Takotsubo cardiomyopathy + Thiazide + Thrombolysis + Torsades de Pointes

Question 1

What is takotsubo cardiomyopathy?

Answer 1

• Takotsubo cardiomyopathy is a type of non-ischaemic cardiomyopathy associated with a transient, apical ballooning of the myocardium
• It may be triggered by stress.

Question 2

What is the pathophysiology of takotsubo cardiomyopathy?

Answer 2

1. The apical ballooning appearance occurs due to severe hypokinesis of the mid and apical segments with preservation of activity of the basal segments
2. In simple terms, the bottom of the heart (the apex) does not contract and therefore appears to balloon out
3. The area closer to the top (the base) continues to contract (creating the neck of the octopus trap)

Question 3

What are the features of takotsubo cardiomyopathy?

Answer 3

1. Chest pain
2. Features of heart failure
3. ECG: ST-elevation
4. Normal coronary angiogram

Question 4

What is the treatment and prognosis of takotsubo cardiomyopathy?

Answer 4

• Treatment is supportive
• Majority of patients improve with supportive treatment

Question 5

How do thiazide diuretics work?

Answer 5

• Inhibit sodium reabsorption at the beginning of the distal convoluted tubule (DCT) by blocking the thiazide-sensitive Na+-Cl− symporter
• Potassium is lost as a result of more sodium reaching the collecting ducts.
• Thiazide diuretics have a role in the treatment of mild heart failure although loop diuretics are better for reducing overload.
• The main use of bendroflumethiazide was in the management of hypertension but recent NICE guidelines now recommend other thiazide-like diuretics such as indapamide and chlortalidone.

Question 6

What are commona adverse effects of thiazide diuretics?

Answer 6

• Dehydration
• Postural hypotension
• Hyponatraemia, hypokalaemia, hypercalcaemia*
• Gout
• Impaired glucose tolerance
• Impotence

Question 7

What are rare side effects of thiazide diuretics?

Answer 7

1. Thrombocytopaenia
2. Agranulocytosis
3. Photosensitivity rash
4. Pancreatitis

Question 8

How do thrombolytic drugs work?

Answer 8

• Thrombolytic drugs activate plasminogen to form plasmin
• This in turn degrades fibrin and help breaks up thrombin

Question 9

When is thrombolysis indicated?

Answer 9

• They in primarily used in STEMI
• Other indications include acute ischaemic stroke and pulmonary embolism

Question 10

What are examples of thrombolytic drugs?

Answer 10

1. Alteplase
2. Tenecteplase
3. Streptokinase

Question 11

What are contraindications to thrombolysis?

Answer 11

• active internal bleeding
• recent haemorrhage, trauma or surgery (including dental extraction)
• coagulation and bleeding disorders
• intracranial neoplasm
• stroke < 3 months
• aortic dissection
• recent head injury
• pregnancy
• severe hypertension

Question 12

What are side effects of thrombolysis?

Answer 12

• Haemorrhage
• Hypotension - more common with streptokinase
• Allergic reactions may occur with streptokinase

Question 13

What is torsades de pointes?

Answer 13

• Torsades de pointes (‘twisting of the points’) is a form of polymorphic ventricular tachycardia associated with a long QT interval
• It may deteriorate into ventricular fibrillation ==> sudden death.

Question 14

What is the management of torsades de pointes?

Answer 14

IV magnesium sulphate