Sudden cardiac death in infiltrative cardiomyopathies: sarcoidosis, scleroderma, amyloidosis, hemachromatosis

Multifaceted roles of neutrophils in cardiac disease

Neutrophils, the most abundant leukocytes in human blood, have long been recognized as critical first responders in the innate immune system's defense against pathogens. Some of the more notable innate antimicrobial properties of neutrophils include generation of superoxide free radicals like myeloperoxidase, production of proteases that reshape the extracellular matrix allowing for easier access to infected tissues, and release of neutrophil extracellular traps, extruded pieces of DNA that ensnare bacterial and fungi. These mechanisms developed to provide neutrophils with a vast array of specialized functions to provide the host defense against infection in an acute setting. However, emerging evidence over the past few decades has revealed a far more complex and nuanced role for these neutrophil-driven processes in various chronic conditions, particularly in cardiovascular diseases. The pathophysiology of cardiac diseases involves a complex interplay of hemodynamic, neurohumoral, and inflammatory factors. Neutrophils, as key mediators of inflammation, contribute significantly to this intricate network. Their involvement extends far beyond their classical role in pathogen clearance, encompassing diverse functions that can both exacerbate tissue damage and contribute to repair processes. Here, we consider the contributions of neutrophils to myocardial infarction, heart failure, cardiac arrhythmias, and nonischemic cardiomyopathies. Understanding these complex interactions is crucial for developing novel therapeutic strategies aimed at modulating neutrophil functions in these highly morbid cardiac diseases.

Neurological, cardiac, musculoskeletal, and renal manifestations of scleroderma along with insights into its genetics, pathophysiology, diagnostic, and therapeutic updates

Background

Scleroderma, also referred to as systemic sclerosis, is a multifaceted autoimmune condition characterized by abnormal fibrosis and impaired vascular function. Pathologically, it encompasses the persistent presence of inflammation, abnormal collagen buildup, and restructuring of blood vessels in various organs, resulting in a wide range of clinical symptoms. This review incorporates the most recent scientific literature on scleroderma, with a particular emphasis on its pathophysiology, clinical manifestations, diagnostic approaches, and treatment options.

Methodology

A comprehensive investigation was carried out on numerous databases, such as PubMed, MEDLINE, Scopus, Web of Science, and Google Scholar, to collect pertinent studies covering diverse facets of scleroderma research.

Results

Scleroderma presents with a range of systemic manifestations, such as interstitial lung disease, gastrointestinal dysmotility, Raynaud's phenomenon, pulmonary arterial hypertension, renal complications, neurological symptoms, and cardiac abnormalities. Serological markers, such as antinuclear antibodies, anti-centromere antibodies, and anti-topoisomerase antibodies, are important for classifying diseases and predicting their outcomes.

Discussion

The precise identification of scleroderma is crucial for promptly and correctly implementing effective treatment plans. Treatment approaches aim to improve symptoms, reduce complications, and slow down the progression of the disease. An integrated approach that combines pharmacological agents, including immunosuppressants, endothelin receptor antagonists, and prostanoids, with nonpharmacological interventions such as physical and occupational therapy is essential for maximizing patient care.

Conclusion

Through the clarification of existing gaps in knowledge and identification of emerging trends, our goal is to improve the accuracy of diagnosis, enhance the effectiveness of therapeutic interventions, and ultimately enhance the overall quality of life for individuals suffering from scleroderma. Ongoing cooperation and creative research are necessary to advance the field and achieve improved patient outcomes and new therapeutic discoveries.

Licochalcone a improves cardiac functions after ischemia-reperfusion via reduction of ferroptosis in rats

Myocardial ischemia-reperfusion (I/R) injury triggers several cell death types, including apoptosis, autophagy, and ferroptosis. Licochalcone A (LCA), a natural flavonoid compound isolated from the root of Glycyrrhiza glabra, has been demonstrated to exert potential pharmacological benefits, such as antioxidant, antitumor, and anti-inflammatory activities. The present study aimed to investigate the involvement of ferroptosis in the pathogenesis of I/R and determine whether LCA can inhibit ferroptosis to prevent the myocardial I/R injury in rats. The effects of LCA on myocardial I/R injury were detected by examining the left ventricular-developed pressure and triphenyltetrazolium chloride staining. We conducted Western blotting analyses, ELISA assay, and quantitative real-time PCR to determine the levels of ferroptosis-related molecules. To demonstrate the cardioprotective effect of LCA in vitro, H9c2 and primary neonatal rat cardiomyocytes were co-treated with ferroptosis inducers (erastin, RSL3, or Fe-SP) and LCA for 16 and 24 h. Our ex vivo study showed that LCA increased the cardiac contractility, and reduced the infarct volume and ferroptosis-related biomarkers in rat hearts after I/R. Moreover, LCA reduced the levels of ferroptosis inducers-induced reactive oxygen species generation, lipid peroxidation, and ferroptosis-related biomarkers in cultured H9c2 cells and cardiomyocytes. LCA also reduced the Fe-SP-increased nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 protein levels in cultured cardiomyocytes. In the present study, we showed that the LCA-induced cardioprotective effects in attenuating the myocardial I/R injury were correlated with ferroptosis regulation, and provided a possible new therapeutic strategy for prevention or therapy of the myocardial I/R injury.

Trends in the Prevalence of Infiltrative Cardiomyopathy Among Patients With in-Hospital Cardiac Arrest

Sarcoidosis, amyloidosis, hemochromatosis and scleroderma are the most forms of infiltrative/nonischemic cardiomyopathy (NICM) associated with sudden cardiac death. In patients who undergo in-hospital cardiac arrest, a high index of suspicion is required to rule out NICM as an underlying contributor. We aimed to analyze the prevalence of NICM among patients with in-hospital cardiac arrest and identify factors associated with increased mortality. We analyzed data from the National Inpatient Sample, and identified patients who were hospitalized across 10 years from 2010 to 2019 with a diagnosis of cardiac arrest and NICM. The total number of patients with in-hospital cardiac arrest was 19,34,260. The total number with NICM was 14,803 (0.77%). Mean age was 63 years. Overall prevalence of NICM across the years ranged between 0.75% to 0.9%, with a significant temporal increase (P < 0.01). Incidence of in-hospital mortality ranged between 61% to 76% for females and 30% to 38% for males. The following comorbidities were more prevalent in patients with NICM than those without: heart failure, chronic obstructive pulmonary disease (COPD), chronic kidney disease, anemia, malignancy, coagulopathy, ventricular tachycardia, acute kidney injury and stroke. The following factors were independent predictors of in-hospital mortality-age, female gender, Hispanic race, history of COPD and presence of malignancy (P = 0.042). The prevalence of infiltrative cardiomyopathy in patients with in-hospital cardiac arrest is increasing. Females, older patients and Hispanic population are at an increased risk of mortality. Sex and race-based disparities in the prevalence of NICM in patients with in-hospital cardiac arrest is an area of further research.

Sudden Onset Iron Overload Cardiomyopathy After Liver Transplantation

Iron overload cardiomyopathy has been described in patients who develop acute heart failure after liver transplantation but few reports of this are available. We present a case of a patient with end-stage liver disease who underwent a deceased donor liver transplantation and developed acute onset systolic heart failure with reduced left ventricular ejection fraction. A cardiac magnetic resonance image demonstrated late gadolinium enhancement with diffuse enhancement globally and T1 mapping with severely decreased pre-contrast T1 values suggesting iron overload cardiomyopathy. The patient was treated with iron chelating therapy as well as heart failure guideline-directed medical therapy with subsequent improvement in cardiac function on follow-up magnetic resonance images. Despite our patient's diagnosis of iron overload cardiomyopathy, her iron studies showed normal serum iron and ferritin levels and no evidence of hepatic iron deposition in the transplanted liver.

Arrhythmias and Conduction Disturbances in Patients with Systemic Sclerosis—A Systematic Literature Review

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and internal organ fibrosis and microvascular impairment, which can affect major organs, including the heart. Arrhythmias are responsible for approximately 6% of deaths in patients with SSc, and mainly occur due to myocardial fibrosis, which causes electrical inhomogeneity. The aim of this study was to determine the frequency of arrhythmias and conduction disturbances in SSc cohorts, and to identify the characteristics and risk factors associated with the occurrence of dysrhythmias in patients with SSc. A systematic literature review using PubMed, Embase, Web of Science and Scopus databases was performed. Full-text articles in English with arrhythmias as the main topic published until 21 April 2022 were included. Most prevalent arrhythmias were premature supraventricular and ventricular contractions, while the most frequent conduction disturbance was represented by right bundle branch block (RBBB). Elevated concentrations of N-terminal prohormones of brain natriuretic peptides (NT-pro BNP) were associated with numerous types of atrial and ventricular arrhythmias, and with the occurrence of RBBB. A lower value of the turbulence slope (TS) emerged as an independent predictor for ventricular arrhythmias. In conclusion, dysrhythmias are frequent in SSc cohorts. Paraclinical and laboratory parameters are useful instruments that could lead to early diagnosis in the course of the disease.

Cardiovascular manifestations in hospitalized patients with hemochromatosis in the United States

BACKGROUND

Heart complications are the main cause of morbidity and mortality in hemochromatosis, but the liver is the main site for iron deposition in these patients. Large multicenter studies have described cardiovascular (CV) manifestations in patients with secondary hemochromatosis. However, the overall prevalence and risk of CV manifestations in patients with hemochromatosis at the population level are unknown.

OBJECTIVE

To examine the prevalence and risk of CV manifestations in patients with hemochromatosis.

METHODS

A retrospective cohort from the National Inpatient Sample database between 2012 and 2014 was studied. We identified hemochromatosis using ICD-9-CM diagnostic codes. CV manifestations were defined by the presence of conduction disorders, arrhythmias, congestive heart failure (CHF), pulmonary hypertension, and non-ischemic cardiomyopathy (NISCM).

RESULTS

Of the 63,846,188 weighted hospitalizations that met the inclusion criteria, 64,590 (0.1%) had hemochromatosis and 13,200,000 (20.7%) had one or more CV manifestations. Of those with hemochromatosis, 5.3% had primary and 94.7% had secondary hemochromatosis. 27.8% of all hemochromatosis patients had one or more CV manifestations, 16% cardiac arrhythmias, 10.6% supraventricular arrhythmias (SVA), 0.8% ventricular arrhythmias, 9.3% CHF, 7.4% pulmonary hypertension, 4.2% NISCM, 2% conduction disorders, and 0.4% cardiac arrest. SVA (14.6% vs 10.4%, P < 0.001) was more prevalent in primary hemochromatosis compared to secondary while pulmonary hypertension (7.7% vs 2.6%, P < 0.001) was more prevalent in secondary hemochromatosis compared to primary. In multivariate modelling, only the adjusted odds of composite CV manifestations (odds ratio [OR] 1.24, 95% confidence interval [CI]: 1.03-1.48, P < 0.05) and SVA (OR 1.59, 95% CI: 1.28-1.96, P < 0.001) were significantly higher in patients with primary hemochromatosis compared with patients without hemochromatosis. In patients with secondary hemochromatosis, the adjusted odds of composite CV manifestations (OR 1.84, 95% CI: 1.74-1.95, P < 0.001), CHF (OR 1.46, 95% CI: 1.35-1.57, P < 0.001), conduction disorder (OR 1.52, 95% CI: 1.33-1.73, P < 0.001), pulmonary hypertension (OR 4.43, 95% CI: 3.97-4.94, P < 0.001), SVA (OR 1.39, 95% CI: 1.29-1.48, P < 0.001), and NISCM (OR 1.98, 95% CI: 1.79-2.20, P < 0.001) were significantly higher compared with patients without hemochromatosis.

CONCLUSION

Supraventricular arrhythmias, congestive heart failure, and pulmonary hypertension were the most common CV disorders in hemochromatosis patients. Risk-adjusted burden of supraventricular arrhythmias was significantly higher in primary and secondary hemochromatosis while patients with secondary hemochromatosis had a higher risk of congestive heart failure, pulmonary hypertension, conduction disorders, and non-ischemic cardiomyopathy.

Updating the Risk Stratification for Sudden Cardiac Death in Cardiomyopathies: The Evolving Role of Cardiac Magnetic Resonance Imaging. An Approach for the Electrophysiologist

The prevention of sudden cardiac death (SCD) in cardiomyopathies (CM) remains a challenge. The current guidelines still favor the implantation of devices for the primary prevention of SCD only in patients with severely reduced left ventricular ejection fraction (LVEF) and heart failure (HF) symptoms. The implantation of an implantable cardioverter-defibrillator (ICD) is a protective barrier against arrhythmic events in CMs, but the benefit does not outweigh the cost in low risk patients. The identification of high risk patients is the key to an individualized prevention strategy. Cardiac magnetic resonance (CMR) provides reliable and reproducible information about biventricular function and tissue characterization. Furthermore, late gadolinium enhancement (LGE) quantification and pattern of distribution, as well as abnormal T1 mapping and extracellular volume (ECV), representing indices of diffuse fibrosis, can enhance our ability to detect high risk patients. CMR can also complement electro-anatomical mapping (EAM), a technique already applied in the risk evaluation and in the ventricular arrhythmias ablation therapy of CM patients, providing a more accurate assessment of fibrosis and arrhythmic corridors. As a result, CMR provides a new insight into the pathological substrate of CM. CMR may help identify high risk CM patients and, combined with EAM, can provide an integrated evaluation of scar and arrhythmic corridors in the ablative therapy of ventricular arrhythmias.

Electrocardiographic markers for the prediction of ventricular arrhythmias in patients with systemic sclerosis

SSc is an autoimmune disease characterized by microvascular damage, endothelial dysfunction and fibrosis of the skin and the internal organs. Cardiac manifestation in patients with SSc is one of the major organ involvements. Approximately 20% of SSc patients suffer from primary cardiovascular disease and another 20% may have secondary cardiac involvement. Although cardiac arrhythmias are mostly linked to myocardial fibrosis, atrioventricular conduction abnormalities are secondary to the fibrosis of the pulse conduction system. Despite the severe consequences of ventricular rhythm disturbances in patients with SSc, the exact role of electrocardiographic markers in the prediction of these arrhythmias has not yet been clearly elucidated. Therefore, the question is whether certain ECG parameters reflecting ventricular repolarization may help to recognize scleroderma patients with increased risk for ventricular arrhythmias and sudden cardiac death.

Development and validation of the Scleroderma Clinical Trials Consortium Damage Index (SCTC-DI): a novel instrument to quantify organ damage in systemic sclerosis

OBJECTIVE

We sought to develop the first Damage Index (DI) in systemic sclerosis (SSc).

METHODS

The conceptual definition of 'damage' in SSc was determined through consensus by a working group of the Scleroderma Clinical Trials Consortium (SCTC). Systematic literature review and consultation with patient partners and non-rheumatologist experts produced a list of potential items for inclusion in the DI. These steps were used to reduce the items: (1) Expert members of the SCTC (n=331) were invited to rate the appropriateness of each item for inclusion, using a web-based survey. Items with >60% consensus were retained; (2) Using a prospectively acquired Australian cohort data set of 1568 patients, the univariable relationships between the remaining items and the endpoints of mortality and morbidity (Physical Component Summary score of the Short Form 36) were analysed, and items with p<0.10 were retained; (3) using multivariable regression analysis, coefficients were used to determine a weighted score for each item. The DI was externally validated in a Canadian cohort.

RESULTS

Ninety-three (28.1%) complete survey responses were analysed; 58 of 83 items were retained. The univariable relationships with death and/or morbidity endpoints were statistically significant for 22 items, with one additional item forced into the multivariable model by experts due to clinical importance, to create a 23-item weighted SCTC DI (SCTC-DI). The SCTC-DI was predictive of morbidity and mortality in the external cohort.

CONCLUSIONS

Through the combined use of consensus and data-driven methods, a 23-item SCTC-DI was developed and retrospectively validated.

Electrocardiographic Findings in Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune connective tissue disease which affects various tissues and organs, including skin, lungs, kidneys, gastrointestinal tract and cardiovascular system. Cardiac involvement is the most commonly recognized problem and a significant cause of morbidity. Abnormal ECG is present in 25-75% of patients with SSc and is considered to be an independent predictor of mortality. It is known that the supraventricular arrhythmias are considered as more common in SSc patients, occurring in about two-thirds of the cases, and more often than ventricular tachyarrhythmias. It has been established that right bundle branch block is associated with an increased risk of mortality and that it is an independent predictor of mortality, and should be considered as a marker of the severity of the disease in SSc. Th e prolonged QTc interval is an independent risk factor for a sudden cardiac death reflecting the instability of repolarization and predisposing the onset of cardiac arrhythmias.The prognosis of the disease depends on the SSc subtype and the involvement of internal organs. SSc is a lifelong disease and cannot be cured, but knowing that cardiac dysfunction significantly worsens the prognosis, early detection of cardiac complications and appropriate therapy can influence its progress and improve the patients’ quality of life.

Prospects of using cardiovascular magnetic resonance in the identification of arrhythmogenic substrate in autoimmune rheumatic diseases

Sudden cardiac death (SCD) is due to ventricular tachycardia/fibrillation (VT/VF) and may occur with or without any structural or functional heart disease. The presence of myocardial edema, ischemia and/or fibrosis plays a crucial role in the pathogenesis of VT/VF, irrespective of the pathophysiologic background of the disease. Specifically, in autoimmune rheumatic diseases (ARDs), various entities such as myocardial/vascular inflammation, ischemia and fibrosis may lead to VT/VF. Furthermore, autonomic dysfunction, commonly found in ARDs, may also contribute to SCD in these patients. The only non-invasive, radiation-free imaging modality that can perform functional assessment and tissue characterization is cardiovascular magnetic resonance (CMR). Due to its capability to detect and quantify edema, ischemia and fibrosis in parallel with ventricular function assessment, CMR has the great potential to identify ARD patients at high risk for VT/VF, thus influencing both cardiac and anti-rheumatic treatment and modifying perhaps the criteria for implantation of cardioverter defibrillators.

Digoxin use in systemic light-chain (AL) amyloidosis: contra-indicated or cautious use?

AIM

Digoxin is considered contraindicated in light-chain (AL) amyloidosis, given reports of increased toxicity published 30-50 years ago. We sought to determine the frequency of digoxin toxicity in patients with AL.

METHODS

We identified 107 patients with AL amyloidosis who received digoxin between 2000 and 2015.

RESULTS

The median age was 65 and the median digoxin dose and estimated glomerular filtration rate were 0.125 mg/d and 55 ml/min/1.73 m², respectively. Digoxin dose was reduced in 16% of the patients, mainly due to high serum drug concentration or worsening renal function. The median duration of therapy was 5 months, with half of the patients stopping treatment, primarily due to physician preference. Significant arrhythmias developed in 11% of patients, almost exclusively in newly diagnosed patients. Arrhythmias presented as terminal events in five patients; four with bradycardia followed by pulseless electrical activity (PEA) with ventricular tachycardia/fibrillation (VT/VF) during resuscitation; all patients had acute renal failure and severe, decompensated heart failure. One patient had ventricular tachycardia as a terminal event. Only one patient was treated with digoxin antibody therapy.

CONCLUSIONS

Digoxin may be cautiously utilized in AL amyloidosis patients. We suggest its use in lower doses and frequent drug concentration monitoring along with close monitoring of electrolytes and renal function. Nonetheless, toxicity at low serum concentration cannot be excluded due to potential for toxic concentration at the tissue level and should be taken under consideration when prescribing digoxin for these patients. Studies with higher-level evidence are needed to confirm these findings.

Hemochromatosis as Junctional Tachycardia, a Rare Presentation

We present here a 45-year-old male with no past medical problem who presented with palpitations. He was found to have supraventricular tachycardia intractable to medical therapy. Later his rhythm converted to junctional tachycardia. Further workup revealed hemochromatosis to be primary etiology causing the arrhythmia. The low index of suspicion for additional workup is key to diagnosis and successful outcome.

[Sudden cardiac death: A better understanting for a better prevention]

Sudden cardiac death is defined as a natural and unexpected death, in a previous apparently healthy individual. It represents a major public health issue, with up to 50% of the cardiovascular mortality. Using data from the Paris Sudden Death Expertise Centre registry, this article summarises the main cardiovascular abnormalities associated with sudden cardiac death, the different preventives approaches, and provides a systematic diagnostic approach.

The Assessment of Tp-e Interval and Tp-e/QT Ratio in Patients With Systemic Sclerosis

Objectives

This study aims to investigate ventricular repolarization using T-peak to T-end (Tp-e) intervals and Tp-e/QT ratios in patients with systemic sclerosis (SSc).

Patients and methods

Totally 65 patients (8 males, 57 females; mean age 49.8 years; range 20 to 77 years) with SSc and 63 control subjects (8 males, 55 females; mean age 49.3 years; range 20 to 77 years) were enrolled. Tp-e intervals, Tp-e/QT, and Tp-e/corrected QT (QTc) ratios were measured from the 12-lead electrocardiogram.

Results

Tp-e intervals, QT intervals, QTc intervals, Tp-e/QT, and Tp-e/QTc ratios were significantly higher in patients with SSc than control subjects (all p<0.01). There was no difference between patients with diffuse and limited cutaneous SSc in terms of electrocardiogram and echocardiographic findings. Correlation analysis revealed no correlation between Tp-e intervals, Tp-e/QT, and Tp-e/QTc ratios with disease duration and anti-Sjögren's syndrome antigen A antibody levels in patients with SSc (all p>0.05).

Conclusion

Our study showed that Tp-e intervals, Tp-e/QT, and Tp-e/QTc ratios were increased in patients with SSc than control subjects. The increased frequency of ventricular arrhythmias can be clarified by increased indexes of ventricular repolarization parameters in patients with SSc.

Cardiac manifestations in systemic sclerosis

Primary cardiac involvement, which develops as a direct consequence of systemic sclerosis (SSc), may manifest as myocardial damage, fibrosis of the conduction system, pericardial and, less frequently, as valvular disease. In addition, cardiac complications in SSc may develop as a secondary phenomenon due to pulmonary arterial hypertension and kidney pathology. The prevalence of primary cardiac involvement in SSc is variable and difficult to determine because of the diversity of cardiac manifestations, the presence of subclinical periods, the type of diagnostic tools applied, and the diversity of patient populations. When clinically manifested, cardiac involvement is thought to be an important prognostic factor. Profound microvascular disease is a pathognomonic feature of SSc, as both vasospasm and structural alterations are present. Such alterations are thought to predict macrovascular atherosclerosis over time. There are contradictory reports regarding the prevalence of atherosclerosis in SSc. According to some authors, the prevalence of atherosclerosis of the large epicardial coronary arteries is similar to that of the general population, in contrast with other rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the level of inflammation in SSc is inferior. Thus, the atherosclerotic process may not be as aggressive and not easily detectable in smaller studies. Echocardiography (especially tissue Doppler imaging), single-photon emission computed tomography, magnetic resonance imaging and cardiac computed tomography are sensitive techniques for earlier detection of both structural and functional scleroderma-related cardiac pathologies. Screening for subclinical cardiac involvement via modern, sensitive tools provides an opportunity for early diagnosis and treatment, which is of crucial importance for a positive outcome.

Pediatric cardiomyopathies: causes, epidemiology, clinical course, preventive strategies and therapies

Pediatric cardiomyopathies, which are rare but serious disorders of the muscles of the heart, affect at least one in every 100,000 children in the USA. Approximately 40% of children with symptomatic cardiomyopathy undergo heart transplantation or die from cardiac complications within 2 years. However, a significant number of children suffering from cardiomyopathy are surviving into adulthood, making it an important chronic illness for both pediatric and adult clinicians to understand. The natural history, risk factors, prevalence and incidence of this pediatric condition were not fully understood before the 1990s. Questions regarding optimal diagnostic, prognostic and treatment methods remain. Children require long-term follow-up into adulthood in order to identify the factors associated with best clinical practice including diagnostic approaches, as well as optimal treatment approaches. In this article, we comprehensively review current research on various presentations of this disease, along with current knowledge about their causes, treatments and clinical outcomes.

Spontaneously occurring restrictive nonhypertrophied cardiomyopathy in domestic cats: a new animal model of human disease

BACKGROUND

Spontaneously occurring small animal models of myocardial disease, closely resembling the human condition, have been reported for hypertrophic cardiomyopathy (in cats) and arrhythmogenic right ventricular cardiomyopathy (in cats and boxer dogs). Nonhypertrophied restrictive cardiomyopathy (RCM) is a well-recognized but relatively uncommon primary heart muscle disease causing substantial morbidity in humans. We describe RCM occurring in felines here as a potential model of human disease.

METHODS

We used two-dimensional and Doppler echocardiography to define morphologic and functional features of RCM in 35 domestic cats (25 male; 10±4 years old) presenting to a subspecialty veterinary clinic. Ten underwent complete necropsy examination. Echocardiographic parameters of diastolic filling were compared to those in 41 normal controls.

RESULTS

The 35 cats presented with congestive heart failure (n=32), lethargy (n=2), or syncope (n=1), associated with thromboembolism in 5 and supraventricular tachyarrhythmias in 8. During an average 4.4-year follow-up period, 18 died or were euthanized due to profound heart failure, and 3 died suddenly; survival from clinical presentation to death was 0.1 to 52 months. Echocardiographic and necropsy examination showed biatrial enlargement, nondilated ventricular chambers, and normal wall thicknesses and atrioventricular valves. Histopathology demonstrated disorganized myocyte architecture and patchy replacement myocardial fibrosis. Pulsed Doppler demonstrated restrictive physiology with increased early (E) mitral filling velocity (1.1±0.3 m/s) and peak E to peak late (A) flow ratios (4.3±1.2), reduced A filling velocity (0.3±0.1 m/s), and shortened mitral deceleration time (40.7±9.3 ms; all P<.001 vs. controls), with preserved left ventricular systolic function.

CONCLUSIONS

A primary myocardial disease occurring spontaneously in domestic cats is remarkably similar to restrictive nondilated and nonhypertrophied cardiomyopathy in man and represents another potential animal model for human disease.

Implantable cardioverter defibrillator to prevent sudden cardiac death in a patient with systemic sclerosis: A clinical case

Ventricular arrhythmias are frequent in patients with systemic sclerosis and may result in sudden cardiac death. We report the case of a patient with systemic sclerosis and recent syncopes in whom induction of unstable sustained ventricular tachycardia of 2 different morphologies accompanied by syncopal event was demonstrated at the electrophysiological study. He was then implanted a 3rd generation implantable cardioverter defibrillator and remained thereafter asymptomatic. We suggest that aggressive testing is warranted in systemic sclerosis patients with suspected malignant arrhythmias to identify candidates for defibrillator implantation and prevent sudden deaths.

Inherited arrhythmia syndromes

Inherited arrhythmia syndromes are an important contributor to sudden death in children and adults. These cardiac ‘channelopathies’ lead to arrhythmias in a structurally normal myocardium and are often variable in penetrance and expressivity. The clinical features and management options for the four major channelopathies are outlined.

Systemic sclerosis and the heart: current diagnosis and management

PURPOSE OF REVIEW

When present clinically, cardiac involvement in systemic sclerosis (SSc) is a major risk factor for death. It is therefore vitally important to understand the epidemiology, screening, diagnosis, and treatment of the cardiac manifestations of SSc.

RECENT FINDINGS

The epidemiology of cardiac involvement in SSc has been the subject of several recent studies. Most importantly, the prevalence of overt left ventricular (LV) systolic dysfunction and its associated risk factors have been defined, and patients with diffuse cutaneous SSc appear to be most susceptible to direct cardiac involvement. From a diagnostic and screening standpoint, tissue Doppler echocardiography and natriuretic peptides have provided fresh insight into subclinical cardiac dysfunction in SSc. Newer techniques, such as speckle-tracking echocardiography, diffuse myocardial fibrosis imaging, and absolute myocardial perfusion imaging, are poised to further advance our knowledge. Lastly, there is now consistent observational data to suggest a central role for calcium channel blockers in the treatment of microvascular ischemia and prevention of overt LV systolic dysfunction, although randomized controlled trials are lacking.

SUMMARY

Recent studies have improved our understanding of cardiac involvement in SSc. Nevertheless, key questions regarding screening, diagnosis, and treatment remain. Novel diagnostic techniques and multicenter studies should yield important new data, which will hopefully ultimately result in improved outcomes.

Anesthetic management of vaginal delivery in a parturient with hemochromatosis induced end-organ failure

The vast majority of females affected by hemochromatosis are asymptomatic during childbearing years. We were able to provide effective obstetric anesthesia care to a 35-year-old woman with severe hemochromatosis. She had systolic heart failure with a left ventricular ejection fraction of 15%, severe pulmonary hypertension, mitral insufficiency, a history of ventricular tachycardia, cirrhosis, obstructive sleep apnea, gestational diabetes, and severe scoliosis. A multidisciplinary approach was used to stabilize her heart failure and prepare her for childbirth. An arterial line and epidural analgesic were placed before induction of labor. Vaginal delivery was accomplished with passive decent of the fetus and forceps assistance. We discuss hemochromatosis and its implications for the parturient.

Iron overload cardiomyopathy: better understanding of an increasing disorder

The prevalence of iron overload cardiomyopathy (IOC) is increasing. The spectrum of symptoms of IOC is varied. Early in the disease process, patients may be asymptomatic, whereas severely overloaded patients can have terminal heart failure complaints that are refractory to treatment. It has been shown that early recognition and intervention may alter outcomes. Biochemical markers and tissue biopsy, which have traditionally been used to diagnose and guide therapy, are not sensitive enough to detect early cardiac iron deposition. Newer diagnostic modalities such as magnetic resonance imaging are noninvasive and can assess quantitative cardiac iron load. Phlebotomy and chelating drugs are suboptimal means of treating IOC; hence, the roles of gene therapy, hepcidin, and calcium channel blockers are being actively investigated. There is a need for the development of clinical guidelines in order to improve the management of this emerging complex disease.

Heart rate turbulence impairment and ventricular arrhythmias in patients with systemic sclerosis

BACKGROUND

Arrhythmias, conduction disturbances, and cardiac autonomic nervous system dysfunction are the most frequent cardiovascular complications in systemic sclerosis (scleroderma). The aim of the study was to assess heart rate turbulence (HRT) in systemic sclerosis patients and to identify the relationship between HRT and occurrence of arrhythmias.

METHODS

Forty-five patients with scleroderma (aged 54.6 +/- 14.7 years) and 30 healthy sex- and age-matched subjects were examined. In addition to routine studies, 24-hour Holter monitoring with assessment of HRT was performed.

RESULTS

As compared to controls, HRT was significantly impaired in systemic sclerosis patients. Abnormal HRT defined as turbulence onset (TO) > or =0.0% and/or turbulence slope (TS) < or =2.5 ms/RR (ms/RR interval) was found in 19 (42%) scleroderma patients and in no members of the control group. Serious ventricular arrhythmias Lown class IV (VA-LownIV), for example, couplets and/or nonsustained ventricular tachycardias, were observed in 16 (36%) scleroderma patients. The median value of TS was significantly lower in systemic sclerosis patients with VA-LownIV than in patients without VA-LownIV (3.68 vs 7.00 ms/RR, P = 0.02). The area under curve of ROC analysis for prediction of VA-LownIV was 0.72 (95% confidence interval [CI] 0.56-0.87) and revealed that TS <9.0 ms/RR was associated with VA-Lown IV occurrence, with sensitivity of 93.7% and specificity of 44.8%. Univariate and multivariate analyses confirmed that lower values of TS were associated with VA-LownIV occurrence (odds ratio 1.52, 95% CI 1.09-2.12, P = 0.01).

CONCLUSIONS

Patients with systemic sclerosis are characterized by significant HRT impairment. Assessment of HRT and especially TS is useful in the identification of patients at risk for ventricular arrhythmias.

Protective effect of geranylgeranylacetone via enhancement of HSPB8 induction in desmin-related cardiomyopathy

Background

An arg120gly (R120G) missense mutation in HSPB5 (α-β-crystallin ), which belongs to the small heat shock protein (HSP) family, causes desmin-related cardiomyopathy (DRM), a muscle disease that is characterized by the formation of inclusion bodies, which can contain pre-amyloid oligomer intermediates (amyloid oligomer). While we have shown that small HSPs can directly interrupt amyloid oligomer formation, the in vivo protective effects of the small HSPs on the development of DRM is still uncertain.

Methodology/Principal Findings

In order to extend the previous in vitro findings to in vivo, we used geranylgeranylacetone (GGA), a potent HSP inducer. Oral administration of GGA resulted not only in up-regulation of the expression level of HSPB8 and HSPB1 in the heart of HSPB5 R120G transgenic (R120G TG) mice, but also reduced amyloid oligomer levels and aggregates. Furthermore, R120G TG mice treated with GGA exhibited decreased heart size and less interstitial fibrosis, as well as improved cardiac function and survival compared to untreated R120G TG mice. To address possible mechanism(s) for these beneficial effects, cardiac-specific transgenic mice expressing HSPB8 were generated. Overexpression of HSPB8 led to a reduction in amyloid oligomer and aggregate formation, resulting in improved cardiac function and survival. Treatment with GGA as well as the overexpression of HSPB8 also inhibited cytochrome c release from mitochondria, activation of caspase-3 and TUNEL-positive cardiomyocyte death in the R120G TG mice.

Conclusions/Significance

Expression of small HSPs such as HSPB8 and HSPB1 by GGA may be a new therapeutic strategy for patients with DRM.