Late potentials during left ventricular healing of acute myocardial infarction.

Background: Late potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodelling has not been fully evaluated.

Methods: We evaluated clinical characteristics, coronary angiographic findings and radionuclide angiographic measures about 1 month after an acute myocardial infarction in patients with and without late potentials.

Results: Although the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P < 0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P < 0.001). The root mean square of the voltage in the terminal 40 ms and the low-amplitude signal duration of < 40 microV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P < 0.02, and r = 0.39, P < 0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P < 0.01).

Conclusion: A larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.