title: Standard Deviation of normal interbeat intervals as a risk marker in patients with left ventricular systolic dysfunction: a meta-analysis.
abstract: Our aim was to evaluate the Standard Deviation of Normal-Normal (SDNN) interbeat interval as a risk marker in left ventricular systolic dysfunction (LVSD) patients through a meta-analysis. We searched PubMed for studies that evaluated SDNN as a predictor of all-cause-death, cardiac death, transplantation, and progressive clinical deterioration using a search strategy validated for MEDLINE. Mean values and SD for SDNN in sixteen studies included were 115+/-48 ms in survivors versus 87+/-40 ms in non-survivors, resulting in a statistically significant standardized mean difference (0.594, 95%CI 0.385 to 0.803). In conclusion, SDNN may be a useful prognostic marker in LVSD. Additional studies must evaluate if SDNN may be used to subsidize therapeutic decisions.
authors.forename: Marcos R
authors.initials: MR
authors.lastname: de Sousa
authors.forename: Marco P T
authors.initials: MP
authors.lastname: Barbosa
authors.forename: Federico
authors.initials: F
authors.lastname: Lombardi
authors.forename: Antonio L P
authors.initials: AL
authors.lastname: Ribeiro
mesh_terms: D003627:Data Interpretation, Statistical; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D013599:Systole / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology