For a driver with a history of heart failure, which parameter is significant to consider during certification?

When considering certification for a driver with a history of heart failure, the Left Ventricular Ejection Fraction (LVEF) is a critical parameter. LVEF measures the percentage of blood that is pumped out of the heart's left ventricle with each contraction. This measurement is vital because it provides insight into the heart's pumping ability and overall function.

A low LVEF indicates that the heart may not be functioning effectively, which can significantly impact a driver’s ability to operate a vehicle safely. For FMCSA certification, an LVEF below a certain threshold may disqualify an individual from driving, as it suggests a higher risk for heart-related events that could impair driving capabilities.

Other parameters, such as age, weight, and the duration of heart issues, while relevant in a broader health context, do not provide as specific information about the driver's current cardiac function and risk levels as LVEF does. Therefore, LVEF is the most significant factor to assess when determining the safety and fitness of a driver with a history of heart failure.