To calculate the sample size we considered the primary endpoint (concordance of the diagnosis of diastolic dysfunction between IC and echocardiography). Thus, considering a hypothesized positive predictive value of 70 ± 5% of the parameters obtained by IC, 77 individuals are estimated to be able to verify the expected positive predictive value with 95% confidence. Since the prevalence of diastolic dysfunction in patients with AHT estimated to be approximately 50% in most studies, the sample size is doubled for 154 hypertensive patients.