Preliminary Study: Learning the Impact of Simulation Time on Reentry Location and Morphology Induced by Personalized Cardiac Modeling

Personalized cardiac modeling is widely used for studying the mechanisms of cardiac arrythmias. Due to the high demanding of computational resource of modeling, the arrhythmias induced in the models are usually simulated for just a few seconds. In clinic, it is common that arrhythmias last for more than several minutes and the morphologies of reentries are not always stable, so it is not clear that whether the simulation of arrythmias for just a few seconds is long enough to match the arrhythmias detected in patients. This study aimed to observe how long simulation of the induced arrhythmias in the personalized cardiac models is sufficient to match the arrhythmias detected in patients. A total of 5 contrast enhanced MRI datasets of patient hearts with myocardial infarction were used in this study. Then, a classification method based on Gaussian mixture model was used to detect the infarct tissue. For each reentry, 3 s and 10 s were simulated. The characteristics of each reentry simulated for different duration were studied. Reentries were induced in all 5 ventricular models and sustained reentries were induced at 39 stimulation sites in the model. By analyzing the simulation results, we found that 41% of the sustained reentries in the 3 s simulation group terminated in the longer simulation groups (10 s). The second finding in our simulation was that only 23.1% of the sustained reentries in the 3 s simulation did not change location and morphology in the extended 10 s simulation. The third finding was that 35.9% reentries were stable in the 3 s simulation and should be extended for the simulation time. The fourth finding was that the simulation results in 10 s simulation matched better with the clinical measurements than the 3 s simulation. It was shown that 10 s simulation was sufficient to make simulation results stable. The findings of this study not only improve the simulation accuracy, but also reduce the unnecessary simulation time to achieve the optimal use of computer resources to improve the simulation efficiency and shorten the simulation time to meet the time node requirements of clinical operation on patients.

A randomized trial evaluating the safety profile of sugammadex in high surgical risk ASA physical class 3 or 4 participants

Background The aim of this randomized, double-blind trial was to evaluate the safety and tolerability profile, including cardiac safety, of sugammadex-mediated recovery from neuromuscular block in participants undergoing surgery who met the American Society of Anesthesiologists (ASA) Physical Class 3 or 4 criteria. Specifically, this study assessed the impact of sugammadex on cardiac adverse events (AEs) and other prespecified AEs of clinical interest. Methods Participants meeting ASA Class 3 and 4 criteria were stratified by ASA Class and NMBA (rocuronium or vecuronium) then randomized to one of the following: 1) Moderate neuromuscular block, sugammadex 2 mg/kg; 2) Moderate neuromuscular block, neostigmine and glycopyrrolate (neostigmine/glycopyrrolate); 3) Deep neuromuscular block, sugammadex 4 mg/kg; 4) Deep neuromuscular block, sugammadex 16 mg/kg (rocuronium only). Primary endpoints included incidences of treatment-emergent (TE) sinus bradycardia, TE sinus tachycardia and other TE cardiac arrhythmias. Results Of 344 participants randomized, 331 received treatment (61% male, BMI 28.5 ± 5.3 kg/m2, age 69 ± 11 years). Incidence of TE sinus bradycardia was significantly lower in the sugammadex 2 mg/kg group vs neostigmine/glycopyrrolate. The incidence of TE sinus tachycardia was significantly lower in the sugammadex 2 and 4 mg/kg groups vs neostigmine/glycopyrrolate. No significant differences in other TE cardiac arrythmias were seen between sugammadex groups and neostigmine/glycopyrrolate. There were no cases of adjudicated anaphylaxis or hypersensitivity reactions in this study. Conclusions Compared with neostigmine/glycopyrrolate, incidence of TE sinus bradycardia was significantly lower with sugammadex 2 mg/kg and incidence of TE sinus tachycardia was significantly lower with sugammadex 2 mg/kg and 4 mg/kg. These results support the safety of sugammadex for reversing rocuronium- or vecuronium-induced moderate and deep neuromuscular block in ASA Class 3 or 4 participants. Trial registration ClinicalTrials.gov Identifier: NCT03346057.

COVID-19 and Cardiovascular Disease: Mechanisms and Implications

We are living and fighting serious COVID-19 pandemic, which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. Cardiovascular diseases are highly prevalent in the infected individuals, which modifies their treatment and prognosis. The injury of the myocardium is reported in over 15% of hospitalized severely ill patients, mostly presented in the form of acute heart failure, acute coronary syndrome, cardiac arrythmias, myocarditis and thromboembolic complications. All these complications may appear at early in the course of the disease, during the disease progress or in the later stage of the COVID-19 disease. Thromboembolic complications accompany more severe cases, caused by excessive inflammation, platelet activation, endothelial dysfunction, and stasis. This new virus pandemic is a global challenge for health care system where we still have much to learn.

Potassium and Cardiac Surgery

Potassium homeostasis affects cardiac rhythm and contractility, along with vascular reactivity and vascular smooth muscle proliferation. This chapter will focus on potassium dynamics during and after cardiac surgery involving cardioplegic arrest and cardiopulmonary bypass (CPB). Hyperkalemic, hypothermic solutions are frequently used to induce cardioplegic arrest and protect the heart during cardiac surgery involving CPB. Common consequences of hyperkalemic cardioplegic arrest and reperfusion include microvascular dysfunction involving several organ systems and myocardial dysfunction. Immediately after CPB, blood potassium levels often drop precipitously due to a variety of factors, including CPB -induced electrolyte depletion and frequent, long-term administration of insulin during and after surgery. Meanwhile, some patients with pre-existing kidney dysfunction may experience postoperative hyperkalemia following cardioplegia. Any degree of postoperative hyper/hypokalemia significantly elevates the risk of cardiac arrythmias and subsequent myocardial failure. Therefore, proper management of blood potassium levels during and after cardioplegia/CPB is crucial for optimizing patient outcomes following cardiac surgery.

Illustrations of the heart by Arthur Keith: His work with James Mackenzie on the pathophysiology of the heart 1903–08

The University of Manchester Museum of Medicine and Health holds a collection of drawings of human hearts by anatomist Sir Arthur Keith (1866–1955). The specimens were provided by the cardiologist, Sir James Mackenzie (1853–1925) who was using a polygraph to investigate patients with cardiac arrhythmias. Keith’s dissections helped to establish the anatomy and pathology of the atrioventricular conduction system and assisted Mackenzie to interpret his polygraph recordings and understand the origin of cardiac arrythmias.

A collection of illustrations of the heart by Arthur Keith, and his work with James Mackenzie on the pathophysiology of the heart 1903–1908

The University of Manchester Museum of Medicine and Health holds of collection of drawings of human hearts by anatomist Sir Arthur Keith (1866–1955). The specimens were provided by the cardiologist, Sir James Mackenzie (1853–1925) who was using a polygraph to investigate patients with cardiac arrhythmias. Keith’s dissections helped to establish the anatomy and pathology of the atrioventricular conduction system and assisted Mackenzie to interpret his polygraph recordings and understand the origin of cardiac arrythmias.

Wheat pill poisoning: complications and management

Wheat pill (zinc or aluminum phosphide) is used as rodenticide in wheat and rice storage reservoirs also known as rice pill. In developing countries like Pakistan there has been an increase in the number of aluminum phosphide (wheat-pill) poisoning with suicidal intent due to easy accessibility. It has high mortality rate, with no antidote available. A young female presented with wheat pill poisoning in June 2019, upon arrival she had classical signs and symptoms of wheat pill poisoning although during her stay she developed cardiac arrythmias leading to shock, Hematuria, Pleural effusion, and hyperglycemia due to acute pancreatitis. Due to the appropriate recognition and management of complications, patient was able to recuperate. felicitous transfer to Intensive Care Unit and prompt recognition of complications can lead to virtuous outcomes. We recommend that there should be nationwide cognizance campaign regarding the lethal consequences of wheat-pill consumption by humans and proper Continuous...

An audit on the management of patients with chronic hypoparathyroidism in a district general hospital in the UK

Chronic Hypoparathyroidism is a rare condition but can be responsible for a wide range of co-morbidities including nephrocalcinosis and nephrolithiasis, neuropsychiatric disorders, seizures, brain fog, prolonged QT interval on ECG (from hypocalcemia) and Cardiac Arrythmias, Dilated Cardiomyopathy and Cataract. The National (UK) Survey for the management of Chronic Hypoparathyroidism is currently ongoing (Year 2020) and our Hospital has participated in it, Therefore, I performed this Audit comparing our performance with the prevalent Guidelines on management of Chronic Hypoparathyroidism