Cardiovascular Mechanisms of Functional Aerobic Impairment in Patients with Coronary Heart Disease

Abstract

Maximal oxygen uptake V O O2 max ) and functional aerobic impairment (FAI) were determined by treadmill test in 42 men with coronary heart disease and in 11 slightly older healthy men. Patients were separated according to occurrence or nonoccurrence of angina with exercise. At rest and at four levels of submaximal exercise on a bicycle ergometer, cardiac output (Q), using the direct Fick principle, heart rate (HR), mean systemic and pulmonary arterial pressures, and arterial-mixed venous oxygen difference (A-V O 2 D) were evaluated in relation to relative aerobic requirement (% V o o2 max ). Q was highly correlated with V o o2 , and both the level and the rate of change of Q were lower in patients with angina at all submaximal workloads. Stroke volume (SV) and HR were significantly restricted at the higher workloads. Although peripheral resistance was increased, there was no compensatory increase in A-V O 2 D. Both restricted SV and reduced HR are responsible for cardiovascular components of the abnormal FAI found in patients with myocardial ischemia due to coronary arterial disease.

Exploratory Study on Oxygen Consumption On-kinetics During Treadmill Walking in Women With Systemic Lupus Erythematosus

“…Peak VO 2 in the women with SLE was also far below values reported after 10 days of bed rest in healthy women of similar ages55. In the women with SLE, peak VO 2 was 32.0 ± 13.3% lower than levels expected for healthy, sedentary women of similar ages, as determined by the well established algorithm of Bruce43, 44. The decreases in peak VO 2 9, 11, 13, 56, and anaerobic threshold11, 13, 53, 56 in the women with SLE in this study were also similar to previous reports on patients with SLE.…”

“…In the control group, peak VO 2 was similar to age predicted, population normative values as determined by the well-established algorithm of Bruce43, 44. Anaerobic threshold occurred on average at approximately 62% of peak VO 2 , a level typical of healthy adults45, 46.…”

Is a high-intensity exercise test better than a graded exercise test in eliciting exercise-related arrhythmias?

“… 1 , 2 , 3 Such GXT protocols were not specifically designed to assess for arrhythmia. In fact, the protocol designed by Bruce and colleagues 4 in 1973 ( Bruce protocol ) was initially proposed to assess cardiac impairment owing to coronary artery disease in adult patients. Despite its aim, the Bruce protocol (or a variation of it) remains the most commonly used exercise test, and has been validated for pediatric patients.…”

Correlation of ACSM's walking equation and directly measured Vo2 max in Indian population: A pilot study

“…Peterson et al also found that ACSM's equation overestimated VO 2max in older fit men and women and concluded that equation is not appropriate to use when treadmill testing [14]. The study done by Bruce et al, suggest that there is a physiological difference in various population and each has a unique relationship of workload with VO2 [15,16].…”