Serial changes in regional diastolic left ventricular function after a first acute myocardial infraction

Area of Science:

• Cardiology
• Cardiac Imaging
• Myocardial Infarction Research

Background:

• Regional diastolic dysfunction can persist after acute myocardial infarction (AMI) even when systolic function appears normal.
• The long-term implications and relationship to myocardial viability of post-AMI diastolic abnormalities remain unclear.

Purpose of the Study:

• To investigate the temporal changes in regional diastolic and systolic function after AMI.
• To determine the relationship between these functional changes and myocardial viability.

Main Methods:

• 106 patients with a first AMI were assessed using echocardiography with color kinesis.
• Regional left ventricular function (systole and diastole) was evaluated on days 1, and at 1, 3, and 6 months post-AMI.
• The percentage of segments with abnormal wall motion was calculated for both systolic and diastolic function.

Main Results:

• The area of diastolic wall-motion abnormality decreased significantly from baseline (38%) to 6 months (30%) post-AMI (P=.001).
• No significant change was observed in systolic wall-motion abnormality over the same period (18% to 19%, P=.66).
• Patients with myocardial viability showed a significant reduction in diastolic abnormalities, primarily in regions with only diastolic dysfunction, unlike those without viability.

Conclusions:

• Abnormal diastolic wall motion is common after AMI and tends to resolve more than systolic abnormalities, particularly in patients with viable myocardium.
• These findings suggest that post-AMI diastolic dysfunction may represent a transient phenomenon, termed 'diastolic stunning'.
• Myocardial viability and N-terminal pro-brain natriuretic peptide levels are associated with the resolution of diastolic wall-motion abnormalities.