Heart ratevariability inidiopathic dilated cardiomyopathy: relation todisease severity and prognosis

Objective-To assess theclinical importanceofheartratevariability (HRV)in patients withidiopathic dilated cardiomyopathy(DCM). Patients and methods-Timedomain analysis of24hourHRV wasperformed in 64patients withDCM, 19oftheir relatives withleft ventricular enlargement (possibleearlyDCM),and33healthy control subjects. ofHRV werereduced inpatients withDCM comparedwith controls (P 50ms (P= 0-0002, at12months; P = 0-0001, during overall followup).Stepwise multiple regression analysis showedthatSDNN < 50ms identified, independently ofother clinical variables, patients who wereat increased riskofdeveloping progressive heartfailure (P= 0.0004). Conclusions-HRV isreducedinpatients withDCM andrelated todisease severity. HRV isclinically useful asanearlynoninvasive markerofDCM deterioration.