The authors summarize the recent developments in speckle-tracking echocardiography (STE), a relatively new technique that can be used in conjunction with two-dimensional or three-dimensional echocardiography for resolving the multidirectional components of left ventricular (LV) deformation. The tracking system is based on grayscale B-mode images and is obtained by automatic measurement of the distance between 2 pixels of an LV segment during the cardiac cycle, independent of the angle of insonation. The integration of STE with real-time cardiac ultrasound imaging overcomes some of the limitations of previous work in the field and has the potential to provide a unified framework to more accurately quantify the regional and global function of the left ventricle. STE holds promise to reduce interobserver and intraobserver variability in assessing regional LV function and to improve patient care while reducing health care costs through the early identification of subclinical disease. Following a brief overview of the approach, the authors pool the initial observations from clinical studies on the development, validation, merits, and limitations of STE.

Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications

The clinical expert consensus statement on takotsubo syndrome (TTS) part II focuses on the diagnostic workup, outcome, and management. The recommendations are based on interpretation of the limited clinical trial data currently available and experience of international TTS experts. It summarizes the diagnostic approach, which may facilitate correct and timely diagnosis. Furthermore, the document covers areas where controversies still exist in risk stratification and management of TTS. Based on available data the document provides recommendations on optimal care of such patients for practising physicians.

https://www.zora.uzh.ch/id/eprint/162489/1/ehy077.pdf

International Expert Consensus Document on Takotsubo Syndrome (Part II): Diagnostic Workup, Outcome, and Management

Takotsubo syndrome is an acute cardiac syndrome first described in 1990 and characterized by transient left ventricular dysfunction affecting more than one coronary artery territory, often in a circumferential apical, mid-ventricular, or basal distribution. Several pathophysiological explanations have been proposed for this syndrome and its intriguing appearance, and awareness is growing that these explanations might not be mutually exclusive. The reversible apical myocardial dysfunction observed might result from more than one pathophysiological phenomenon. The pathophysiology of Takotsubo syndrome is complex and integrates neuroendocrine physiology, potentially involving the cognitive centres of the brain, and including the hypothalamic-pituitary-adrenal axis. Cardiovascular responses are caused by the sudden sympathetic activation and surge in concentrations of circulating catecholamines. The multiple morphological changes seen in the myocardium match those seen after catecholamine-induced cardiotoxicity. The acute prognosis and recurrence rate are now known to be worse than initially thought, and much still needs to be learned about the epidemiology and the underlying pathophysiology of this fascinating condition in order to improve diagnostic and treatment pathways.

/pdf/epidemiology-and-pathophysiology-of-takotsubo-syndrome-1dhpxlmoni.pdf

Epidemiology and pathophysiology of Takotsubo syndrome

Stress cardiomyopathy, also referred to as Takotsubo cardiomyopathy, transient apical ballooning or broken heart syndrome, is a disorder associated with transient left ventricular dysfunction. Symptoms include acute chest pain and dyspnea accompanied by electrocardiographic changes, such as ST-segment elevation and T-wave inversions, minimal elevation of cardiac enzyme levels and transient wall-motion abnormalities in the absence of substantial coronary artery obstruction. Complete recovery of contractile function has been documented in nearly all cases, but the mechanisms of disease remain unclear and the cause has not been established. Coronary artery vasospasm, microcirculation dysfunction, and transient obstruction of the left ventricular outflow tract have been proposed as possible causes of this disorder. An excessive release of catecholamines also seems to have a pivotal role in the development of stress cardiomyopathy. This Review summarizes published data on stress cardiomyopathy, focusing primarily on the most likely causes of this cardiac entity.

Mechanisms of stress (Takotsubo) cardiomyopathy

Tako-Tsubo cardiomyopathy (TTC) is a reversible cardiomyopathy with a clinical presentation indistinguishable from myocardial infarction. TTC is estimated to represent 1%–2% of patients presenting with acute myocardial infarction. It most commonly occurs in postmenopausal women and is frequently precipitated by a stressful event. Chest pain and dyspnea are the typical presenting symptoms. Transient ST-segment elevation on ECG and a small rise in cardiac biomarkers are common. Characteristic wall motion abnormalities extend beyond the territory of a single epicardial coronary artery in the absence of obstructive coronary lesions. Supportive treatment leads to spontaneous rapid recovery in nearly all patients. The prognosis is excellent, and recurrence occurs in < 10% of patients. In this article, we review the clinical features of TTC that form the basis of the Mayo Clinic diagnostic criteria, as well as the long-term prognosis for this type of cardiomyopathy.

Proposed Mayo Clinic criteria for the diagnosis of Tako-Tsubo cardiomyopathy and long-term prognosis.

Prevalence and characteristics of left ventricular outflow tract obstruction in Tako-Tsubo syndrome.

The aim of this study was to characterize left ventricular (LV) systolic function using 2-dimensional strain in Tako-Tsubo cardiomyopathy (TTC). Forty-two women were prospectively studied using 2-dimensional speckle-tracking echocardiography, divided into 3 groups: 14 patients with TTC (group 1), 14 patients with coronary artery disease (group 2), and 14 healthy patients (group 3). In patients with TTC, mean values of systolic peak velocity, strain, and strain rate were significantly lower than those in group 3 (p <0.04), but these values were similar between the basal septum and lateral wall, between the middle septum and lateral wall, and between the apical septum and lateral wall. LV ejection fractions were significantly improved during follow-up (p <0.0001). All values of velocities were significantly increased at day 7 compared with the acute phase (p < or =0.01). This improvement differed between the middle septum and lateral wall (p <0.0001), and values for the middle septum and lateral wall in patients with TTC were not significantly different from those observed in patients with coronary artery disease (p = NS). At 1-month follow-up, no significant difference was noted between patients in groups 1 and 3. In conclusion, 2-dimensional speckle-tracking echocardiography is a reliable tool for assessing circular dysfunction in patients with TTC. Once the acute phase has passed, TTC may mimic the LV systematized dysfunction observed in patients with coronary artery disease and so lead to misdiagnosis. This novel echocardiographic technique can also be used in the follow-up of LV functional recovery.

Nacéra Abbou

Papers

Prevalence and characteristics of left ventricular outflow tract obstruction in Tako-Tsubo syndrome.

Usefulness of two-dimensional speckle tracking echocardiography for assessment of Tako-Tsubo cardiomyopathy.

Apical-sparing variant of Tako-Tsubo cardiomyopathy: Prevalence and characteristics