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The evolution of left ventricular assist devices (LVADs) from large, pulsatile systems to compact, continuous-flow pumps has significantly improved implantation outcomes and patient mobility. Minimally invasive surgical techniques have emerged that offer reduced morbidity and enhanced recovery for LVAD recipients. Innovations in wireless power transfer technologies aim to mitigate driveline-related complications, enhancing patient safety and quality of life. Pediatric ventricular assist devices (VADs) remain a critical unmet need; challenges in developing pediatric VADs include device sizing and managing congenital heart disease. Advances in LVAD technology adapted for use in right ventricular assist devices (RVADs) make possible the effective management of right ventricular failure in patients with acute cardiac conditions or congenital heart defects. To address disparities in mechanical circulatory support (MCS) access, cost-effective VAD designs have been developed internationally. The Vitalmex device from Mexico City combines pulsatile-flow technology with a paracorporeal design, utilizing cost-effective materials like silicone-elastic and titanium, and features a reusable pump housing to minimize manufacturing and operational costs. Romanian researchers have used advanced mathematical modeling and three-dimensional (3D) printing to produce a rim-driven, hubless axial-flow pump, achieving efficient blood flow with a compact design that includes a wireless power supply to reduce infection risk. In conclusion, MCS continues to advance with technological innovation and global collaboration. Ongoing efforts are essential to optimize outcomes, expand indications, and improve access to life-saving therapies worldwide.

The need to develop wearable devices for personal health monitoring, diagnostics, and therapy has inspired the production of innovative on-demand, customizable technologies. Several of these technologies enable printing of raw electronic materials directly onto biological organs and tissues. However, few of them have been thoroughly investigated for biocompatibility of the raw materials on the cellular, tissue, and organ levels or with different cell types. In addition, highly accurate multiday in vivo monitoring using such on-demand, in situ fabricated devices has yet to be done. Presented herein is the first fully biocompatible, on-skin fabricated electronics for multiple cell types and tissues that can capture electrophysiological signals with high fidelity. While also demonstrating improved mechanical and electrical properties, the drawn-on-skin ink retains its properties under various writing conditions, which minimizes the variation in electrical performance. Furthermore, the drawn-on-skin ink shows excellent biocompatibility with cardiomyocytes, neurons, mice skin tissue, and human skin. The high signal-to-noise ratios of the electrophysiological signals recorded with the DoS sensor over multiple days demonstrate its potential for personalized, long-term, and accurate electrophysiological health monitoring.

In patients with heart failure, evaluating left ventricular (LV) diastolic function is vital, offering crucial insights into hemodynamic impact and prognostic accuracy. Echocardiography remains the primary imaging modality for diastolic function assessment, and using it effectively requires a profound understanding of the underlying pathology. This review covers four main topics: first, the fundamental driving forces behind each phase of normal diastolic dynamics, along with the physiological basis of two widely used echocardiographic assessment parameters, E/e’ and mitral annulus early diastolic velocity (e’); second, the intricate functional relationship between the left atrium and LV in patients with varying degrees of LV diastolic dysfunction (LVDD); third, the role of stress echocardiography in diagnosing LVDD and the significance of echocardiographic parameter changes; and fourth, the clinical utility of evaluating diastolic function from echocardiography images across diverse cardiovascular care areas.

During the preclinical research process, multiple factors can be difficult to implement without the careful consideration and planning of each step. As research has become more advanced with the use of increasingly complex technology, animal models have also become essential for understanding the potential impact of devices, drug therapies, and surgical techniques on humans before clinical trials are conducted. The use of an in vivo animal model is a key and necessary step in the progression of preclinical research studies that will lead to future medical inventions and innovation. Here, we describe the three phases of effectively designing a preclinical research protocol: the research, preprocedural planning, and experimental phases. Furthermore, we provide researchers with guidance through these phases and discuss important considerations.

Complete atrioventricular block (AVB) is an abnormal heart rhythm resulting from a defect in the cardiac conduction system. Patients with complete AVB are at risk of symptoms ranging from syncope or hypotension to cardiovascular collapse or sudden cardiac death. A reliable animal model of complete AVB is essential for understanding the mechanisms underlying the fatal hemodynamic effects and alterations in electrical conductivity associated with this arrhythmia. We evaluated the use of ethanol injections in a systematic surgical approach to create a complete AVB model in rats. We used eight Sprague Dawley rats (8 weeks old, 220 ± 30 g): four received a 70% ethanol injection in the AV node, and four received a similar injection of 0.9% sodium chloride. Our surgical approach involved performing a partial sternotomy, using the epicardial fat as a landmark for ethanol injections. Animals were followed for 7 and 14 days. Complete AVB was successfully induced in all four rats that received ethanol injections. Rats in the control group experienced a transient AVB with a return to sinus rhythm. Our study found that using 70% ethanol injections in a systematic surgical approach is a reliable, safe, and reproducible way of creating a complete AVB model in rats.

Abstract Objective Delayed cardiac tamponade, a life‐threatening complication of pericardial effusion in humans, has rarely been described in large animal models. We report here a pig with cardiac tamponade that developed 29 days after cardiac surgery. Study Design Case report. Animals One 45‐kg domestic pig. Methods Open‐chest surgery was performed on a pig to induce chronic heart failure. At 15 days after surgery, the pig's breathing appeared laboured; induced heart failure was considered the cause. Routine heart failure medications were administered. Results On day 28, the pig's status deteriorated. On day 29, echocardiography performed just before the pig's death showed a large pericardial effusion, mainly in the lateral and anterior walls of the right heart, with several fibre exudation bands. The right heart was severely compressed with an extremely small right ventricle. An emergency sternotomy was unsuccessful. Pathologic examination showed a severely thickened, fibrous pericardium. The pericardial sac was distended (up to 4.5 cm) and was full of dark brown, soft, friable material. Epicardial haemorrhage with a fresh, organised thrombus was noted in the pericardium. Conclusion Delayed tamponade occurring at least 15 days after open‐chest surgery is easy to misdiagnose or overlook in large animal models where attention is often focused on primary pathological model changes. To decrease mortality in animal models, researchers should be aware of potential complications and use the same level of follow‐up monitoring of large animals as in clinical care.

The use of large animal models in the preclinical setting has expanded and become increasingly valuable for evaluating the safety and efficacy of new therapies and devices. Here, we report normal hemodynamic values, including aortic and pulmonary blood flow, in a bovine model at rest and during exercise after a control procedure. We performed a left lateral thoracotomy and implanted fluid-filled pressure lines (aortic pressure, right atrial pressure, left atrial pressure, pulmonary artery pressure) and left (systemic) and right (pulmonary) flow probe lines. Throughout the postoperative period, the calf’s physiologic pressures, vital signs, aortic and pulmonary blood flow, and pulmonary and systemic vascular resistance were recorded hourly at rest and during treadmill exercise evaluations. When pressures and flow rates at baseline and during treadmill trials were compared, we observed a physiologic response to exercise similar to that seen in humans, with a sympathetic discharge that increased systolic blood pressure. However, the rise in mean arterial pressure was much lower due to an overall decrease in vascular resistance, which increased blood flow. This study provides investigators, device engineers, and manufacturers with normal bovine cardiovascular physiology data that can be used for technical consideration during device development for preclinical trials.

The evolution of left ventricular assist devices (LVADs) from large, pulsatile systems to compact, continuous-flow pumps has significantly improved implantation outcomes and patient mobility. Minimally invasive surgical techniques have emerged that offer reduced morbidity and enhanced recovery for LVAD recipients. Innovations in wireless power transfer technologies aim to mitigate driveline-related complications, enhancing patient safety and quality of life. Pediatric ventricular assist devices (VADs) remain a critical unmet need; challenges in developing pediatric VADs include device sizing and managing congenital heart disease. Advances in LVAD technology adapted for use in right ventricular assist devices (RVADs) make possible the effective management of right ventricular failure in patients with acute cardiac conditions or congenital heart defects. To address disparities in mechanical circulatory support (MCS) access, cost-effective VAD designs have been developed internationally. The Vitalmex device from Mexico City combines pulsatile-flow technology with a paracorporeal design, utilizing cost-effective materials like silicone-elastic and titanium, and features a reusable pump housing to minimize manufacturing and operational costs. Romanian researchers have used advanced mathematical modeling and three-dimensional (3D) printing to produce a rim-driven, hubless axial-flow pump, achieving efficient blood flow with a compact design that includes a wireless power supply to reduce infection risk. In conclusion, MCS continues to advance with technological innovation and global collaboration. Ongoing efforts are essential to optimize outcomes, expand indications, and improve access to life-saving therapies worldwide. [ABSTRACT FROM AUTHOR]

Heart failure with preserved ejection fraction (HFpEF) is characterized by a complex, heterogeneous spectrum of pathologic features combined with average left ventricular volume and diastolic dysfunction. HFpEF is a significant public health problem associated with high morbidity and mortality rates. Currently, effective treatments for HFpEF represent the greatest unmet need in cardiovascular medicine. A lack of an efficient preclinical model has hampered the development of new devices and medications for HFpEF. Because large animal models have similar physiologic traits as humans and appropriate organ sizes, they are the best option for limiting practical constraints. HFpEF is a highly integrated, multiorgan, systemic disorder requiring a multipronged investigative approach. Here, we review the large animal models of HFpEF reported to date and describe the methods that have been used to create HFpEF, including surgery-induced pressure overloading, medicine-induced pressure overloading, and diet-induced metabolic syndrome. In addition, for the first time to our knowledge, we use two established clinical HFpEF algorithms (HFA-PEFF and H2FPEF scores) to evaluate the currently available large animal models. We also discuss new technologies, such as continuous remote pressure monitors and inflatable aortic cuffs, as well as how the models could be improved. Based on current progress and our own experience, we believe an efficient large animal model of HFpEF should simultaneously encompass multiple pathophysiologic factors, along with multiorgan dysfunction. This could be fully evaluated through available methods (imaging, blood work). Although many models have been studied, only a few studies completely meet clinical score standards. Therefore, it is critical to address the deficiencies of each model and incorporate novel techniques to establish a more reliable model, which will help facilitate the understanding of HFpEF mechanisms and the development of a treatment.

Congestive heart failure (HF) is a devastating disease leading to prolonged hospitalization, high morbidity and mortality rates, and increased costs. Well-established treatments for decompensated or unstable patients include medications and mechanical cardiac support devices. For acute HF decompensation, new devices are being developed to help relieve symptoms and recover heart and renal function in these patients. A recent device-based classification scheme, collectively classified as DRI2P2S, has been proposed to better describe these new device-based therapies based on their mechanism: dilators (increase venous capacitance), removers (direct removal of sodium and water), inotropes (increase left ventricular contractility), interstitials (accelerate removal of lymph), pushers (increase renal arterial pressure), pullers (decrease renal venous pressure), and selective (selective intrarenal drug infusion). In this review, we describe the new class of medical devices with the most current results reported in preclinical models and clinical trials.

In patients with heart failure, evaluating left ventricular (LV) diastolic function is vital, offering crucial insights into hemodynamic impact and prognostic accuracy. Echocardiography remains the primary imaging modality for diastolic function assessment, and using it effectively requires a profound understanding of the underlying pathology. This review covers four main topics: first, the fundamental driving forces behind each phase of normal diastolic dynamics, along with the physiological basis of two widely used echocardiographic assessment parameters, E/e' and mitral annulus early diastolic velocity (e'); second, the intricate functional relationship between the left atrium and LV in patients with varying degrees of LV diastolic dysfunction (LVDD); third, the role of stress echocardiography in diagnosing LVDD and the significance of echocardiographic parameter changes; and fourth, the clinical utility of evaluating diastolic function from echocardiography images across diverse cardiovascular care areas. [ABSTRACT FROM AUTHOR]

We examined the changes in variables that could be recorded on wearable devices during the early stages of acute myocardial infarction (AMI) in an animal model. Early diagnosis of AMI is important for prognosis; however, delayed diagnosis is common because of patient hesitation and lack of timely evaluations. Wearable devices are becoming increasingly sophisticated in the ability to track indicators. In this study, we retrospectively reviewed the changes in four variables during AMI in a pig model to assess their ability to help predict AMI onset. AMI was created in 33 pigs by 90-min balloon occlusion of the left anterior descending artery. Blood pressure, EKG, and lactate and cardiac troponin I levels were recorded during the occlusion period. Blood pressure declined significantly within 15 min after balloon inflation (mean arterial pressure, from 61 ± 8 to 50 ± 8 mmHg) and remained at this low level. Within 5 min of balloon inflation, the EKG showed ST-elevation in precordial leads V1–V3. Blood lactate levels increased gradually after occlusion and peaked at 60 min (from 1.48 to 2.53 mmol/L). The continuous transdermal troponin sensor demonstrated a gradual increase in troponin levels over time. Our data suggest that significant changes in key indicators (blood pressure, EKG leads V1–V3, and lactate and troponin levels) occurred at the onset of AMI. Monitoring of these variables could be used to develop an algorithm and alert patients early at the onset of AMI with the help of a wearable device.

During the preclinical research process, multiple factors can be difficult to implement without the careful consideration and planning of each step. As research has become more advanced with the use of increasingly complex technology, animal models have also become essential for understanding the potential impact of devices, drug therapies, and surgical techniques on humans before clinical trials are conducted. The use of an in vivo animal model is a key and necessary step in the progression of preclinical research studies that will lead to future medical inventions and innovation. Here, we describe the three phases of effectively designing a preclinical research protocol: the research, preprocedural planning, and experimental phases. Furthermore, we provide researchers with guidance through these phases and discuss important considerations. [ABSTRACT FROM AUTHOR]

[This corrects the article DOI: 10.1371/journal.pone.0211339.].

Various strategies have been attempted to replace esophageal defects with natural or artificial substitutes using tissue engineering. However, these methods have not yet reached clinical application because of the high risks related to their immunogenicity or insufficient biocompatibility. In this study, we developed a scaffold-free structure with a mixture of cell types using bio-three-dimensional (3D) printing technology and assessed its characteristics in vitro and in vivo after transplantation into rats. Normal human dermal fibroblasts, human esophageal smooth muscle cells, human bone marrow-derived mesenchymal stem cells, and human umbilical vein endothelial cells were purchased and used as a cell source. After the preparation of multicellular spheroids, esophageal-like tube structures were prepared by bio-3D printing. The structures were matured in a bioreactor and transplanted into 10-12-week-old F344 male rats as esophageal grafts under general anesthesia. Mechanical and histochemical assessment of the structures were performed. Among 4 types of structures evaluated, those with the larger proportion of mesenchymal stem cells tended to show greater strength and expansion on mechanical testing and highly expressed α-smooth muscle actin and vascular endothelial growth factor on immunohistochemistry. Therefore, the structure with the larger proportion of mesenchymal stem cells was selected for transplantation. The scaffold-free structures had sufficient strength for transplantation between the esophagus and stomach using silicon stents. The structures were maintained in vivo for 30 days after transplantation. Smooth muscle cells were maintained, and flat epithelium extended and covered the inner surface of the lumen. Food had also passed through the structure. These results suggested that the esophagus-like scaffold-free tubular structures created using bio-3D printing could hold promise as a substitute for the repair of esophageal defects.