PREVALENCE AND RELEVANCE OF A SEPTAL DIASTOLIC NOTCH DURING DOBUTAMINE STRESS ECHOCARDIOGRAPHY

Background Dobutamine stress echocardiography has become an accepted s imple and inexpensive method of detecting coronary artery disease. In this pharmacological stress test, particular attention has been paid t o transient systolic wall motion abnormalities. Our group has noted an abnormal diastolic ventricular septal motion, a 'diastolic notch', du ring dobutamine stress echocardiography that has not been previously d escribed. Methods and Results To find out whether this anomalous septa l motion is related to coronary artery disease we have analysed the st ress studies of 125 patients (69 men, age 6119 years) with chest pain, no previous myocardial infarction and no left bundle branch block, wh o underwent a dobutamine stress test. Dobutamine was infused up to 40 mu . kg.(-1) min(-1) in 3 min stages. A positive stress test was defin ed as the appearance of transient asynergy. Dobutamine time was the ti me from the infusion of dobutamine to the appearance of transient asyn ergy. The diastolic notch time was the time at which diastolic notch w as first detected. Diastolic notch was detected in 21 patients with si ngle coronary artery disease, 19 of whom had a severe left anterior de scending artery stenosis. Diastolic notch was present in 19 out of 27 patients (70%) with single left anterior descending stenosis. Twenty-s ix out of 44 patients with multivessel coronary artery disease had evi dence of a diastolic notch and 20 of these 26 had severe stenosis of t he left anterior descending artery. Finally, all three patients with l eft main coronary artery disease had a diastolic notch while no patien t with angiographically normal coronary arteries had this sign. In pat ients with a diastolic notch and a positive dobutamine stress test, di astolic notch time was shorter than dobutamine time (9 +/- 4 min vs 11 +/- 3 min, P<0.05). Conclusions In patients without previous myocardi al infarction and without left bundle branch block (1) the appearance of a septal diastolic notch during dobutamine stress echocardiography is very specific for the presence of coronary artery disease; (2) the detection of diastolic notch is mostly related to the existence of sev ere left anterior descending artery stenosis; (3) diastolic notch prec edes the development of ventricular asynergy.