Significance of persistent left ventricular dysfunction during recovery after dobutamine stress echocardiography

Abstract

Objectives: This study sought to determine the duration of new or worsening left ventricular regional wall motion abnormalities (RWMAs) after dobutamine stress echocardiography (DSE) and their relation to the extent of coronary artery disease (CAD).

Background: Despite extensive reports on DSE, little is known about the duration of new or worsening RWMAs during recovery. We hypothesized that the persistence of RWMAs during recovery may be associated with the extent of CAD and therefore ischemia.

Methods: Sixty-five consecutive patients with positive results on DSE and angiographically documented CAD were studied. Each patient underwent 12-lead electrocardiography and two-dimensional echocardiography at rest, during dobutamine infusion and continuously during recovery to assess the recovery time of ischemic myocardial regions.

Results: All patients had at least one ischemic region during DSE. Complete resolution of RWMAs occurred within 25 min in patients with multivessel CAD, within 20 min in those with two-vessel disease and within 15 min in those with single-vessel disease (p < 0.001). The greater the wall motion score index at peak stress, the longer the duration of RWMAs into the recovery phase (p < 0.01). RWMAs persisted long after normalization of each patient's symptoms, electrocardiographic (ECG) changes, heart rate and rate-pressure product during recovery.

Conclusions: We demonstrated that normalization of left ventricular RWMAs occurs after resolution of symptoms and ECG changes during recovery. The time to recovery is related to the extent of CAD and myocardial ischemia as well as to the presence or absence of collateral circulation. These findings may represent stunned myocardium after brief period of ischemia.