Features of Apical Ballooning Syndrome
Apical ballooning syndrome (also described as tako-tsubo cardiomyopathy, stress-induced cardiomyopathy, and the broken-heart syndrome) is an increasingly recognized condition that can closely mimic acute myocardial infarction. Its incidence is estimated to be 1 to 2% among patients who present with a presumed acute myocardial infarction. It classically affects postmenopausal women in the fifth to seventh decade, and the onset of the condition is often precipitated by emotional stress. Key features of apical ballooning syndrome are the absence of obstructive coronary artery disease in the setting of characteristic “ballooning” of the left ventricle from severe anteroapical akinesis and hypercontractility of the basal segments. Heart failure is present in approximately 50% of patients with apical ballooning syndrome, and cardiogenic shock occurs in up to 15%. Approximately 20% of these patients also have a transient systolic murmur associated with subvalvular pressure gradients that can mimic hypertrophic obstructive cardiomyopathy.
Diagnosis of Apical Ballooning Syndrome
Although it is critical to differentiate apical ballooning syndrome from acute myocardial infarction quickly, it can be challenging to do so. There are no electrocardiographic findings that clearly distinguish apical ballooning syndrome from acute myocardial infarction. With apical ballooning syndrome, the elevations in troponin are typically much lower than would be expected on the basis of the wall-motion abnormalities. However, it is difficult to rely on cardiac biomarkers alone, since these are often only modestly elevated during the early stages of an acute myocardial infarction. Thus, the diagnosis frequently becomes evident only in the cardiac catheterization laboratory, when no angiographically significant coronary artery disease is found. It is generally not advisable to withhold antithrombotic treatments such as heparin and aspirin while the diagnosis remains uncertain, since acute myocardial infarction is much more common. Decisions about fibrinolytic therapy are more complicated, given its associated risk of intracerebral hemorrhage. Whenever feasible, emergency coronary angiography should be performed to assist in clinical decision making.
What is the pathophysiology of apical ballooning syndrome?
A: The pathophysiology of apical ballooning syndrome has not been clearly elucidated. Leading hypotheses include transient catecholamine toxicity, aborted ST-elevation myocardial infarction with spontaneous lysis of thrombus, coronary vasospasm, and microcirculatory dysfunction. Similar wall-motion abnormalities have been seen in other states of catecholamine excess, such as subarachnoid hemorrhage and pheochromocytoma.
What is the recommended treatment for apical ballooning syndrome?
A: In patients with acute outflow tract obstruction, treatment should focus on ensuring adequate intravascular volume. Beta-blockers may also be considered in an attempt to slow the heart rate and increase the diastolic filling time. Although data from clinical trials are scant, some experts suggest treating patients with apical ballooning syndrome with beta-blockers and angiotensin-converting–enzyme inhibitors until left ventricular systolic function normalizes; it has also been hypothesized that treatment with beta-blockers may reduce the risk of recurrence (which is reported in a case series to be approximately 10%). Inotropic agents should be avoided, since they may exacerbate the outflow tract gradient. Aspirin should be considered for patients who have coexisting coronary artery disease. Some clinicians recommend anticoagulation with warfarin for several weeks in patients with severe systolic dysfunction in order to prevent left ventricular thrombus formation. In most patients with apical ballooning syndrome, the condition improves rapidly with supportive measures. Complete recovery of systolic function is typically observed within 4 to 6 weeks, and the overall prognosis tends to be excellent.
NEJM - Vol. 361, No. 10, September 3, 2009