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Biomedical subjects

David L Hayes

Publications and source records attributed to David L Hayes.

At least 37 records · Page 2Linked to original sources
PubMed2004

Electroconvulsive therapy in patients with cardiac pacemakers and implantable cardioverter defibrillators.

Electroconvulsive therapy (ECT) is used to treat major depressive illness, especially in elderly and medically frail patients. Not uncommonly, these patients have cardiac pacemakers or implantable cardioverter defibrillators (ICDs). Only a few case reports in the literature describe the use of ECT in such patients. Herein we review our ECT experience treating 26 pacemaker patients and 3 ICD patients. All patients obtained significant antidepressant benefits with ETC. Only one serious cardiac event occurred, a case of supraventricular tachycardia (SVT) requiring a stay on the cardiac intensive care unit. The SVT resolved and the patient went on to receive further uncomplicated ECT treatments. We conclude from this experience that with proper pre-ECT cardiac and pacemaker/defibrillator assessment, ECT can be safely and effectively administered to patients with an implanted cardiac device.

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PubMed2004

Potential for Personal Digital Assistant interference with implantable cardiac devices.

OBJECTIVE: To determine whether the wireless local area network (WLAN) technology, specifically the Personal Digital Assistant (PDA), interferes with implantable cardiac pacemakers and defibrillators. MATERIAL AND METHODS: Various pacemakers and defibrillators were tested in vitro at the Mayo Clinic in Rochester, Minn, between March 6 and July 30, 2003. These cardiac devices were exposed to an HP Compaq IPAQ PDA fitted with a Cisco Aironet WLAN card. Initial testing was designed to show whether the Aironet card radiated energy in a consistent pattern from the antenna of the PDA to ensure that subsequent cardiac device testing would not be affected by the orientation of the PDA to the cardiac device. Testing involved placing individual cardiac devices in a simulator and uniformly exposing each device at its most sensitive programmable value to the WLAN card set to maximum power. RESULTS: During testing with the Cisco WLAN Aironet card, all devices programmed to the unipolar or bipolar configuration single- or dual-chamber mode had normal pacing and sensing functions and exhibited no effects of electromagnetic interference except for 1 implantable cardioverter-defibrillator (ICD). This aberration was determined to relate to the design of the investigators' testing apparatus and not to the output of the PDA. The ICD device appropriately identified and labeled the electromagnetic aberration as "noise." CONCLUSIONS: We documented no electromagnetic interference caused by the WLAN technology by using in vitro testing of pacemakers and ICDs; however, testing ideally should be completed in vivo to confirm the lack of any clinically important interactions.

Artifacts↗
PubMed2003

Significant effects of atrioventricular node ablation and pacemaker implantation on left ventricular function and long-term survival in patients with atrial fibrillation and left ventricular dysfunction.

Control of ventricular rate by atrioventricular node ablation and pacemaker implantation in patients with drug-refractory atrial fibrillation (AF) is associated with improved left ventricular (LV) function. The objective of this study was to determine the effect of atrioventricular node ablation on long-term survival in patients with AF and LV dysfunction. Survival was determined by the Kaplan-Meier method for 56 study patients with LV ejection fraction (EF) < or =40% who underwent atrioventricular node ablation and pacemaker implantation and 56 age- and gender-matched control patients with AF and LVEF >40%, and age- and gender-matched control subjects from Minnesota. Groups were compared using the log-rank test. In study patients (age 69 +/- 10 years; 45 men), LVEF was 26% +/- 8% and 34% +/- 13% (p <0.001) before and after ablation, respectively. During follow-up (40 +/- 23 months), 23 patients died. Observed survival was worse than that of normal subjects (p <0.001) and control patients (p = 0.005). After ablation, LVEF nearly normalized (> or =45%) in 16 study patients (29%), in whom observed survival was comparable to that of normal subjects (p = 0.37). Coronary artery disease, hyperlipidemia, chronic renal failure, previous myocardial infarction, and coronary artery operation were independent predictors for mortality. Near normalization of LVEF occurred in 29% of study patients, suggesting that AF-induced EF reduction is reversible in many patients. Normal survival in patients with reversible LV dysfunction highlights potential survival benefits of rate control. Poor survival in patients with persistent LV dysfunction confirms the importance of optimal medical therapy.

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PubMed2003

Discrepancies between the upper limit of vulnerability and defibrillation threshold: prevalence and clinical predictors.

INTRODUCTION: Upper limit of vulnerability (ULV) has a strong correlation with defibrillation threshold (DFT) in patients with implantable cardioverter defibrillators (ICDs). Significant discrepancies between ULV and DFT are infrequent. The aim of this study was to characterize patients with such discrepancies. METHODS AND RESULTS: The ULV and DFT were determined in 167 ICD patients. Univariate and multivariate analyses were used to evaluate clinical predictors of a significant difference (> or =10 J) between ULV and DFT. Only 8 patients (5%) had > or =10 J difference. ULV exceeded DFT in all of them. Absence of coronary artery disease (6/8 vs 48/159 patients; P = 0.05) and absence of documented ventricular arrhythmias (4/8 vs 12/159 patients; P = 0.01) were the only independent predictors of a significant ULV-DFT discrepancy. CONCLUSION: Significant discrepancies between ULV and DFT occur in 5% of patients with ICDs. Absence of coronary disease and documented ventricular arrhythmias predict such a discrepancy. At ICD implant, DFT testing is recommended in these patients and in patients with a high (>20 J) ULV before first-shock energy and the need for lead repositioning are determined.

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PubMed2003

Ethical analysis of withdrawal of pacemaker or implantable cardioverter-defibrillator support at the end of life.

OBJECTIVE: To describe a series of terminally ill patients who requested (or whose surrogates requested) withdrawal of pacemaker or implantable cardioverter-defibrillator (ICD) support and the ethical issues pertaining to these requests. PATIENTS AND METHODS: We performed a retrospective review of the medical records of patients seen at the Mayo Clinic in Rochester, Minn, between January 1996 and June 2002 and identified 6 terminally ill patients who requested (or whose family members requested) withdrawal of pacemaker or ICD support. Potential interventions were an ethics consultation and subsequent withdrawal of pacemaker or ICD support. The study's main outcome measures were death and the context in which it occurred. RESULTS: The mean age of the 6 patients (3 men, 3 women) was 75.5 years. Five had pacemakers, and 1 had an ICD. Five patients had advance directives that indicated a desire to withdraw medical interventions if death was inevitable. Two patients and 4 surrogates requested withdrawal of pacemaker or ICD support. One patient died without withdrawal of support despite an ethics consultation that endorsed its permissibility. Another died while an ethics consultation was in progress. The request to withdraw support was granted in 4 patients, all of whom died within 5 days of withdrawal of support. CONCLUSIONS: Granting terminally ill patients' requests to withdraw unwanted medical support is legal and ethical. Death after withdrawal of support is attributable to the patient's underlying pathology and is not the same as physician-assisted suicide or euthanasia. Clinician familiarity with these concepts may lead to more expeditious withdrawal of unwanted medical support from terminally ill patients.

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PubMed2002

Sudden death after radiofrequency ablation of the atrioventricular node in patients with atrial fibrillation.

OBJECTIVES: We evaluated the incidence and predictors of sudden death after atrioventricular (AV) node ablation and pacemaker implantation. BACKGROUND: Sudden death may occur after radiofrequency catheter ablation of the AV node and pacemaker implantation in patients with atrial fibrillation (AF). Whether it is related to the procedure or to pre-existing heart disease remains unclear. METHODS: All patients who had radiofrequency catheter ablation of the AV node and pacemaker implantation for rate control of medically refractory AF were identified retrospectively and observed prospectively. All patients with sudden death after ablation were identified. The relationship between the procedure and sudden death was defined on the basis of the time between the two as "likely," "possibly" or "unlikely." RESULTS: Of 334 consecutive patients with AF who underwent AV node ablation, nine had sudden death after the ablation. Four patients (1.2%) had sudden death likely related to the procedure: in 3 patients, arrest occurred within 48 h after the procedure; in one patient, arrest occurred four days after the procedure. In three other patients (0.9%), sudden death was possibly related to the procedure because the event occurred within three months afterward. The remaining two deaths were unrelated to the procedure. Diabetes, New York Heart Association functional class (>or=II), preprocedure ventricular arrhythmia, mitral or aortic stenosis, aortic regurgitation and chronic obstructive pulmonary disease were independent predictors for sudden death. CONCLUSIONS: Sudden death likely or possibly related to catheter ablation occurred in 7 of 334 patients (2.1%). Risk of sudden death is highest within two days after the procedure.

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PubMed2002

Cardiac resynchronization in chronic heart failure.

BACKGROUND: Previous studies have suggested that cardiac resynchronization achieved through atrial-synchronized biventricular pacing produces clinical benefits in patients with heart failure who have an intraventricular conduction delay. We conducted a double-blind trial to evaluate this therapeutic approach. METHODS: Four hundred fifty-three patients with moderate-to-severe symptoms of heart failure associated with an ejection fraction of 35 percent or less and a QRS interval of 130 msec or more were randomly assigned to a cardiac-resynchronization group (228 patients) or to a control group (225 patients) for six months, while conventional therapy for heart failure was maintained. The primary end points were the New York Heart Association functional class, quality of life, and the distance walked in six minutes. RESULTS: As compared with the control group, patients assigned to cardiac resynchronization experienced an improvement in the distance walked in six minutes (+39 vs. +10 m, P=0.005), functional class (P<0.001), quality of life (-18.0 vs. -9.0 points, P= 0.001), time on the treadmill during exercise testing (+81 vs. +19 sec, P=0.001), and ejection fraction (+4.6 percent vs. -0.2 percent, P<0.001). In addition, fewer patients in the group assigned to cardiac resynchronization than control patients required hospitalization (8 percent vs. 15 percent) or intravenous medications (7 percent vs. 15 percent) for the treatment of heart failure (P<0.05 for both comparisons). Implantation of the device was unsuccessful in 8 percent of patients and was complicated by refractory hypotension, bradycardia, or asystole in four patients (two of whom died) and by perforation of the coronary sinus requiring pericardiocentesis in two others. CONCLUSIONS: Cardiac resynchronization results in significant clinical improvement in patients who have moderate-to-severe heart failure and an intraventricular conduction delay.

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PubMed2002

Difference in mechanical atrioventricular delay between atrial sensing and atrial pacing modes in patients with hypertrophic and dilated cardiomyopathy: an electrical hemodynamic catheterization study.

UNLABELLED: For optimal pacemaker programming in patients with cardiomyopathy, it is important to understand the relationship between the programmed right atrial and ventricular delay and the mechanical contraction delay of the left atrium and left ventricle. METHODS: We analyzed data from 34 patients with dilated cardiomyopathy (14) or hypertrophic obstructive cardiomyopathy (20) who had dual-chamber P-synchronous pacing (VDD) and atrioventricular sequential pacing (DVI) during hemodynamic catheterization. Using multiple atrioventricular intervals during VDD and DVI pacing, the relationship of the programmed right atrial-right ventricular interval to the mechanical left atrial-left ventricular delay (assessed by high-fidelity pressures) was determined. RESULTS: We found that the optimal mechanical left atrial-left ventricular delay was 120 ms, which required a programmed right atrial-right ventricular interval of 160 ms during DVI pacing. Also, the mean difference in right atrial-right ventricular pacing interval between VDD and DVI modes was 54 +/- 28 ms (range, 10-120 ms) in the hypertrophic obstructive cardiomyopathy group and 64 +/- 38 ms (range, 20-150 ms) in the dilated cardiomyopathy group. CONCLUSIONS: We concluded that the optimal right atrial-right ventricular interval during DVI pacing was 160 ms and that, to achieve the same mechanical left atrial-left ventricular delay, the programmed right atrial-right ventricular interval during VDD pacing was approximately 50 ms to 60 ms shorter than during DVI pacing. However, the difference of electrical atrioventricular pacing interval in VDD and DVI may vary widely from patient to patient.

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PubMed2002

The use of radiofrequency catheter ablation to extract a chronic permanent pacemaker lead after failed laser extraction.

Even with the latest advances in pacemaker lead extraction techniques, successful lead extraction via percutaneous techniques still cannot be achieved in up to 2% of procedures at qualified centers reiterating the need for further development in this area. We present an example of a novel technique using radiofrequency (RF) energy delivered with a steerable ablation catheter to facilitate lead removal using an 8-french guiding sheath (SRO, Daig corporation) and a bidirectional steerable 4 mm tip ablation catheter (EPT). With a short series of RF ablations, the pacemaker lead tip was successfully freed without complications.

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PubMed2002

Pacemaker component allergy: case report and review of the literature.

Pacemaker component allergy is a relatively uncommon cause of erythema and pain at the site of an implanted pacemaker. Allergies to multiple pacemaker components have been well described. We present a case in which 2 component allergies were documented on separate occasions. Although attempts were made to protect the patient by "coating" the pacemaker, the protective coating was incomplete and the patient again had a clinical reaction. More complete coating corrected the problem. Diagnosis of a pacemaker component allergy first requires awareness of the problem and then thorough allergy testing with appropriate components.

Coated Materials, Biocompatible↗
PubMed2002

The revised NASPE/BPEG generic code for antibradycardia, adaptive-rate, and multisite pacing. North American Society of Pacing and Electrophysiology/British Pacing and Electrophysiology Group.

In light of evolving pacemaker technology and increasing interest in multisite pacing, the Committee on the Development of Position Statements (CDPS) of the North American Society of Pacing and Electrophysiology (NASPE) created an ad hoc Pacemaker Mode Code Task Force in April 2001 under the chairmanship of David L. Hayes, MD, for the purpose of bringing the NASPE/British Pacing and Electrophysiology Group (BPEG) Generic Pacemaker Code (NBG Code) up to date. The task force, whose members are the authors of this article, designed a revised NBG Code in which three major issues were taken into account. First, it was recognized that all modern pacemakerpulse generators are capable of extensive bidirectional communication with an external programming device, making them "communicating" pulse generators as defined by the current (1987) NBG Code. Second, it was decided that a means of providing basic information regarding the location of multisite pacing would be a useful ingredient of the NBG Code. Third, in view of the extensive antibradycardia pacing capabilities common in modern implantable cardioverter defibrillators and the availability of the NASPE/BPEG Defibrillator Code (NBD Code), it was considered unnecessary for the NBG Code to address the presence or absence of antitachycardia features. The resulting updated version of the NBG Code as described herein was endorsed by the BPEG on September 20, 2001 and adopted by the NASPE Board of Trustees on October 18, 2001. The structure of the revised NBG Code differs from that of the previous version in two respects alone: Position IV specifies only the presence or absence of rate modulation, and Position V specifies only the location or absence of multisite pacing (i.e., biatrial or biventricular pacing with at least two stimulation sites in each case) more than one stimulation site in any single cardiac chamber, or any combination of these. The revised NBG Code is deliberately configured to avoid confusion with earlier mode codes, and it is the authors' hope that it will serve as an enhanced resource for communication among those engaged in every phase of the multidisciplinary practice of cardiac rhythm management.

Bradycardia↗