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late ventricular potentials

Johannes T Kowallick, Miguel Silva Vieira, Shelby Kutty, Joachim Lotz, Gerd Hasenfu, Amedeo Chiribiri, Andreas Schuster
OBJECTIVES: Hypertrophic cardiomyopathy (HCM) is associated with left atrial (LA) functional abnormalities. The determinants and the degree of LA dysfunction in the course of HCM are not fully understood. We aimed to characterize LA mechanics in HCM, according to the extent of left ventricular (LV) hypertrophy and fibrosis. METHODS AND RESULTS: Seventy-three HCM patients and 23 age- and sex-matched controls underwent cardiovascular magnetic resonance imaging including late gadolinium enhancement (LGE)...
October 12, 2016: Investigative Radiology
Pengwei Zhuang, Yingying Huang, Zhiqiang Lu, Zhen Yang, Liman Xu, Fengjiao Sun, Yanjun Zhang, Jinao Duan
Aconiti Lateralis Radix Praeparata (Fuzi) and Fritillariae Thunbergii bulbus (Beimu) have been widely used clinically to treat cardiopulmonary related diseases in China. However, according to the classic rules of traditional Chinese medicine, Fuzi and Beimu should be prohibited to use as a combination for their incompatibility. Therefore, it is critical to elucidate the paradox on the use of Fuzi and Beimu combination therapy. Monocrotaline-induced pulmonary hypertension rats were treated with either Fuzi, Beimu, or their combination at different stages of PH...
October 14, 2016: Scientific Reports
Boyang Liu, Nicola C Edwards, Simon Ray, Richard P Steeds
Mitral regurgitation (MR) is the second most common form of valvular disease requiring surgery. Correct identification of surgical candidates and optimising the timing of surgery is key in management. For primary MR, this relies upon a balance between the perioperative risks and rates of successful repair in patients undergoing early surgery when asymptomatic with the potential risk of irreversible left ventricular dysfunction if intervention is performed too late. For secondary MR, recognition that this is a highly dynamic condition where MR severity may change is key, although data on outcomes in determining whether concomitant valve intervention is performed with revascularisation has raised questions regarding timing of surgery...
October 13, 2016: Echo Research and Practice
Sophie Le Page, Marjorie Niro, Jérémy Fauconnier, Laura Cellier, Sophie Tamareille, Abdallah Gharib, Arnaud Chevrollier, Laurent Loufrani, Céline Grenier, Rima Kamel, Emmanuelle Sarzi, Alain Lacampagne, Michel Ovize, Daniel Henrion, Pascal Reynier, Guy Lenaers, Delphine Mirebeau-Prunier, Fabrice Prunier
BACKGROUND: Recent data suggests the involvement of mitochondrial dynamics in cardiac ischemia/reperfusion (I/R) injuries. Whilst excessive mitochondrial fission has been described as detrimental, the role of fusion proteins in this context remains uncertain. OBJECTIVES: To investigate whether Opa1 (protein involved in mitochondrial inner-membrane fusion) deficiency affects I/R injuries. METHODS AND RESULTS: We examined mice exhibiting Opa1delTTAG mutations (Opa1+/-), showing 70% Opa1 protein expression in the myocardium as compared to their wild-type (WT) littermates...
2016: PloS One
Gerrit Frommeyer, Catharina Clauss, Christian Ellermann, Harilaos Bogossian, Dirk G Dechering, Simon Kochhäuser, Florian Reinke, Christian Pott, Lars Eckardt
AIMS: The antiarrhythmic drug vernakalant exerts antiarrhythmic effects in atrial fibrillation. Recent experimental data suggest interactions with the late sodium current and antiarrhythmic effects in ventricular arrhythmias. We aimed at investigating whether treatment with vernakalant reduces polymorphic ventricular tachycardia (VT) in an experimental model of Long-QT-syndrome (LQTS). METHODS AND RESULTS: Twenty-nine isolated rabbit hearts were assigned to two groups and treated with erythromycin (300 µM, n = 15) or veratridine (0...
October 4, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Rosanne C Schoonbeek, Satoshi Takebayashi, Chikashi Aoki, Toru Shimaoka, Matthew A Harris, Gregory L Fu, Timothy S Kim, Yoav Dori, Jeremy McGarvey, Harold Litt, Wobbe Bouma, Gerald Zsido, Andrew C Glatz, Jonathan J Rome, Robert C Gorman, Joseph H Gorman, Matthew J Gillespie
BACKGROUND: Pulmonary insufficiency is the nexus of late morbidity and mortality after transannular patch repair of tetralogy of Fallot. This study aimed to establish the feasibility of implantation of the novel Medtronic Harmony transcatheter pulmonary valve (hTPV) and to assess its effect on pulmonary insufficiency and ventricular function in an ovine model of chronic postoperative pulmonary insufficiency. METHODS AND RESULTS: Thirteen sheep underwent baseline cardiac magnetic resonance imaging, surgical pulmonary valvectomy, and transannular patch repair...
October 2016: Circulation. Cardiovascular Interventions
Sandeep A Saha, Kousik Krishnan, Christopher Madias, Richard G Trohman
A 34-year-old man with Brugada syndrome (BrS) presented with electrical storm, manifested as multiple appropriate shocks from his implantable cardioverter-defibrillator over a period of 7 hours. He had not tolerated prior treatment with quinidine, and had self-discontinued cilostazol citing persistent palpitations. After stabilization with intravenous isoproterenol, an electrophysiology study was performed but no spontaneous or induced ventricular ectopic beats were identified. A three-dimensional (3D) endocardial electro-anatomic map of the right ventricular outflow tract (RVOT), pulmonic valve, and pulmonary artery, as well as a 3D epicardial map of the RVOT, were created...
September 19, 2016: Cardiology and Therapy
Qin Xu, Dakshesh Patel, Xian Zhang, Richard D Veenstra
Histone deacetylase (HDAC) inhibitors are small molecule anti-cancer therapeutics that exhibit limiting cardiotoxicities including QT interval prolongation and life-threatening cardiac arrhythmias. Because the molecular mechanisms for HDAC inhibitor-induced cardiotoxicity are poorly understood, we performed whole cell patch voltage clamp experiments to measure cardiac sodium currents (INa) from wild-type neonatal mouse ventricular or human induced pluripotent stem cell derived cardiomyocytes treated with trichostatin A (TSA), vorinostat (VOR), or romidepsin (FK228)...
September 16, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Veronique M F Meijborg, Mark Potse, Chantal E Conrath, Charly N W Belterman, Jacques M T De Bakker, Ruben Coronel
BACKGROUND: J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. METHODS: Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal)...
2016: Frontiers in Physiology
Jan-Christian Reil, Marcus Tauchnitz, Qinghai Tian, Mathias Hohl, Dominik Linz, Martin Oberhofer, Lars Kaestner, Gert-Hinrich Reil, Holger Thiele, Paul Steendijk, Michael Böhm, Hans-Ruprecht Neuberger, Peter Lipp
Patients with hypertension and hyperaldosteronism show an increased risk of stroke compared with patients with essential hypertension. Aim of the study was to assess the effects of aldosterone on left atrial function in rats as a potential contributor to thromboembolism. Osmotic mini-pumps delivering 1.5 μg aldosterone/h were implanted in rats subcutaneously (Aldo, n = 39; controls, n = 38). After 8 wk, left ventricular pressure-volume analysis of isolated working hearts was performed, and left atrial systolic and diastolic function was also assessed by atrial pressure-diameter loops...
October 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Roxana C Rimbaş, Sorina Mihăilă, Oana A Enescu, Dragoş Vinereanu
BACKGROUND: 2D speckle tracking echocardiography (2DSTE) was proved to be accurate for the assessment of the RV function. However, normal values for RV strain refer mostly to 3- or 6-segment models, excluding the contribution of other RV walls to RV function. We analyze RV function by 2DSTE in a normal population, using parasternal two-(2C) and apical four-chamber (4C) RV views, and creating a new 12-segment model for a potential better definition of RV function. METHODS: We prospectively evaluated 100 normals using 2DE and STE...
September 10, 2016: Echocardiography
Dominik P Guensch, Janelle Yu, Gobinath Nadeshalingam, Kady Fischer, Jane Shearer, Matthias G Friedrich
BACKGROUND: Previous serological studies have shown controversial results whether defibrillation or cardioversion can cause myocardial injury. Cardiovascular Magnetic Resonance (CMR) can be used to detect myocardial edema, hyperemia and capillary leak as features of acute myocardial injury. The aim of this study was to assess for myocardial and skeletal muscle injury in swine following transthoracic shocks. METHODS: Seventeen anaesthetized swine were examined, with 11 undergoing five synchronized transthoracic shocks (200J)...
2016: PloS One
R B Clark, W R Giles
It is now well established that the slowly inactivating component of the Na(+) current (INa-L) in the mammalian heart is a significant regulator of the action potential waveform. This insight has led to detailed studies of the role of INa-L in a number of important and challenging pathophysiological settings. These include genetically based ventricular arrhythmias (LQT 1, 2, and 3), ventricular arrhythmias arising from progressive cardiomyopathies (including diabetic), and proarrhythmic abnormalities that develop during local or global ventricular ischemia...
2016: Current Topics in Membranes
Mary Kearney, Richard W Orrell, Michael Fahey, Ruth Brassington, Massimo Pandolfo
BACKGROUND: Friedreich ataxia is a rare inherited autosomal recessive neurological disorder, characterised initially by unsteadiness in standing and walking, slowly progressing to wheelchair dependency usually in the late teens or early twenties. It is associated with slurred speech, scoliosis, and pes cavus. Heart abnormalities cause premature death in 60% of people with the disorder. There is no easily defined clinical or biochemical marker and no known treatment. This is the second update of a review first published in 2009 and previously updated in 2012...
2016: Cochrane Database of Systematic Reviews
Chao Wang, Lei-Lei Wang, Chi Zhang, Zhen-Zhen Cao, An-Tao Luo, Pei-Hua Zhang, Xin-Rong Fan, Ji-Hua Ma
AIM: The augmentation of late sodium current (INa.L) not only causes intracellular Na(+) accumulation, which results in intracellular Ca(2+) overload via the reverse mode of the Na(+)/Ca(2+) exchange current (reverse-INCX), but also prolongs APD and induces early afterdepolarizations (EAD), which can lead to arrhythmia and cardiac dysfunction. Thus, the inhibition of INa.L is considered to be a potential way for therapeutic intervention in ischemia and heart failure. In this study we investigated the effects of tolterodine (Tol), a competitive muscarinic receptor antagonist, on normal and veratridine (Ver)-augmented INa...
August 29, 2016: Acta Pharmacologica Sinica
Daniel K L Cheuk, Elske Sieswerda, Elvira C van Dalen, Aleida Postma, Leontien C M Kremer
BACKGROUND: Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity. This review is an update of a previously published Cochrane review...
2016: Cochrane Database of Systematic Reviews
Yuzhi Jia, Hsiang-Chun Chang, Matthew J Schipma, Jing Liu, Varsha Shete, Ning Liu, Tatsuya Sato, Edward B Thorp, Philip M Barger, Yi-Jun Zhu, Navin Viswakarma, Yashpal S Kanwar, Hossein Ardehali, Bayar Thimmapaya, Janardan K Reddy
Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure...
2016: PloS One
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
Christos-Konstantinos Antoniou, Ippokratis Bournellis, Achilleas Papadopoulos, Dimitris Tsiachris, Petros Arsenos, Polychronis Dilaveris, Ioannis Diakogiannis, Skevos Sideris, Ioannis Kallikazaros, Konstantinos A Gatzoulis, Dimitrios Tousoulis
BACKGROUND: Sudden cardiac death (SCD) occurs three times more often in psychiatric patients than in the general population. QRS fragmentation (QRSfr) and signal-averaged electrocardiography (SAECG) are simple, inexpensive, readily available tools for detecting the presence of abnormal depolarization and late potentials (LPs) in these patients, a result of either the underlying disease or treatment. METHODS: Frequency of LP detection by SAECG and QRSfr was studied in 52 psychiatric patients and compared with 30 healthy (without known structural heart disease or occurrence of ventricular arrhythmia) controls...
November 1, 2016: International Journal of Cardiology
Coşkun Usta, Nur Tükel Turgut, Aslı Bedel
Platelet aggregation is a crucial feature in coronary artery thrombus formation and is a major causative factor in both acute coronary syndromes (ACS) and reocclusion after percutaneous coronary interventions (PCI). The glycoprotein (GP) IIb/IIIa (αIIbβ3) integrin receptor is the pivotal mediator of platelet aggregation. In late 1990s, the introduction of GP IIb/IIIa inhibitors (GPI) was associated with a reduction of ischemic complication, and a clear clinical benefit in PCI during ACS, for both non ST-elevation (NSTE) and ST-segment elevation myocardial infarction (STEMI)...
November 1, 2016: International Journal of Cardiology
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