Diagnostic Value of the First and Second Derivatives of the Arterial Pressure Pulse in Aortic Valve Disease and in Hypertrophic Subaortic Stenosis

Abstract

The brachial arterial dp/dt was continuously computed by means of an electronic differentiating circuit in 117 patients and 23 normal subjects. The peak dp/dt averaged 1092±372 (S.D.) mm. Hg/sec. in 32 patients with idiopathic hypertrophic subaortic stenosis, 547±94 mm. Hg/sec. in six patients with discrete subvalvular subaortic stenosis, 811±185 mm. Hg/sec. in 23 normal subjects, 358±85 mm. Hg/sec. in 29 patients with valvular aortic stenosis, 724±212 mm. Hg/sec. in 25 patients with combined aortic stenosis and regurgitation, and 1736±530 mm. Hg/sec. in 24 patients with pure aortic regurgitation. It is suggested that the elevated peak dp/dt seen in patients with hypertrophic stenosis is due to the absence of obstruction to ejection early in systole. In contrast, patients with valvular and discrete subvalvular stenosis, who exhibit fixed obstruction to outflow throughout ventricular systole, had a peak dp/dt that tended to be lower than normal. Calculation of the second derivative (d 2 p/dt 2 ) of the arterial pressure pulse provided even better separation of the various groups of patients studied. The analyses of the dp/dt and of the d 2 p/dt 2 of the brachial artery pressure pulse afford a simple and reliable assessment of the nature and location of left ventricular outflow obstruction and are helpful in the differentiation of valvular aortic stenosis, combined stenosis and regurgitation, and pure aortic regurgitation.