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Takotsubo cardiomyopathy (TTC) is an acute, transient, reversible cardiac syndrome, which mimics acute coronary syndrome, with ECG changes, troponin elevation and characteristic ballooning and akinesia of the left ventricular (LV) apex that usually resolves after seven to eight days. The coronary arteries are angiographically unobstructed and the left ventricular dysfunction is not localised to any specific coronary vascular territory.
Takotsubo is a Japanese word and literally means “octopus pot’’ (Tako is octopus and Tsubo denotes a pot). The pot has a narrow neck and a bulbous base, which the Japanese use to trap and store octopus. The angiographic appearance of the heart in this condition (bulging and ectatic apex), resembles a takotsubo.
When it was first described by Hikaru Sato and colleagues from Japan in 1990 (the initial published report comprised five cases), it was thought to be due to genetic and behavioural factors peculiar to the Japanese people.1 However, from 1998 there were case reports from the USA with a statistical study in 2008 revealing 6,837 documented cases.2 In Sweden, the first case of takotsubo was diagnosed in February 2005 at Sahlgrenska University Hospital. Currently, the Swedish coronary angiographic register records about 30 to 50 cases per month of TTC.3 Approximately 2% of patients investigated for acute myocardial infarction are found to have TTC, with a world wide incidence which is no different from Japan.
History
It has been well known for sometime that acute neurological events, such as traumatic brain injury, subarachnoid haemorrhage (SAH), cerebral haemorrhage, ischaemic stroke, encephalitis and meningitis can cause acute and substantial dysfunction in other organs such as the lungs and the heart. Examples are neurogenic acute pulmonary oedema and acute ECG changes, such as QT prolongation, ST depression and T wave inversion, which happen in up to 25–75% of patients with SAH, together with an increase in the serum markers of cardiac injury in 20–30% of patients.4 These changes are attributed to neurogenic stress-related cardiomyopathy (NSC), due to intense sympathetic activation.
Typically, Takotsubo syndrome is precipitated by acute emotional stress or physical stress and has also been known as the “broken heart syndrome’’ or stress induced cardiomyopathy. The emotionally stressful events that can trigger the cardiac symptoms of TTC may include situations, such as a bereavement, a severe financial loss, an angry confrontation, a divorce or separation, a newly diagnosed disease, an upcoming operation and such other stressful conditions. The exclusion of coronary artery obstruction and myocarditis are the sine qua non for the diagnosis of primary TTC. Of the affected patients, 90% are post-menopausal females and 90% of cases occur between the ages of 60 to 75 years.5,6 There are occasional confirmed reports in young adults and in children.
Clinical presentation and treatment
Almost all of patients with TTC present with cardiac type of chest pain and other symptoms associated with an acute coronary syndrome. Acute ECG changes may occur, identical to those of cardiac ischaemia or infarction, with a minimal or moderate elevation of troponins. Such patients are invariably investigated with coronary angiography, which shows unobstructed coronary arteries, with a substantial and characteristic left ventricular wall motion abnormality in the form of ballooning and hypokinesia or akinesia of the cardiac apex. Brain natriuretic peptide, NT-Pro-BNP levels and troponins are always elevated.5,6 There is an apex sparing variant with ventricular basal hypokinesia, but this is rare.
The LV wall motion abnormality is detected on echocardiography or MRI angiography. Congestive cardiac failure and ventricular arrhythmia may occur, needing appropriate treatment and supportive measures with beta-blockers, ACE inhibitors and diuretics. Coronary stenting and anti-platelet agents are not indicated.5 Spontaneous recovery occurs in two to four weeks in primary TTC, whereas in secondary TTC triggered by acute neurological injury, the recovery may be linked to the precipitating comorbid disorder.
Pathogenesis and prognosis
Intense neuro-sympathetic stimulation, with catecholamine overload in the myocardium, is the generally accepted pathogenic process, causing a specific tissue phenomenon of myocardial “contraction band necrosis’’. This is characterised by hypercontraction of sarcomeric myofibrils, eosinophilic transverse bands and interstitial mononuclear infiltration. MIBG (Meta-iodobenzylguanidine) scintigraphy scans have been used to assess the sympathetic viability and function. MIBG bears a structural resemblance to norepinephrine and the uptake of MIBG in various tissues parallels that of norepinephrine. Current studies support the hypothesis that in stress-related cardiomyopathy, an initial surge in catecholamine leads to micro-vascular dysfunction and myocardial tissue injury followed by myocardial sympathetic denervation.4
Full recovery is the rule for primary Takotsubo syndrome when there are no other comorbid conditions. However, rare complications have been documented such as ventricular rupture, mural thrombosis, ventricular septal defect, ventricular tachycardia and congestive cardiac failure.6,7
Discussion
Takotsubo cardiomyopathy has now gained world-wide acceptance as a distinctive clinical and pathological condition. The prognosis is good with recovery in two to four weeks. The mortality rate is approximately 4% and recurrence rate is at around 2%. These figures vary in different studies, depending on the comorbidities and the precipitating factors.
The immediate and long-term prognosis, is better for primary TTC patients with unobstructed coronary arteries than for patients with coronary occlusion and myocardial infarction.
KEY POINTS: |
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|---|---|
1 |
Postmenopausal females account for 90% of cases of TTC |
2 |
Acute chest pain, acute ECG abnormalities and Troponin elevation suggestive of an acute coronary syndrome |
3 |
BNP and NT-pro-BNP are significantly elevated |
4 |
Coronary angiogram shows unobstructed coronary arteries and no evidence of plaque rupture |
5 |
Ventriculogram at angiography shows a ballooning of the cardiac apex with grossly impaired LV wall motion. |
6 |
Troponin although elevated, is disproportionately low as compared to the LV wall motion impairment. |
7 |
LV function improves within seven to eight days and normality restored at four weeks in the majority of patients. |
Dr Rajiv Ghurye, GP, Isle of Wright
Dr Dalla Price, Consultant cardiologist, Isle of Wright and Portsmouth NHS hospitals
Conflict of interest: none declared
References
1. Sato H, Tateishi H, et al. Myocadial stunning due to simultaneous multivessel. Coronary spasms: a review of 5 cases. Journal of Cardiology 1991; 21(2): 203–2
2. Deshmukh A, Kumar G, Pant S, et al. Prevalence of takotsubo cardiomyopathy. In the United States. Am Heart J 2012; 164(1): 66-71
3. Omerovic E. How to think about stress-induced cardiomyopathy?Think out of the box’. Scand Cardiovasc J 2011; 45: 67–71
4. Mazzeo AT, Micalizzi L, Mascia A, et al. Brain-heart crosstalk:the many face of stress-related cardiomyopathy syndromes in anaesthesia and intensive care.British J of Anaesthesia 2014; 112(5): 803–15
5. Koulouris S, Pastromas S, Sakellariou D, et al. Takotsubo cardiomyopathy. “The broken Heart’’ Syndrome. Hellenic J Cardiol 2010; 51: 451–57
6. Lyon AR, Bossone E, Schneider B, et al. Current state of knowledge on Takotsubo syndrome:a position statement from the Taskforce on Takotsubo syndrome of the Heart Failure Association of the European Society of cardiology. Eur J Heart Fail 2016; 18(1): 8–27
7. Lyon, Rees et al. Nature Clinical Practice. Cardiovascular Medicine 2008; 5: 22–29