Q-WAVE AND NON-Q-WAVE MYOCARDIAL-INFARCTION AFTER THROMBOLYSIS

Objectives. We studied the clinical outcome of Q wave and non-Q wave i nfarction after thrombolytic therapy. Background. Controversy exists o ver the clinical significance of Q waves after thrombolysis. Methods. We studied postthrombolytic angiographic results and short- and long-t erm clinical outcome in 150 patients with acute myocardial infarction classified as Q wave and non-Q wave on the 24-h and discharge electroc ardiograms (ECGs). The results from the two groups were then compared. Results. Eighty percent of patients had a Q wave and 20% a non-Q wave infarction on the 24-h EGG. The latter patients had lower peak creati ne kinase (CK) levels (p < 0.001), but the two groups did not differ s ignificantly otherwise. In 18 patients with a Q wave infarction on the 24-h EGG, pathologic Q waves disappeared. However, in seven patients with a non-Q wave infarction on the 24-h EGG, pathologic Q waves appea red throughout the hospital period. Q wave regression was associated w ith lower peak CK levels (p < 0.001) and an improvement in left ventri cular ejection fraction (p < 0.01). Thus, only 72% of patients had a Q wave and 28% a non-Q wave infarction on the discharge EGG. Patients w ith a non-Q wave infarction on the discharge ECG had higher patency of the infarct-related artery (p < 0.04),lower mean peak CK levels (p < 0.0001), a higher ejection fraction (p = 0.001) and a lower incidence of heart failure (p = 0.06) than patients with a Q wave infarction on the discharge EGG. Although the 2-year incidence of reinfarction and r evascularization was higher in patients with a non-Q wave infarction o n the discharge ECG (p < 0.05), 2-year mortality was lower (p = 0.08). Conclusions. Although the early postthrombolytic distinction between Q wave and non-Q wave infarction conveys no significant information, d uring the hospital period, non-Q wave infarction is associated with a smaller infarct area, improved left ventricular function and lower mor tality.