by Dr Costas O'Mahony, specialist registrar in cardiology, and Dr Charles Knight, consultant cardiologist, both from the London Chest Hospital
Tako-tsubo cardiomyopathy (TTC) is an increasingly recognised disease of the heart characterised by the temporary enlargement and weakening of the heart muscle.
TTC was first described in Japan in the 1990s and derives its name from the similarity of the abnormal shape of the heart to a Japanese octopus fishing pot (tako=octopus, tsubo=pot).
Since the original description, this condition has also been described as stress-induced cardiomyopathy, ampulla syndrome, apical ballooning syndrome, and broken heart syndrome.
This article addresses the general aspects of TTC, including diagnosis, treatment and prognosis.
Who gets tako-tsubo cardiomyopathy and why?
TTC affects primarily women over the age of 50 years, but younger women and men can also be affected. It is often precipitated by a stressful emotional event such as bereavement (hence broken heart syndrome), inter personal conflict, public speaking and even surprise birthday parties. Physical stresses such as a severe illness, surgery or severe pain can also induce the disease.
The exact cause of TTC is not known. Stressful events may lead to excessive levels of adrenaline and adrenaline-like hormones in the bloodstream. These may stun the heart and lead to impairment in function. Unlike other diseases of the heart muscle, such as hypertrophic cardiomyopathy and dilated cardiomyopathy, there is no clear genetic link.
How common is tako-tsubo cardiomyopathy?
Approximately 2,500 people per year are said to be affected in the UK. The majority of patients with TTC seek medical attention for symptoms that mimic a heart attack, and one to two per cent of patients thought to have a heart attack are eventually diagnosed with the disease.
What are the symptoms?
Patients with TTC often complain of sudden onset chest pain and shortness of breath, typically after a stressful event. Unfortunately these symptoms are indistinguishable from the symptoms of a heart attack leading to a delay in diagnosis. Less commonly, the blood pressure may be very low leading to shock, and infrequently chaotic heart rhythms develop leading to cardiac arrest.
What are the common investigations?
A number of investigations are carried out to guide diagnosis and treatment:
â™¥ Electrocardiogram (ECG): This looks at the way that electricity is conducted in the heart. The ECG is often abnormal but the abnormalities are not specific to TTC and are similar to those seen in heart attacks.
â™¥ Blood tests: Blood markers of heart muscle damage are moderately elevated.
â™¥ Echocardiogram (echo): This provides information about the structure and function of the heart muscle and valves using ultrasound waves. In TTC, the heart function is depressed and the heart is enlarged particularly at its tip and middle portions, with the characteristic octopus pot look.
â™¥ Cardiac magnetic resonance imaging (cardiac MRI or CMR): This test uses a powerful magnet to look at the structure and function of the heart muscle. It is useful in patients where echo is not adequate to visualise the heart clearly. In addition, CMR is very helpful in excluding other causes of heart dysfunction such as viral infections of the heart muscle.
â™¥ Coronary angiogram: This minimally invasive procedure provides information about the blood supply to the heart muscle, the coronary arteries. It is very important to establish that the coronary arteries are free from significant narrowing or blockages before reaching the diagnosis of TTC.
â™¥ Urine tests: Urine is collected for 24 hours to establish levels of adrenaline and related hormones. In rare cases, TTC is associated with an uncommon tumour of the adrenal glands that secretes excessive levels of adrenaline (phaeochromocytoma) and requires surgical removal.
|The heart's abnormal shape, using X-rays and the injecton of dye, is said to resemble an octopus pot|
How is tako-tsubo cardiomyopathy diagnosed?
To establish the diagnosis the following need to be present:
â™¥ Abnormal ECG or blood test indicating heart muscle damage
â™¥ Absence of narrowing or clot in the coronary arteries during coronary angiography
â™¥ Weakness of the heart muscle using echo or CMR or during angiography, with appearances similar to the picture above.
â™¥ No other diagnosis to account for the heart muscle weakness, for example adrenaline producing tumours or viral infections of the heart muscle.
What is the treatment?
The early stages of the disease are managed in hospital. Most patients will initially receive treatment for a heart attack until the coronary arteries are shown to be free of clots and narrowings.
Once the diagnosis of TTC is reached, betablockers (such as bisoprolol and atenolol) and ACE inhibitors (such as ramipril and lisinopril) are used to help the recovery of the heart muscle.
Breathlessness because of the accumulation of fluid in the lungs is often treated with diuretics. Blood clots in the heart, caused by stagnating blood, are treated with blood thinning medication (such as warfarin).
Supportive medication via a drip or mechanical means (intra-aortic balloon pump) may be required in patients with very low blood pressure.
In patients who experienced a cardiac arrest, an implantable cardioverter defibrillator should be considered.
It is important to note that the treatment of this condition is not based on data from large trials, but relies on experience and data from the treatment of other cardiac conditions. As a consequence, there are no uniformly agreed treatment protocols.
What is the prognosis?
Prognosis is good and in most cases there is recovery to normal or near normal heart function in a few weeks.
The clinical course can be complicated by fluid in the lungs caused by heart failure, irregularities of the heart rhythm, and stroke caused by blood clots in the heart.
A small subgroup of patients experience a recurrence of TTC, often after similar stressful events.
TTC is an acute heart muscle disease, often brought on by emotional or physical stress, and results in a transient impairment of heart function.
The majority of patients recover with supportive treatment, but can reoccur in some.