Abstract
The aim of the present study was to test the hypothesis that inadequate improvement in heart rate variability (HRV) in the healing stage of acute myocardial infarction (AMI) is associated with left ventricular (LV) remodeling. The study group comprised 20 patients (14 men, 6 women; mean age, 61±12 years) with a reperfused first anterior AMI (≤24 h). The standard deviation of normal RR intervals (SDNN) was calculated from the 24-h ambulatory electrocardiogram recorded on day 3 of admission and at predischarge from the hospital. Left ventriculography was performed immediately after primary angioplasty and at predischarge. The change in SDNN (ΔSDNN) was compared with the change in the LV end-systolic volume index (ΔLVESVI), a parameter of LV remodeling. SDNN increased from 73±19 ms on day 3 to 109±35 ms at predischarge (p=0.0003). SDNN at predicharge and ΔSDNN correlated negatively with ΔLVESVI (r=-0.52, p=0.02, and r=-0.61, p=0.004, respectively), whereas SDNN on day 3 did not correlate with ΔLVESVI. Multiple regression analysis selected ΔLVESVI (p=0.02) as an independent factor of ΔSDNN. This study indicates that ΔSDNN and SDNN at predicharge are associated with ΔLVESVI in patients with a reperfused first anterior wall AMI, indicating that persistently reduced HRV is associated with postinfarction LV remodeling. (Circ J 2003; 67: 225 - 228)
