Takotsubo Cardiomyopathy

A 77-year-old woman presents to the emergency department with sudden onset chest pain and shortness of breath 2 days after the death of her husband. Her ECG shows ST-segment elevation. Coronary angiography reveals no significant coronary artery stenosis.

Pathophysiology

Takotsubo cardiomyopathy (TCM), also known as stress-induced cardiomyopathy or transient apical ballooning syndrome, is characterized by transient systolic dysfunction of the apical and/or mid segments of the left ventricle. This dysfunction is not due to coronary artery disease but rather a transient ballooning of the apex of the left ventricle during systole. This is often accompanied by hyperkinesis (increased contractility) of the basal segments of the left ventricle. The exact mechanism of this dysfunction is not fully understood, but it is thought to be triggered by a surge of catecholamines in response to emotional or physical stress. Proposed mechanisms include:

• Coronary Artery Spasm: Catecholamines can cause transient spasms in the coronary arteries, leading to reduced blood flow to the myocardium.
• Microvascular Dysfunction: The small blood vessels in the heart may be affected by catecholamines, leading to impaired blood flow.
• Direct Myocardial Toxicity: Catecholamines may have a direct toxic effect on heart muscle cells.

Aetiology

The exact cause of TCM is unknown, but it is strongly associated with intense emotional or physical stress.

Examples of emotional stressors include:

• Grief or bereavement
• Anger or intense arguments
• Fear or anxiety
• Financial distress
• Public speaking

Examples of physical stressors include:

• Surgery
• Severe illness or infection
• Asthma exacerbation
• Stroke

Epidemiology and Risk Factors

TCM is a relatively rare condition, but it is being increasingly recognized. It most commonly affects postmenopausal women over the age of 60. Other risk factors include:

• Female sex: TCM is much more common in women than men.
• Pre-existing psychiatric conditions: Anxiety, depression, and post-traumatic stress disorder have been linked to an increased risk of TCM.
• Neurological disorders: such as stroke, seizures and subarachnoid haemorrhage
• Medications: that increase cholinergic burden such as adrenaline and dobutamine

Clinical Features

The clinical presentation of TCM is often similar to that of acute myocardial infarction (AMI). Common symptoms include:

• Chest pain: This is often described as a sudden, intense pain in the centre of the chest.
• Dyspnoea
• Nausea and vomiting
• Syncope

Physical examination findings may include:

• Tachycardia
• Hypotension
• Pulmonary oedema

Investigations

• Electrocardiogram: may show ST-segment elevation or T-wave inversions, mimicking AMI.
• Cardiac Biomarkers: cardiac troponin may be elevated, further mimicking AMI.
• Echocardiography: the key diagnostic test for TCM. It shows the characteristic apical ballooning and reduced left ventricular systolic function.
• Coronary Angiography: typically performed to rule out significant coronary artery disease. In TCM, the coronary arteries are found to be normal or have only mild, non-obstructive disease.
• Left Ventriculography: This imaging test involves injecting dye into the left ventricle to visualize its function. In TCM, it will show the characteristic apical ballooning.

Management

The management of TCM is primarily supportive. Most patients recover fully within a few weeks.

Medical Management:

• Supportive Care:
  • Oxygen Therapy
  • Pain Relief: Medications such as nitroglycerin or morphine may be given to relieve chest pain.
  • Intravenous Fluids: To maintain hydration and blood pressure.
• Medications to Manage Complications:
  • Angiotensin-Converting Enzyme (ACE) Inhibitors or Angiotensin Receptor Blockers (ARBs): These medications help reduce the workload on the heart and improve blood flow.
  • Beta-blockers: To slow the heart rate and reduce the effects of catecholamines.
  • Diuretics

Surgical Management:

Surgery is rarely required in TCM. However, if complications such as left ventricular outflow tract obstruction or rupture occur, surgical intervention may be necessary.

Complications and Prognosis

Most patients with TCM have a good prognosis and make a full recovery. However, some patients may experience complications such as:

• Heart Failure
• Arrhythmias: such as atrial fibrillation or ventricular tachycardia.
• Left Ventricular Outflow Tract Obstruction: The ballooning of the apex can obstruct blood flow out of the left ventricle.
• Cardiac Rupture: Although rare, this is a life-threatening complication.
• Thromboembolism: Blood clots can form in the weakened left ventricle and travel to other parts of the body, causing stroke or pulmonary embolism.
• Recurrence: TCM can recur, especially in individuals with persistent stressors.