Strength training early after myocardial infarction.

BACKGROUND: Many activities of daily living require significant amounts of muscular strength. Time lines for current strength training guidelines preclude many myocardial infarction patients from receiving strength training as part of their cardiac rehabilitation program. This study was designed to examine the effectiveness and safety of low-to-moderate level strength training in patients early after myocardial infarction. METHODS: Fifty-seven low-risk men ( < 61 years of age, 6-16 weeks post-infarction) were randomly assigned to a control group or one of three treatment groups. All groups trained aerobically, three times per week for 12 weeks. The three treatment groups performed additional strength exercises on each training day of the last 10 weeks. These groups differed in their strength training stimulus with Group 20 performing 20 reps of 20% of 1 repetition maximum (1 RM), Group 40 performing 10 repetitions of 40% of 1 RM, and Group 60 performing 7 repetitions of 60% of 1 RM. RESULTS: Maximal strength remained unchanged in the control group (+0.5%), but increased in Groups 20, 40, and 60 by +10.5%, +11.9%, and +13.5%, respectively. The increases in strength in the treatment groups were all significantly different (P < .001) from the results of the control group, but were not significantly different from each other. For the three treatment groups, 30 of 42 subjects had one or more cardiovascular complication (arrhythmias, angina, ischemia, hypertension, hypotension) during the aerobic exercises as compared to only 1 subject with complications during the resistive exercises (P < .01). CONCLUSIONS: In selected patients, low-to-moderate intensity strength training performed early after infarction is effective and may have lower rates of cardiovascular problems than aerobic exercise.

Report of the NASPE Policy Conference on antibradycardia pacemaker follow-up: effectiveness, needs, and resources. North American Society of Pacing and Electrophysiology.

On May 4-5, 1993, a policy conference was held in San Diego, California, under the sponsorship of the North American Society of Pacing and Electrophysiology (NASPE) to identify the fundamental goals of antibradycardia pacemaker follow-up, evaluate the effectiveness with which it achieves those goals, and formulate specific recommendations as to how it can be made more effective. The conference addressed clinical, administrative, and educational objectives, focusing on existing and potential resources for follow-up testing and the appropriate frequency of their application. The training of physicians and associated professionals engaged in follow-up also was addressed, as were regulatory and reimbursement issues. This report summarizes the conclusions and recommendations arrived at during the conference and subsequently approved by the NASPE Board of Trustees.

Decompression sickness: an increasing risk for the private pilot.

Decompression sickness is not an appreciated hazard among the private pilot community. This is of growing concern with the increasing number of nonpressurized aircraft capable of flying to altitudes in excess of 5,468 m (18,000 ft). A case report is presented of a 42-year-old pilot who apparently experienced decompression sickness at flight level 250 which went unrecognized until several months after the incident.

The impact of pacemaker implantation on cognitive functioning in elderly patients.

OBJECTIVE: To describe and quantify the impact of pacemaker implantation on cognitive functioning in the elderly. DESIGN: Prospective case-control, non-randomized trial. Data were collected from clinical and family interviews and from a psychological test battery. SETTING: Pacemaker clinic in a tertiary care hospital. PARTICIPANTS: Nineteen elderly (65+ years) patients undergoing new or replacement pacemaker implantation for dysrhythmias and volunteer controls matched for age, sex, and short Mental Status Questionnaire test results, without dysrhythmia or intervention. MAIN OUTCOME MEASURES: Subjective and clinical impressions based on family interviews; results of psychological test battery before and 6-12 months after pacemaker implantation. RESULTS: Prior to pacemaker implantation, three patients met DSM-III criteria for dementia and two for delirium. Paced patients demonstrated deficiency in immediate memory, language, memory for less structured information, and learning of abstract materials. These deficits were due primarily to the poor performance of patients with complete heart block. Despite clinical and subjective impressions of improvement, there was no change in psychologic test performance subsequent to pacemaker implantation. CONCLUSIONS: Impaired cognitive functioning is not always clinically apparent but appears common in patients with cardiac dysrhythmias; it is not altered 6-12 months after pacemaker implantation.

Effect of rate-adapting atrioventricular delay on stroke volume and cardiac output during atrial synchronous pacing.

The need to adjust atrioventricular delay relative to pacing rate in atrial synchronous pacemakers was assessed in eight subjects treated for complete heart block (mean age 61 +/- 3.4 years). First, an inverse relationship between heart rate and PR interval was confirmed in two groups of healthy subjects and one group of patients recovering from myocardial infarction. Due to the limitations of the available pacemakers this relationship could not be precisely reproduced. Subjects with pacemakers performed an initial exercise test on a bicycle ergometer to determine heart rate response; this information was used in part 2 to program atrioventricular delay relative to heart rate. During a second exercise test, a rate-adapting atrioventricular delay was compared to a constant atrioventricular delay of 200 ms at matched heart rates. Cardiac output was measured noninvasively by impedance cardiography. The results of part 1 showed an abnormal pattern in the response of stroke volume to exercise in seven subjects. Part 2 results demonstrated no significant difference (P greater than 0.05) between a rate-adapting atrioventricular delay and a constant delay of 200 ms for heart rate, stroke volume, cardiac output, blood pressure or Borg scale. A trend towards increased stroke volume with a rate-adapting atrioventricular delay was observed. Stroke volume was 13% larger with a rate-adapting atrioventricular delay of 125 ms at a heart rate of 125 beats/min. These results suggest that subjects with atrial synchronous pacemakers have a variable stroke volume response to exercise. It appears that in these subjects the ability to increase heart rate is the key factor for raising cardiac output during exercise.

Megestrol acetate versus tamoxifen in advanced breast cancer: 5-year analysis--a phase III trial of the Piedmont Oncology Association.

One hundred thirty-eight patients with recurrent or metastatic breast cancer were randomized to receive megestrol acetate 40 mg orally four times daily or tamoxifen 10 mg orally twice a day. Upon treatment failure patients were crossed over to the alternate treatment. Eligibility required that either the estrogen receptor (ER) or progesterone receptor (PR) be positive or that both values be unknown, and that the patients be at least 2 years post-spontaneous menopause or over 50 years of age. Pretreatment characteristics including performance status (PS), disease-free interval (DFI), receptor status, and prior treatment were similar for both groups. Only three patients had previous hormonal therapy while one third had prior chemotherapy. Objective response was determined using strict International Union Against Cancer (UICC) criteria. Seventeen of 61 patients achieved complete response (CR) or partial response (PR) on megestrol (28%) while 20 of 64 patients achieved CR or PR on tamoxifen (31%). Responses of skin and bone lesions were similar for both agents; however, more patients with visceral disease responded to tamoxifen. Response did not correlate with the level of ER or PR but was correlated with age. Both unadjusted and adjusted analysis of time to progression and adjusted analysis (for pretreatment variables) of survival showed significant differences favoring tamoxifen. Six of 44 patients (14%) crossed from megestrol to tamoxifen achieved CR or PR while only two of 38 patients (5%) crossed from tamoxifen to megestrol achieved response. Only one of the original patients randomized to megestrol remains on study, while 12 patients still remain on tamoxifen. These data indicate similar response rates for megestrol and tamoxifen; however, time to progression and overall survival significantly favor tamoxifen when used as first-line therapy in this trial.

Single agent vincristine by infusion in refractory multiple myeloma.

A phase 2 trial of vincristine infusion was conducted in a group of 21 patients with refractory multiple myeloma. Patients were generally heavily pretreated with radiotherapy and chemotherapy. Vincristine was given intravenously (IV) as a 0.5 mg bolus and followed immediately by infusion of 0.25 to 0.50 mg/m2/d for 5 days. Courses were repeated every 3 weeks in the absence of disease progression or prohibitive toxicity. Objective responses (partial) were noted in two patients (10%), both of whom were administered 0.5 mg/m2/d infusions. Response durations were brief (2.2 and 1.2 months). Toxicity consisted of neurotoxicity and myelosuppression. In addition to the occurrence of paresthesias and myalgias, ileus (two cases) and moderately severe loss of motor function (two cases) were observed. The mean lowest WBC count following treatment was 2.67 X 10(3)/microL v 3.96 X 10(3)/microL pretreatment (P = .008). The mean lowest platelet count was 75.0 X 10(3)/microL v 106.8 X 10(3)/microL pretreatment (P = .008). Vincristine infusion appears to have limited activity in the treatment of refractory multiple myeloma. Additionally, response durations were short lived and toxicity, both neurologic and hematologic, was appreciable.

Megestrol acetate v tamoxifen in advanced breast cancer: a phase III trial of the Piedmont Oncology Association (POA).

One hundred twenty-four patients with recurrent or metastatic breast cancer were randomized to receive megestrol acetate 40 mg orally, four times daily, or tamoxifen 10 mg orally twice daily. If therapy failed patients were crossed over to the alternate treatment. Eligibility required that either the estrogen or progesterone receptor be positive or that both values be unknown, and that patients be at least 2 years postspontaneous menopause or over 50 years of age. Pretreatment characteristics were similar for both groups. Three patients had had previous hormonal therapy while one third had had chemotherapy. Objective response for evaluable patients based on strict UICC criteria was 29% with megestrol acetate and 31% with tamoxifen. Responses in patients with bone and soft tissue disease were similar for both regimens; however, 7 of 19 (37%) patients with visceral disease responded to tamoxifen but none of 18 (0%) responded to megestrol acetate. Response did not correlate with amount of estrogen or progesterone receptor. Unadjusted analysis of time to progression and survival showed no significant differences between regimens. With adjustment for pretreatment characteristics, patients on tamoxifen had a statistically significant prolongation of both of these parameters. Crossover data show 3 of 24 patients responding to tamoxifen after failure on megestrol acetate and 1 of 24 responding to megestrol acetate after failure on tamoxifen. However, crossover data should be viewed cautiously, as patients who are currently responding to initial treatment are those who would be most likely to respond to crossover therapy.

Improved tolerance of vincristine by glutamic acid. A preliminary report.

In a murine model system, glutamic acid has demonstrated host protective properties during administration of vincristine (VCR). Subsequently, glutamic acid has been evaluated in patients receiving VCR during adjuvant chemotherapy for stage II carcinoma of the breast. The cumulative VCR dosage and toxicities incurred in 16 patients receiving glutamic acid have been compared to those observed in 88 patients who previously received VCR without glutamic acid in the same chemotherapy program. All patients received VCR 1.0 mg/m2 weekly for 6 weeks with dose modification for neurotoxicity. Treatment patients received glutamic acid 1.5 grams p.o. daily in three divided doses during the induction course. Of the 16 treatment patients, 9 (56%) received 100% ideal dosage of VCR during induction therapy whereas only 24 of 88 (27%) comparison patients attained this dosage level (p less than .025). Gastrointestinal and hematologic toxicities were similar in both groups. These preliminary results suggest the need for an expanded trial of this agent during administration of VCR.