Background: Dicrotic Notch (DN) is known to dampen with age, with increasing arterial stiffness probably due to arterial calcification. Since arterial calcification has recently been shown to predominantly involve descending thoracic aorta, we hypothesized that calcification in different segments of thoracic aorta will have a different impact on DN.

Methods: A sample of 44 patients with invasive thoracic aortic pressure tracings during cardiac catheterization was selected for this study. Non-contrast CT scans were evaluated for presence of calcification in aortic segments (ascending aorta (AA), aortic arch (arch) and descending aorta (DA)) and then quantified. DN was categorized based on aortic pressure tracings into 4 grades. Grade 1 represented normal DN; grades 2, 3 and 4 represented progressively diminishing DN, where grade 4 represented absent DN. Compliance was calculated as a change in stroke volume over aortic pulse pressure with both measurements obtained from echocardiography reports done within one year of catheterization.

Results: The mean age of the sample population was 64.6 ± 10.5 years. Out of the 44 patients, 14 (32%) had a calcified AA, 25 (56%) had a calcified DA and n=28 (63%) had a calcified arch. Furthermore, 14 (32%) patients had only one segment calcified, whereas 10 (23%) had two and 11 (25%) had all three segments calcified. Abnormal DN was present in 16 (36%) patients. The odds of having an abnormal DN in the presence of calcified AA were more than 3 times (OR: 3.67; p=0.05). Compliance was higher in those with a normal DN versus those with an abnormal DN (1.64 ml/mmHg vs. 1.21 ml/mmHg) (p = 0.09). There was no significant association between calcification in the DA or arch of aorta.

Conclusion: There was no association between dicrotic notch and presence of calcification in the arch of the aorta and descending aorta.