Remote preconditioning in normal and hypertrophic rat hearts

<p>Abstract</p> <p>Background</p> <p>The aim of our study was to investigate whether remote preconditioning (RPC) improves myocardial function after ischemia/reperfusion injury in both normal and hypertrophic isolated rat hearts. This is the first time in world literature that cardioprotection by RPC in hypertrophic myocardium is investigated.</p> <p>Methods</p> <p>Four groups of 7 male Wistar rats each, were used: Normal control, normal preconditioned, hypertrophic control and hypertrophic preconditioned groups. Moderate cardiac hypertrophy was induced by fludrocortisone acetate and salt administration for 30 days. Remote preconditioning of the rat heart was achieved by 20 minutes transient right hind limb ischemia and 10 minutes reperfusion of the anaesthetized animal. Isolated Langendorff-perfused animal hearts were then subjected to 30 minutes of global ischemia and reperfusion for 60 minutes. Contractile function and heart rhythm were monitored. Preconditioned groups were compared to control groups.</p> <p>Results</p> <p>Left ventricular developed pressure (LVDP) and the product LVDP × heart rate (HR) were significantly higher in the hypertrophic preconditioned group than the hypertrophic control group while left ventricular end diastolic pressure (LVEDP) and severe arrhythmia episodes did not differ. Variances between the normal heart groups were not significantly different except for the values of the LVEDP in the beginning of reperfusion.</p> <p>Conclusions</p> <p>Remote preconditioning seems to protect myocardial contractile function in hypertrophic myocardium, while it has no beneficial effect in normal myocardium.</p

How to develop a national heart failure clinics network: a consensus document of the Hellenic Heart Failure Association

Heart failure (HF) is rapidly growing, conferring considerable mortality, morbidity, and costs. Dedicated HF clinics improve patient outcomes, and the development of a national HF clinics network aims at addressing this need at national level. Such a network should respect the existing health care infrastructures, and according to the capacities of hosting facilities, it can be organized into three levels. Establishing the continuous communication and interaction among the components of the network is crucial, while supportive actions that can enhance its efficiency include involvement of multidisciplinary health care professionals, use of structured HF-specific documents, such as discharge notes, patient information leaflets, and patient booklets, and implementation of an HF-specific electronic health care record and database platform

The Left Atrium: From the Research Laboratory to the Clinic

Studies of left atrial (LA) function, until the latter part of the 20th century, were mostly limited to experimental animal models and to studies related to clinical research in the cardiac catheterization laboratory. For this reason, LA function has received considerably less attention than left ventricular (LV) functions, even though evidence suggests that LA myopathy and failure may exist as an isolated entity, precede and/or coexist with LV myopathy. The introduction of echocardiography and Doppler echocardiography in clinical practice has contributed significantly to our understanding of LA function and its interrelationships with the LV, aorta, pulmonary artery and other parts of the cardiovascular system. In addition, LA with the secretion of atrial natriuretic peptides is playing an important role in cardiovascular and neurohumoral homeostasis. Today, it is well known that LA structural and functional abnormalities that are present in many diseases and disorders constitute a powerful prognostic indicator. As technology (echocardiography, magnetic resonance imaging, computed tomography and others) continues to evolve, it is expected that, in the near future, LA structure and function will be routinely used as LV function is used today. (C) 2014 S. Karger AG, Base

Myocardial Protection and Current Cancer Therapy: Two Opposite Targets with Inevitable Cost

Myocardial protection against ischemia/reperfusion injury (IRI) is mediated by various ligands, activating different cellular signaling cascades. These include classical cytosolic mediators such as cyclic-GMP (c-GMP), various kinases such as Phosphatydilinositol-3- (PI3K), Protein Kinase B (Akt), Mitogen-Activated-Protein- (MAPK) and AMP-activated (AMPK) kinases, transcription factors such as signal transducer and activator of transcription 3 (STAT3) and bioactive molecules such as vascular endothelial growth factor (VEGF). Most of the aforementioned signaling molecules constitute targets of anticancer therapy; as they are also involved in carcinogenesis, most of the current anti-neoplastic drugs lead to concomitant weakening or even complete abrogation of myocardial cell tolerance to ischemic or oxidative stress. Furthermore, many anti-neoplastic drugs may directly induce cardiotoxicity via their pharmacological effects, or indirectly via their cardiovascular side effects. The combination of direct drug cardiotoxicity, indirect cardiovascular side effects and neutralization of the cardioprotective defense mechanisms of the heart by prolonged cancer treatment may induce long-term ventricular dysfunction, or even clinically manifested heart failure. We present a narrative review of three therapeutic interventions, namely VEGF, proteasome and Immune Checkpoint inhibitors, having opposing effects on the same intracellular signal cascades thereby affecting the heart. Moreover, we herein comment on the current guidelines for managing cardiotoxicity in the clinical setting and on the role of cardiovascular confounders in cardiotoxicity

Peak exercise myocardial deformation indices during cardiopulmonary exercise testing are associated with exercise capacity and ventilatory efficiency in patients with dilated cardiomyopathy

Objective: Little is known about the exercise-induced changes in the multidimensional mechanical properties of the heart. We aimed to evaluate the myocardial deformation indices (MDI) at rest and their response at peak exercise during the same cardiopulmonary exercise testing (CPET) session, investigating their relationship to exercise capacity and ventilatory sufficiency in dilated cardiomyopathy (DCM) patients. Methods: We evaluated left ventricular (LV) function using speckle tracking imaging (STI) at rest and peak exercise during the same CPET session in 57 idiopathic DCM patients in New York Heart Association (NYHA) I–II class [54 ± 12 years, 42 males, ejection fraction (EF) 33 ± 9%]. We measured global longitudinal strain (GLS), longitudinal strain rate at systole (LSRS) and diastole (LSRD), and circumferential strain rate (CircS). Results: Resting GLS, LSRS, and LSRD were impaired compared with the predicted values but were improved at peak exercise (p −1.10 sec−1 (AUC = 0.80, p −13% (AUC = 0.81, p = 0.002) predicted impaired exercise capacity (peak VO2 34). In multiple regression analysis, peak exercise LSRS and GLS were independently related to the peak VO2 (Beta = −0.39, p = 0.003) and VE/VCO2 slope (Beta = 0.35, p = 0.02), respectively. Conclusions: Peak exercise LSRS and GLS in NYHA I–II DCM patients subjected to CPET were associated with aerobic exercise capacity and ventilatory efficiency. Consequently, LSRS and GLS at peak exercise, through their association with CPET-derived CV risk indices, may underline the severity of heart failure and predict future CV events in this DCM population

Distribution, infrastructure, and expertise of heart failure and cardio-oncology clinics in a developing network: temporal evolution and challenges during the coronavirus disease 2019 pandemic

The Hellenic Heart Failure Association has undertaken the initiative to develop a national network of heart failure clinics (HFCs) and cardio-oncology clinics (COCs). We conducted two questionnaire surveys among these clinics within 17 months and another during the coronavirus disease 2019 outbreak to assess adjustments of the developing network to the pandemic. Out of 68 HFCs comprising the network, 52 participated in the first survey and 55 in the second survey. The median number of patients assessed per week is 10. Changes in engaged personnel were encountered between the two surveys, along with increasing use of advanced echocardiographic techniques (23.1% in 2018 vs. 34.5% in 2020). Drawbacks were encountered, concerning magnetic resonance imaging and ergospirometry use (being available in 14.6% and 29% of HFCs, respectively), exercise rehabilitation programmes (applied only in 5.5%), and telemedicine applications (used in 16.4%). There are 13 COCs in the country with nine of them in the capital region; the median number of patients being assessed per week is 10. Platforms for virtual consultations and video calls are used in 38.5%. Coronavirus disease 2019 outbreak affected provision of HFC services dramatically as only 18.5% continued to function regularly, imposing hurdles that need to be addressed, at least temporarily, possibly by alternative methods of follow-up such as remote consultation. The function of COCs, in contrast, seemed to be much less affected during the pandemic (77% of them continued to follow up their patients). This staged, survey-based procedure may serve as a blueprint to help building national HFC/COC networks and provides the means to address changes during healthcare crises

Left atrial remodelling contributes to the progression of asymptomatic left ventricular systolic dysfunction to chronic symptomatic heart failure

Systolic heart failure (HF) is a progressive disorder that often begins with asymptomatic left ventricular (LV) systolic dysfunction and culminates in symptoms from fluid overload and poor end-organ perfusion. The progression to symptomatic HF is accompanied by marked activation of neurohormonal and cytokine systems, as well as a series of adaptive LV anatomical and functional changes, collectively referred to as LV remodelling. However, the mechanisms underlying symptom appearance have not been delineated and the weight of experimental and clinical evidence suggests that the development of symptomatic HF occurs independently of the haemodynamic status of the patient. The left atrium is a muscular chamber strategically located between the left ventricle and the pulmonary circulation with important mechanical function (modulation of LV filling), which is closely coupled with its endocrine (atrial natriuretic peptide synthesis and secretion) and regulatory (contribution to the control of sympathetic activity and vasopressin release) functions. In this narrative review we provide evidence supporting the concept that left atrial dilation and systolic dysfunction (left atrial remodelling) contributes to the progression of asymptomatic LV dysfunction to chronic symptomatic systolic HF as it is a prerequisite for the development of the pulmonary congestion and marked neuronhormoral activity that characterize the symptomatic state