Doppler and echocardiographic study of normal systolic murmurs

To elucidate the genesis of normal ejection systolic murmurs, we performed phono and Doppler echocardiography in 42 normal subjects. Individuals with hypertension, ST · T changes on ECG, anemia or other cases with definite cardiovascular findings were excluded from the study. Their ages ranged from 22 to 61 years with an average of 48.1 years. They were classified in 2 groups; 9 with Levine 2/6 systolic murmur and 33 without murmur or with 1/6 murmur. Fifteen patients with pure aortic regurgitation or with aortic prosthesis but without significant stenosis, and 7 patients with pulmonic valvular stenosis were served as control. We correlated the intensity and timing of murmur with maximal flow velocity, acceleration time and other parameters. All systolic murmurs were early systolic. Mid-systolic murmur was not noted. Peak of flow velocity increased at the aortic orifice than at the left ventricular outflow tract or pulmonary orifice. Left-sided peak flow velocity occurred earlier than the right-sided peak flow velocity. Early systolic maximal flow velocity of the aorta significantly increased in 9 subjects with murmur than in the remaining 33 without significant murmur. Ejection fraction, hematocrit and body surface area did not difier between the groups with and without significant murmur. Systolic blood pressure and age, however, were higher in subjects with murmur. In aortic valvular disease, systolic murmurs and peak flow signals were early systolic, but in pulmonary stenosis these were mid-systolic in timing. In conclusion, normal ejection systolic murmurs were early systolic and originated at the aortic orifice. Mid-systolic murmurs were unlikely as left-sided murmur in origin. Flow velocity was the most important determinant of the intensity of ejection murmur.