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Xiaodong Huang, Tae Yun Kim, Gideon Koren, Bum-Rak Choi, Zhilin Qu
The occurrence of early afterdepolarizations (EADs) and increased dispersion of repolarization are two known factors for arrhythmogenesis in long QT syndrome. However, increased dispersion of repolarization tends to suppress EADs due to the source-sink effect, and thus how the two competing factors cause initiation of arrhythmias remains incompletely understood. Here we used optical mapping and computer simulation to investigate the mechanisms underlying spontaneous initiation of arrhythmias in type 2 long QT (LQT2) syndrome...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Cecilia U D Stenfors, Linda M Hanson, Töres Theorell, Walter S Osika
Objective: Executive cognitive functioning is essential in private and working life and is sensitive to stress and aging. Cardiovascular (CV) health factors are related to cognitive decline and dementia, but there is relatively few studies of the role of CV autonomic regulation, a key component in stress responses and risk factor for cardiovascular disease (CVD), and executive processes. An emerging pattern of results from previous studies suggest that different executive processes may be differentially associated with CV autonomic regulation...
2016: Frontiers in Psychology
Altuğ Ösken, Nizamettin Selçuk Yelgeç, Regayip Zehir, Tuğba Kemaloğlu Öz, Selçuk Yaylacı, Ramazan Akdemir, Hüseyin Gündüz
Drug-induced torsades de pointes (TdP) is a rare but potentially fatal adverse effect of commonly prescribed medications including cardiac and noncardiac drugs. Importantly, many drugs have been reported to cause the characteristic Brugada syndrome-linked electrocardiography (ECG) abnormalities and/or (fatal) ventricular tachyarrhythmias. Chlorpheniramine and propranolol have the arrhythmogenic effects reported previously. A review of literature revealed a large number of case reports of chlorpheniramine or propranolol use resulting in QTc prolongation, TdP, or both...
July 2016: Indian Journal of Pharmacology
Erik K Grasser, Barbara Ernst, Martin Thurnheer, Bernd Schultes
BACKGROUND: A shortening of electrocardiographic QT interval has been observed in obese subjects after weight loss, but previous results may have been biased by inappropriate heart rate (HR) correction. METHODS: Electrocardiography (ECG) recordings of 49 (35 females) severely obese patients before and 12 months after Roux-en-Y gastric bypass (RYGB) surgery were analysed. QT interval (QTc) was calculated by using four different equations, i.e. Bazett, Fridericia, Framingham and Hodges...
October 8, 2016: Obesity Surgery
Sara I Liin, Johan E Larsson, Rene Barro-Soria, Bo Hjorth Bentzen, H Peter Larson
About 300 loss-of-function mutations in the IKs channel have been identified in patients with Long QT syndrome and cardiac arrhythmia. How specific mutations cause arrhythmia is largely unknown and there are no approved IKs channel activators for treatment of these arrhythmias. We find that several Long QT syndrome-associated IKs channel mutations shift channel voltage dependence and accelerate channel closing. Voltage-clamp fluorometry experiments and kinetic modeling suggest that similar mutation-induced alterations in IKs channel currents may be caused by different molecular mechanisms...
September 30, 2016: ELife
Steve Malangone, Christopher J Campen
A 60-year-old man initially presented with pain in the right upper quadrant in October 2010. A computed tomography (CT) scan of the abdomen pelvis completed at that time showed a mass at the junction of the body and tail of the pancreas and multiple large liver lesions. A CT-guided liver biopsy revealed low-grade neuroendocrine carcinoma. The patient was initially started on systemic treatment with sunitinib (Sutent) and octreotide. He developed intolerable side effects, including nausea and migraine. Therapy was discontinued in October 2011, when a CT scan revealed evidence of disease progression...
November 2015: Journal of the Advanced Practitioner in Oncology
Agnieszka Noszczyk-Nowak, Urszula Pasławska, Jacek Gajek, Adrian Janiszewski, Robert Pasławski, Dorota Zyśko, Józef Nicpoń
BACKGROUND: Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals. OBJECTIVES: The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC). MATERIAL AND METHODS: The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed...
May 2016: Advances in Clinical and Experimental Medicine: Official Organ Wroclaw Medical University
John R Feiner, Richard B Weiskopf
OBJECTIVES: PaO2/FIO2 is used commonly for diagnosis of lung injury (acute respiratory distress syndrome and transfusion-related acute lung injury), for assessment of pulmonary disease course and therapy, and in pulmonary transplantation for evaluation of donor lungs and clinical outcome. It was developed for convenience, without formal mathematical and graphic assessment to validate its suitability for these purposes. DESIGN: We examined, mathematically and graphically, the relationship of PaO2/FIO2 to FIO2 at constant normal and several degrees of increased intrapulmonary shunting (QS/QT), assessing the impact of intra- and extrapulmonary factors on the relationship and thus the reliability of PaO2/FIO2...
September 9, 2016: Critical Care Medicine
Tarek Magdy, Brian T Burmeister, Paul W Burridge
The cardiotoxicity of certain chemotherapeutic agents is now well-established, and has led to the development the field cardio-oncology, increased cardiac screening of cancer patients, and limitation of patients' maximum cumulative chemotherapeutic dose. The effect of chemotherapeutic regimes on the heart largely involves cardiomyocyte death, leading to cardiomyopathy and heart failure, or the induction of arrhythmias. Of these cardiotoxic drugs, those resulting in clinical cardiotoxicity can range from 8 to 26% for doxorubicin, 7-28% for trastuzumab, or 5-30% for paclitaxel...
September 5, 2016: Pharmacology & Therapeutics
Arthur A M Wilde, Arthur J Moss, Elizabeth S Kaufman, Wataru Shimizu, Derick R Peterson, Jesaia Benhorin, Coeli Lopes, Jeffrey A Towbin, Carla Spazzolini, Lia Crotti, Wojciech Zareba, Ilan Goldenberg, Jørgen K Kanters, Jennifer L Robinson, Ming Qi, Nynke Hofman, David J Tester, Connie R Bezzina, Marielle Alders, Takeshi Aiba, Shiro Kamakura, Yoshihiro Miyamoto, Mark L Andrews, Scott McNitt, Bronislava Polonsky, Peter J Schwartz, Michael J Ackerman
BACKGROUND: Risk stratification in patients with type 3 long-QT syndrome (LQT3) by clinical and genetic characteristics and effectiveness of β-blocker therapy has not been studied previously in a large LQT3 population. METHODS: The study population included 406 LQT3 patients with 51 sodium channel mutations; 391 patients were known to be event free during the first year of life and were the focus of our study. Clinical, electrocardiographic, and genetic parameters were acquired for patients from 7 participating LQT3 registries...
September 20, 2016: Circulation
M A Hieger, K F Maskell, M J Moss, S W Powell, K L Cumpston
Dofetilide is a class III antiarrhythmic used for treating atrial dysrhythmias. Though its adverse effects are well described in routine use, very little is known about dofetilide toxicity in overdose. This is a retrospective case series of consecutive patients reported to our poison center after dofetilide overdose. Twenty-seven cases were included. Seventeen patients were treated at a healthcare facility, and of these, eight were admitted. Twenty-one patients took one extra capsule, four took someone else's medication, one took three extra capsules, and one had a large intentional overdose...
August 26, 2016: Cardiovascular Toxicology
Pei-Chi Yang, Nesrine El-Bizri, Lucia Romero, Wayne R Giles, Sridharan Rajamani, Luiz Belardinelli, Colleen E Clancy
BACKGROUND: The QT interval is a phase of the cardiac cycle that corresponds to action potential duration (APD) including cellular repolarization (T-wave). In both clinical and experimental settings, prolongation of the QT interval of the electrocardiogram (ECG) and related proarrhythmia have been so strongly associated that a prolonged QT interval is largely accepted as surrogate marker for proarrhythmia. Accordingly, drugs that prolong the QT interval are not considered for further preclinical development resulting in removal of many promising drugs from development...
August 18, 2016: Journal of Molecular and Cellular Cardiology
Lia Crotti, Annukka M Lahtinen, Carla Spazzolini, Elisa Mastantuono, Maria Cristina Monti, Caterina Morassutto, Gianfranco Parati, Marshall Heradien, Althea Goosen, Peter Lichtner, Thomas Meitinger, Paul A Brink, Kimmo Kontula, Heikki Swan, Peter J Schwartz
BACKGROUND: Long-QT syndrome is an inherited cardiac channelopathy characterized by delayed repolarization, risk of life-threatening arrhythmia, and significant clinical variability even within families. Three single-nucleotide polymorphisms (SNPs) in the 3' untranslated region of KCNQ1 were recently suggested to be associated with suppressed gene expression and hence decreased disease severity when located on the same haplotype with a disease-causing KCNQ1 mutation. We sought to replicate this finding in a larger and a genetically more homogeneous population of KCNQ1 mutation carriers...
August 2016: Circulation. Cardiovascular Genetics
Jiesheng Kang, David R Compton, Roy J Vaz, David Rampe
Loperamide is a μ-opioid receptor agonist commonly used to treat diarrhea and often available as an over-the-counter medication. Recently, numerous reports of QRS widening accompanied by dramatic QT interval prolongation, torsades de pointe arrhythmia, and death have been reported in opioid abusers consuming large amounts of the drug to produce euphoria or prevent opiate withdrawal. The present study was undertaken to determine the mechanisms of this cardiotoxicity. Using whole-cell patch clamp electrophysiology, we tested loperamide on the cloned human cardiac sodium channel (Nav1...
October 2016: Naunyn-Schmiedeberg's Archives of Pharmacology
Nathalie Moise, Yulia Khodneva, Joshua Richman, Daichi Shimbo, Ian Kronish, Monika M Safford
BACKGROUND: Depression is a relapsing and remitting disease. Prior studies on the association between depressive symptoms and incident cardiovascular disease (CVD) have been limited by single measurements, and few if any have examined both incident coronary heart disease and stroke in a large biracial national cohort. We aimed to assess whether time-dependent depressive symptoms conferred increased risk of incident CVD. METHODS AND RESULTS: Between 2003 to 2007, 22 666 black and white participants (aged ≥45 years) without baseline CVD in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were recruited...
August 12, 2016: Journal of the American Heart Association
Giuseppe Molinari, Natale Daniele Brunetti, Luigi Biasco, Sandro Squarcia, Yvonne Cristoforetti, Riccardo Bennicelli, Cecilia Del Vecchio, Cecilia Viacava, Carla Giustetto, Fiorenzo Gaita
OBJECTIVE: The objective of this study was to derive normal electrocardiographic values and to report the abnormal findings in a large contemporary European cohort of physically active children and young adolescents. METHODS: In a 3-month period, data derived from subjects aged between 3 and 14 years and referred to the Telecardiology Centre (Genoa, Italy) for electrocardiogram (ECG) evaluation as pre-participation screening for non-competitive sports were analyzed...
August 11, 2016: Sports Medicine
Limin Zhang, Sihua Qi
BACKGROUND: We conducted a retrospective cohort study of a large sample to assess whether electrocardiographic (ECG) abnormalities are independently associated with the occurrence of neurogenic pulmonary edema (NPE), delayed cerebral ischemia (DCI), and in-hospital death after nontraumatic subarachnoid hemorrhage (SAH). METHODS: In this retrospective observational study, patients who were admitted within 72 hours of SAH symptom onset between 2013 and 2015 were enrolled...
July 28, 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
David S Auerbach, Scott McNitt, Robert A Gross, Wojciech Zareba, Robert T Dirksen, Arthur J Moss
OBJECTIVES: The coprevalence, severity, and biomarkers for seizures and arrhythmias in long QT syndrome (LQTS) remain incompletely understood. METHODS: Using the Rochester-based LQTS Registry, this study included large cohorts of LQTS1-3 participants (LQTS(+), n = 965) and those without a LQTS mutation (LQTS(-), n = 936). RESULTS: Compared to LQTS(-) participants, there was a higher prevalence of LQTS1, LQTS2, and LQTS(+) participants classified as having seizures (p < 0...
October 18, 2016: Neurology
Patricia Vaughn, Michelle M K Solik, Shiv Bagga, Benzy J Padanilam
A 20-year-old man presented with recurrent syncope and abnormal electrocardiogram (ECG). His evaluation revealed a prolonged QT interval >600 milliseconds, witnessed torsades de pointes (TdP), and dilated cardiomyopathy. At his initial admission, an ICD was implanted and atrial pacing at 80 beats per minute suppressed ventricular arrhythmias. The patient was readmitted with device infection and recurrent TdP leading to intubation. This led to the discovery of a hitherto unrevealed loperamide abuse and his cardiac arrhythmias and LV dysfunction were determined to be related to large doses of loperamide...
October 2016: Journal of Cardiovascular Electrophysiology
John Garcia, Jackie Tahiliani, Nicole Marie Johnson, Sienna Aguilar, Daniel Beltran, Amy Daly, Emily Decker, Eden Haverfield, Blanca Herrera, Laura Murillo, Keith Nykamp, Scott Topper
Advances in DNA sequencing have made large, diagnostic gene panels affordable and efficient. Broad adoption of such panels has begun to deliver on the promises of personalized medicine, but has also brought new challenges such as the presence of unexpected results, or results of uncertain clinical significance. Genetic analysis of inherited cardiac conditions is particularly challenging due to the extensive genetic heterogeneity underlying cardiac phenotypes, and the overlapping, variable, and incompletely penetrant nature of their clinical presentations...
2016: Frontiers in Cardiovascular Medicine
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