Primary PCI is associated with different cardiac autonomic patterns in relation to the site of myocardial infarction

Abstract

Aim: Reflex alterations of cardiac autonomic modulation have been described after acute myocardial infarction (AMI). The non-homogeneous autonomic innervation of the heart gives reason of different patterns of autonomic modulation depending upon the site of AMI. Conflicting data are available on cardiac autonomic modifications after primary percutaneous coronary intervention (pPCI). We evaluated cardiac autonomic changes in patients with ST-elevation myocardial infarction (STEMI) after pPCI, either within 24h after revascularization (T0) and at clinical stability (T1, 6±2days), taking into account the site of infarction.

Methods and results: We enrolled 33 consecutive patients with STEMI treated with pPCI (25 males, mean age 61±12.1yr); 15 had an anterior wall STEMI (ANT) and 18 had an inferior wall STEMI (INF). ECG and respiration were recorded at T0 and at T1. Cardiac autonomic modulation was evaluated by means of symbolic analysis of heart rate variability. At T0, At T0, 0V% (marker of sympathetic modulation) was higher in INF compared to ANT [31% (18-43) vs 18% (7-32), p=0.014]. Moreover, ANT had a higher 2LV%, index of vagal modulation, compared to INF [8% (7-15) vs 5% (2-8), p=0.006].

Conclusion: After pPCI, these preliminary results suggest that patients with INF were characterized by a sympathetic predominance, while ANT by a predominant vagal modulation. Our data suggest that pPCI can be associated with specific autonomic patterns, which are different for ANT and INF STEMI, according to the different autonomic innervation. Future ad hoc studies are needed to confirm these preliminary observations.

Keywords: Heart rate variability; Primary percutaneous coronary intervention; ST-elevation myocardial infarction; Symbolic analysis; Sympathetic.