Midori Tanaka

Comparison of Two Ultrasonic Methods of One-point Measurement of Pulse Wave Velocity—Where to Set the Echo-tracking Positions, in the Adventitia or Intima?

Background and purpose: Arterial stiffness parameter (β) and pulse wave velocities (PWV’s) can be obtained simultaneously in the carotid artery by using a combined color-Doppler and echo-tracking system. However, the values of measured indices depend on the echo-tracking positions in arterial wall for measuring diameter change. The present study was designed to compare the values of β and PWV’s obtained by echo tracking in the adventitia and intima, and to determine the most appropriate positions for echo tracking in the carotid artery.

A Noninvasive Method of Measuring Force-Frequency Relations to Evaluate Cardiac Contractile State of Patients during Exercise for Cardiac Rehabilitation

Background 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.

Noninvasive assessment of left ventricular force-frequency relationships by measuring carotid arterial wave intensity during exercise stress

Background: Evaluation of the contractile state of the left ventricle during exercise is important in drawing up a protocol of cardiac rehabilitation. It has been demonstrated that color Doppler- and echo tracking-derived carotid arterial wave intensity is a sensitive index of global left ventricular (LV) contractility. Objectives: We assessed the feasibility of measuring carotid arterial wave intensity and determining force-frequency (contractility-heart rate) relationships (FFRs) during exercise totally noninvasively. Methods: We measured carotid arterial wave intensity with a combined color Doppler and echo tracking system in 15 healthy young male volunteers (age 20.8 ± 1.3 years) at rest and during exercise. FFRs were constructed by plotting the maximum value of wave intensity (WD1) against heart rate (HR). Results: WD1 increased linearly with an increase in HR. The goodness-of-fit of the regression line of WD1 on HR in each subject was very high (r2 0.67 ~ 0.91, p <; 0.0001 respectively). The slope of the WD1-HR relation ranged from 0.31 to 1.52 [m/s3(beat/min)]. Conclusions: A global LV FFR can be generated in healthy young volunteers with an entirely noninvasive combination of exercise and wave intensity. These data should show the potential usefulness of FFR in the context of cardiac rehabilitation.

Effects of Moderate Short-Term Intermittent Aerobic Exercise on Arterial Stiffness — Evaluation by Stiffness Parameter and Pressure-Strain Elastic Modulus—

Background and purpose: Aerobic exercise decreases arterial stiffness. However, the direct measurements of alterations in pulsatile arterial diameter change have been poorly reported. Using echo-tracking method, we measured pulsatile changes in carotid arterial diameter, and evaluated the alteration in arterial stiffness effected by aerobic exercise.