Erica C. Campos

Coronary Microvascular Disease in Chronic Chagas Cardiomyopathy Including an Overview on History, Pathology, and Other Proposed Pathogenic Mechanisms

This review focuses on the short and bewildered history of Brazilian scientist Carlos Chagass discovery and subsequent developments, the anatomopathological features of chronic Chagas cardiomyopathy (CCC), an overview on the controversies surrounding theories concerning its pathogenesis, and studies that support the microvascular hypothesis to further explain the pathological features and clinical course of CCC. It is our belief that knowledge of this particular and remarkable cardiomyopathy will shed light not only on the microvascular involvement of its pathogenesis, but also on the pathogenetic processes of other cardiomyopathies, which will hopefully provide a better understanding of the various changes that may lead to an end-stage heart disease with similar features. This review is written to celebrate the 100th anniversary of the discovery of Chagas disease.

Increased sarcolemmal permeability as an early event in experimental septic cardiomyopathy: a potential role for oxidative damage to lipids and proteins.

This study describes increased sarcolemmal permeability and myofilamentar damage that occur together with lipid peroxidation and protein nitration in the myocardium in severe sepsis induced by cecal ligation and puncture. Male C57BL/6 mice were submitted to moderate and severe septic injury and sham operation. Using light and laser confocal microscopy, diffuse foci of myocytolysis associated with focal disruption of the actin/myosin contractile apparatus could be seen in hearts with severe septic injury. The myocardial expressions of the sarcomeric proteins myosin and actin were downregulated by both severe and moderate injuries. The detection of albumin staining in the cytoplasm of myocytes to evaluate sarcolemmal permeability provided evidence of severe and mild injury of the plasma membrane in hearts with severe and moderate septic injury, respectively. The administration of a superoxide scavenger caused marked reduction of sarcolemmal permeability, indicating the involvement of free radicals in its genesis. On electron microscopy, these changes were seen to correspond to spread blocks of a few myocytes with fragmentation and dissolution of myofibrils, intracellular edema, and, occasionally, rupture of the sarcolemma. In addition, oxidative damage to lipids, using anti-4-hydroxynonenal, an indicator of oxidative stress and disruption of plasma membrane lipids, and to proteins, using antinitrotyrosine, a stable biomarker of peroxynitrite-mediated protein nitration, was demonstrated. These findings make plausible the hypothesis that increased sarcolemmal permeability might be a primary event in myocardial injury in severe sepsis possibly due to oxidative damage to lipids and proteins that could precede phenotypic changes that characterize a septic cardiomyopathy.

Disruption of Calcium Homeostasis in Cardiomyocytes Underlies Cardiac Structural and Functional Changes in Severe Sepsis

Sepsis, a major cause of morbidity/mortality in intensive care units worldwide, is commonly associated with cardiac dysfunction, which worsens the prognosis dramatically for patients. Although in recent years the concept of septic cardiomyopathy has evolved, the importance of myocardial structural alterations in sepsis has not been fully explored. This study offers novel and mechanistic data to clarify subcellular events that occur in the pathogenesis of septic cardiomyopathy and myocardial dysfunction in severe sepsis. Cultured neonatal mice cardiomyocytes subjected to serum obtained from mice with severe sepsis presented striking increment of [Ca2+]i and calpain-1 levels associated with decreased expression of dystrophin and disruption and derangement of F-actin filaments and cytoplasmic bleb formation. Severe sepsis induced in mice led to an increased expression of calpain-1 in cardiomyocytes. Moreover, decreased myocardial amounts of dystrophin, sarcomeric actin, and myosin heavy chain were observed in septic hearts associated with depressed cardiac contractile dysfunction and a very low survival rate. Actin and myosin from the sarcomere are first disassembled by calpain and then ubiquitinated and degraded by proteasome or sequestered inside specialized vacuoles called autophagosomes, delivered to the lysosome for degradation forming autophagolysosomes. Verapamil and dantrolene prevented the increase of calpain-1 levels and preserved dystrophin, actin, and myosin loss/reduction as well cardiac contractile dysfunction associated with strikingly improved survival rate. These abnormal parameters emerge as therapeutic targets, which modulation may provide beneficial effects on future vascular outcomes and mortality in sepsis. Further studies are needed to shed light on this mechanism, mainly regarding specific calpain inhibitors.

Isoproterenol induces primary loss of dystrophin in rat hearts: correlation with myocardial injury.

The mechanism of isoproterenol‐induced myocardial damage is unknown, but a mismatch of oxygen supply vs. demand following coronary hypotension and myocardial hyperactivity is the best explanation for the complex morphological alterations observed. Severe alterations in the structural integrity of the sarcolemma of cardiomyocytes have been demonstrated to be caused by isoproterenol. Taking into account that the sarcolemmal integrity is stabilized by the dystrophin‐glycoprotein complex (DGC) that connects actin and laminin in contractile machinery and extracellular matrix and by integrins, this study tests the hypothesis that isoproterenol affects sarcolemmal stability through changes in the DGC and integrins. We found different sensitivity of the DGC and integrin to isoproterenol subcutaneous administration. Immunofluorescent staining revealed that dystrophin is the most sensitive among the structures connecting the actin in the cardiomyocyte cytoskeleton and the extracellular matrix. The sarcomeric actin dissolution occurred after the reduction or loss of dystrophin. Subsequently, after lysis of myofilaments, γ‐sarcoglycan, β‐dystroglycan, β1‐integrin, and laminin α‐2 expressions were reduced followed by their breakdown, as epiphenomena of the myocytolytic process. In conclusion, administration of isoproterenol to rats results in primary loss of dystrophin, the most sensitive among the structural proteins that form the DGC that connects the extracellular matrix and the cytoskeleton in cardiomyocyte. These changes, related to ischaemic injury, explain the severe alterations in the structural integrity of the sarcolemma of cardiomyocytes and hence severe and irreversible injury induced by isoproterenol.

Early dystrophin disruption in the pathogenesis of experimental chronic Chagas cardiomyopathy

Chronic Chagas cardiomyopathy evolves over a long period of time after initial infection by Trypanosoma cruzi. Similarly, a cardiomyopathy appears later in life in muscular dystrophies. This study tested the hypothesis that dystrophin levels are decreased in the early stage of T. cruzi-infected mice that precedes the later development of a cardiomyopathy. CD1 mice were infected with T. cruzi (Brazil strain), killed at 30 and 100 days post infection (dpi), and the intensity of inflammation, percentage of interstitial fibrosis, and dystrophin levels evaluated. Echocardiography and magnetic resonance imaging data were evaluated from 15 to 100 dpi. At 30 dpi an intense acute myocarditis with ruptured or intact intracellular parasite nests was observed. At 100 dpi a mild chronic fibrosing myocarditis was detected without parasites in the myocardium. Dystrophin was focally reduced or completely lost in cardiomyocytes at 30 dpi, with the reduction maintained up to 100 dpi. Concurrently, ejection fraction was reduced and the right ventricle was dilated. These findings support the hypothesis that the initial parasitic infection-induced myocardial dystrophin reduction/loss, maintained over time, might be essential to the late development of a cardiomyopathy in mice.

Early detection of doxorubicin myocardial injury by ultrasonic tissue characterization in an experimental animal model

In the clinical setting, the early detection of myocardial injury induced by doxorubicin (DXR) is still considered a challenge. To assess whether ultrasonic tissue characterization (UTC) can identify early DXR-related myocardial lesions and their correlation with collagen myocardial percentages, we studied 60 rats at basal status and prospectively after 2mg/Kg/week DXR endovenous infusion. Echocardiographic examinations were conducted at baseline and at 8,10,12,14 and 16 mg/Kg DXR cumulative dose. The left ventricle ejection fraction (LVEF), shortening fraction (SF), and the UTC indices: corrected coefficient of integrated backscatter (IBS) (tissue IBS intensity/ phantom IBS intensity) (CC-IBS) and the cyclic variation magnitude of this intensity curve (MCV) were measured. The variation of each parameter of study through DXR dose was expressed by the average and standard error at specific DXR dosages and those at baseline. The collagen percent (%) was calculated in six control group animals and 24 DXR group animals. CC-IBS increased (1.29±0.27 x 1.1±0.26-basal; p=0.005) and MCV decreased (9.1± 2.8 x 11.02±2.6-basal; p=0.006) from 8 mg/Kg to 16mg/Kg DXR. LVEF presented only a slight but significant decrease (80.4±6.9% x 85.3±6.9%-basal, p=0.005) from 8 mg/Kg to 16 mg/Kg DXR. CC-IBS was 72.2% sensitive and 83.3% specific to detect collagen deposition of 4.24%(AUC=0.76). LVEF was not accurate to detect initial collagen deposition (AUC=0.54). In conclusion: UTC was able to early identify the DXR myocardial lesion when compared to LVEF, showing good accuracy to detect the initial collagen deposition in this experimental animal model.

Increased Atrial β-Adrenergic Receptors and GRK-2 Gene Expression Can Play a Fundamental Role in Heart Failure After Repair of Congenital Heart Disease with Cardiopulmonary Bypass

Surgeries to correct congenital heart diseases are increasing in Brazil and worldwide. However, even with the advances in surgical techniques and perfusion, some cases, especially the more complex ones, can develop heart failure and death. A retrospective study of patients who underwent surgery for correction of congenital heart diseases with cardiopulmonary bypass (CPB) in a university tertiary-care hospital that died, showed infarction in different stages of evolution and scattered microcalcifications in the myocardium, even without coronary obstruction. CPB is a process routinely used during cardiac surgery for congenital heart disease. However, CPB has been related to increased endogenous catecholamines that can lead to major injuries in cardiomyocytes. The mechanisms involved are not completely understood. The aim of this study was to evaluate the alterations induced in the β-adrenergic receptors and GRK-2 present in atrial cardiomyocytes of infants with congenital heart disease undergoing surgical repair with CPB and correlate the alterations with functional and biochemical markers of ischemia/myocardial injury. The study consisted of right atrial biopsies of infants undergoing surgical correction in HC-FMRPUSP. Thirty-three cases were selected. Atrial biopsies were obtained at the beginning of CPB (group G1) and at the end of CPB (group G2). Real-time PCR, Western blotting, and immunofluorescence analysis were conducted to evaluate the expression of β1, β2-adrenergic receptors, and GRK-2 in atrial myocardium. Cardiac function was evaluated by echocardiography and biochemical analysis (N-terminal pro-brain natriuretic peptide (NT-ProBNP), lactate, and cardiac troponin I). We observed an increase in serum lactate, NT-proBNP, and troponin I at the end of CPB indicating tissue hypoxia/ischemia. Even without major clinical consequences in cardiac function, these alterations were followed by a significant increase in gene expression of β1 and β2 receptors and GRK-2, suggesting that this is one of the mechanisms responsible for the exacerbated response of cardiomyocytes to circulating catecholamines. These alterations could explain the irreversible myocardial damage and lipid peroxidation of membranes classically attributed to catecholamine excess, observed in some infants who develop heart failure and postoperative death. Although other factors may be involved, this study confirms that CPB acts as a potent inducer of increased gene expression of β- adrenergic receptors and GRK-2, making the myocardium of these infants more susceptible to the effects of circulating endogenous catecholamines, which may contribute to the development of irreversible myocardial damage and death.

Activation of both the calpain and ubiquitin-proteasome systems contributes to septic cardiomyopathy through dystrophin loss/disruption and mTOR inhibition

Cardiac dysfunction caused by the impairment of myocardial contractility has been recognized as an important factor contributing to the high mortality in sepsis. Calpain activation in the heart takes place in response to increased intracellular calcium influx resulting in proteolysis of structural and contractile proteins with subsequent myocardial dysfunction. The purpose of the present study was to test the hypothesis that increased levels of calpain in the septic heart leads to disruption of structural and contractile proteins and that administration of calpain inhibitor-1 (N-acetyl-leucinyl-leucinyl-norleucinal (ALLN)) after sepsis induced by cecal ligation and puncture prevents cardiac protein degradation. We also tested the hypothesis that calpain plays a role in the modulation of protein synthesis/degradation through the activation of proteasome-dependent proteolysis and inhibition of the mTOR pathway. Severe sepsis significantly increased heart calpain-1 levels and promoted ubiquitin and Pa28β over-expression with a reduction in the mTOR levels. In addition, sepsis reduced the expression of structural proteins dystrophin and β-dystroglycan as well as the contractile proteins actin and myosin. ALLN administration prevented sepsis-induced increases in calpain and ubiquitin levels in the heart, which resulted in decreased of structural and contractile proteins degradation and basal mTOR expression levels were re-established. Our results support the concept that increased calpain concentrations may be part of an important mechanism of sepsis-induced cardiac muscle proteolysis.

Calpain-1 inhibitor prevent loss of dystrophin in experimental septic cardiomyopathy induced by cecal ligation and puncture (CLP)

Objective: The small incisions of minimally invasive surgery have the proposed benefits of less surgical trauma, less pain, and an improved cosmetic outcome; all of which correspond to a faster postoperative recovery. Opponents claim smaller incisions lead to poor exposure, making the operation longer, more difficult and dangerous. Here, we report our experience performing minimally invasive aortic valve replacements, via a minimally invasive anterior thoracotomy or mini-sternotomy approach, in comparison to conventional sternotomy.AIMS To evaluate the efficacy of a unique healthy and happy lifestyle (HLS) program in regression of coronary atherosclerosis and reduction in cardiac events in an open trial. METHODS One hundred and twenty three angiographically documented moderate to severe coronary artery disease (CAD) patients were administered HLS comprising of low-fat, high-fiber vegetarian diet, moderate aerobic exercise and stress-management through Rajyoga meditation. Its most salient feature was training in self-responsibility (heal+thy) and self-empowerment through inner-self consciousness (swasth; swa=innerself, sth=consciousness) approach using Rajyoga meditation. Following a seven day in-house sojourn, patients were invited for six month follow-up for reassessment and advanced training. At the end of two years, all patients were asked to undergo repeat angiography. RESULTS Three hundred and sixty coronary lesions were analysed by two independent angiographers. In CAD patients with most adherence, percent diameter stenosis regressed by 18.23 +/- 12.04 absolute percentage points. 91% patients showed a trend towards regression and 51.4% lesions regressed by more than 10 absolute percentage points. The cardiac events in coronary artery disease patients were: 11 in most adherence, and 38 in least adherence over a follow-up period of 6.48 yrs. (risk ratio; most vs least adherence: 4.32; 95% CI: 1.69-11.705; P < 0.002). CONCLUSION Overall healthy changes in cardiovascular, metabolic and psychological parameters, decline in absolute percent diameter coronary stenosis and cardiac events in patients of CAD were closely related to HLS adherence. However, more than 50% adherence is essential to achieve a significant change.Introduction: Despite major advancements in coronary revascularization therapy, including percutaneous coronary intervention and coronary artery bypass grafting, many patients are ineligible for interventional therapy or remain symptomatic despite optimal treatment. For this group of patients, pain often significantly limits physical activity and contributes to a poor quality of life. Spinal cord stimulation (SCS) has been described as a potential safe and effective treatment modality for this select group of patients.Segmental contractions were quantified from images of electrocardiographic-gated single-photon emission computed tomography. Counts were integrated in 64 angles about the centre on short-axis images and projected onto a cylindrical screen. Changes in the projected count were shown to obey the equation of continuity for two-dimensional fluids (the Poisson equation). Displacements of each pixel point were calculated from the velocity field to quantify the amount of dislocation. Changes in the configuration of the pixel points were projected back on the cardiac wall, and finally segmental contractions were evaluated as a percentage reduction of the area. Computer simulations were performed for numerical models of circumferential and long-axial contractions, uneven eccentric contractions and rotations. These models were blurred with a three-dimensional Gaussian function. The results obtained using this method (quantification of segmental function by solving the Poisson equation (QSFP)) were compared with the wall-thickening method (WTM) and the maximum-count method. Both QSFP and WTM yielded good agreement with predicted values for circumferential and long-axial contractions. Only QSFP gave satisfactory results for uneven eccentric contractions, and rotation models. QSFP should provide a useful tool for in vivo quantification of contraction tangential to the cardiac wall by eliminating errors due to displacements.I is difficult to study the effect of cigarette smoke on humans in a systematic way; therefore, we studied the effect of cigarette smoke exposure on cardiac transplant survival and the development of myocardial infarction in rat models. In this experimental study, we investigated early consequences of tobacco smoke exposure in cardiac transplant donors and recipients with an emphasis on alloinflammatory mediators of graft outcome using heterotopic rat cardiac transplantation; we tested the effects of donor or recipient tobacco smoke exposure. Our experiments reveal that pre-transplantation tobacco exposure in donors and/or recipients results in heightened systemic inflammation and increased oxidative stress reduces post-transplantation cardiac allograft survival. Our studies with cigarettes without nicotine demonstrated significantly lesser detrimental effects on cardiac transplant survival.N oxide (NO) is a multifunctional signaling molecule, intricately involved with maintaining a host of physiological processes including but not limited to host defense, neuronal communication and the regulation of vascular tone. The endothelium-derived NO plays a crucial role in regulating a wide spectrum of functionsin the cardiovascular system, including vasorelaxation, inhibition of leukocyte-endothelial adhesion, vascular smooth muscle cell (SMC) migration and proliferation, as well as platelet aggregation. In this regard, NO is a potent vasodilator as well as a powerful anti-platelet and anti-leukocyte factor. NO is one of the most important signaling molecules in our body. Loss of NO function is one of the earliest indicators or markers of disease. Experimental and clinical studies provide evidence that defects of endothelial NO production, referred to as endothelial dysfunction, is not only associated with all major cardiovascular risk factors such as hyperlipidemia, diabetes, hypertension, erectile dysfunction, smoking and severity of atherosclerosis, but also has a profound predictive value for future atherosclerotic disease progression. Emerging published literature reveals that NO insufficiency may manifest itself differently in different patients. Thirty plus years after its discovery and over 14 years since a Nobel Prize was awarded for its discovery, there have been no hallmark therapeutic breakthroughs. We will review the current state of the science surrounding nitric oxide in the etiology of a number of different disease states and reveal the latest technology to safely and effectively restore nitric oxide in patients. The audience will learn the challenges and opportunities that exist in understand NO homeostasis in their patients and how this may translate into better management of their patients.BACKGROUND It has been recently reported that inflammatory mechanisms play an important role in in-stent restenosis (ISR) processes. Inflammatory factors after percutaneous coronary intervention (PCI) for dynamic monitoring can probably predict ISR. Functional polymorphisms in the promoter region of genes coding for inflammatory factors might be important for determining the magnitude of the inflammatory response. Thus, in the present study, we aimed to investigate the serial changes in serum interleukin-6 (IL-6) levels before and after PCI and the relationship between the -572C/G polymorphism in the promoter region of the IL-6 gene and ISR. We also discussed genetic polymorphisms in the inflammatory response to PCI. METHODS A total of 437 patients who successfully underwent bare metal stent (BMS) implantation with a follow-up angiography were divided into an ISR group (n = 166) and a non-ISR (NISR) group (n = 271). The IL-6 gene promoter polymorphism at position -572 was determined by restricted fragment length polymorphism using the polymerase chain reaction (PCR-RFLP) method. The serum IL-6 levels before and one day, five days and 180 days after PCI were determined by the radioimmunoassay method. RESULTS ISR patients showed higher IL-6 serum levels than NISR patients before PCI ((324.42 ± 28.14) ng/L vs. (283.22 ± 47.30) ng/L, P < 0.001), and one day post-PCI IL-6 serum levels in the ISR group also showed a significantly higher level than in the NISR group (P < 0.001). Increased IL-6 after PCI persisted at a statistically significant level throughout the study in ISR patients, whereas IL-6 levels had normalized five days after the procedure in NISR patients. One day post-PCI serum IL-6 level was the most accurate marker for diagnosis of ISR, the area under the ROC curve being 0.927 (95%CI 0.878 - 0.977). The cut-off value for IL-6 to predict ISR was over 355.50 ng/L, with a sensitivity of 0.968 and a specificity of 0.865. There were no significant differences in frequencies of -572 genotype and allele between the two groups (P > 0.05). One day post-PCI IL-6 serum levels in patients with the G allele was significantly higher than in patients without the G allele ((366.99 ± 49.37) ng/L vs. (347.20 ± 55.30) ng/L, P < 0.05). In the ISR group, one day post-PCI serum levels of IL-6 in patients with the G allele was also significantly higher than that in patients without the G allele ((405.67 ± 26.56) ng/L vs. (375.69 ± 38.81) ng/L, P < 0.05). Multivariate Logistic regression analysis revealed positive correlations between male gender, one day post-PCI serum levels of IL-6, the pre-PCI degree of stenosis, the length of the target lesion stenosis, and restenosis; and there were negative correlations between the stent diameter, the diameter of the reference vessel before stent implantation and restenosis. CONCLUSIONS IL-6 is an early post-PCI inflammatory cytokine, and one day post-PCI serum IL-6 level is an independent risk factor for restenosis. The frequencies of IL-6 gene -572 genotype and allele are not different between patients with and without ISR in a Chinese Tianjin Han population, but carrying the IL-6 -572G allele is likely to increase an individuals susceptibility to ISR by promoting serum IL-6 levels.Background: Propofol is an anesthetic drug with a very attractive pharmacokinetic profile, which makes it the induction agent of choice, especially in day-case surgery. Data on its potential proarrhythmic effects in patients with Brugada syndrome (BS) patients are still lacking. The aim of our study was to investigate whether a single dose of propofol triggered any adverse events in consecutive high-risk patients with BS.Intact heart muscles are believed to contract synchronously to produce maximum effective work at a minimum energy cost. Temporal correlation coefficients between the left ventricular volume and muscle contraction were introduced to assess the synchronicity of left ventricular contraction (synchronous contraction index, SCI), and applied to eight normal volunteers. Area-contraction and length-shortening parallel to and perpendicular to the long axis were computed from electrocardiogram (ECG)-gated single-photon emission computed tomographies (SPECT) using a homemade computer programme. The cardiac wall was divided into nine segments, and the average values of accumulation of perfusion agents, amplitude of contraction and SCI were obtained in each segment. The area-SCI was 91.4% +/- 4.3% and relatively uniform over the whole cardiac wall (p = 0.014, analysis of variance (ANOVA)), whereas the accumulation and amplitude of contraction varied significantly in different segments (p < 0.0001, ANOVA). This study suggested that in normal subjects the myocardial contraction was synchronous, and that the amplitude of contraction was not spatially uniform.

Disruption of sarcolemmal dystrophin and β-dystroglycan may be a potential mechanism for myocardial dysfunction in severe sepsis

Evidence from our laboratory has shown alterations in myocardial structure in severe sepsis/septic shock. The morphological alterations are heralded by sarcolemmal damage, characterized by increased plasma membrane permeability caused by oxidative damage to lipids and proteins. The critical importance of the dystrophin-glycoprotein complex (DGC) in maintaining sarcolemmal stability led us to hypothesize that loss of dystrophin and associated glycoproteins could be involved in early increased sarcolemmal permeability in experimentally induced septic cardiomyopathy.