Takotsubo syndrome is an acute reversible heart failure syndrome that is increasingly recognized in modern cardiology practice. This Position Statement from the European Society of Cardiology Heart Failure Association provides a comprehensive review of the various clinical and pathophysiological facets of Takotsubo syndrome, including nomenclature, definition, and diagnosis, primary and secondary clinical subtypes, anatomical variants, triggers, epidemiology, pathophysiology, clinical presentation, complications, prognosis, clinical investigations, and treatment approaches. Novel structured approaches to diagnosis, risk stratification, and management are presented, with new algorithms to aid decision-making by practising clinicians. These also cover more complex areas (e.g. uncertain diagnosis and delayed presentation) and the management of complex cases with ongoing symptoms after recovery, recurrent episodes, or spontaneous presentation. The unmet needs and future directions for research in this syndrome are also discussed.

Nonischemic dilated cardiomyopathy is a common heart muscle disease with a prevalence of at least 1 in 2500 adults.¹ It is characterized by left ventricular cavity enlargement and impaired contractility in the absence of significant coronary artery disease.¹ The condition is associated with significant morbidity and mortality due to progressive heart failure (HF) and sudden cardiac death (SCD).² Despite therapeutic advances, 5-year mortality remains as high as 20%.² Risk stratification in dilated cardiomyopathy therefore constitutes a crucial part of patient management with implications for surveillance, treatment, and outcome. Currently, risk stratification is heavily dependent on the assessment of left ventricular ejection fraction (LVEF), as exemplified by its use as the key determinant of device implantation.³ Although LVEF is an important prognostic factor in dilated cardiomyopathy,^4,5 effective risk stratification remains challenging, particularly with respect to SCD.^6,7 Most patients who experience SCD do not have severely reduced LVEF, and many patients with significant impairment of LVEF may still be at low risk for SCD.^7,8 Identification of better independent prognostic factors is necessary to enable clinicians to more accurately stratify risk in patients with dilated cardiomyopathy and tailor management accordingly.

Background— Cardiac amyloidosis can be diagnostically challenging. Cardiovascular magnetic resonance (CMR) can assess abnormal myocardial interstitium. Methods and Results— Late gadolinium enhancement CMR was performed in 30 patients with cardiac amyloidosis. In 22 of these, myocardial gadolinium kinetics with T ₁ mapping was compared with that in 16 hypertensive controls. One patient had CMR and autopsy only. Subendocardial T ₁ in amyloid patients was shorter than in controls (at 4 minutes: 427±73 versus 579±75 ms; P <0.01), was shorter than subepicardium T ₁ for the first 8 minutes ( P ≤0.01), and was correlated with markers of increased myocardial amyloid load, as follows: left ventricular (LV) mass ( r =−0.51, P =0.013); wall thickness ( r =−0.54 to −0.63, P <0.04); interatrial septal thickness ( r =−0.52, P =0.001); and diastolic function ( r =−0.42, P =0.025). Global subendocardial late gadolinium enhancement was found in 20 amyloid patients (69%); these patients had greater LV mass (126±30 versus 93±25 g/m ² ; P =0.009) than unenhanced patients. Histological quantification showed substantial interstitial expansion with amyloid (30.5%) but only minor fibrosis (1.3%). Amyloid was dominantly subendocardial (42%) compared with midwall (29%) and subepicardium (18%). There was 97% concordance in diagnosis of cardiac amyloid by combining the presence of late gadolinium enhancement and an optimized T ₁ threshold (191 ms at 4 minutes) between myocardium and blood. Conclusions— In cardiac amyloidosis, CMR shows a characteristic pattern of global subendocardial late enhancement coupled with abnormal myocardial and blood-pool gadolinium kinetics. The findings agree with the transmural histological distribution of amyloid protein and the cardiac amyloid load and may prove to have value in diagnosis and treatment follow-up.