**3. Clinical subtypes: the primary and secondary Takotsubo syndrome**

An attempt to classify Takotsubo patients based on the evolving clinical scenario has helped outline two elemental subtypes. The primary form of the syndrome includes patients developing acute cardiac symptoms, possibly in the wake of a stressful trigger, as also those whose co-morbid conditions act as predisposing factors indirectly contributing to rising levels of catecholamines. The secondary form comprises patients, wherein the result is essentially a response to either a primary medical condition or treatment, and the pathophysiological process is probably mediated by a sudden activation of the sympathetic nervous system or at times by an increased catecholamine activity [11]. Some examples of triggers for the secondary Takotsubo syndrome include acute neuromuscular crises, especially if involving acute respiratory failure (acute myasthenia gravis, acute Guillain-Barre syndrome), attempted suicide, severe sepsis, infection, babesiosis, pacemaker implantation, electrical DC conversion for atrial fibrillation, acute pulmonary embolism, acute pneumothorax, pheochromocytoma, Addisonian crisis, hyperglycaemic hyperosmolar state, blood transfusions, thrombotic thrombocytopenic purpura, acute exacerbation of asthma or COPD, induction of general anaesthesia, cocaine abuse, acute cholecystitis, acute pancreatitis, surgery, dobutamine stress echocardiography, etc.
