Q-wave prediction of myocardial infarct location, size and transmural extent at magnetic resonance imaging.
OBJECTIVE
We investigated how pathologic Q waves or equivalents predict location, size and transmural extent of myocardial infarction (MI).


METHODS
MI characteristics, detected by contrast-enhanced magnetic resonance imaging, were compared with 12-lead electrocardiogram in 79 patients with previous first MI.


RESULTS
Q waves involved only the anterior leads (V1-V4) in 13 patients: in all patients MI involved the anterior and anteroseptal walls and apex; 81% of scar tissue was within these regions. Q waves involved only the inferior leads (II, III, aVF) in 13 patients: in 12 of these patients MI involved the inferior and inferoseptal walls; however, only 59% of scar occupied these regions. Q waves involved only lateral leads (V5, V6, I, aVL) in 11 patients: in nine of these patients MI involved the lateral wall but only 27% of scar tissue was within this wall. Q waves involved two electrocardiogram locations in 42 patients. In the 79 patients as a whole, the number of anterior Q waves was related to anterior MI size (r=0.70); however, the number of inferior and lateral Q waves was only weakly related to MI size in corresponding territories (r=0.35 and 0.33). A tall and broad R wave in V1-V2 was a more powerful predictor of lateral MI size than Q waves. Finally, the number of Q waves accurately reflected the transmural extent of the infarction (r=0.70) only in anterior infarctions.


CONCLUSIONS
Q waves reliably predict MI location, size and transmural extent only in patients with anterior infarction. A tall and broad R wave in V1-V2 reflects a lateral MI.
Rovai
Daniele
D
CNR, Clinical Physiology, Italy. drovai@ifc.cnr.it
Di Bella
Gianluca
G
Rossi
Giuseppe
G
Lombardi
Massimo
M
Aquaro
Giovanni D
GD
L'Abbate
Antonio
A
Pingitore
Alessandro
A
D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology*; D011379:Prognosis; D012008:Recurrence; D015203:Reproducibility of Results; D012720:Severity of Illness Index