The blog, "ACP Internist" has an occasional feature called "Medical News of the Obvious". A recent news item in the AMA morning E mailed report stated " Study Indicates abnormal heart function may impeded ability to exercise"seems to break new ground in that regard but actually what the referenced article demonstrated was significant and not what we really knew all alone. Just a somewhat sloppy headline by the reporter.
The article entitled "Left Ventricular Function and Exercise Capacity" involving over 2800 patients studied at Mayo Clinic (see here for abstract, subscription needed for full text) has this paragraph for a conclusion:
In this large cross-sectional study of those referred for exercise echocardiography and not limited by ischemia, abnormalities of left ventricular diastolic ( my bold) function were independently associated with exercise capacity.
Diastolic function , until fairly recently, has not been regularly measured and this article gives strong data indicating that patients with diastolic dysfunction (such as many of the elderly and hypertensive patients with normal ejection fractions and smallish, poorly compliant left ventricles) may well have exercise limitation on a cardiac basis. This would seem a bit obvious simply from a consideration of the physiology of cardiac function but this study does provide much data documenting the relationship between exercise capacity and diastolic dysfunction. In evaluating a complaint of exertional dyspnea a cardiac cause is not excluded by a normal ejection fraction.