Measurement of left ventricular function during arm ergometry using the VEST nuclear probe

Area of Science:

• Cardiovascular Physiology
• Nuclear Cardiology
• Exercise Physiology

Background:

• Assessing left ventricular (LV) function during exercise is crucial for understanding cardiovascular adaptation.
• Traditional methods face limitations, especially during dynamic arm exercise.
• The VEST probe offers a potential solution for noninvasive LV function monitoring.

Purpose of the Study:

• To introduce and validate a chest-mounted nuclear probe (VEST) for assessing LV function during arm and leg ergometry.
• To evaluate the validity and reproducibility of LV function measurements at rest and during exercise using the VEST.
• To compare LV responses to arm versus leg exercise.

Main Methods:

• Utilized a chest-mounted nuclear probe (VEST) for LV function assessment.
• Subjects performed arm and leg ergometry at rest and during exercise.
• Measured LV ejection fraction, end-systolic volume, and end-diastolic volume.

Main Results:

• Transient changes in LV function and volumes were observed during both arm and leg ergometry.
• LV ejection fraction and volumes were significantly lower during arm exercise compared to leg exercise (25-30%).
• Peak exercise showed increased LV ejection fraction and relative LV end-systolic volume, followed by normalization, with a greater effect during arm exercise.

Conclusions:

• The VEST probe enables rapid, noninvasive assessment of LV function during arm exercise, overcoming limitations of other techniques.
• Arm ergometry imposes a greater afterload on the LV compared to leg ergometry, due to higher intramuscular and arterial pressures.
• The VEST system demonstrates validity and reproducibility for LV function assessment during dynamic exercise protocols.