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https://www.readbyqxmd.com/read/28643891/direct-comparison-of-high-temporal-resolution-cine-mri-with-doppler-ultrasound-for-assessment-of-diastolic-dysfunction-in-mice
#1
Thomas A Roberts, Anthony N Price, Laurence H Jackson, Valerie Taylor, Anna L David, Mark F Lythgoe, Daniel J Stuckey
Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one-dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high-temporal-resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user-independent technique...
June 23, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28630171/distinctive-left-ventricular-activations-associated-with-ecg-pattern-in-heart-failure-patients
#2
Nicolas Derval, Josselin Duchateau, Saagar Mahida, Romain Eschalier, Frederic Sacher, Joost Lumens, Hubert Cochet, Arnaud Denis, Xavier Pillois, Seigo Yamashita, Yuki Komatsu, Sylvain Ploux, Sana Amraoui, Adlane Zemmoura, Philippe Ritter, Mélèze Hocini, Michel Haissaguerre, Pierre Jaïs, Pierre Bordachar
BACKGROUND: In contrast to patients with left bundle branch block (LBBB), heart failure patients with narrow QRS and nonspecific intraventricular conduction delay (NICD) display a relatively limited response to cardiac resynchronization therapy. We sought to compare left ventricular (LV) activation patterns in heart failure patients with narrow QRS and NICD to patients with LBBB using high-density electroanatomic activation maps. METHODS AND RESULTS: Fifty-two heart failure patients (narrow QRS [n=18], LBBB [n=11], NICD [n=23]) underwent 3-dimensional electroanatomic mapping with a high density of mapping points (387±349 LV)...
June 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28624975/deleterious-acute-and-chronic-effects-of-bradycardic-right-ventricular-apex-pacing-consequences-for-arrhythmic-outcome
#3
T R G Stams, A Dunnink, W M van Everdingen, H D M Beekman, R van der Nagel, B Kok, M F A Bierhuizen, M J Cramer, M Meine, M A Vos
In the chronic complete atrioventricular (AV) block dog (CAVB) model, both bradycardia and altered ventricular activation due to the uncontrolled idioventricular rhythm contribute to ventricular remodeling and the enhanced susceptibility to Torsade de Pointes (TdP) arrhythmias. We investigated the effect of permanent bradycardic right ventricular apex (RVA) pacing on mechanical and electrical remodeling and TdP. In 23 anesthetized dogs, serial experiments were performed at sinus rhythm (SR), acutely after AV block (AAVB) and 3 weeks of remodeling CAVB at a fixed pacing rate of 60/min...
July 2017: Basic Research in Cardiology
https://www.readbyqxmd.com/read/28616729/prediction-of-the-estimated-5-year-risk-of-sudden-cardiac-death-and-syncope-or-non-sustained-ventricular-tachycardia-in-patients-with-hypertrophic-cardiomyopathy-using-late-gadolinium-enhancement-and-extracellular-volume-cmr
#4
Maxim Avanesov, Julia Münch, Julius Weinrich, Lennart Well, Dennis Säring, Christian Stehning, Enver Tahir, Sebastian Bohnen, Ulf K Radunski, Kai Muellerleile, Gerhard Adam, Monica Patten, Gunnar Lund
OBJECTIVES: To evaluate the ability of late gadolinium enhancement (LGE) and mapping cardiac magnetic resonance (CMR) including native T1 and global extracellular volume (ECV) to identify hypertrophic cardiomyopathy (HCM) patients at risk for sudden cardiac death (SCD) and to predict syncope or non-sustained ventricular tachycardia (VT). METHODS: A 1.5-T CMR was performed in 73 HCM patients and 16 controls. LGE size was quantified using the 3SD, 5SD and full width at half maximum (FWHM) method...
June 14, 2017: European Radiology
https://www.readbyqxmd.com/read/28608635/cardiac-and-metabolic-variables-in-obese-dogs
#5
M Tropf, O L Nelson, P M Lee, H Y Weng
BACKGROUND: The etiology of obesity-related cardiac dysfunction (ORCD) is linked to metabolic syndrome in people. Studies have indicated that obese dogs have components of metabolic syndrome, warranting evaluation for ORCD in obese dogs. OBJECTIVES: To evaluate cardiac structure and function and metabolic variables in obese dogs compared to ideal weight dogs. ANIMALS: Forty-six healthy, small-breed (<25 pounds), obese dogs (n = 29) compared to ideal weight dogs (n = 17)...
June 13, 2017: Journal of Veterinary Internal Medicine
https://www.readbyqxmd.com/read/28597532/substrate-characterization-and-catheter-ablation-in-patients-with-scar-related-ventricular-tachycardia-using-ultra-high-density-3d-mapping
#6
Jana M Nührich, Lukas Kaiser, Ruken Özge Akbulak, Benjamin N Schäffer, Christian Eickholt, Michael Schwarzl, Pawel Kuklik, Julia Moser, Mario Jularic, Stephan Willems, Christian Meyer
BACKGROUND: Ablation of scar-related ventricular tachycardia (VT), especially in non-inducible VT or hemodynamically unstable patients, can be challenging. Thus, we evaluated feasibility of an ultra high-density 3D-mapping approach to characterize the ventricular substrate and, if possible, to map VT. METHODS AND RESULTS: Twenty-two patients (67±2 years, mean LV-EF 36±3%) with both ischemic and non-ischemic cardiomyopathy and documented VT underwent mapping and catheter ablation using a 64-electrode mini-basket catheter...
June 8, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28594399/essential-but-partially-redundant-roles-for-pou4f1-brn-3a-and-pou4f2-brn-3b-transcription-factors-in-the-developing-heart
#7
Lauren J Maskell, Kashif Qamar, Aram A Babakr, Thomas A Hawkins, Richard J Heads, Vishwanie S Budhram-Mahadeo
Congenital heart defects contribute to embryonic or neonatal lethality but due to the complexity of cardiac development, the molecular changes associated with such defects are not fully understood. Here, we report that transcription factors (TFs) Brn-3a (POU4F1) and Brn-3b (POU4F2) are important for normal cardiac development. Brn-3a directly represses Brn-3b promoter in cardiomyocytes and consequently Brn-3a knockout (KO) mutant hearts express increased Brn-3b mRNA during mid-gestation, which is linked to hyperplastic growth associated with elevated cyclin D1, a known Brn-3b target gene...
June 8, 2017: Cell Death & Disease
https://www.readbyqxmd.com/read/28592592/late-systolic-myocardial-loading-is-associated-with-left-atrial-dysfunction-in-hypertension
#8
Julio A Chirinos, Timothy S Phan, Amer A Syed, Zeba Hashmath, Harry G Oldland, Maheswara R Koppula, Ali Tariq, Khuzaima Javaid, Rachana Miller, Swapna Varakantam, Anjaneyulu Dunde, Vadde Neetha, Scott R Akers
BACKGROUND: Late systolic load has been shown to cause diastolic dysfunction in animal models. Although the systolic loading sequence of the ventricular myocardium likely affects its coupling with the left atrium (LA), this issue has not been investigated in humans. We aimed to assess the relationship between the myocardial loading sequence and LA function in human hypertension. METHODS AND RESULTS: We studied 260 subjects with hypertension and 19 normotensive age- and sex-matched controls...
June 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28592193/permanent-chronotropic-impairment-after-closure-of-atrial-or-ventricular-septal-defect
#9
Johan Heiberg, Camilla Nyboe, Vibeke E Hjortdal
OBJECTIVES: Atrial and ventricular septal defects are commonly closed surgically with low rates of post-operative morbidity, and the long-term outcome has widely been described as benign. Nevertheless, there is an increasing understanding of late morbidity, and the possibility of postoperative chronotropic impairment is continuously questioned. Furthermore, potentially abnormal chronotropic responses may be associated with the recently demonstrated overrepresentation of late arrhythmias...
June 8, 2017: Scandinavian Cardiovascular Journal: SCJ
https://www.readbyqxmd.com/read/28590042/changes-in-arrhythmogenic-properties-and-five-year-prognosis-after-carbon-ion-radiotherapy-in-patients-with-mediastinum-cancer
#10
Mari Amino, Koichiro Yoshioka, Makiyoshi Shima, Tohru Okada, Mio Nakajima, Yoshiya Furusawa, Shigetaka Kanda, Sadaki Inokuchi, Teruhisa Tanabe, Yuji Ikari, Tadashi Kamada
INTRODUCTION: Carbon-ion irradiation of rabbit hearts has improved left ventricular conduction abnormalities through upregulation of gap junctions. However, to date, there has been no investigation on the effect of carbon-ion irradiation on electrophysiological properties in human. We investigated this effect in patients with mediastinum extra-cardiac cancer treated with carbon-ion radiotherapy that included irradiating the heart. METHODS AND RESULTS: In April-December 2009, eight patients were prospectively enrolled (including two male, aged 72...
June 7, 2017: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/28570022/slow-antegrade-excitation-and-delayed-retrograde-activation-through-an-inexcitable-zone-a-basis-for-arrhythmia-formation-in-infarcted-myocardium-ex-vivo
#11
Eugene Patterson, Benjamin J Scherlag
INTRODUCTION: The electrophysiologic mechanism for rate-dependent PVBs associated with double potentials (DPs) was investigated in infarcted canine hearts using bipolar and intracellular microelectrode recordings. METHODS AND RESULTS: Dogs exhibiting rate-related ventricular ectopic beats (coupling interval, 390 ± 54 milliseconds) during sinus rhythm or atrial pacing were studied 4-5 days (N = 63) or 25 days (N = 16) following anterior descending coronary artery ligation...
June 1, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28554967/basal-late-sodium-current-is-a-significant-contributor-to-the-duration-of-action-potential-of-guinea-pig-ventricular-myocytes
#12
Yejia Song, Luiz Belardinelli
In cardiac myocytes, an enhancement of late sodium current (INaL) under pathological conditions is known to cause prolongation of action potential duration (APD). This study investigated the contribution of INaL under basal, physiological conditions to the APD Whole-cell INaL and the APD of ventricular myocytes isolated from healthy adult guinea pigs were measured at 36°C. The INaL inhibitor GS967 or TTX was applied to block INaL The amplitude of basal INaL and the APD at 50% repolarization in myocytes stimulated at a frequency of 0...
May 2017: Physiological Reports
https://www.readbyqxmd.com/read/28552884/ranolazine-facilitates-termination-of-ventricular-tachyarrhythmia-associated-with-acute-myocardial-ischemia-through-suppression-of-late-ina-mediated-focal-activity
#13
Takashi Ogawa, Haruo Honjo, Masatoshi Yamazaki, Yasunori Kushiyama, Ichiro Sakuma, Itsuo Kodama, Kaichiro Kamiya
BACKGROUND: Ventricular tachycardia/fibrillation (VT/VF) associated with acute myocardial ischemia is the most common cause of sudden cardiac death, but its underlying mechanisms are incompletely understood. It is hypothesized that late Na(+)current (INa) contributes to arrhythmogenic activity in ischemic myocardium.Methods and Results:Langendorff-perfused rabbit hearts with regional ischemia in ventricles were optically mapped. Perfusion with ranolazine (10 μmol/L), a selective inhibitor of lateINa, significantly reduced excitation frequency and facilitated termination of VT/VF induced after occlusion of the left main coronary trunk...
May 26, 2017: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/28551784/mitochondrial-function-in-non-ischemic-heart-failure
#14
Anisha A Gupte, Dale J Hamilton
Provision for the continuous demand for energy from the beating heart relies heavily on efficient mitochondrial activity. Non-ischemic cardiomyopathy in which oxygen supply is not limiting results from etiologies such as pressure overload. It is associated with progressive development of metabolic stress culminating in energy depletion and heart failure. The mitochondria from the ventricular walls undergoing non-ischemic cardiomyopathy are subjected to long periods of adaptation to support the changing metabolic milieu, which has been described as mal-adaptation since it ultimately results in loss of cardiac contractile function...
2017: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/28505345/cardio-oncology-a-multidisciplinary-approach-for-detection-prevention-and-management-of-cardiac-dysfunction-in-cancer-patients
#15
Kazuko Tajiri, Kazutaka Aonuma, Ikuo Sekine
Cardiac dysfunction that develops during or after completion of cancer therapy is a growing health concern that should be addressed in a multidisciplinary setting. Cardio-oncology is a new discipline that focuses on screening, monitoring and treating cardiovascular disease during and after cancer treatment. A baseline cardiovascular risk assessment is essential. For high-risk patients, a tailored and detailed plan for cardiovascular management throughout treatment and beyond should also be established. Anthracycline and/or trastuzumab-containing chemotherapy and chest-directed radiation therapy are well known cardiotoxic cancer therapies...
May 15, 2017: Japanese Journal of Clinical Oncology
https://www.readbyqxmd.com/read/28498644/early-versus-late-percutaneous-revascularization-in-patients-hospitalized-with-non-st-segment-elevation-myocardial-infarction-the-atherosclerosis-risk-in-communities-surveillance-study
#16
Sameer Arora, Kunihiro Matsushita, Arman Qamar, R Brandon Stacey, Melissa C Caughey
BACKGROUND: Current guidelines recommend early invasive intervention (<24 hr) for high risk patients with non-ST-segment elevation myocardial infarction (NSTEMI). A delayed invasive strategy (24-72 hr) is considered reasonable for low risk patients. The real-world effectiveness of this strategy is unknown. METHODS: The ARIC Study has conducted hospital surveillance of acute myocardial infarction (MI) since 1987. NSTEMI was classified using a validated algorithm...
May 12, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28497431/effect-of-catheter-based-renal-denervation-on-left-ventricular-function-mass-and-un-twist-with-two-dimensional-speckle-tracking-echocardiography
#17
Lida Feyz, Bas M van Dalen, Marcel L Geleijnse, Nicolas M Van Mieghem, Ron T van Domburg, Joost Daemen
BACKGROUND: Speckle tracking echocardiography (STE) is an echocardiography modality that is able to measure left ventricular (LV) characteristics, including rotation, strain and strain rate. Strain measures myocardial fibre contraction and relaxation. This study aims to assess the effect of renal sympathetic denervation (RDN) on functional myocardial parameters, including STE, and to identify potential differences between responders and non-responders. METHODS: The study population consisted of 31 consecutive patients undergoing RDN in the context of treatment for resistant hypertension...
May 11, 2017: Journal of Echocardiography
https://www.readbyqxmd.com/read/28489502/advances-in-cardiac-pacing-and-defibrillation
#18
Kristin Ellison, Parikshit S Sharma, Richard Trohman
There have been many evolutionary milestones in cardiac implantable electronic device (CIED) therapy over the past few decades. These advancements have created new  challenges. Right ventricular pacing was the original (late 1950s) breakthrough, however the risk of pacing induced dyssynchrony has become evident. Biventricular pacing provided a viable way to mitigate dyssynchrony, but only benefits certain patients (primarily left bundle branch block and QRS duration ≥150 ms with depressed left ventricular (LV) function)...
June 2017: Expert Review of Cardiovascular Therapy
https://www.readbyqxmd.com/read/28487470/discrepant-effects-of-heart-failure-on-electrophysiological%C3%A2-property-in-right-ventricular-outflow-tract-and-left-ventricular-outflow-tract-cardiomyocytes
#19
Yen-Yu Lu, Chen-Chuan Cheng, Chin-Feng Tsai, Yung Kuo Lin, Ting-I Lee, Yao-Chang Chen, Shih-Ann Chen, Yi Jen Chen
Ventricular arrhythmias commonly arise from the right and left ventricular outflow tracts (RVOT/LVOT) in patients without structural heart disease. Heart failure (HF) significantly increases the risk of ventricular arrhythmias. The regional differences and how HF affects the electrophysiological characteristics of RVOT and LVOT cardiomyocytes remain unclear. The whole-cell patch clamp technique was used to investigate the action potentials and ionic currents in isolated single RVOT and LVOT cardiomyocytes from control and rapid ventricular pacing-induced HF rabbit...
May 9, 2017: Clinical Science (1979-)
https://www.readbyqxmd.com/read/28485545/substrate-dependent-risk-stratification-for-implantable-cardioverter-defibrillator-therapies-using-cardiac-magnetic-resonance-imaging-the-importance-of-t1-mapping-in-nonischemic-patients
#20
Simon Claridge, Silvia Mennuni, Thomas Jackson, Jonathan M Behar, Bradley Porter, Benjamin Sieniewicz, Julian Bostock, Mark O'Neill, Francis Murgatroyd, Jaswinder Gill, Gerald Carr-White, Amedeo Chiribiri, Reza Razavi, Zhong Chen, Christopher Aldo Rinaldi
INTRODUCTION: The role of implantable cardioverter defibrillators (ICDs) in nonischemic cardiomyopathy is unclear and better risk-stratification is required. We sought to determine if T1 mapping predicts appropriate defibrillator therapy in patients with nonischemic cardiomyopathy. We studied a mixed cohort of ischemic and nonischemic patients to determine whether different cardiac magnetic resonance (CMR) applications (T1 mapping, late gadolinium enhancement, and Grayzone) were selectively predictive of therapies for the different arrhythmic substrates...
May 9, 2017: Journal of Cardiovascular Electrophysiology
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