Clavicular Auscultation. Preferential clavicular transmission and amplification of aortic valve murmurs.

Clavicular transmission of aortic valve murmurs was investigated in 15 consecutive patients. In all patients, transmission to the clavicle of aortic systolic murmurs was detected both by auscultation and by phonocardiographic studies. Of seven patients with aortic diastolic murmurs, auscultation revealed clavicular transmission in six, but only four were recordable. There was increased murmur amplitude over the clavicle in 13 out of 15 cases. In contrast, murmurs were attenuated over the subclavian artery in eight out of nine and over the carotid artery in nine out of 11 patients. We conclude that clavicular auscultation regularly discloses aortic valve murmurs. The aortic systolic murmurs are consistently propagated to the clavicle, where they are usually conspicuously amplified. Aortic systolic murmurs are less frequently transmitted to the carotid and subclavian arteries, where they are usually considerably attenuated. Clavicular auscultation appears to be more rewarding than the traditional search for transmission of aortic murmurs to the carotid artery.