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Biomedical subjects

William P Batsford

Publications and source records attributed to William P Batsford.

7 recordsLinked to original sources

Benefits of cardiac rehabilitation in patients with implantable cardioverter-defibrillators: a patient survey.

OBJECTIVES: To determine whether participation in an outpatient cardiac rehabilitation (OCR) program increases exercise levels and decreases shocks in patients with implantable cardioverter-defibrillators (ICDs). DESIGN: Retrospective comparative survey. SETTING: University tertiary-care ICD clinic. PARTICIPANTS: Patients with ICDs and coronary artery disease. INTERVENTION: Participation in OCR (nonrandomized). MAIN OUTCOME MEASURES: Exercise levels and OCR participation were determined through a telephone survey of patients with ICDs. The incidence of shock-treated arrhythmia was determined by review of charts and ICD data storage disks. RESULTS: Of 82 patients (85% men; mean age, 61+/-8 y), 28 (34%) participated in OCR after receiving an ICD. There was no difference in age, sex, ejection fraction, or length of follow-up between OCR and non-OCR groups. Median intensity of regular exercise was 5.3 metabolic equivalents (METS) for OCR patients versus 3.5 METS for non-OCR patients (P<.02). In follow-up (mean, 48+/-3 mo), non-OCR patients were more likely to receive any shock, shocks during exercise, or shocks for ventricular arrhythmia during exercise than OCR patients (all P<.05). Non-OCR remained a predictor of shock after adjustment for exercise limitation (P<.05). CONCLUSIONS: OCR patients exercised more and had fewer shocks. Physicians and health plans should encourage ICD patients to participate in OCR.

Adolescent↗

Effects of psychologic stress on repolarization and relationship to autonomic and hemodynamic factors.

INTRODUCTION: Psychological stress can precipitate ventricular arrhythmias in patients with ICDs, as well as sudden death. However, the physiologic pathways remain unknown. We sought to determine whether psychological stress induced in the laboratory setting alters indices of repolarization associated with arrhythmogenesis. METHODS AND RESULTS: Patients with ICDs and a history of ventricular arrhythmia underwent ambulatory ECG monitoring during a laboratory mental stress protocol (anger recall and mental arithmetic). Continuous changes in repolarization indices which have correlated with temporal and spatial myocardial heterogeneity of repolarization, including T-wave alternans (TWA), T-wave amplitude (Tamp), and T-wave area (Tarea) were analyzed in the time domain. In the 33 patients (85% male, 88% with coronary artery disease, mean ejection fraction 30%), norepinephrine, epinephrine, BP, and HR increased during mental stress. TWA increased from 22 (interquartile range 16-27) at baseline to 29 (21-38) uV during mental stress (P < 0.001). Changes in TWA correlated with changes in HR, systolic BP, and catecholamines. Tamp and Tarea also increased with mental stress (P < 0.01) but did not correlate with changes in other variables. CONCLUSION: Psychological stress increased TWA, Tamp, and Tarea. Autonomically mediated repolarization changes may be a pathophysiologic link between emotion and arrhythmia in susceptible patients.

Autonomic Nervous System↗

Usefulness of procainamide challenge for electrophysiologic arrhythmia risk stratification.

Among 58 consecutive patients who underwent electrophysiologic testing for risk assessment and who subsequently received a third-generation implantable cardioverter-defibrillator, 39 had ventricular tachycardia induced in the baseline state and 19 had ventricular tachycardia induced only after administration of intravenous procainamide, increasing the yield of electrophysiologic risk assessment by 49%. At follow-up, ventricular arrhythmias requiring implantable cardioverter-defibrillator termination occurred in 14 of 39 patients inducible in the baseline state and in 7 of 19 patients inducible only with intravenous procainamide. The provocative use of intravenous procainamide during electrophysiologic risk assessment increases the detection rate for risk of sustained ventricular arrhythmias with no loss of positive predictive value.

Aged↗

Gender differences in ventricular arrhythmia recurrence in patients with coronary artery disease and implantable cardioverter-defibrillators.

OBJECTIVES: We sought to determine whether men and women with coronary artery disease (CAD) and implantable cardioverter-defibrillators (ICDs) differ in frequency of arrhythmia recurrence and whether gender differences are independent of clinical, electrocardiographic, and electrophysiologic characteristics. BACKGROUND: Epidemiologic studies show that women have a lower rate of sudden cardiac death (SCD) than men, even among patients with CAD. Whether this is due to differing susceptibilities to ischemia or to arrhythmia is unknown. METHODS: The clinical records and ICD data disks of 340 men and 59 women with CAD who received an ICD between June 1990 and June 2000 were reviewed. Ventricular tachycardia (VT) or ventricular fibrillation (VF) recurrences were compared between genders and relationship with other factors was analyzed. RESULTS: Sustained VT/VF occurred in 52% of men and 34% of women (p < 0.01). Men experienced more total VT/VF events (p < 0.01), more shock-treated VT/VF events (p < 0.03), more electrical storms (p < 0.001), and had VT/VF on more days in follow-up (p < 0.01). Gender differences were independent of measured clinical, electrocardiographic, and electrophysiologic factors. In stratified analyses, the gender differences in VT/VF recurrence were greatest in patients presenting with sustained monomorphic VT and those with inducible VT at electrophysiology study. CONCLUSIONS: Women were less likely to experience VT/VF, and had fewer VT/VF episodes, than men. These findings were strongest in patients with evidence of a stable anatomic VT circuit: those with clinical or electrophysiologically induced VT. This study suggests that differing susceptibility to arrhythmia triggering may underlie the known differences in SCD rates between men and women.

Aged↗

Hyperkalemia induced T wave oversensing leading to loss of biventricular pacing and inappropriate ICD shocks.

Inappropriate ICD shocks remain a common problem. Double counting of single ventricular events can occur with biventricular ICDs implanted before univentricular sensing was available. Often this is due to a tachyarrhythmia or loss of left ventricular capture. This report describes a patient who developed hyperkalemia during hemodialysis, received inappropriate ICD shocks and experienced loss of biventricular pacing due to T wave rather than QRS double counting. Oversensing was abolished by reducing the potassium content of the dialysis bath. This underscores the need for careful interpretation of saved electrograms to determine the cause for, and appropriate treatment of, device related problems.

Defibrillators, Implantable↗

Emotional and physical precipitants of ventricular arrhythmia.

BACKGROUND: Observational studies have suggested that psychological stress increases the incidence of sudden cardiac death. Whether emotional or physical stressors can trigger spontaneous ventricular arrhythmias in patients at risk has not been systematically evaluated. METHODS AND RESULTS: Patients with implantable cardioverter-defibrillators (ICDs) were given diaries to record levels of defined mood states and physical activity, using a 5-point intensity scale, during 2 periods preceding spontaneously occurring ICD shocks (0 to 15 minutes and 15 minutes to 2 hours) and during control periods 1 week later. ICD-stored electrograms confirmed the rhythm at the time of shock. A total of 107 confirmed ventricular arrhythmias requiring shock were reported by 42 patients (33 men; mean age, 65 years; 78% had coronary artery disease) between August 1996 and September 1999. In the 15 minutes preceding shock, an anger level > or =3 preceded 15% of events compared with 3% of control periods (P<0.04; odds ratio, 1.83; 95% confidence intervals, 1.04 to 3.16) Other mood states (anxiety, worry, sadness, happiness, challenge, feeling in control, or interest) did not differ. Patients were more physically active preceding shock than in control periods. Anger and physical activity were independently associated with the preshock period. CONCLUSIONS: Anger and physical activity can trigger ventricular arrhythmias in patients with ICDs. Future investigations of therapies aimed at blocking a response to these stressors may decrease ventricular arrhythmias and shocks in these patients.

Affect↗