RT-104
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Heart rate variability and
signal averaged ECG as predictors of clinical outcome in patients with acute myocardial
infarction
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Maria Stella Fera, Alessandro
Carunchio, Andrea Mazza, Maurizio Burattini, Maria Margherita Matinelli, Vincenzo Ceci.
Division of Cardiology, S. Spirito Hospital, Rome, Italy
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Abstract
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Background. Uncertain is the role of
heart rate variability (HRV) and ventricular late potentials (LP) in relation to the
clinical outcome and their correlation with the haemodynamic failure (HFa) and/or the
ischemic recurrences (IR) in patients after acute myo-cardial infarction (AMI).
Aim. of our study was to evaluate the prognostic value of HRV and LP
for HFa and/or IR during the first year of follow-up after AMI.
Methods. Eighty-seven patients affected by first anterior and
inferior AMI, with mean LVEF 40 ± 7% at discharge, underwent time- and frequency-domain
24-hour HRV analysis and signal-averaged ECG in pharmacological wash-out after 1 month
from the AMI. Left ventricular ejection fraction EF % (LVEF) were calculated. All patients
were followed up for 13 ± 3 months.
Results. During the follow-up 26 patients (30%) (Gr. 1) had HFa (16
pts) or IR (10 pts) and 61 pts (70%) (Gr. 2) were symptom-free. HRV was significantly
reduced in Gr. 1: SDNN 87 ± 17 ms vs 130 ± 22 ms (p < 0.001), SDANN/5 81 ± 16 ms vs
119 ± 29 ms (p < 0.001), SDNN < 70 ms 18/26 patients (69%) in Gr. 1 vs 9/61 (16%)
in Gr. 2 (p < 0.001), LF 250 ± 70 ms2 and HF 108 ± 98 ms2 in Gr
1 vs 470 ± 98 ms2 and HF 240 ± 75 ms2 in Gr. 2, LF/HF 3.1 ± 1.7
in Gr. 1 vs 2.3 ± 1.4 in Gr. 2 (p < 0.05). LP were positive in 7/26 patients (26%) in
Gr. 1 vs 12/61 (19%) in Gr. 2 (p = ns). LVEF was < 40% in 26/26 patients of group 1 vs
20/61 patients of group 2 (p < 0.001). The positive and negative predictive value for
identifying patients who were at a high risk of clinical deterioration were, respectively,
per SDNN < 70 ms 67%, 87%, per LP 37%, 72%, per SDNN < 70 ms + LP 47%, 74%, SDNN
< 70 ms + LVEF < 40%, 78%, 87%.
Conclusions. These results suggest that low HRV and LVEF < 40% may
be useful in predicting high risk clinical deterioration, after myocardial infarction. The
diagnostic value of LP is rather low. Combining LVEF and HRV resulted in an improvement in
post-infarct risk stratification.
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Key Words
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Signal averaged ECG
heart rate variability, late potentials, predictors of clinical outcome, acute myocardial
infarction, left ventricular ejection fraction, OA
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