Q wave and non-Q wave myocarditis with special reference to clinical significance.

This study was designed to evaluate the differences in clinical findings between patients with and without Q waves in acute myocarditis. Among a total of 24 patients, eleven patients had Q waves and thirteen did not. Echocardiographic findings, in-hospital complications and follow-up results were compared between the two groups. In the acute stage, the Q wave group showed significantly higher creatine kinase (CK) values and a more impaired left ventricular ejection fraction than the non-Q wave group (40 +/- 11% vs 57 +/- 10%, p < 0.001). Transient left ventricular hypertrophy was also prominent in the Q wave group. The incidence of cardiogenic shock (55%) and conduction disturbances (64%) were higher in the Q wave group than in the non-Q wave group (0% and 15%, respectively). In-hospital mortality rate was 27% in the Q wave group and 8% in the non-Q wave group, respectively. Since rapid improvement occurred in survivors with Q waves, long-term prognosis was favorable for the two groups. In conclusion, Q waves might indicate a more severe course in early illness.