Takotsubo: Broken-Heart Syndrome

mcdc7_dilatedcardiomyopathy
The appearance and causes of most cardiomyopathies are unlike those of broken-heart syndrome.

Perhaps because so many of us complain about light stress, we sometimes underestimate the impact of both chronic stress and intense stress brought on by the death of loved ones or by a sudden romantic breakup.

Doctors had long known about various forms of cardiomyopathy, a functional or structural abnormality in the ventricular muscular wall of the heart. Cardiomyopathies involve one or more chambers affected by a variety of factors, ranging from cocaine use to neoplasms, and from selenium deficiency to bacterial or viral infections.

But only in the 1990s was another form of cardiomyopathy recognized. Known as takotsubo cardiomyopathy (broken-heart syndrome), it affects mostly women who are older than 50.  Due to chest pains and shortness of breath, patients typically mistake the onset of the syndrome for a heart attack. It has confused more than a few doctors who only diagnose it after an x-ray and dye reveal that there’s no arterial plaque in the heart of the patient. Instead the left ventricle takes on the shape of a Japanese ceramic pot (a takotsubo), which is used to trap lobsters.

Takotsubo
The X-ray revealing takotsubo cardiomyopathy, and on the right, a Japanese pot which it resembles. A composite image from two sites(http://circ.ahajournals.org & http://www.bjmp.org/)

Traditional causes of heart disease such as smoking, sedentary lifestyle, diet and diabetes are not the causes of this syndrome. It’s neither a congenital defect nor an inherited one. In 85% of the cases it is caused by the autonomic nervous system’s pronounced response to something highly stressful. The symptoms appear just minutes or hours after a sudden death of a loved one, a job loss, an intense argument with a spouse or any jarring event.

epinephrine2
Epinephrine(adrenaline),C9H13NO3

Specifically, a high concentration of adrenaline and other hormones may be damaging the ventricular wall, leading to the distortion of its shape. The hypothesis is supported by the fact that the syndrome can also be brought on by an accidental adrenaline-overdose and by an adrenaline-producing tumor. Fortunately, the muscle eventually recovers, and no long-term damage ensues. In 2000, only two research papers investigated broken-heart syndrome. A decade later, 300 such papers were published, but it’s still not exactly known why women over 50 are strongly predisposed.

estradiolMy non-expert notion is that it’s tied in to the chemical characteristics of post-menopause. Women in that stage of their lives have less 17 ß-estradiol, the main estrogen hormone, and lower concentrations of other sex hormones. Since estrogen and testosterone play a role in how organisms react to stress, an intense event in the presence of less estrogen and other hormones could produce an overreaction and overproduction of adrenaline from their autonomic nervous system. Regardless of the cause, takotsubo is something far more explosive than a hot flash from pre-menopause.

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