To the Editor: In their prospective study, Gaddam et al1 have examined the effects of spironolactone on cardiac structure in 34 patients with resistant hypertension who were separated according to their plasma aldosterone levels. At baseline, cardiac volume overload was detected in patients with higher aldosterone levels that was significantly and rapidly reduced by spironolactone, whereas left ventricular (LV) mass was comparable at baseline and decreased significantly after treatment in both patients with higher and lower plasma aldosterone. Detection of comparable baseline LV mass even in the presence of significant volume overload is difficult to explain. As …