Pathophysiology of Q waves in II, III, avF in systemic lupus erythematosus. Evaluation using cardiovascular magnetic resonance imaging
Exclusive author commentary
Mavrogeni S et al. – Q in II, III, avF in systemic lupus erythematosus (SLE) may indicate myocardial infarction, acute or past inflammation or be a positional finding. The lack of Q does not exclude the possibility of infarction or inflammation. Cardiovascular magnetic resonance (CMR) is the best tool to reveal the pathophysiology of Q waves in SLE and guide treatment of heart involvement in these patients.Methods
- Inflammation evaluation by CMR using T2, early (EGE) and late gadolinium enhanced images (LGE) was performed in 20 SLE patients with mild cardiac symptoms and Q in leads II, III, avF of ECG.
- Their results were compared with 20 SLE patients with the same symptoms and normal ECG.
- In both groups, T2, EGE and left ventricular ejection fraction were normal.
- However, in 3/20 with Q in II, III, avF, CMR revealed lesions indicative of acute myocarditis.
- In the rest of them, CMR documented transmural LGE, due to past inferior myocardial infarction in 4/20 and epicardial LGE due to past myocarditis in 8/20 (4/8 in the inferior and 4/8 in the lateral wall of left ventricle).
- No LGE was found in 5/20 and the Q was attributed to the position of the heart.
- In 3/20 with normal ECG, CMR detected past myocarditis in 2/3 and myocardial infarction in 1/3.
- Coronary angiography assessed coronary artery disease in all SLE with evidence of myocardial infarction and normal coronaries in 9/10 patients with past myocarditis.
Sophie Mavrogeni (06/05/2012) comments:
Systemic lupus erythematosus (SLE) is an autoimmune disease with frequent cardiac involvement either as myocardial infarction or as myocardial inflammation (lupus myocarditis). ECG is the first line examination to evaluate the presence of coronary artery disease and Q waves are traditionally considered as an evidence of myocardial infarction. Although this is true for Q waves in V1-V6, the presence of Q in II, III, avF in may indicate not only myocardial infarction, but also acute or past inflammation or be a positional finding. Furthermore, the lack of Q does not exclude the possibility of infarction or inflammation. Cardiovascular magnetic resonance (CMR) using gadolinium, a noninvasive, nonradiating technique, is the best diagnostic tool to reveal the pathophysiology behind the Q waves in SLE and guide treatment of heart involvement in these patients.