Valvular Heart Diseases and Treatments

Murmurs are a common sign of valvular heart conditions; however the presence of a murmur may be associated with other cardiovascular conditions. As a medical examiner, you must distinguish between functional murmurs and pathological murmurs that are medically disqualifying.

Classification of Murmur Severity

The intensity of murmurs is classified on a scale of I to VI, from the least pronounced murmur to the loudest. Classification is rated as follows:

• Grade I – Must strain to hear a murmur.
• Grade II – Can hear a faint murmur without straining.
• Grade III – Can easily hear a moderately loud murmur.
• Grade IV – Can easily hear a moderately loud murmur that has a thrill.
• Grade V – Can hear the murmur when only part of the stethoscope is in contact with the skin.
• Grade VI – Can hear the murmur with the stethoscope close to the skin; it does not have to be in contact with the skin to detect the murmur.

Murmurs that are:

• Systolic and grade I or II are usually benign if the driver has no signs or symptoms of heart disease.
• Mid-systolic are usually benign if the driver has no signs or symptoms of heart disease.

Additional evaluation is recommended when murmurs are:

• Systolic, grade I or II, and the driver has signs or symptoms of heart disease.
• Systolic and grade III or higher.
• Holosystolic or late systolic.
• Diastolic or continuous.

Exceptions are common with the higher grade murmurs. When in doubt about the severity of a heart murmur, you should obtain additional evaluation.