Stress cardiomyopathy and other resembling conditions.

Sir,

We read with great interest the article ‘Broken-heart syndrome’ …Be aware….[1] Many clinicians may not be aware of such phenomena. However, we need to broaden differential diagnosis in such case scenarios. Apart from Takotsubo cardiomyopathy, there are other conditions which can present as Takotsubo ‘LIKE’ syndrome [Figure 1]. Acute myocardial ischemia during an anaphylactic reaction can be due to (1) stress or Takotsubo cardiomyopathy, (2) Kounis syndrome or allergic myocardial infarction and (3) hypersensitive myocarditis. Kounis syndrome was first elaborated in 1991 as the simultaneous happening of allergic reactions and chest pain along with clinical and electrocardiographic evidence of acute myocardial ischemia.[2] The pathophysiologic mechanism for Kounis syndrome is the occurrence of concomitant coronary artery spasm or atherosclerotic plaque rupture induced by inflammatory mediators released during the severe allergic insult.[2] Kounis syndrome has been described in three varieties. Patients have normal coronary arteries in Type I. Type II has patients with established coronary artery disease.[2] Type III is associated with drug-eluting stent thrombosis.[3] In severe systemic allergic reactions, the sudden release of histamine and other inflammatory mediators can cause coronary vasoconstriction with the resultant acute coronary syndrome. In such cases, a myocardial biopsy will be suggestive of a normal myocardium. Yanagawa et al. described a case of Kounis syndrome associated with Takotsubo cardiomyopathy in which variant angina and arrhythmia induced by asthma disappeared after the correction of eosinophilia by steroids along with the reversal of akinesis of the apical ventricular area.[4] Not only anaphylactic reactions but supratherapeutic dose of intravenous epinephrine administered for the management of anaphylaxis can also produce a similar condition.[5] In hypersensitive myocarditis, hypersensitive reactions will also be occurring in the heart evidenced by the presence of atypical lymphocytes, eosinophils and giant cells in the myocardial biopsy. It is a real hard task to differentiate Kounis syndrome from hypersensitive myocarditis clinically as both conditions present with similar features. Always suspect Kounis syndrome when patient presents with anaphylaxis and acute myocardial ischaemia. Even the management needs special attention. Morphine conventionally given in acute coronary syndrome may be detrimental in such case scenario due to histamine release. The prompt use of steroids and antihistaminics can alleviate both cardiac and allergic symptoms.

Figure 1

Takotsubo cardiomyopathy and Takotsubo like syndrome

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