Ischemic and viable myocardium in patients with non-Q-wave or Q-wave myocardial infarction and left ventricular dysfunction: a clinical study using positron emission tomography, echocardiography, and electrocardiography.

Abstract

OBJECTIVES:

We investigated whether patients with non-Q-wave myocardial infarction (NQMI) have more ischemic viable myocardium (IVM) than patients with Q-wave myocardial infarction (QMI).

BACKGROUND:

Non-Q-wave myocardial infarction is associated with higher incidences of cardiac events than QMI, suggesting more myocardium at risk in NQMI.

METHODS:

To identify myocardial ischemia, hibernation, and scar, the resting and stress (82)rubidium perfusion and F-18 fluorodeoxyglucose metabolic positron emission tomographic imaging (PET) was performed in 64 consecutive patients with NQMI (n = 21) or QMI (n = 43). Echocardiography was performed for assessment of left ventricular function and wall motion index (WMI). The relationships between PET, echocardiographic, and electrocardiographic findings were analyzed.

RESULTS:

There were no significant differences in left ventricular ejection fraction (LVEF) between NQMI and QMI groups (28 +/- 10% vs. 25 +/- 11%, p > 0.05). Ischemic and viable myocardium was more common in NQMI than in QMI (91% vs. 61%, p < 0.05). The total amount of IVM was significantly higher in NQMI than in QMI (6.5 +/- 5.2 vs. 2.9 +/- 2.8 segments, p < 0.001). Neither the number of Q waves, residual ST-segment depression of >or=0.5 mm or elevation of >or=1 mm, nor LVEF and WMI were significant predictors for IVM. Wall motion index correlated with scar segments (r = 0.54, p < 0.001) and LVEF (r = -0.67, p < 0.001).

CONCLUSIONS:

Ischemic and viable myocardium is common in patients with NQMI and left ventricular dysfunction, suggesting that aggressive approaches should be taken to salvage the myocardium at risk in such patients.

• Authors: Hua Yang, Min Pu, David Rodriguez, Donald Underwood, Brian P Griffin, Vidyasagar Kalahasti, James D Thomas, Richard C Brunken
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 43 Issue 4 Pg. 592-8 (Feb 18 2004) ISSN: 0735-1097 [Print] United States
• PMID: 14975469 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Radiopharmaceuticals
• Rubidium Radioisotopes
• Fluorodeoxyglucose F18

Topics

• Case-Control Studies
• Echocardiography
• Electrocardiography
• Female
• Fluorodeoxyglucose F18
• Heart (diagnostic imaging)
• Humans
• Male
• Middle Aged
• Myocardial Infarction (diagnosis, physiopathology)
• Myocardial Ischemia (diagnosis, physiopathology)
• Prognosis
• Radiopharmaceuticals
• Rubidium Radioisotopes
• Stroke Volume (physiology)
• Tomography, Emission-Computed
• Ventricular Dysfunction, Left (physiopathology)