Takotsubo Cardiomyopathy

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The acute onset of substernal chest pain during vigorous exercise prompted a 70-year-old woman to seek emergency medical attention. She reported chest pressure, left arm numbness, shortness of breath, and severe sweating.

The patient had mild chronic obstructive pulmonary disease, osteoporosis, and medically controlled
ulcerative colitis. She had no history of cardiac symptoms. An ECG obtained during a complete physical examination performed 6 days before this event had appeared normal.

In the emergency department, the patient was in severe respiratory distress. She was afebrile and had a blood pressure of 87/70 mm Hg, heart rate of 88 beats per minute, respiration rate of 25 breaths per minute, and oxygen saturation of 83% while breathing room air. She had bilateral rales, normal heart sounds, and a grade 2/3 systolic murmur over the apex that radiated into the axilla.

Troponin T level was 0.89 µg/L (greater than 0.07 µg/L is considered abnormal); thyroid-stimulating hormone level was slightly decreased, with normal free thyroxine and total triiodothyronine levels; and white blood cell count was 23,500/µL, with 93.6% neutrophils. Remaining laboratory tests revealed no significant abnormalities. Findings from computed radiography were consistent with pulmonary edema. An ECG revealed normal sinus rhythm and ST elevation in V3-V5.

The preliminary diagnosis was acute anterior wall myocardial infarction (MI) with cardiogenic shock and pulmonary edema. The patient received tenecteplase, low-dose aspirin, and heparin. She was then transferred emergently to our facility for urgent cardiac catheterization and angioplasty.

Despite thrombolytic therapy, the ECG did not demonstrate significant changes. Cardiac catheterization showed normal coronary arteries (A and B), a left ventricular (LV) ejection fraction of 20%, and grade 2 to grade 4 mitral regurgitation. Findings on an aortogram were normal. A ventriculogram showed transient LV apical ballooning syndrome (also known as takotsubo cardiomyopathy [TC]) and akinesia (C and D).

A myocardial biopsy specimen showed mild hypertrophy of the myocytes and a small amount of interstitial fat (E). These nonspecific findings can be seen with cardiomyopathy of undetermined cause. A follow-up echocardiogram on day 22 showed an ejection fraction of 60% with normal-appearing valves and heart chamber. The patient continued to improve, and on day 23 was sent home to complete a cardiac rehabilitation program.

TC is a transient and reversible LV dysfunction characterized by apical and midventricular dyskinesia with basal hyperkinesis, in response to an insult. The mechanism is yet to be identified and is most probably multifactorial. The most popular hypothesis is catecholaminergic or adrenoceptor-hyperactive cardiomyopathy,^1,2 coupled with stress-induced transient coronary endothelial dysfunction,^3,4 possibly aggravated by estrogen deficiency.⁵

TC mostly occurs in women older than 60 and is often preceded by emotional or physical stress. The diagnosis is usually made on the basis of the history and clinical presentation as well as the findings from the ECG, coronary angiogram, and ventriculogram. The symptoms and presentation resemble those of acute MI. In TC, however, levels of myocardial serum markers are elevated, coronary arteries are disease-free, and the heart is shaped like a takotsubo (the Japanese word for a pot used to catch octopus). TC generally improves rapidly within a few weeks with supportive management, with almost full recovery of LV function, although traditional heart failure medication has been used. As was the case in this patient, prognosis is very good, with low recurrence and mortality rate. ■