Heart attacks occur when heart cells are deprived of oxygen. In most cases, this oxygen deprivation occurs when coronary arteries are blocked by so much cholesterol plaque that they’re unable to deliver oxygenated blood sufficient for the heart’s metabolic needs.
In the 1990s, however, Japanese physicians began encountering and describing a second etiology for myocardial infarction, which they dubbed “takotsubo” cardiomyopathy,” after the Japanese word for a crab pot because in individuals with this disorder, the heart takes on a distinctive appearance. In this syndrome, blocked blood vessels do not appear to be causally implicated. Instead, patients are likely to have an underlying neurological or psychiatric diagnosis, which has led to the nickname, “broken-heart syndrome.”
Mortality rates for takotsubo cardiomyopathy and cardiovascular disease that’s more clearly linked to blocked blood vessels are similar, and individuals who’ve been diagnosed with broken-heart syndrome are typically treated with the same types of drugs.
What Causes Takotsubo Cardiomyopathy?
In approximately 85% of all cases, takotsubo events were preceded by emotional or physical situations that caused extreme stress.
Grief over the death of a loved one, fear following an assault, fights with significant others, the loss of jobs and similar events may have been triggers. Physical stress linked to health stressors like asthma attacks, surgery and chemotherapy may also have acted as catalysts.
Scientists don’t know exactly what causes takotsubo cardiomyopathy, but most current theories focus on the role of the autonomic nervous system. The autonomic nervous system regulates those physiological functions like respiration, heart rate and blood pressure that are not under conscious control. Strong emotions cause the autonomic nervous system to signal the adrenal glands to release the hormone epinephrine (also called adrenaline).
Epinephrine has many benefits, particularly when it comes to helping the body sustain physical effort and to mediating inflammatory responses that might otherwise lead to anaphylaxis. Epinephrine increases heart rate, blood pressure, and muscle strength, and it makes significant short-term changes in the way the body metabolizes glucose. Epinephrine, though, can also result in unpleasant side effects like shakiness, anxiety, excess sweating, and cardiac arrhythmias. Takotsubo symptoms have been reported in patients who’ve taken an epinephrine overdose as well as in patients with tumors of the adrenal glands.
The individuals most at risk for takotsubo cardiomyopathy are women between the ages of 58 and 75. Indeed, recent research suggests that the syndrome may be implicated in up to five percent of all heart attacks affecting women in the United States.
There are no treatment guidelines that distinguish takotsubo cardiomyopathy from more common cardiomyopathies. Treatment generally includes the administration of beta blockers that can play a role in protecting the heart against the effects of epinephrine.