Objective: To assess the relation of the auscultatory gap during blood pressure measurement to cardiovascular structure and function.
Design: Cross-sectional study.
Setting: A hypertension center in a university hospital.
Patients: 168 persons with hypertension who were otherwise healthy and were not receiving medication.
Measurements: Wideband external pulse recordings and ultrasonographic examination of the left ventricle and extracranial carotid arteries. Vascular stiffness was evaluated using simultaneous carotid pressure waveforms obtained by applanation tonometry of the contralateral carotid artery.
Results: Classic auscultatory gaps were present in 21% of patients and were associated with older age (mean age ±SD, 64 ± 11 years for patients with gaps and 55 ± 13 years for patients without gaps; P < 0.001), female sex (67% of patients with gaps and 44% of patients without gaps were female; P < 0.05), and increased arterial stiffness (arterial stiffness index, 8.5 ± 4.6 in patients with gaps and 5.8 ± 3.2 in patients without gaps; P < 0.005). The prevalence of atherosclerotic plaques was increased more than twofold among patients with gaps compared with patients without gaps (50% compared with 22%; P < 0.002). Patients with and without auscultatory gaps had similar blood pressures, left ventricular structure and function, serum cholesterol levels, and smoking history. Logistic regression analysis indicated that only female sex (P < 0.02), arterial stiffness (P < 0.002), and atherosclerotic plaque (P < 0.02) were independently associated with the presence of an auscultatory gap.
Conclusions: This study provides strong evidence that auscultatory gaps are related to carotid atherosclerosis and to increased arterial stiffness in hypertensive patients, independent of age. Although these observations need to be confirmed prospectively, they suggest that auscultatory gaps may have prognostic relevance.