In 1984, Yock and Popp2 first demonstrated that sPAP can be accurately estimated by Doppler echocardiography, reinforced soon after by others.5,6 However, as with many other areas in medicine, contemporary studies have suggested that the aforementioned methods may not accurately estimate sPAP (Table 1). In contrast, Rich et al7 and Fisher et al10 demonstrated significant discrepancies in sPAP determination, with broad limits of agreement by Bland-Altman analysis in patients with suspected PH referred for RHC. The REVEAL Registry (Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management) showed suboptimal correlations on repeat studies in patients with established pulmonary arterial hypertension.8 The authors acknowledged multiple limitations in their methodology, notably problems with RAP estimation and quality of TR jet, among others (Table 2). One common theme among all these studies not discussed, however, is that all subjects either had or were suspected of having PH and were referred for RHC. As a result, there is a strong referral bias, rendering it impossible to determine positive and negative predictive values, and these are notably absent throughout the literature. For the purposes of screening, these values are critical. The second common theme among the studies is that the limits of agreement were only markedly different in patients with clearly elevated sPAP. This is best illustrated in Hinderliter et al11 and Fisher et al,10 wherein despite limits of agreement of −38.8 to +40 mm Hg, the data showed that only two patients with any degree of PH were “missed” by echocardiography. Screening is used to determine the presence or absence and not necessarily the severity of disease. At this lower end of pulmonary artery pressure, the critical range for the purpose of screening, we want to avoid overdiagnosis and thus exposure to financial and medical risk by RHC. In the Study of Pulmonary Hypertension in America (SOPHIA) study, Walker et al12 showed a false-positive rate of 12%. This low rate suggests that echocardiography screening is useful to avoid unnecessary RHC.