Volume 12 Issue 7, July 2015

Intra-aortic balloon pumping has recently been shown to be ineffective in treating cardiogenic shock due to myocardial infarction. Other, more potent percutaneous pumps have been developed, and their use is growing substantially, but they have not been studied in randomized trials. Two new reports provide provocative information about these devices.

Meta-analyses and large population-based studies have linked shorter body height with increased risk of coronary heart disease (CHD). This complex association is now confirmed at the gene level, indicating that genetic variants affecting body height and associated with short stature seem to have independent roles as risk factors for CHD.

Takotsubo syndrome is an acute cardiac disorder first identified in Japan in 1990. The pathophysiology of Takotsubo syndrome is complex and involves the neuroendocrine system. Cardiovascular responses are often induced by a sudden surge in sympathetic activation and subsequent catecholamine concentration. In this Review, Akashi et al. discuss the epidemiology, diagnosis, and prognosis of the syndrome, as well as some of the proposed pathophysiological mechanisms underlying its development.

Implantable cardiac defibrillators (ICD) are effective in reducing mortality in patient populations at risk for sudden cardiac death, but transvenous ICDs are associated with complications such as infections, pneumothorax, venous thrombosis, lead dislodgement, lead malfunction, and haemopericardium. In this Review, Lewis and Gold describe a novel design of entirely subcutaneous ICDs that avoid some of the complications of transvenous systems, and explore the advantages and disadvantages of both ICD systems.

In the presence of signs and symptoms of myocardial ischaemia, women are more likely than men to have no obstructive coronary artery disease, but might have a higher burden of coronary microvascular dysfunction. In this Review, Dean et al. discuss the prevalence, presentation, diagnosis, and treatment of coronary microvascular dysfunction, with a particular emphasis on sex-specific differences between women and men.

Long noncoding RNAs (lncRNAs) regulate cellular and tissue function by activating or repressing gene expression. In this Review, Devaux and colleagues summarize the mechanisms by which lncRNAs exert their epigenetic effects, and discuss their role in cardiac development and ageing, with emphasis on the importance of chromatin remodelling. The authors also discuss the potential of lncRNAs to be used as biomarkers and therapeutic agents.

Transthoracic echocardiography is a well-established imaging modality for the qualitative and quantitative evaluation of cardiac structure and function. In this Review, Boyd et al. describe the broad principles of traditional echocardiographic techniques, including two-dimensional, colour, and spectral Doppler echocardiography, as well as newer and more advanced techniques, including tissue Doppler, stress, contrast, and three-dimensional echocardiography.