Physiological significance of early deceleration time prolongation in asymptomatic elderly subjects

Background: Alterations in Doppler-derived diastolic filling patterns are c ommon among elderly persons, but their physiological and prognostic signifi cance remains uncertain, particularly in asymptomatic older persons without overt cardiac disease. This study was designed to determine whether early mitral inflow deceleration time (DT) prolongation is of physiological signi ficance in asymptomatic elderly subjects. Methods and Results: In 15 asymptomatic patients aged 60 to 93 years with n o history of heart failure (HF) or edema, we performed two-dimensional and Doppler echocardiography and 60-minute head-out, isothermic water immersion to produce circulatory volume expansion. Plasma levels of atrial natriuret ic peptide (ANP) and brain natriuretic peptide (BNP) were measured immediat ely before and after water immersion. Seven of 15 patients had a normal mit ral early DT (160 to 240 milliseconds; group 1) and 8 of 15 patients had DT prolongation (>240 milliseconds; group 2). Group 2 subjects had significan tly smaller chamber sizes and increased relative wall thickness without inc reased left ventricular mass. Head-out water immersion produced greater inc reases in plasma ANP levels in group 2 subjects with longer DTs despite sim ilar degrees of circulatory volume expansion in each soup. In contrast, pla sma BNP levels did not increase significantly with water immersion in eithe r group. Conclusion: Early DT prolongation in asymptomatic elderly subjects is assoc iated with increased relative wall thickness and enhanced ANP increments af ter central volume expansion. Such exaggerated responses suggest that, in t he elderly, a prolonged DT has physiological significance and may represent a precursor to symptomatic diastolic HF, a condition known to be associate d with advancing age.