Evaluation of the contractile state of the left ventricle during exercise is important for cardiac rehabilitation. As yet, no noninvasive methods for this purpose have been established. The force-frequency relation (FFR) during exercise has the potential for evaluating the contractile state noninvasively. Color Doppler- and echo tracking-derived carotid arterial wave intensity is a sensitive index of global left ventricular (LV) contractility.
We assessed the feasibility of measuring carotid arterial wave intensity and determining FFR’s during exercise totally noninvasively.
We enrolled 18 healthy men (age 20.6 ± 2.1 years). Using ultrasonic diagnostic equipment, we measured wave intensity in the carotid artery and heart rate (HR) before and during ergometer exercise. FFR’s were constructed by plotting the maximum value of wave intensity (WD1) against heart rate (HR).
increased linearly with an increase in HR during exercise. The regression line of WD
on HR represented the FFR.
and gradual exercise test, we obtained FFR’s noninvasively. These data should show the potential usefulness of FFR in practicing cardiac rehabilitation.