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Biomedical subjects

G F Fletcher

Publications and source records attributed to G F Fletcher.

At least 73 records · Page 4Linked to original sources
PubMed1979

Oxygen consumption and hemodynamic response of exercises used in training of patients with recent myocardial infarction.

We investigated oxygen consumption (ml/kg/min) and hemodynamic response (peak heart rate-systolic blood pressure product) to individual exercise activities before and after exercise training in 22 male postmyocardial infarction patients (PMIP). Activities included swimming, walk/jogging, volleyball, calisthenics and exercise dance routines. Oxygen consumption was determined immediately after exercise by the Douglas bag gas collection procedure and, in selected patients, by a Max Planck respirometer during exercise. Hemodynamic data were obtained by pulse count and cuff sphygmomanometer. The increase in oxygen consumption and the decrease in rate-pressure product after each activity were significant (p less than or equal to 0.01). There were no differences in oxygen consumption between the Max Planck respirometer technique and collection (Douglas bag method) immediately after exercise. The oxygen consumption obtained for PMIP compared with available cumulative data on normal subjects is significantly variable, suggesting the need for caution when prescribing exercise for the PMIP based on energy costs of standard exercise measurements in normals. This was particularly relevant because of the significantly high oxygen consumption incurred during swimming.

Body Weight↗
PubMed1977

Ventricular fibrillation in a medically supervised cardiac exercise program. Clinical, angiographic, and surgical correlations.

Five patients with ischemic heart disease were resuscitated after experiencing ventricular fibrillation in a medically supervised exercise program. Four subsequently had successful myocardial revascularization (three prior to hospital discharge), and three have returned to an exercise prescription of reduced intensity. Multivessel operative coronary disease is common in patients experiencing ventricular fibrillation. Ventricular fibrillation may occur unpredictably (two to 48 months) in duration of exercise. Exercise fitness centers for such patients should be medically supervised and equipped with a defibrillator and appropriate drugs.

Adult↗
PubMed1977

Acute drug testing with nitrates: angina relief during treadmill exercise.

To evaluate the effect of sublingual nitroglycerin (N) and chewable isosorbide dinitrate (I) in patients with angina pectoris, 12 subjects underwent treadmill exercise to the point of onset of angina. At that juncture, N or I or placebo (P) was administered and walking was continued until moderately severe angina recurred. For those patients who completed the initial 10-minute exercise period, testing was repeated until moderately severe angina recurred or until a total test time of three hours elapsed. Retesting ensured that each patient was tested separately with N, I and P within a two-week period. Within the I group, four patients experienced the onset of angina relief (AR) at 10 minutes (') 6 seconds (*) +/- 3' 4" with a mean recurrence time (RT) of 154' 3" +/- 4' 27" (P less than or equal to 0.05), for a significant difference. Within the N group, six patients had AR of 8' 3" +/- 1' 1" with an RT of 49' 39" +/- 1' 15" (P less than or equal to 0.01), for a significant effect. Within the P group, only one patient experienced AR. For all other patients in each group, testing was terminated because of moderately severe angina in the 5-8' period of the first test. In comparing subgroups for RT during I therapy (4 patients) versus N therapy (6 patients), a significant difference was noted (154' 3" +/- 27" versus 49' 39" +/- 1' 15") (P less than 0.05). The data suggest a possible benefit of I in selected patients. The effect may last as long as three to four hours. There is also an enhanced benefit of N with the patient in the upright position. This effect may last as long as 40-50'. Treadmill testing is recommended with nitrate administration to determine which drug (I or N) is the more suitable for the specific patient.

Adult↗
PubMed1977

Continuous ambulatory electrocardiographic monitoring. Use in cardiac exercise programs.

In order to evaluate cardiac rate and rhythm in 20 patients with coronary atherosclerotic disease who were engaged in a medically supervised exercise program, continuous ambulatory electrocardiographic monitoring was performed during an exercise training class and the subsequent 24 hours, which included activities at work and home. Sixty-five percent (13) of the 20 patients had abnormal findings on recordings. Of the 20 patients studied, 40 percent (eight) had arrhythmias detected by ambulatory recording that had not been detected either by resting or exercise electrocardiograms. Three patients with ventricular ectopis (multiform premature ventricular beats, couplets, and begeminy) had exercise activities temporarily curtailed and therapy with antiarrhythmic drugs begun, with subsequent resolution or improvement. Two other patients (with recorded heart rates of 160 beats per minute) were instructed to carefully monitor their heart rate in order to not exceed the target maximum. We conclude that 24-hour continuous electrocardiographic monitoring is beneficial in evaluating patients in cardiac exercise programs and frequently influences the management of such patients.

Adult↗
PubMed1977

A hitherto undescribed cause of prosthetic mitral valve obstruction.

A case is described in which severe prosthetic mitral valve obstruction was produced by entanglement of sutures across the central axis of the prosthesis on its ventricular side. The entangled sutures prevented the tilting disc occluder from falling into the left ventricular cavity during ventricular diastole.

Adult↗
PubMed1976

Effect of dietary control and exercise training on daily food intake and serum lipids in postmyocardial infarction patients.

The effects of 12 weeks of exercise training without dietary control (n = 30) and exercise training with dietary control by dietition counseling (n = 30) and exercise training with dietary control by dietition counseling (n = 30) on serum cholesterol, serum triglycerides, and total substrate contents were studied in 60 postmyocardial infarction patients. Both groups showed reductions (P less than 0.01) in mean total daily kilocalories consumed (2867 +/- 82 versus 2088 +/- 77 and 2848 +/- 15 versus 1285 +/- 68, respectively); however, no significant change occurred in total body weight. The dietary control group consumed relatively more kilocalories as protein than the group without dietary control (285 of 1,285 versus 389 of 2,088, respectively) and less (P less than 0.05) as fat (443 of 1285 versus 804 of 2,089, respectively). Both groups had lower (P less than 0.01) mean daily dietary cholesterol after 12 weeks (811 +/- 44 versus 232 +/- 17 mg) versus (325 +/- 18 versus 309 +/- 23 mg, respectively). A reduction in serum cholesterol (P less than 0.05) was seen in the dietary control group (270 +/- 8 versus 243 +/- 7 mg/dl) but not in the group without dietary control (260 +/- 6 versus 261 +/- 7 mg/dl). The dietary control group had a lower mean triglyceride level (P less than 0.05) (229 +/- 24 versus 155 +/- 18 mg/dl)) but no differences were seen in the group without dietary control (189 +/- 15 versus 180 +/- 13 mg/dl). It is concluded that significant reductions in caloric intake and daily cholesterol compliment the effects of exercise training in postmyocardial infarction patients by increasing substrate protein:fat consumption ratio and by reducing serum cholesterol and triglycerides. These effects are not seen with exercise training alone.

Cholesterol↗