Persistent ST-segment elevation and left ventricular wall abnormalities: a 2-dimensional echocardiographic study.

Area of Science:

• Cardiology
• Medical Imaging
• Electrocardiography

Background:

• Persistent ST-segment elevation after anterior wall myocardial infarction (MI) is a common electrocardiographic finding.
• The underlying cause of persistent ST-segment elevation, whether dyskinetic wall motion or left ventricular aneurysm, remains debated.

Purpose of the Study:

• To investigate the relationship between myocardial wall motion abnormalities and persistent ST-segment elevations following anterior wall MI.
• To determine if dyskinetic wall motion or left ventricular aneurysm is more indicative of persistent ST-segment elevation.

Main Methods:

• Utilized 2-dimensional (2-D) echocardiography to assess wall motion abnormalities in patients with anterior wall MI.
• Correlated echocardiographic findings with electrocardiographic (ECG) data, including ST-segment elevation and late follow-up surface ECGs.
• Measured infarct size using peak creatine kinase levels.

Main Results:

• 96% of patients with acute anterior wall MI and persistent ST-segment elevation showed dyskinetic wall motion.
• 86% of patients with chronic anterior wall MI without ST-segment elevation had akinesia of the infarcted segment.
• In acute MI patients, persistent ST-segment elevation developed in 90% of those with initial dyskinetic wall motion, whereas none with akinetic/hypokinetic motion showed late ST-segment elevation. Larger infarct size was associated with dyskinetic motion.

Conclusions:

• Persistent ST-segment elevation after acute anterior wall MI is primarily indicative of dyskinetic wall motion, not aneurysm formation.
• Dyskinesia appears to precede and be responsible for persistent ST-segment elevation on surface ECGs.
• Larger infarct size is associated with the development of dyskinetic wall motion abnormalities.