John Sobolski

Physical Activity and Physical Fitness Levels of Belgian Males Aged 40-55 Years

Physical activity during leisure time and on the job have been measured with standardized interview techniques in 1,513 normal men, aged 40-55 years, who were regularly employed in different industries. Physical fitness was simultaneously estimated by measuring the work load at which a heart rate of 150 bpm was reached on a standardized exercise test. The median energy expenditure from leisure time activities above the basal metabolic rate was 195 kcal/day; 19% of these activities were classified as heavy, 37% as moderate and 43% as light intensity. The median energy expenditure from job physical activity was 1,676 kcal/day including basal metabolic rate. The median physical fitness level was 125 W. The leisure time activity score was significantly related to physical fitness through the light and the heavy intensity subscores. Independently, job physical activity was also significantly related to physical fitness. However, both activity scores accounted for only 2% of the variance in physical fitness. The data illustrate an overall low energy expenditure profile of middle-aged normal men and a low order relationship between physical activity pattern and physical fitness.

Physical fitness does not reflect physical activity patterns in middle-aged workers.

Questionnaires and a sub-maximal exercise test were used to assess occupational and leisure time physical activity as well as physical fitness in a standardized prospective study in 2,565 Belgian and Slovakian middle-aged healthy workers. Less than 5% of the subjects engaged in strenuous work requiring an energy expenditure above 31.5 kJ.min-1. One-third of the Belgians and 50% of the Slovakians reported no heavy leisure time activity during the preceding 12 months. Physical fitness, defined as the workload at heart rate 150 beats.min-1 (standardized for body weight), was significantly higher in Slovakians as compared to Belgians (1.52 +/- 0.28 W.kg-1 and 1.48 +/- 0.28 W.kg-1; P less than 0.001). Occupational physical activity in Belgians and heavy leisure time activity in Slovakians were independently related to fitness levels. However, each activity score explained less than 1% of the variance of physical fitness. We conclude that in these mainly sedentary, middle-aged subjects, fitness levels are independent from the usual physical activity patterns.

Physical Activity, Physical Fitness and Cardiovascular Diseases: Design of a Prospective Epidemiologic Study

From November 1976 to September 1978, a total of 3,179 active men, 40-55 years old, were screened for established or possible risk factors. Standard questionnaires were administered to assess psycho-social behavior and physical activity on and off the job. Physical fitness was determined by means of a graded sub-maximal exercise test. Information on coronary heart disease incidence will be collected over a 6-year period. The main objective of the study is to establish prospectively if physical activity and/or physical capacity are independent risk factors. Intercorrelations between fitness, physical activity and other measured variables will bae analyzed. Doppler ultrasound and 24-hour ECG recording for detecting peripheral vascular disease and rhythm disturbances have also been used; their value and role in screening for cardiovascular disease is further discussed.

Oral sustained-release nitroglycerin in chronic stable angina: A multicenter, double-blind, randomized crossover trial☆

Forty-six patients with stable angina pectoris were randomized to receive either oral sustained-release nitroglycerin (SRNG, 6.5 mg) or placebo (P) 3 times a day for a 2-week double-blind trial. They were investigated for the frequency of anginal episodes, for sublingual nitroglycerin consumption and for exercise tolerance. There was a slight but significant decrease in the number of anginal episodes (6.4 +/- 1.5 episodes/week with P, 4.9 +/- 1.7 with SRNG, p less than 0.005) and sublingual nitroglycerin consumption (3.9 +/- 1 tablets/week with P, 2.7 +/- 1 with SRNG, p less than 0.005). The patients performed 3 upright multistage (increments of 30 W every 3 minutes) exercise tests on a bicycle ergometer before the start of the study and 1 hour after the intake of SRNG or P, at the end of each double-blind phase. Exercise capacity, expressed as exercise duration, increased from 8.9 +/- 3.8 minutes with P to 10.2 +/- 3.8 minutes with SRNG (14.6%; p less than 0.001). At symptom-limited exercise, ST depression was significantly reduced (p less than 0.05) during the SRNG phase. Thirty-four patients (74%) reached a higher peak heart rate (139 beats/min with P, 145 beats/min with SRNG; p less than 0.001) and 35 patients (76%) a higher rate-pressure product (+6%; p less than 0.001). These changes in exercise tolerance are relatively modest and at least 11 patients would have benefited from larger doses of nitrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic effects of SIN-1 in acute left heart failure

SummaryTo assess the hemodynamic effects of SIN-1, the active metabolite of the venodilator molsidomine, after acute as well as chronic intravenous administration, ten patients with exacerbation of chronic heart failure were studied. After a mean bolus dose of 2 mg of SIN-1, mean right atrial pressure (MRAP), mean pulmonary artery pressure (MPAP), and pulmonary capillary wedge pressure (PCAP) decreased significantly up to the 60th minute; pulmonary vascular resistance (PVR) decreased significantly up to the 30th minute, while cardiac index (CI) and systemic vascular resistance (SVR) remained unchanged.During a 24-hour continuous infusion of SIN-1, MRAP, MPAP, and PCAP decreased significantly, while CI, PVR, and SVR remained largely unaltered. No dose adjustment was required to maintain the hemodynamic effects over 24 hours.The absence of noteworthy side effects and tolerance during this prolonged administration indicate that SIN-1 is a potentially useful drug in the management of patients admitted with exacerbation of heart failure.

The new long-acting coronary artery dilator molsidomine and its metabolite SIN-1

We studied the effects of intracoronary injections of SIN-1 (0.8 mg), the active metabolite of molsidomine, on coronary artery diameters and coronary stenoses. In nine patients with abnormal angiograms measurements were made 4 and 8 minutes after SIN-1 administration. There was a statistically significant increase in coronary luminal diameter in proximal, medial, and distal segments as well as at the level of the stenoses. At 4 minutes after administration distal segments showed a mean increase in diameter of 50%, compared to a mean increase of 26% in proximal segments. In six patients with normal angiograms SIN-1 abolished three of four coronary spasms induced by ergonovine maleate. A protective effect of SIN-1 against the vasoconstrictor effects of ergonovine was still present at 8 minutes after administration. Heart rate and blood pressure remained unchanged throughout the study. We conclude that the vasodilation induced by SIN-1 in normal and stenotic coronary arteries is probably an important contribution to the antianginal efficacy of molsidomine and suggests that molsidomine may be effective in the prophylaxis of variant angina.

Clinical and Hemodynamic Observations on Orally Administered Sulmazol (AR115BS) in Refractory Heart Failure

The acute effects of an oral preparation of sulmazol, a recently synthesized cardiotonic agent, were assessed by means of a Swan-Ganz catheter in 10 patients who had advanced heart failure that persis

Effect of oral sustained-release nitroglycerin on exercise capacity in angina pectoris: Dose-response relation and duration of action during double-blind crossover randomized acute therapy

Ten men with documented coronary artery disease and stable exertional angina underwent a double-blind crossover study to examine the benefit and the duration of action on their symptom-limited exercise capacity of 2 doses (2.5 and 6.5 mg) of sustained-release nitroglycerin (SRNG). A multistage bicycle test was performed in the sitting position by steps of 30 W each 3 minutes until the onset of typical angina pectoris. It was performed 24 hours before the start of the study; 1 and 5 hours after administration of placebo, and repeated after 2.5 and 6.5 mg of SRNG administered in a double-blind crossover study according to a 4 successive days protocol. No differences appeared between administration of placebo (1 and 5 hours) and the results obtained at the first exercise test. The dose of 2.5 mg of SRNG was effective on the symptom-limited working capacity but only at 1 hour (+9%; p less than 0.01). The dose of 6.5 mg was more effective both at 1 hour (+25%; p less than 0.001) and at 5 hours (+27%; p less than 0.001). All patients had angina at a higher heart rate (+5 to 8%; p = NS [not significant] and p less than 0.01), whereas systolic blood pressure and double product tended to be slightly but insignificantly increased. S-T depression at the onset of angina was insignificantly changed with placebo, and 2.5 and 6.5 mg of SRNG. It is concluded that 6.5 mg of orally administered SRNG is effective during at least 5 hours, and that the magnitude of the benefit and its duration are dose-related.

Secondary prevention after myocardial infarction: Effects of beta blocking agents and calcium antagonists

SummaryTherapeutic interventions in patients with myocardial infarction, whether during the first hours after coronary occlusion or several days later, aim to reduce mortality and morbidity by several mechanisms: Prevention of fatal ventricular fibrillation, limitation of infarct size, and inhibition of platelet aggregation are some examples of such mechanisms. Results from early intervention trials with beta blocking agents, particularly from ISIS-I, suggest that 1-year mortality is significantly lower in selected patients randomized to active treatment. Late intervention studies also suggest a significant reduction in coronary mortality and morbidity with beta blockade, particularly when data are pooled.Studies with the calcium channel blockers nifedipine and verapamil were unable to demonstrate any beneficial effects of these drugs on mortality or reinfarction.In this review article, attention will be directed to the most recent information about the preventive value of beta adrenergic blocking drugs and slow calcium channel inhibitors.

Analysis of Exercise-Induced R-Wave-Amplitude Changes in Detection of Coronary Artery Disease in Patients with Typical or Atypical Chest Pain under Digitalis Treatment

Specificity and sensitivity of exercise ECG were compared to exercise stress thallium 201 scanning and coronary arteriograms in 70 male patients with typical or atypical chest pain complaints, without previous myocardial infarction. 50 patients (group I) did not receive any treatment; 20 patients (group II) received digitalis as preventive treatment of atrial arrhythmias or for no particular reason. Only subjects with concordant results in radionuclide and angiography examinations were considered as coronary artery disease patients. Exercise stress tests were performed sitting on the bicycle ergometer using a progressive loading profile (30 W for 3 min), to the symptom-limited capacity (VO2SL). Positive exercise ECG were confirmed on ST decrease (1.5 mm) or on absence or increase in R-wave-amplitude modifications (V5). In the group I patients, ECG-ST-modification sensitivity, specificity, predictive value (+) and efficiency were, respectively, 92, 82, 86 and 88%. R-wave-variation sensitivity, specificity, predictive value (+) and efficiency were, respectively, 41, 74, 65 and 56%. In the group II patients, ST-depression sensitivity, specificity, predictive value (+) and efficiency were, respectively, 100, 33, 59 and 65%. R-wave-variation sensitivity, specificity, predictive value (+) and efficiency were, respectively, 50, 70, 63 and 60%. It was concluded that R-wave-amplitude variations induced lower false positive responses than ST-segment depression in patients under digitalis treatment. False negative responses were unfortunately 50% using the R-wave criterion. Exercise ECG was finally judged as a poor indicator of CAD in patients under digitalis treatment.