METHODS
Consecutive patients with stable congestive heart failure
(NYHA class I–III) who were referred to the department of
cardiology at the University of Heidelberg were assessed to
determine their eligibility to participate in the study. The
inclusion criterion was a left ventricular ejection fraction
below 45%, as determined by radionuclide ventriculography.
Patients in NYHA functional class IV were excluded, as were
those who had neurological, orthopaedic, peripheral vascular,
or severe pulmonary diseases which could impair the successful
completion of submaximal or maximal exercise tests.
Patients who were not able to speak fluent German were also
excluded.
The study was approved by the institutional ethics
committee and all patients gave their written informed
consent before enrolment.
Standard medical treatment (for example, with angiotensin
converting enzyme inhibitors, digoxin, and diuretics) was
individually optimised, based on symptoms and renal
function, at least six weeks before exercise testing.
In all patients, the NYHA functional class was determined
by an independent investigator before assessment of peak
oxygen uptake, the six minute walk test, and measurement of