Search Results (8)

The prevalence of heart failure, driven significantly by ischemic heart disease, continues to rise globally. Myocardial viability—the potential ability of dysfunctional myocardium to recover contractile function after revascularization—remains an ongoing key area of research in managing ischemic cardiomyopathy. Advances in imaging modalities, including PET/SPECT, cardiac MRI, and dobutamine stress echocardiography, have enabled identification of viable myocardium that can potentially predict their functional recovery following revascularization. Despite these advances, recent evidence from major trials questions the routine reliance on viability testing for revascularization guidance. These studies found a limited correlation between myocardial viability and improved outcomes in key metrics including mortality. Furthermore, they highlighted the effectiveness of guideline-directed medical therapy in improving left ventricular function independent of revascularization. This narrative review explores the concept of myocardial viability, its assessment through contemporary imaging techniques, its clinical utility in decision making for revascularization, and future directions. Full article

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF. Full article

Ischemic heart disease is the leading cause of mortality worldwide. In this context, myocardial viability is defined as the amount of myocardium that, despite contractile dysfunction, maintains metabolic and electrical function, having the potential for functional enhancement upon revascularization. Recent advances have improved methods to detect myocardial viability. The current paper summarizes the pathophysiological basis of the current methods used to detect myocardial viability in light of the advancements in the development of new radiotracers for cardiac imaging. Full article

The surgical reconstruction of dysfunctional myocardium is necessary for patients with severe heart failure. Autologous biomaterials, such as vascularized patch materials, have a regenerative potential due to in vivo remodeling. However, additional temporary mechanical stabilization of the biomaterials is required to prevent aneurysms or rupture. Degradable magnesium scaffolds could prevent these life-threatening risks. A left ventricular transmural defect was reconstructed in minipigs with a piece of the autologous stomach. Geometrically adaptable and degradable scaffolds made of magnesium alloy LA63 were affixed on the epicardium to stabilize the stomach tissue. The degradation of the magnesium structures, their biocompatibility, physiological remodeling of the stomach, and the heart’s function were examined six months after the procedure via MRI (Magnetic Resonance Imaging), angiography, µ-CT, and light microscopy. All animals survived the surgery. Stable physiological integration of the stomach patch could be detected. No ruptures of the grafts occurred. The magnesium scaffolds showed good biocompatibility. Regenerative surgical approaches for treating severe heart failure are a promising therapeutic alternative to the currently available, far from optimal options. The temporary mechanical stabilization of viable, vascularized grafts facilitates their applicability in clinical scenarios. Full article

Although major advances have occurred lately in medical therapy, ischemic heart failure remains an important cause of death and disability. Viable myocardium represents a cause of reversible ischemic left ventricular dysfunction. Coronary revascularization may improve left ventricular function and prognosis in patients with viable myocardium. Although patients with impaired left ventricular function and multi-vessel coronary artery disease benefit the most from revascularization, they are at high risk of complications related to revascularization procedure. An important element in selecting the patients for myocardial revascularization is the presence of the viable myocardium. Multiple imaging modalities can assess myocardial viability and predict functional improvement after revascularization, with dobutamine stress echocardiography, nuclear imaging tests and magnetic resonance imaging being the most frequently used. However, the role of myocardial viability testing in the management of patients with ischemic heart failure is still controversial due to the failure of randomized controlled trials of revascularization to reveal clear benefits of viability testing. This review summarizes the current knowledge regarding the concept of viable myocardium, depicts the role and tools for viability testing, discusses the research involving this topic and the controversies related to the utility of myocardial viability testing and provides a patient-centered approach for clinical practice. Full article

Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits. Full article

Cardiovascular magnetic resonance is becoming an important imaging modality in clinical cardiology. As an exceptionally accurate and comprehensive diagnostic tool, cardiovascular magnetic resonance is becoming the first-choice modality for imaging the heart and great vessels. Stress cardiovascular magnetic resonance imaging enables the detection of hemodynamically significant coronary artery lesions and the choice of treatment strategy when stenosis is intermediate. Viability assessment is very important as it allows differentiating between dysfunctional but still viable myocardium and predicts the recovery of ventricular function after successful revascularization. However, the availability and costs of cardiovascular magnetic resonance remain the major obstacle and makes the investigation unachievable to many patients. Full article

Chronic ischemic left ventricular dysfunction is present in number of clinical syndromes in which myocardial revascularization results in an improvement of left ventricular function, patients’ functional class, and their survival. Coronary arteriography is of limited value in diagnosis of viability. Noninvasive testing, traditionally nuclear imaging, stress echocardiography and (stress) electrocardiography have been the clinical mainstays for assessing myocardial viability as well as to detect myocardial ischemia. However, cardiovascular magnetic resonance is a rapidly emerging noninvasive imaging technique, providing high-resolution images of the heart in any desired plane and without radiation. Rather than a single technique, cardiovascular magnetic resonance consists of several techniques that can be performed separately or in various combinations during a patient examination. Whereas, no single cardiovascular magnetic resonance technique has a perfect, or near perfect, sensitivity and specificity, therefore, a combination of various cardiovascular magnetic resonance techniques are needed for the assessment of myocardial viability. The aim of this review article is to summarize our current understanding of the concept of myocardial viability, to discuss the clinical value of cardiovascular magnetic resonance (in particular the different cardiovascular magnetic resonance techniques to assess viability) for the evaluation of patients with coronary artery disease and chronic left ventricular dysfunction and to present the current place of cardiovascular magnetic resonance among other techniques for the assessment of viable myocardium. Full article