Dobutamine stress echocardiography is widely used to diagnose coronary artery disease [1], but the safety of this testing procedure is uncertain. Major life-threatening complications-primarily sustained ventricular tachycardia, ventricular fibrillation, myocardial infarction, and cardiac asystole-have been reported to occur in 1 of 300 tests in large series [2, 3]. We report one case of cardiac rupture and death during low-dose dobutamine stress echocardiography done in a 66-year-old patient with recent myocardial infarction admitted to a coronary care unit.

During the first 3 days after admission, mild left ventricular failure requiring diuresis and an episode of atrial fibrillation treated with amiodarone complicated the infarction. On the twelfth day after infarction, dobutamine stress echocardiography was requested because the exercise stress test result was nondiagnostic. At baseline, the resting stress echocardiography showed dyskinesia and diastolic thinning of the proximal inferior wall with preserved global function (ejection fraction, 55% by area length method) (Figure 1). At 5 µg of dobutamine, no change in wall motion was detected. At 10 µg, in the absence of significant changes in heart rate, the patient suddenly had atypical chest pain at the base of the right hemithorax. Simultaneously, a new-onset pericardial effusion was detected by echocardiography. After a few seconds, the patient lost consciousness and pulse. Pericardiocentesis was done immediately, but pericardial effusion continuously recurred. All attempts at cardiopulmonary resuscitation-which were started immediately and performed in cooperation with the anesthesiologists-failed, and the patient died.

View larger version (143K): [in this window] [in a new window]   Figure 1. End-systolic frames of an apical view taken at rest (top left), after 4 of 10 µg of dobutamine per kg of body weight per minute (top right), after 4 minutes 54 seconds of 10 µg of dobutamine per kg per minute (bottom left), and after 5 minutes of 10 µg of dobutamine per kg per minute (bottom right). In resting conditions, there is dyskinesia of the inferobasal segment, virtually unchanged after 4 minutes of dobutamine, 10 µg. In the apical four-chamber view, no effusion is detectable at 4 minutes 54 seconds of 10 µg of dobutamine per kg per minute, and a massive pericardial effusion is obviously present 6 seconds later, producing sudden, catastrophic tamponade.

This case dramatically emphasizes three obvious, albeit sometimes neglected, points. First, pharmacologic stress tests should be done with an attending physician present, which apparently is not always the case in some institutions in the United States [4]. Second, every stress test carries a definite, albeit small, risk. Third, not all stress tests carry the same risk for major adverse reactions, and dobutamine stress testing may be more dangerous than other forms of physical or pharmacologic stress, such as those produced by exercise, dipyridamole, or adenosine [5].