nested Cox models, mitral A-wave had a prognostic value incremental to models with LV systolic (EF and GLS) and diastolic functional parameters (E/A, E/e', and LA volume) and MD. CONCLUSION: LA booster pump function was an independent and incremental predictor of arrhythmias in NICM over GLS and MD, and may aid better risk stratification in this population.

A prospective study of anxiety in ICD patients with a pilot randomized controlled trial of cognitive behavioral therapy for patients with moderate to severe anxiety.

PURPOSE: Stress and anxiety are potential consequences from arrhythmias and implantable cardioverter defibrillator (ICD) shocks that can contribute to substantial morbidity. We assessed anxiety associated with an ICD and whether cognitive behavioral therapy (CBT) reduces anxiety. METHODS: The study consisted of two parts: part 1 (N = 690) was a prospective cross-sectional observational study of consecutive ICD patients. Patients completed the Beck Anxiety Inventory (BAI), Generalized Anxiety Disorder Scale (GAD-7), Florida Shock Anxiety Scale (FSAS), and Florida Patient Acceptance Survey (FPAS) psychometric tests. Part 2 (N = 29) was a pilot randomized controlled trial of CBT (three sessions in 3 months) vs. usual care (UC) in patients with BAI ≥ 19 from part 1. RESULTS: The median BAI and GAD-7 scores were 5 and 2, respectively. By BAI scores, 64.5 % had minimal and 3.9 % had severe anxiety. By GAD-7 scores, 73.0 % had low probability of anxiety and 2.9 % had high anxiety. Higher anxiety levels were associated with recent (p = 0.017) and total number of shocks (p = 0.002). Any shock was associated with fear about shocks (FSAS, p < 0.001) and reduced patient ICD acceptance (FPAS, p = 0.019). In the pilot trial of CBT, median BAI scores decreased from 24.5 to 11 at 1 year (p = 0.031) in the CBT group and GAD-7 scores from 12.5 to 7 (p = 0.063); no significant changes in anxiety scores were observed in the UC group. CONCLUSIONS: Severe anxiety was present in a small proportion of ICD patients, but higher anxiety was associated with recent and total number of shocks. The small pilot study suggested that a simple program of CBT might lower moderate-high anxiety with lasting effects to 1 year and supports the need for a larger trial to validate these results. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00851071. URL: http://clinicaltrials.gov/ct2/show/NCT00851071?term=anxiety+in+icd+patients+cleveland+clinic&rank=1.

Remote monitoring of cardiovascular devices: a time and activity analysis.

BACKGROUND: Expanding indications for cardiovascular implantable electronic devices are accompanied by an increasing burden of device clinic follow-up. Remote monitoring (RM) may be less time-consuming compared to in-office follow-up; however, its effect on the device clinic workflow has not been clarified. OBJECTIVE: To determine the impact of RM on device clinic workflow. METHODS: Detailed workflow data were prospectively collected over a 2-week period in a busy device clinic. RESULTS: Five hundred remote transmissions were received from 434 patients between March 1 and March 16, 2011--346 implantable cardioverter-defibrillator, 84 pacemaker, and 70 implantable loop recorder transmissions--on 4 RM platforms (CareLink 56.4%, Merlin.net 21.4%, LATITUDE 17.8%, and Home Monitoring 4.4%). The mean time spent per transmission was 11.5 ± 7.7 minutes, which was less than in-person interrogations (27.7 ± 9.9 minutes; P <.01). Of 500 transmissions, 135 (27.0%) demonstrated clinically important findings; however, only 41 (8.2%) were forwarded for physician review. Of 500 transmissions, 138 (27.6%) were unscheduled, and these were more likely to contain a clinically important event (56 of 138 [40.6%] vs 79 of 362 [21.8%]; P = .0001). A total of 5.8% of the transmissions were duplicate. Transmissions that revealed clinically important findings took longer to process than those that did not (21.0 ± 7.4 minutes vs 10.1 ± 2.1 minutes; P <.05). A total of 49.2% of the scheduled remote transmissions were missed because of patient noncompliance. Telephone follow-up of patients (mean 21 patients/d) who missed scheduled remote transmissions took a mean of 55.1 (range 20-98) min/d. CONCLUSIONS: Analysis of RM transmissions has significant implications for the device clinic workflow. Nonactionable transmissions are rapidly processed, allowing clinicians to focus on clinically important findings. However, poor patient compliance complicates the workflow efficiency of currently available systems.

Implantable cardioverter-defibrillator FDA safety advisories: Impact on patient mortality and morbidity.

BACKGROUND: A significant proportion of implantable cardioverter-defibrillators (ICDs) have been subject to Food and Drug Administration (FDA) advisories. The impact of device advisories on mortality or patient care is poorly understood. Although estimated risks of ICD generators under advisory are low, dependency on ICD therapies to prevent sudden death justifies the assessment of long-term mortality. OBJECTIVE: To test the association of FDA advisory status with long-term mortality. METHODS: The study was a retrospective, single-center review of clinical outcomes, including device malfunctions, in patients from implantation to either explant or death. Patients with ICDs first implanted at Cleveland Clinic between August 1996 and May 2004 who became subject to FDA advisories on ICD generators were identified. Mortality was determined by using the Social Security Death Index. RESULTS: In 1644 consecutive patients receiving first ICD implants, 704 (43%) became subject to an FDA advisory, of which 172 (10.5%) were class I and 532 (32.3%) were class II. ICDs were explanted before advisory notifications in 14.0% of class I and 10.1% of class II advisories. Among ICDs under advisory, 28 (4.0%) advisory-related and 15 non-advisory- related malfunctions were documented. Over a median follow-up of 70 months, 814 patients died. Kaplan-Meier 5-year survival rate was 65.6% overall, and 64.2, 61.1, and 69.3% in patients with no, class I, and class II advisories, respectively (P = .17). CONCLUSIONS: ICD advisories impacted 43% of the patients. Advisory-related malfunctions affected 4% within the combined advisory group. Based on a conservative management strategy, ICDs under advisory were not associated with increased mortality over a background of significant disease-related mortality.

Use of conventional dual chamber pacemakers with custom lead adapters to induce atrial fibrillation or heart failure in dogs.

PURPOSE: The purpose of this article is to show how custom "Y"-lead adapters and standard dual-chamber pacemakers can be used to produce pacing paradigms that will lead to stable experimental models of heart failure and atrial fibrillation. DESCRIPTION: With two custom lead adapters we used both ports of two dual-chamber clinical pacemakers to independently apply various pacing paradigms to either the ventricles or the atria of dogs. EVALUATION: Because both ports of the ventricular pacemaker were used to apply stimuli through one lead, the device did not have to be modified to obtain ventricular pacing rates that are sufficiently elevated to lead to tachycardia-induced heart failure. Similarly, simultaneous use of both ports of the atrial pacemaker can be used to apply stimuli through one atrial lead to induce sustained atrial fibrillation. CONCLUSIONS: These techniques facilitate induction of experimental models of heart failure and atrial fibrillation without the need for modification of the clinical pacemaker.

Cardiac defibrillation and resynchronization therapies: principles, therapies, and management implications.

Patients with heart failure remain at high risk for sudden cardiac death (SCD) and death due to heart failure progression, despite the incorporation of pharmacologic agents into clinical practice that have been shown to decrease mortality in clinical trials. Most patients experience SCD as their first dysrrhythmic event. The implantable cardioverter defibrillator (ICD) effectively terminates ventricular tachycardia/fibrillation (VT/VF) aborting SCD. Cardiac resynchronization therapy (CRT) complements pharmacologic therapy improving cardiac performance, quality of life, functional status, and exercise capacity in patients with systolic dysfunction despite optimal medical therapy who have a prolonged QRS duration; furthermore, it decreases mortality when compared with optimal medical therapy alone. Implantation of a combination CRT and ICD device, a CRT-D, reduces mortality by aborting SCD and providing the functional benefits of CRT. This article discusses the evolution of CRT-D therapy, the mechanism of operation of a CRT-D device, and nursing implications.

Matching approved "nondedicated" hardware to obtain biventricular pacing and defibrillation: feasibility and troubleshooting.

Biventricular ICDs may offer increased benefit for patients with severe congestive heart failure and ventricular arrhythmia. Currently there are no approved dedicated biventricular ICDs available. Twenty-one consecutive patients who had approved nondedicated hardware implanted for biventricular pacing and defibrillation were included in this study. All device therapies were evaluated using stored electrograms. During mean follow-up at 13 +/- 7 months, 8 (36%) patients had inappropriate shocks. Ventricular fibrillation therapy was delivered for slow ventricular tachycardia because of double counting in two patients. In one patient, AV nodal reentrant tachycardia below detection rate cut off triggered device therapy because of ventricular double counting. Sinus tachycardia or premature atrial contraction initiating AV conduction and ventricular double counting resulted in shocks in five patients. The number of shocks per patient ranged from 1 to 64. Two patients required transient disconnection of the LV lead and subsequent ICD generator replacement for premature battery depletion. Two patients required AV junction ablation and three needed slow pathway ablation. Two patients were treated by upgrading to a device that was capable of a higher atrial tracking rate. The patients with impaired AV conduction or constant ventricular pacing did not have inappropriate therapy for sinus tachycardia or supraventricular arrhythmia. Use of conventional nondedicated hardware for biventricular pacer/defibrillator is feasible but should be considered only in patients with poor AV node function or less likely to require antitachycardic therapy, to avoid ICD double counting of ventricular sensed events and consequent high incidence of inappropriate therapies.