Prevalence and relevance of a septal diastolic notch during dobutamine stress echocardiography.

Background: Dobutamine stress echocardiography has become an accepted simple and inexpensive method of detecting coronary artery disease. In this pharmacological stress test, particular attention has been paid to transient systolic wall motion abnormalities. Our group has noted an abnormal diastolic ventricular septal motion, a 'diastolic notch', during dobutamine stress echocardiography that has not been previously described.

Methods And Results: To find out whether this anomalous septal motion is related to coronary artery disease we have analysed the stress studies of 125 patients (69 men, age 61 +/- 9 years) with chest pain, no previous myocardial infarction and no left bundle branch block, who underwent a dobutamine stress test. Dobutamine was infused up to 40 mu.kg.l-1 min-1 in 3 min stages. A positive stress test was defined as the appearance of transient asynergy. Dobutamine time was the time from the infusion of dobutamine to the appearance of transient asynergy. The diastolic notch time was the time at which diastolic notch was first detected. Diastolic notch was detected in 21 patients with single coronary artery disease, 19 of whom had a severe left anterior descending artery stenosis. Diastolic notch was present in 19 out of 27 patients (70%) with single left anterior descending stenosis. Twenty-six out of 44 patients with multivessel coronary artery disease had evidence of a diastolic notch and 20 of these 26 had severe stenosis of the left anterior descending artery. Finally, all three patients with left main coronary artery disease had a diastolic notch while no patient with angiographically normal coronary arteries had this sign. In patients with a diastolic notch and a positive dobutamine stress test, diastolic notch time was shorter than dobutamine time (9 +/- 4 min vs 11 +/- 3 min, P < 0.05).

Conclusions: In patients without previous myocardial 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 severe left anterior descending artery stenosis; (3) diastolic notch precedes the development of ventricular asynergy.