To evaluate the role of wall motion abnormalities, myocardial ischemia and viability in patients with ST segment elevation in Q-wave ECG leads during dobutamine echocardiographic test, we analyzed a series of 391 dobutamine echocardiographic tests performed 10 ± 2 days after a first myocardial infarction. ST segment elevation was defined as 1 mm greater than baseline at 40 ms occurring in > 1 Q-wave lead. Resting wall motion score index was derived using a 16 segment-4 grade score model. Homozonal myocardial ischemia was defined as worsening or new wall motion abnormalities in infarct-related artery perfusion territory. Myocardial viability was defined as improving resting wall motion abnormalities in at least two infarct-related segments during low-dose dobutamine ehocardiographic test. The extent of homozonal ischemia and myocardial viability was derived calculating the increase and reduction in wall motion abnormalities at peak stress and at low doses, respectively. A greater Incidence of dobutamine-induced ST segment elevation was found in anterior vs inferior myocardial infarction (82/175 vs 77/216, p <0.05). Patients with dobutamine-induced ST segment elevation, in comparison with those without ST segment elevation, showed higher resting wall motion score index (anterior myocardial infarction: 1.67 ± 0.27 vs 1.43 ± 0.30, p = 0.0001; inferior myocardial infarction: 1.44 ± 0.27 vs 1.30 ± 0.18, p = 0.0001) and a similar incidence and extent of myocardial viability and homozonal ischemia. In conclusion, dobutamine-induced ST segment elevation is more common in anterior than inferior Q-wave myocardial infarction. In both anterior and inferior myocardial infarction, ST segment elevation is not related to a higher prevalence and extent of myocardial ischemia or viability but to a greater extent of resting wall motion abnormalities.
|Translated title of the contribution||ST segment evaluation in necrosis during dobutamine echocardiography: Role of ischaemia myocardial viability and ventricular arrhythmia|
|Number of pages||4|
|Publication status||Published - 1996|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Radiology Nuclear Medicine and imaging