A symptom-limited exercise test using a calibrated
electromagnetically braked cycle ergometer with an
electrical seat height adjustment (Ergoselect 100, Ergoline,
Germany) was performed according to a modified
Jones protocol (stepwise increase in work load of
16 Watts/min, starting with unloaded cycling plus the
ergometer related permanent load) [16]. Study details
are given elsewhere [17–19]. In the absence of chest
pain and ECG abnormalities, all tests were continued as