A controlled trial of cardiac rehabilitation in the home setting using electrocardiographic and voice transtelephonic monitoring.

OBJECTIVE: The goal of this study was to compare the effectiveness of home-based, transtelephonically monitored cardiac rehabilitation with standard, on-site, supervised cardiac rehabilitation. BACKGROUND: Participation in cardiac rehabilitation has been demonstrated to increase exercise capacity, decrease cardiovascular symptoms, improve psychosocial status, and decrease total and cardiovascular mortality rates in patients with coronary heart disease. Because of multiple factors, national overall participation is only at 15% of eligible patients. METHODS: Effects of a 3-month home-based, transtelephonically monitored rehabilitation program (n = 83 patients) with simultaneous voice and electrocardiographic transmission to a centrally located nurse coordinator were compared with effects of a standard on-site rehabilitation program (n = 50 patients). The study design was a multicenter, controlled trial. Primary outcome variables were peak aerobic capacity and quality of life, as measured by the Health Status Questionnaire. RESULTS: Patients in the home-based monitoring program increased peak aerobic capacity to a similar degree as patients who exercised on site (18% vs 23%). Quality of life domains of physical functioning, social functioning, physical role limitations, emotional role limitations, bodily pain, and energy/fatigue improved similarly in both groups. There were no circulatory arrests or other major exercise-related medical events in either group. A total of 3100 hours of home exercise were transtelephonically monitored. CONCLUSIONS: Patients with coronary heart disease can effectively participate in home-based, monitored cardiac rehabilitation, with exercise and quality of life improvements comparable to those demonstrated at on-site programs.

Daily variations in the occurrence of symptomatic supraventricular tachycardia as determined by ambulatory event monitoring.

The diurnal incidence of supraventricular tachycardia (SVT), including atrial fibrillation and atrial flutter, has been quantified by examining 7,891 cases of symptomatic arrhythmia in 5,869 patients assigned to ambulatory monitoring using electrocardiographic event recorders with transtelephonic reporting. The probability of occurrence of SVT was found to be high and moderately variable throughout the normally active hours of the day between 8 A.M. and 8 P.M. and to be uniformly low during the inactive hours between 1 and 5 A.M. Age-related peaks within the active phase were independently associated with the older half of the study population (9 A.M.) and with the younger half (6 P.M.). The daily incidence of SVT is primarily characterized by 2 states of activity, active and quiescent. Quiescence of SVT is associated with normal sleep and inactivity.

Cost-effectiveness of cardiac rehabilitation after myocardial infarction.

BACKGROUND: Cardiac rehabilitation is commonly prescribed after myocardial infarction (MI) to coordinate exercise training and secondary preventive services. Cost-effectiveness analysis allows the quantitative comparison of the relative economic worth of cardiac rehabilitation in relation to other common interventions. METHODS: The cost-effectiveness of cardiac rehabilitation, in dollars per year of life saved ($/YLS), was calculated by combining published results of randomized trials of cardiac rehabilitation on mortality rates, epidemiologic studies of long-term survival in the overall postinfarction population, and studies of patient charges for rehabilitation services and averted medical expenses for hospitalizations after rehabilitation. RESULTS: Cardiac rehabilitation participants experienced an incremental life expectancy of 0.202 years during a 15-year period. In 1988, the average cost of rehabilitation and exercise testing was $1,485, partially offset by averted cardiac rehospitalizations of $850 per patient. A cost-effectiveness value of 2,130 $/YLS was determined for the late 1980s, projected to a value of 4,950 $/YLS for 1995. A sensitivity analysis supports the study results. CONCLUSIONS: Compared with other post-MI treatment interventions, cardiac rehabilitation is more cost-effective than thrombolytic therapy, coronary bypass surgery, and cholesterol lowering drugs, though less cost-effective than smoking cessation programs. Cardiac rehabilitation should stand alongside these therapies as standard of care in the post-MI setting.

Optogalvanic spectra of neon and argon in glow discharge lamps.

Optogalvanic spectra of atomic neon and argon have been obtained by irradiating miniature glow discharge lamps with a pulsed, tunable dye laser. The method is shown to be useful for wavelength calibration of tunable lasers, and the resonant lines are cataloged. Two-photon absorption lines in neon are observed when the laser is focused into a small region of the discharge.

Resonance coherent anti-Stokes Raman scattering spectra of fluorescent biological chromophores: Vibrational evidence for hydrogen bonding of flavin to glucose oxidase and for rapid solvent exchange.

Coherent anti-Stokes Raman scattering (CARS) spectra are reported for flavin adenine dinucleotide (FAD) and glucose oxidase (beta-D-glucose:oxygen 1-oxidoreductase; EC 1.1.3.4), in resonance with the 450 nm flavin absorption band. Several isoalloxazine ring modes were observed (1635, 1584, 1507, 1416, and 1359 cm(-1)). A 12 cm(-1) increase in one component of the 1359 cm(-1) band upon binding to glucose oxidase was attributed to hydrogen bonding of the N3 proton to a protein acceptor. This interpretation is consistent with deuteration results. Smaller decreases (5-7 cm(-1)) on binding were observed for the 1635 and 1416 cm(-1) modes (and also a 1297 cm(-1) mode of deuterated FAD) and were attributed to environmental effects. Deuteration of bound FAD was observed within 5 min of mixing glucose oxidase with D(2)O, demonstrating ready access to solvent. Lorentzian CARS peaks were observed with omega(as) at the peak of the 450 nm absorption band, a condition which corresponds to maximum resonance enhancement if the peak corresponds to the envelope of 0-1 vibronic transitions. If omega(1) was tuned to the peak, then dispersion lineshapes were observed, reflecting a loss of Raman enhancement relative to the electronic background.