7th March 2024

Unclassified – including Takotsubo Cardiomyopathy and Left Ventricular non-compaction

Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy occurs in the context of transient but significant sympathetic nervous system activation, typically after a significantly emotional event such as a bereavement or sudden bad news, though it can also occur in response to a substantial positive emotion or significant physical event such as prolonged vomiting. The underlying pathophysiology is not completely understood, but it typically leads to apical ballooning of the left ventricle with preserved basal function, and this picture on imaging should raise suspicion of a takotsubo cardiomyopathy.

Signs and symptoms

As alluded to above, takotsubo cardiomyopathy typically occurs in the context of a significant physiological stressor or emotional event, so the history will normally be suggestive of this. 

Subsequent to this, the patient will classically complain of significant chest pain, which may well sound ischaemic in nature – crushing, central, causing shortness of breath – which can progress to acute left ventricular failure and pulmonary oedema. This occurs due to a sudden reduction in the function of the left ventricle, typically the mid and apical portions, manifesting as worsening shortness of breath, orthopnoea and signs of pulmonary congestion with crepitations on examination.

Investigations

The diagnosis of Takotsubo’s cardiomyopathy is commonly suspected due to a typical history of a stressful emotional or physical event with ischaemic sounding chest pain. It is a diagnosis of exclusion, and an acute coronary syndrome should be excluded in the first instance through invasive coronary angiography. If there are no clear culprit lesions for the disease on angiography, then Takotsubo can be considered.

Classical Takotsubo’s can be suspected by typical echocardiographic findings of left ventricular mid cavity and apical ballooning with relative preservation of basal ventricular function. In general, if there are regional wall motion abnormalities that do not fit a particular coronary pattern, then takotsubo should be considered. There are non-classical versions of Takotsubo’s cardiomyopathy in which apical and mid-cavity ballooning are not the echocardiographic findings but these are less common.

ECG will typically show ST segment change or T wave inversion, similar to that of an acute coronary syndrome, though it may not be consistent with a particular coronary territory and is more likely to be global.

Bloods – Troponin and BNP will typically be elevated, which normally leads to suspicion of an acute coronary syndrome in the acute setting.

As a diagnosis of exclusion, it also must be ensured that there is no concomitant myocarditis, head trauma or phaeochromocytoma to cause a similar but pathophysiologically distinct syndrome.

Treatment

Once diagnosed, if there is any evidence of impaired LV function it is typically treated as per any other cause of heart failure. This will entail optimal medical therapy, with echocardiographic and outpatient cardiology follow up.

Some centres will give aspirin or anticoagulation, though there is no good data to support this approach and current treatments are not backed by any well evidenced guidelines.

Left Ventricular non-compaction

Left ventricular non-compaction presents with prominent left ventricular trabeculae and deep inter-trabeculae recesses. They have thickened myocardial walls with a thin compacted epicardial layer and thickened endocardial layer.

 It is not easily classified and it is unclear if it is a separate cardiomyopathy or a morphological trait seen in many distinct pathologies. It frequently has a genetic component, with abnormalities in actin and lamin implicated, whilst asymptomatic relatives of an index case often show abnormalities on imaging.

Signs and symptoms

Symptoms of LV non-compaction can be relatively vague and non-specific. In some patients, it may be picked up incidentally on imaging, whilst in others they may present with arrhythmias or symptoms from thromboemboli, though the typical signs and symptoms of heart failure are the commonest presenting feature.

Investigations

LV noncompaction is a diagnosis made via imaging techniques, most commonly echocardiography and often followed up with MRI. There are different diagnostic criteria, but a commonly used one includes the following:

• A two layered myocardium in which the non-compacted layer is thicker than the compacted myocardium
• >3 prominent trabeculations protruding from the LV wall, apical to the papillary muscles
• Perfused intertrabecular space

Cardiac MR gives improved tissue resolution in comparison to Echo and can better differentiate between compacted and non-compacted myocardium and it is often used to help make the diagnosis when good echo images are not achievable.

Treatment

Patients with symptomatic heart failure are treated as per standard heart failure protocols, depending on their ejection fraction. Patients with persistent arrhythmias are treated according to the nature of their arrhythmia while those with regular ventricular arrhythmias can be provided with implantable cardioverter defibrillators to reduce the risk of sudden death. 

Hypertrabeculation of the left ventricle also predisposes to clot formation. As a result, many of these patients are formally anticoagulated, either with a coumadin or, more commonly, a direct oral anticoagulant, to reduce the risk of systemic embolisation.

References 

• https://academic.oup.com/eurheartj/article/39/22/2047/5025411
• https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-8/Takotsubo-cardiomyopathy
• https://www.ncbi.nlm.nih.gov/books/NBK537025/
• https://www.hindawi.com/journals/crp/2016/5172308/tab1/