Heart rate variability from 24 hours versus 72 hours holter monitoring in patients with mitral valve prolapse

ABSTRACT

To compare recorded heart rate variability from 24 hours with that recorded from 72 hours holter monitoring in patients with mitral valve prolapse. Cross sectional study. Department of Clinical Cardiac Electrophysiology Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi from May 2007 to March 2008. Patients from 15 to 38 years of age with confirmed diagnosis of mitral valve prolapse on 2 dimensional echocardiography were included. Patients with acute myocardial infarction [MI], Ischemic heart disease, diabetes mellitus or hypertension were excluded. Total 37 patients were included in the study through non-probability consecutive sampling. All these patients underwent 72 hours holter monitoring using Reynolds medical holter monitors 'life card CF'. Statistical time domain measures of heart rate variability i.e. standard deviation of all NN intervals [SDNN], standard deviation of the averages of NN intervals [SDANN] and square root of the mean of the squares of differences between adjacent NN intervals [RMSSD]. Mean values of SDNN, SDANN and RMSSD from 24 hours holter monitoring were 141.62 ms, 125.16 ms and 28.40 ms whereas those recorded from 48 hours of holter monitoring were 136.94 ms, 122.37 ms and 26.46 ms respectively. Difference between none of the variables from the two recordings was significant. Heart rate variability remains the same irrespectively of the length of holter monitoring