Bradycardia, renal failure, atrioventricular (AV) blockade, shock, and hyperkalemia (BRASH) syndrome is an uncommon and relatively new entity that results from synergy between AV nodal blockade and renal failure leading to a vicious cycle of hypotension, profound bradycardia, and hyperkalemia. Classically, this syndrome is seen in a patient taking AV nodal blocking agents and underlying renal insufficiency. We are presenting a case of a 76-year-old female with a medical history of essential hypertension and non-insulin-dependent type 2 diabetes mellitus presented to the emergency room with a chief complaint of dizziness and generalized weakness. The patient was taking metoprolol tartrate 200 mg twice a day, amlodipine 10 mg once daily, clonidine 0.1 mg twice daily, enalapril 20 mg twice daily, and Metformin 750 mg twice daily. On presentation, the patient had symptomatic bradycardia resistant to atropine with heart rate in 30s and hypotension resistant to volume expansion. The laboratory results showed that the patient also had acute kidney injury and severe resistant hyperkalemia. The whole presentation raised the suspicion of BRASH syndrome. The patient was started on peripheral dopamine infusion for bradycardia and symptomatic hypotension. Nephrology was consulted, and the patient was started on urgent dialysis for resistant hyperkalemia. The patient was admitted to the cardiovascular intensive care unit, and all antihypertensive medication, including beta-blockers, were stopped. The patient clinically improved on the next day, the dopamine infusion was stopped, and the patient remained vitally stable. The patient was eventually discharged home with cardiology and nephrology follow-up. The purpose of this case report is to help with the early diagnosis of this under-recognized and new clinical condition and to discuss the pathophysiology and management.

Cardiac sarcoidosis (CS) can be silent in most patients with extrapulmonary sarcoidosis. Atrioventricular (AV) block is the most common clinical presentation, but it can also present as fatal ventricular arrhythmias and sudden cardiac death. Endomyocardial biopsy is the gold standard; however, it is not sensitive since CS can involve the myocardium in a patchy distribution. Our case depicts a female who presented with syncope; however, her hospital course was complicated by multiple cardiac arrests. Her initial laboratory tests, including an autoimmune workup, were unremarkable. Cardiac magnetic resonance and fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging revealed intramyocardial delayed enhancement of the basal anteroseptal (non-ischemic distribution) and patchy foci of increased uptake in the anteroseptal and inferior myocardial region, respectively. The patient was started on intravenous methylprednisolone, and her condition slowly improved. Post-discharge, the patient followed in the outpatient clinic with a repeat FDG-PET scan revealing resolution of myocardial FDG uptake. She also underwent bronchoscopy with lymph node biopsy showing granulomas and endobronchial biopsy confirming pulmonary sarcoidosis.

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The relative influence of momentum diffusivity and thermal diffusivity, in terms of the Prandtl number (Pr), on the finite-amplitude instability of a non-isothermal annular Poiseuille flow (NAPF) is analyzed. The limiting value of the growth of instabilities under nonlinear effects is studied by deriving a cubic Landau equation. Emphasis is given especially on studying the impact of the low Prandtl number and the curvature parameter (C) on the bifurcation and the pattern variation of the secondary flow for both axisymmetric and non-axisymmetric disturbances. The finite-amplitude analysis predicts that in contrast to NAPF of water or fluid with Pr ≥ O(1) where the flow is supercritically unstable, the NAPF of low Pr fluids, particularly liquid metals, has shown both supercritical and subcritical bifurcation in the vicinity as well as away from the critical point. The nonlinear interaction of different harmonics for the liquid metal predicts a lower heat transfer rate than those by the laminar flow model, whereas for a fluid with Pr > 2, it is the other way. The maximum heat transfer takes place for the considered minimum value of C. For fluids with low Pr, a probable lower critical Rayleigh number is obtained. The corresponding variation in neutral stability curves as a function of wavenumber reveals that the instability that is supercritical for some wavenumber may be subcritical or vice versa at other nearby wavenumbers. The structural feature of the pattern of the secondary flow under the linear theory differs significantly from those of the secondary flow under nonlinear theory away from the bifurcation point. This is a consequence of the intrinsic interaction of different harmonics that are responsible for the stabilizing or the destabilizing nature of different components in the disturbance kinetic energy balance.

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The bifurcation and instability of nonisothermal annular Poiseuille flow (NAPF) of air as well as water is studied. We have emphasized the impact of a gap between cylinders in terms of curvature parameter (C) for axisymmetric as well as nonaxisymmetric disturbances. The results from the linear stability analysis reveal that the first azimuthal mode acts as a least stable mode of the NAPF of air for relatively small values of C. In this situation, even though for some values of C, the NAPF has supercritical bifurcation, but the same flow may experience subcritical bifurcation under zero azimuthal mode. It has also been observed that for relatively larger values of the Reynolds number (Re) and lower values of C, the NAPF under axisymmetric disturbance always exhibits subcritical bifurcation. However, for small values of Re, the NAPF exhibits only supercritical bifurcation. The finite amplitude analysis predicts only supercritical bifurcation of NAPF of water. The influence of nonlinear interaction of different harmonics on the amplitude profile as well as kinetic energy spectrum is investigated. The amplitude profile possesses a jump in the vicinity of a point where the type of bifurcation is changed. In the subcritical regime, the induced shear production due to modification of the gradient production acts as a main destabilizing factor balanced by the gradient production of kinetic energy.

Arrhythmogenic right ventricular dysplasia (ARVD) is a heart muscle disease that predominantly affects the right ventricle; however, biventricular involvement is increasingly being recognized. Fibrofatty tissue replacement is a central feature of ARVD. The majority of the identified genes, including protein plakophilin-2 (PKP-2), involved in cell-to-cell adhesion, can be seen in most genetic cases. Clinically, affected individuals present with palpitations, syncope, or sudden death due to ventricular arrhythmias, such as ventricular tachycardia (VT) or fibrillation, with symptomatic heart failure usually only in later stages. In this study, we present a male patient with ARVD who underwent a genetic test that revealed ARVD with PKP-2 mutation after multiple admissions for heart failure and arrhythmias. He ultimately underwent orthotopic heart transplantation (OHT). Early detection is important for further management, risk stratification, and reduced hospitalization in patients with ARVD.

Weakly nonlinear finite amplitude analysis is used to analyze the bifurcation and instability of parallel flow induced by an external pressure gradient and buoyancy force in a linearly heated vertical channel filled with fluid saturated high permeable porous medium. It is an extension of the recent article of Sharma et al [1] where form drag coefficient (c F) is independent of Reynold's number (Re). However, in most of the studies to reduce the number of parameter c F is treated as inversely proportional to Re. In the present article a comparative study is made to understand the bifurcation and instability of above flow under above two situations.