Dr Rich chose to focus on the many limitations of echocardiography, but he ignored the weaknesses of RHC. As already mentioned, a PAP, pulmonary vascular resistance, cardiac output, and pulmonary capillary wedge pressure cannot possibly begin to yield the wealth and depth of information gleaned from a well-performed echocardiogram. RHC is the “gold standard” for the diagnosis of PAH, and the diagnostic criteria are exclusively based on this technique. In 1985, Stuart Rich et al5 studied the magnitude and implications of spontaneous hemodynamic variability in primary PH by serial RHC measures 1 h apart in 12 subjects with PH. The mean coefficient of variation for PAP was 8.4%±3.8% (95% CI, 22%). One-third of the subjects had a coefficient of variation of >10%, and in reviewing the two individual patient data curves provided, the hour-to-hour variation in RHC-derived PAP exceeded 20 to 25 mm Hg. The authors also noted greater variability in pulmonary vascular resistance at higher measures. Could it, therefore, be possible that echocardiography is just as correct, or incorrect, as RHC at higher values? Just as the “gold standard” is no longer counted on to support a currency, one must adapt to the times and perhaps incorporate other indices to support a diagnosis of PH.