Current Cardiology Reviews (v.9, #3)
Peripartum Cardiomyopathy: Moving Towards a More Central Role of Genetics by Roberto Cemin, Rajesh Janardhanan, Luca Donazzan, Massimo Daves (179-184).
Peripartum cardiomyopathy (PCM) is a relatively rare disease with potentially devasting consequences requiringprompt identification and correct treatment. Overall prognosis is good in majority of the cases, although some patientsmay progress to irreversible heart failure. Early diagnosis is important and effective treatment reduces mortality rates andincreases the chance of complete recovery of ventricular systolic function.The aetiology and pathogenesis seems to be multifactorial and poorly understood, with the available literature rather conflicting.In recent years, there has been increased interest in the role played by genetic predisposition in the developmentof PCM. It probably develops as a result of a complex interaction of pregnancy-associated factors and genetic factors andrecently there have been many observations pointing out the central role played by a genetic predisposition. The direct andindirect observations on genetic susceptibility may offer new insights into the pathogenesis of PCM. However, largerstudies are needed before advising routine genetic testing in these patients.
Emerging Concepts for Myocardial Late Gadolinium Enhancement MRI by Adelina Doltra, Brage Hoyem Amundsen, Rolf Gebker, Eckart Fleck, Sebastian Kelle (185-190).
Late gadolinium enhancement is a useful tool for scar detection, based on differences in the volume of distributionof gadolinium, an extracellular agent. The presence of fibrosis in the myocardium amenable to be detected with lategadolinium enhancement MRI is found not only in ischemic cardiomyopathy, in which it offers information regarding viabilityand prognosis, but also in a wide variety of non-ischemic cardiomyopathies. In the following review we will discussthe methodological aspects of gadolinium-based imaging, as well as its applications and anticipated future developments.
TakoTsubo Cardiomyopathy A Short Review by Shahbaz Roshanzamir, Refai Showkathali (191-196).
Takotsubo cardiomyopathy (TCM), otherwise cardiomyopathy,apical ballooning syndrome or broken heartsyndrome is a reversible cardiomyopathy, predominantly occurs in post-menopausal women and commonly due toemotional or physical stress. Typically, patients present with chest pain and ST elevation or T wave inversion on theirelectrocardiogram mimicking acute coronary syndrome, but with normal or non-flow limiting coronary artery disease.Acute dyspnoea, hypotension and even cardiogenic shock may be the presenting feature of this condition. The wall motionabnormalities typically involve akinesia of the apex of the left ventricle with hyperkinesia of the base of the heart.Atypical forms of TCM have also recently been described. An urgent left ventriculogram or echocardiogram is the key investigationto identify this syndrome. Characteristically, there is only a limited release of cardiac enzymes disproportionateto the extent of regional wall motion abnormality. Transient right ventricular dysfunction may occur and is associatedwith more complications, longer hospitalisation and worse left ventricular systolic dysfunction. Recently, cardiac MRI hasbeen increasingly used to diagnose this condition and to differentiate from acute coronary syndrome in those who haveabnormal coronary arteries. Treatment is often supportive, however beta-blocker and angiotensin-converting enzyme inhibitoror angiotensin II receptor blocking agent are being used in routine clinical practice. The syndrome is usually spontaneouslyreversible and cardiovascular function returns to normal after a few weeks. This review article will elaborate onthe pathophysiology, clinical features including the variant forms, latest diagnostic tools, management and prognosis ofthis condition.
The Spatial QRS-T Angle: Implications in Clinical Practice by Christina Voulgari, Stamatina Pagoni, Solomon Tesfaye, Nicholas Tentolouris (197-210).
The ventricular gradient (VG) as a concept was conceived in the 1930s and its calculation yielded informationthat was not otherwise obtainable. The VG was not utilized by clinicians at large because it was not easy to understandand its computation time-consuming. The contemporary spatial QRS-T angle is based on the concept of the VG and definedas its mathematical and physiological integral. Its current major clinical use is to assess the cardiac primary repolarizationabnormalities in 3-dimensional spatial vectorial plans which are normally untraced in the presence of secondaryelectrophysiological activity in a 2-dimensional routine electrocardiogram (ECG). Currently the calculation of the spatialQRS-T angle can be easily computed on the basis of a classical ECG and contributes to localization of arrhythmogenic areasin the heart by assessing overall and local heterogeneity of the myocardial ventricular action potention duration. Recentpopulation-based studies suggest that the spatial QRS-T angle is a dominant ECG predictor of future cardiovascularevents and death and it is superior to more conventional ECG parameters. Its assessment warrants consideration for intensifiedprimary and secondary cardiovascular prevention efforts and should be included in everyday clinical practice. Thisreview addresses the nature and diagnostic potential of the spatial QRS-T angle. The main focus is its role in ECG assessmentof dispersion of repolarization, a key factor in arrythmogeneity.
Coarctation of the Aorta - The Current State of Surgical and Transcatheter Therapies by Jeffrey E. Vergales, James J. Gangemi, Karen S. Rhueban, D. Scott Lim (211-219).
Aortic coarctation represents a distinct anatomic obstruction as blood moves from the ascending to the descendingaorta and can present in a range of ages from infancy to adulthood. While it is often an isolated and discrete narrowing,it can also be seen in the more extreme scenario of severe arch hypoplasia as seen in the hypoplastic left heartsyndrome or in conjunction with numerous other congenital heart defects. Since the first description of an anatomic surgicalrepair over sixty years ago, an evolution of both surgical and transcatheter therapies has occurred allowing cliniciansto manage and treat this disease with excellent results and low morbidity and mortality. This review focuses on the currentstate of both transcatheter and surgical therapies, paying special attention to recent data on long-term follow-up of bothapproaches. Further, current thoughts will be explored about future therapeutic options that attempt to improve upon historicallong-term outcomes.
Exercise and Cardiac Preconditioning Against Ischemia Reperfusion Injury by John C. Quindry, Karyn L. Hamilton (220-229).
Cardiovascular disease (CVD), including ischemia reperfusion (IR) injury, remains a major cause of morbidityand mortality in industrialized nations. Ongoing research is aimed at uncovering therapeutic interventions against IR injury.Regular exercise participation is recognized as an important lifestyle intervention in the prevention and treatment ofCVD and IR injury. More recent understanding reveals that moderate intensity aerobic exercise is also an important experimentalmodel for understanding the cellular mechanisms of cardioprotection against IR injury. An important discoveryin this regard was the observation that one-to-several days of exercise will attenuate IR injury. This phenomenon hasbeen observed in young and old hearts of both sexes. Due to the short time course of exercise induced protection, IR injuryprevention must be mediated by acute biochemical alterations within the myocardium. Research over the last decadereveals that redundant mechanisms account for exercise induced cardioprotection against IR. While much is now knownabout exercise preconditioning against IR injury, many questions remain. Perhaps most pressing, is what mechanisms mediatecardioprotection in aged hearts and what sex-dependent differences exist. Given that that exercise preconditioning isa polygenic effect, it is likely that multiple mediators of exercise induced cardioprotection have yet to be uncovered. Alsounknown, is whether post translational modifications due to exercise are responsible for IR injury prevention. This reviewwill provide an overview the major mechanisms of IR injury and exercise preconditioning. The discussion highlightsmany promising avenues for further research and describes how exercise preconditioning may continue to be an importantscientific paradigm in the translation of cardioprotection research to the clinic.
The Autocrine/Paracrine Loop After Myocardial Stretch: Mineralocorticoid Receptor Activation by Irene L. Ennis, Ernesto A. Aiello, Horacio E. Cingolani, Nestor G. Perez (230-240).
The stretch of cardiac muscle increases developed force in two phases. The first phase, which occurs rapidly,constitutes the well-known Frank-Starling mechanism and it is generally attributed to enhanced myofilament responsivenessto Ca2+. The second phase or slow force response (SFR) occurs gradually and is due to an increase in the calciumtransient amplitude as a result of a stretch-triggered autocrine/paracrine mechanism. We previously showed that Ca2+ entrythrough reverse Na+/Ca2+ exchange underlies the SFR, as the final step of an autocrine/paracrine cascade involving releaseof angiotensin II/endothelin, and a Na+/H+ exchanger (NHE-1) activation-mediated rise in Na+. In the present reviewwe mainly focus on our three latest contributions to the understanding of this signalling pathway triggered by myocardialstretch: 1) The finding that an increased production of reactive oxygen species (ROS) from mitochondrial origin is criticalin the activation of the NHE-1 and therefore in the genesis of the SFR; 2) the demonstration of a key role played by thetransactivation of the epidermal growth factor receptor; and 3) the involvement of mineralocorticoid receptors (MR) activationin the stretch-triggered cascade leading to the SFR. Among these novel contributions, the critical role played by theMR is perhaps the most important one. This finding may conceivably provide a mechanistic explanation to the recentlydiscovered strikingly beneficial effects of MR antagonism in humans with cardiac hypertrophy and failure.
Advanced Echocardiographic Imaging of the Congenitally Malformed Heart by Black D, Vettukattil J (241-252).
There have been significant advancements in the ability of echocardiography to provide both morphologicaland functional information in children with congenitally malformed hearts. This progress has come through the developmentof improved technology such as matrix array probes and software which allows for the off line analysis of images toa high standard. This article focuses on these developments and discusses some newer concepts in advanced echocardiographysuch is multi-planar reformatting [MPR] and tissue motion annular displacement [TMAD].Our aim is to discuss important aspects related to the quality and reproducibility of data, to review the most recent publisheddata regarding advanced echocardiography in the malformed heart and to guide the reader to appropriate text forovercoming the technical challenges of using these methods. Many of the technical aspects of image acquisition and postprocessing have been discussed in recent reviews by the authors and we would urge readers to study these texts to gain agreater understanding . The quality of the two dimensional image is paramount in both strain analysis and three dimensionalechocardiography. An awareness of how to improve image quality is vital to acquiring accurate and usable data.Three dimensional echocardiography (3DE) is an attempt to visualise the dynamic morphology of the heart. Althoughpublished media is the basis for theoretical knowledge of how to practically acquire images, electronic media[eg.www.3dechocardiography.com] is the only way of visualising the advantages of this technology in real time.It is important to be aware of the limitations of this technology and that much of the data gleaned from using these methodsis at a research stage and not yet in regular clinical practice.
Nitrogen Biobank for Cardiovascular Research by Antonella Mercuri, Stefano Turchi, Andrea Borghini, Maria Rosa Chiesa, Guido Lazzerini, Laura Musacchio, Ottavio Zirilli, Maria Grazia Andreassi (253-259).
Biobanks play a crucial role in "-Omics" research providing well-annotated samples to study major diseases,their pathways and mechanisms. Accordingly, there are major efforts worldwide to professionalize biobanks in order toprovide high quality preservation and storage of biological samples with potentially greater scientific impact. Biobanksare an important resource to elucidate relevant disease mechanisms as well as to improve the diagnosis, prognosis, andtreatment of both pediatric and adult cardiovascular disease. High-quality biological sample collections housed in specializedbio-repositories are needed to discover new genetic factors and molecular mechanisms of congenital heart diseaseand inherited cardiomyopathies in order to prevent the potential risk of having a fatal cardiac condition as well as to facilitaterational drug design around molecular diseases (personalized medicine). Biological samples are also required toimprove the understanding the environmental mechanisms of heart disease (environmental cardiology). The goal of thispaper is to focus on preanalytical issues (informed consent, sample type, time of collection, temperature and processingprocedure) related to collection of biological samples for research purposes. In addition, the paper provides an overviewof the efforts made recently by our Institute in designing and implementing a high-security liquid nitrogen storage system(-196°C). We described the implementations of reliable preservation technologies and appropriate quality control (theright temperature, the right environment, fully traceable with all possible back-up systems) in order to ensure maximumsecurity for personnel as well as the quality and suitability of the stored samples.
Management of Retained Intervention Guide-wire: A Literature Review by Abdulrahman M. Al-Moghairi, Hussein S. Al-Amri (260-266).
Percutaneous coronary angioplasty is increasingly employed in the treatment of patients with complex coronaryartery disease.Different steerable guide wires used to open occluded vessel and facilitate balloon and stent deployment. However, theguide-wire itself is not without hazard: it may perforate or dissect the vessel, but fracture or entrapment is uncommon. Itsmanagement depends on the clinical situation of the patient, as well as the position and length of the remnant.In this review we discuss the angioplasty guide-wire fracture and entrapment risk factors, potential risks and management.