Giant Left Ventricular Aneurysm With Dynamic Right Ventricular Compression and Subsequent End-Stage Heart Failure.

We report a case of a patient with a missed anterior myocardial infarction and associated ischemic cardiomyopathy. The patient had a massive true left ventricular aneurysm causing dynamic right ventricular compression, with associated cardiogenic shock, for which a heart transplantation was ultimately performed.

The importance of professional responsibility and fetal viability in the management of abortion.

In June 2022, the Dobbs v. Jackson Women's Health Organization Supreme Court decision ended the constitutional right to the professional practice of abortion throughout the United States. The removal of the constitutional right to abortion has significantly altered the practice of obstetricians and gynecologists across the US. It potentially increases risks to pregnant patients, leads to profound changes in how physicians can provide care, especially in states with strict bans or gestational limits to abortion, and has introduced personal challenges, including moral distress and injury as well as legal risks for patients and clinicians alike. The professional responsibility model is based on the ethical concept of medicine as a profession and has been influential in shaping medical ethics in the field of obstetrics and gynecology. It provides the framework for the importance of ethical and professional conduct in obstetrics and gynecology. Viability marks a stage where the fetus is a patient with a claim to access to medical care. By allowing unrestricted abortions past this stage without adequate justifications, such as those concerning the life and health of the pregnant individual, or in instances of serious fetal anomalies, the states may not be upholding the equitable ethical consideration owed to the fetus as a patient. Using the professional responsibility model, we emphasize the need for nuanced, evidence-based policies that allow abortion management prior to viability without restrictions and allow abortion after viability to protect the pregnant patient's life and health, as well as permitting abortion for serious fetal anomalies.

Addressing challenges related to the professional practice of abortion post-Roe.

The landmark Roe vs Wade Supreme Court decision in 1973 established a constitutional right to abortion. In June 2022, the Dobbs vs Jackson Women's Health Organization Supreme Court decision brought an end to the established professional practice of abortion throughout the United States. Rights-based reductionism and zealotry threaten the professional practice of abortion. Rights-based reductionism is generally the view that moral or ethical issues can be reduced exclusively to matters of rights. In relation to abortion, there are 2 opposing forms of rights-based reductionism, namely fetal rights reductionism, which emphasizes the rights for the fetus while disregarding the rights and autonomy of the pregnant patient, and pregnant patient rights reductionism, which supports unlimited abortion without regards for the fetus. The 2 positions are irreconcilable. This article provides historical examples of the destructive nature of zealotry, which is characterized by extreme devotion to one's beliefs and an intolerant stance to opposing viewpoints, and of the importance of enlightenment to limit zealotry. This article then explores the professional responsibility model as a clinically ethically sound approach to overcome the clashing forms of rights-based reductionism and zealotry and to address the professional practice of abortion. The professional responsibility model refers to the ethical and professional obligations that obstetricians and other healthcare providers have toward pregnant patients, fetuses, and the society at large. It provides a more balanced and nuanced approach to the abortion debate, avoiding the pitfalls of reductionism and zealotry, and allows both the rights of the woman and the obligations to pregnant and fetal patients to be considered alongside broader ethical, medical, and societal implications. Constructive and respectful dialogue is crucial in addressing diverse perspectives and finding common ground. Embracing the professional responsibility model enables professionals to manage abortion responsibly, thereby prioritizing patients' interests and navigating between absolutist viewpoints to find balanced ethical solutions.

Mechanical Resistance to Micro-Heart Tissue Contractility unveils early Structural and Functional Pathology in iPSC Models of Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy is the most common cause of sudden death in the young. Because the disease exhibits variable penetrance, there are likely nongenetic factors that contribute to the manifestation of the disease phenotype. Clinically, hypertension is a major cause of morbidity and mortality in patients with HCM, suggesting a potential synergistic role for the sarcomeric mutations associated with HCM and mechanical stress on the heart. We developed an in vitro physiological model to investigate how the afterload that the heart muscle works against during contraction acts together with HCM-linked MYBPC3 mutations to trigger a disease phenotype. Micro-heart muscle arrays (µHM) were engineered from iPSC-derived cardiomyocytes bearing MYBPC3 loss-of-function mutations and challenged to contract against mechanical resistance with substrates stiffnesses ranging from the of embryonic hearts (0.4 kPa) up to the stiffness of fibrotic adult hearts (114 kPa). Whereas MYBPC3 +/- iPSC-cardiomyocytes showed little signs of disease pathology in standard 2D culture, µHMs that included components of afterload revealed several hallmarks of HCM, including cellular hypertrophy, impaired contractile energetics, and maladaptive calcium handling. Remarkably, we discovered changes in troponin C and T localization in the MYBPC3 +/- µHM that were entirely absent in 2D culture. Pharmacologic studies suggested that excessive Ca 2+ intake through membrane-embedded channels, rather than sarcoplasmic reticulum Ca 2+ ATPase (SERCA) dysfunction or Ca 2+ buffering at myofilaments underlie the observed electrophysiological abnormalities. These results illustrate the power of physiologically relevant engineered tissue models to study inherited disease mechanisms with iPSC technology.

Counseling for the option of termination of pregnancy for severe fetal anomalies in light of the recent Supreme Court ruling to remove the constitutional right to an abortion.

A birth defect is a structural or chromosomal change present at birth that can affect almost any part or parts of the body. Birth defects can vary from mild to severe. On June 24, 2022, with its Dobbs v Jackson Women's Health Organization decision the Supreme Court of the United States overturned Roe v. Wade, removing the longstanding landmark 1973 ruling that secured a person's constitutional right to an abortion. With this decision individual states can now decide their own abortion laws. In about one-half of the states that continue the legality of pregnancy termination, the process of offering, discussing, and performing terminations of pregnancy remain the same as previously. In states where abortions are not legal, there will be conflicts between the law and the ethical responsibility of physicians to offer and discuss termination of pregnancy for severe anomalies.

Emerging methods to model cardiac ion channel and myocyte electrophysiology.

In the field of cardiac electrophysiology, modeling has played a central role for many decades. However, even though the effort is well-established, it has recently seen a rapid and sustained evolution in the complexity and predictive power of the models being created. In particular, new approaches to modeling have allowed the tracking of parallel and interconnected processes that span from the nanometers and femtoseconds that determine ion channel gating to the centimeters and minutes needed to describe an arrhythmia. The connection between scales has brought unprecedented insight into cardiac arrhythmia mechanisms and drug therapies. This review focuses on the generation of these models from first principles, generation of detailed models to describe ion channel kinetics, algorithms to create and numerically solve kinetic models, and new approaches toward data gathering that parameterize these models. While we focus on application of these models for cardiac arrhythmia, these concepts are widely applicable to model the physiology and pathophysiology of any excitable cell.

A Reinterpretation of the Relationship Between Persistent and Resurgent Sodium Currents.

The resurgent sodium current (INaR) activates on membrane repolarization, such as during the downstroke of neuronal action potentials. Due to its unique activation properties, INaR is thought to drive high rates of repetitive neuronal firing. However, INaR is often studied in combination with the persistent or non-inactivating portion of sodium currents (INaP). We used dynamic clamp to test how INaR and INaP individually affect repetitive firing in adult cerebellar Purkinje neurons. We learned INaR does not scale repetitive firing rates due to its rapid decay at subthreshold voltages, and that subthreshold INaP is critical in regulating neuronal firing rate. Adjustments to the Nav conductance model used in these studies revealed INaP and INaR can be inversely scaled by adjusting occupancy in the slow inactivated kinetic state. Together with additional dynamic clamp experiments, these data suggest the regulation of sodium channel slow inactivation can fine-tune INaP and Purkinje neuron repetitive firing rates.

Autonomy and Social Responsibility: The Post-Pandemic Challenge.

Over the last 80 years, a series of critical events has led to reconsideration of the basic premises of medical ethics. One of these events was the recognition of horrific medical experiments performed by German medical scientists in World War II concentration camps, resulting in intensified emphasis on a consent requirement, later understood as grounded in the bioethical principle of respect for autonomy, as well as on the moral accountability of the experimenter. Another important event that is forcing a reconsideration of respect for autonomy in medicine and health care is the COVID-19 pandemic. But this time the matter pulls in a different direction, from respect for autonomy to social responsibility, represented in problems as disparate as the wearing of masks, vaccination requirements, and equity in vaccine access and distribution. How can modern bioethics, in part a creature of the response to Nazi crimes, accommodate the intensified sensitivity about public health needs that has accompanied the shock of the pandemic? The responses of European medical ethics to the Nazi era provide tools for bioethics as it faces the challenge now at hand. This article uses historical context from postwar Europe to argue that, in light of the pandemic experience, respect for autonomy must systematically incorporate a commitment to social responsibility.

Is Russia's Research Ethics Culture Reliable?

The Russian invasion of Ukraine has led to the imposition of economic sanctions intended to isolate Russia from much of global commerce, which implicitly includes the medical research enterprise. The prospect of ongoing isolation of Russia's substantial research enterprise raises issues related to but distinct from the more familiar problem of corruption. In this paper, we identify reasons that the culture of research ethics in Russia may have been weak even before the war, contributing to hard questions about its future role in the global clinical research community.

Robust, Automated Analysis of Electrophysiology in Induced Pluripotent Stem Cell-Derived Micro-Heart Muscle for Drug Toxicity.

Drugs are often removed from clinical trials or market progression owing to their unforeseen effects on cardiac action potential and calcium handling. Induced pluripotent stem cell-derived cardiomyocytes and tissues fabricated from these cells are promising as screening tools for early identification of these potential cardiac liabilities. In this study, we describe an automated, open-source MATLAB-based analysis software for calculating cardiac action potentials and calcium transients from fluorescent reporters. We first identified the most robust manner in which to automatically identify the initiation point for action potentials and calcium transients in a user-independent manner, and used this approach to quantify the duration and morphology of these signals. We then demonstrate the software by assessing changes to action potentials and calcium transients in our micro-heart muscles after exposure to hydroxychloroquine, an antimalarial drug with known cardiac liability. Consistent with clinical observations, our system predicted mild action potential prolongation. However, we also observed marked calcium transient suppression, highlighting the advantage of testing multiple physiologic readouts in cardiomyocytes rather than relying on heterologous overexpression of single channels such as the human ether-a-go-go-related gene channel. This open-source software can serve as a useful, high-throughput tool for analyzing cardiomyocyte physiology from fluorescence imaging.

John Stuart Mill is relevant to COVID-19 vaccination in pregnancy today.

The scientific evidence about COVID-19 and pregnancy is conclusive: COVID-19 infections increase the risk of stillbirths and preterm births, and pregnant and postpartum patients are more likely to get severely ill with COVID-19 and die when compared with people who are not pregnant. Getting a COVID-19 vaccine protects from severe illness from COVID-19 and risk of death. COVID-19 vaccination is recommended for pregnant patients, those trying to conceive, and who are breastfeeding, or might become pregnant in the future. The justification for government involvement in public health measures that restrict personal liberty that we are so familiar with today emanated from a philosophical source at the same time as the progress in managing infectious disease. John Stuart Mill (1806-1873), an empiricist and a utilitarian, was not specifically addressing the ethics of public health in his classic On Liberty (1859), but his arguments have become the reference point for liberal democracies and public health measures. Mill was in search of a philosophical principle that could justify constraints on personal freedom. John Stuart Mill gives direct guidance to our approach supporting not only strong recommendations for pregnant patients to accept vaccinations against COVID-19 but also for those working in healthcare setting to be required to be vaccinated. This approach is respectful to our patient's liberty while doing all that's reasonable to protect them from harm. Based on our professional experience we recognize that some physicians and patients have fixed false beliefs. Physicians espousing fixed false beliefs against COVID-19 vaccines should be censured.

Creating Ion Channel Kinetic Models Using Cloud Computing.

Computational modeling of ion channels provides key insight into experimental electrophysiology results and can be used to connect channel dynamics to emergent phenomena observed at the tissue and organ levels. However, creation of these models requires substantial mathematical and computational background. This tutorial seeks to lower the barrier to creating these models by providing an automated pipeline for creating Markov models of an ion channel kinetics dataset. We start by detailing how to encode sample voltage-clamp protocols and experimental data into the program and its implementation in a cloud computing environment. We guide the reader on how to build a containerized instance, push the machine image, and finally run the routine on cluster nodes. While providing open-source code has become more standard in computational studies, this tutorial provides unprecedented detail on the use of the program and the creation of channel models, starting from inputting the raw experimental data. © 2022 Wiley Periodicals LLC. Basic Protocol: Creation of ion channel kinetic models with a cloud computing environment Alternate Protocol: Instructions for use in a standard high-performance compute cluster.

Intrinsic mechanisms in the gating of resurgent Na+ currents.

The resurgent component of the voltage-gated sodium current (INaR) is a depolarizing conductance, revealed on membrane hyperpolarizations following brief depolarizing voltage steps, which has been shown to contribute to regulating the firing properties of numerous neuronal cell types throughout the central and peripheral nervous systems. Although mediated by the same voltage-gated sodium (Nav) channels that underlie the transient and persistent Nav current components, the gating mechanisms that contribute to the generation of INaR remain unclear. Here, we characterized Nav currents in mouse cerebellar Purkinje neurons, and used tailored voltage-clamp protocols to define how the voltage and the duration of the initial membrane depolarization affect the amplitudes and kinetics of INaR. Using the acquired voltage-clamp data, we developed a novel Markov kinetic state model with parallel (fast and slow) inactivation pathways and, we show that this model reproduces the properties of the resurgent, as well as the transient and persistent, Nav currents recorded in (mouse) cerebellar Purkinje neurons. Based on the acquired experimental data and the simulations, we propose that resurgent Na+ influx occurs as a result of fast inactivating Nav channels transitioning into an open/conducting state on membrane hyperpolarization, and that the decay of INaR reflects the slow accumulation of recovered/opened Nav channels into a second, alternative and more slowly populated, inactivated state. Additional simulations reveal that extrinsic factors that affect the kinetics of fast or slow Nav channel inactivation and/or impact the relative distribution of Nav channels in the fast- and slow-inactivated states, such as the accessory Navß4 channel subunit, can modulate the amplitude of INaR.

Angiotensin II Type 1 Receptor Antibody-mediated Rejection Following Orthotopic Heart Transplant: A Single-center Experience.

BACKGROUND: Antibody-mediated rejection (AMR) following orthotopic heart transplant (OHT) causes significant morbidity and mortality. There are limited data on antibodies to the angiotensin II type 1 receptor antibody (AT1R-Ab) causing rejection following OHT. METHODS: This is a retrospective, single-center study that presents our 2-y experience with a series of 11 patients with evidence of nonspecific graft dysfunction and pathologic levels of AT1R-Ab. The clinical outcomes and treatments were compared to a group of 10 patients, also with evidence of nonspecific graft dysfunction, but who had nonsignificant AT1R-Ab titers. RESULTS: The mean age of the AT1R-Ab cohort was 52% and 73% were bridged to transplant with an left ventricular assist device. The average left ventricular ejection fraction at presentation was 45%, and most were not on an angiotensin receptor blocker (ARB). Endomyocardial biopsies in those with elevated AT1R-Ab levels frequently showed reactive endothelium/endocardium without C4d or intravascular CD68 staining. Ten patients (91%) were started on an ARB. Other therapies included plasmapheresis and IVIg (64%), with 4 patients also receiving rituximab. Most patients had symptom improvement, but minimal change in graft function at an average 6 mo of follow-up. CONCLUSIONS: The role of AT1R-Ab-mediated rejection in OHT recipients remains poorly understood. More than half of patients at our center who presented with graft dysfunction in the absence of acute cellular rejection or AMR were found to have elevated AT1R-Ab titers. Empiric AMR treatment in conjunction with ARB therapy may improve patient outcomes. Future studies are needed to better define the optimal treatment modalities for ATR1-Ab-mediated AMR.