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QRS morphology

John Rickard, Henry Michtalik, Ritu Sharma, Zackary Berger, Emmanuel Iyoha, Ariel R Green, Nowreen Haq, Karen A Robinson
BACKGROUND: Multiple studies have sought to determine variables associated with improved "response" to cardiac resynchronization therapy(CRT). Such variables, however, are often derived from inadequately controlled, single center cohort studies calling external validity into question. We sought to determine predictors of response to CRT-D and CRT-P utilizing the methods of systematic review. METHODS: We searched MEDLINE, Embase®, and the Cochrane Central Register of Controlled Trials (CENTRAL) from January 1, 1995, as this is the date of first article reporting use of CRT through October 20, 2014...
September 25, 2016: International Journal of Cardiology
Ru-Xing Wang, Hon-Chi Lee, Jia-Ping Li, David O Hodge, Yong-Mei Cha, Paul A Friedman, Thomas M Munger, Komandoor Srivathsan, Behzad B Pavri, Win-Kuang Shen
BACKGROUND: Although sudden death (SD) is a rare complication after atrioventricular junction (AVJ) ablation and permanent pacemaker implantation, the risk factors leading to this SD remain unknown. The purpose of this study was to investigate SD and its risk factors after ablate-and-pace strategy for rate control in atrial fibrillation (AF) patients during long-term follow-up. HYPOTHESIS: METHODS: From January 2005 to December 2009, we enrolled into this study 517 AF patients with AVJ ablation and right ventricular pacemaker implantation...
October 17, 2016: Clinical Cardiology
Claudia Schaarschmidt, Christof Kolb
The subcutaneous implantable defibrillator (S-ICD) has become an established tool for the prevention of sudden cardiac death. Based on its detection properties, the S‑ICD is essentially dependent on correct morphology discrimination of the QRS complex and avoidance of potential T‑wave sensing. We report on a patient who experienced multiple inappropriate S‑ICD shocks due to T‑wave oversensing in the setting of new onset of right bundle branch block. Strategies for the optimisation of the device programming are discussed...
October 13, 2016: Herzschrittmachertherapie & Elektrophysiologie
Hui Yang, Fabio Leonelli
QRS morphology is commonly used in the electrocardiographic diagnosis of ventricular depolarization such as left bundle branch block (LBBB) and ventricular septal infarction. We investigated whether pattern matching of QRS loops in the 3-dimensional vectorcardiogram (VCG) will improve the grouping of patients whose space-time electrical activity akin to each other, thereby assisting in clinical decision making. First, pattern dissimilarity of VCG QRS loops is qualitatively measured and characterized among patients, resulting in a 93×93 distance matrix of patient-to-patient dissimilarity...
September 28, 2016: Computers in Biology and Medicine
Andrew W Cairns, Raymond R Bond, Dewar D Finlay, Cathal Breen, Daniel Guldenring, Robert Gaffney, Anthony G Gallagher, Aaron J Peace, Pat Henn
INTRODUCTION: The 12-lead Electrocardiogram (ECG) presents a plethora of information and demands extensive knowledge and a high cognitive workload to interpret. Whilst the ECG is an important clinical tool, it is frequently incorrectly interpreted. Even expert clinicians are known to impulsively provide a diagnosis based on their first impression and often miss co-abnormalities. Given it is widely reported that there is a lack of competency in ECG interpretation, it is imperative to optimise the interpretation process...
September 26, 2016: Journal of Biomedical Informatics
Kim M J Verdurmen, Noortje B Eijsvoogel, Carlijn Lempersz, Rik Vullings, Christian Schroer, Judith O E H van Laar, S Guid Oei
BACKGROUND: Congenital heart disease (CHD) is the most common severe congenital anomaly worldwide. Diagnosis early in pregnancy is important, but the detection rate by two-dimensional ultrasonography is only 65%-81%. OBJECTIVES: To evaluate existing data on CHD and noninvasive abdominal fetal electrocardiography (ECG). SEARCH STRATEGY: A systematic review was performed through a search of the Cochrane Library, PubMed, and Embase for studies published up to April 2016 using the terms "congenital heart disease," "fetal electrocardiogram," and other similar keywords...
November 2016: International Journal of Gynaecology and Obstetrics
M A Oyama, M J Hezzell, D S Laughlin, C L Thorn, M S Kraus, A R Gelzer
Management of symptomatic bradyarrhythmias such as complete atrioventricular block often involves permanent implantation of a transvenous pacemaker. Both during and after implantation, the operator can telemetrically assess and adjust a variety of electrical parameters associated with the pacemaker function in order to optimize the sensitivity, reliability, and power consumption of the device. Herein, we report an unexpected change in the paced electrocardiographic QRS complex morphology in two dogs undergoing bipolar pacing associated with changes in the pacemaker output amplitude settings first detected during threshold testing...
September 6, 2016: Journal of Veterinary Cardiology: the Official Journal of the European Society of Veterinary Cardiology
Takuya Taniguchi, Naoki Maruyama, Takehiro Ogata, Takeru Kasahara, Naohiko Nakanishi, Kotaro Miyagawa, Daisuke Naito, Tetsuro Hamaoka, Masahiro Nishi, Satoaki Matoba, Tomomi Ueyama
Mutations in the PTRF/Cavin-1 gene cause congenital generalized lipodystrophy type 4 (CGL4) associated with myopathy. Additionally, long-QT syndrome and fatal cardiac arrhythmia are observed in patients with CGL4 who have homozygous PTRF/Cavin-1 mutations. PTRF/Cavin-1 deficiency shows reductions of caveolae and caveolin-3 (Cav3) protein expression in skeletal muscle, and Cav3 deficiency in the heart causes cardiac hypertrophy with loss of caveolae. However, it remains unknown how loss of PTRF/Cavin-1 affects cardiac morphology and function...
2016: PloS One
David Sedmera, Jan Neckar, Jiri Benes, Jana Pospisilova, Jiri Petrak, Kamil Sedlacek, Vojtech Melenovsky
Volume overload leads to development of eccentric cardiac hypertrophy and heart failure. In our previous report, we have shown myocyte hypertrophy with no fibrosis and decrease in gap junctional coupling via connexin43 in a rat model of aorto-caval fistula at 21 weeks. Here we set to analyze the electrophysiological and protein expression changes in the left ventricle and correlate them with phenotypic severity based upon ventricles to body weight ratio. ECG analysis showed increased amplitude and duration of the P wave, prolongation of PR and QRS interval, ST segment elevation and decreased T wave amplitude in the fistula group...
2016: Frontiers in Physiology
Thomas Brüggemann, Daniel Dahlke, Amin Chebbo, Ilka Neumann
Implantable cardioverter-defibrillators (ICD) have to reliably sense, detect, and treat malignant ventricular tachyarrhythmias. Inappropriate treatment of non life-threatening tachyarrhythmias should be avoided. This article outlines the functionality of ICDs developed and manufactured by BIOTRONIK. Proper sensing is achieved by an automatic sensitivity control which can be individually tailored to solve special under- and oversensing situations. The programming of detection zones for ventricular fibrillation (VF), ventricular tachycardia (VT), and zones to monitor other tachyarrhythmias is outlined...
September 2016: Herzschrittmachertherapie & Elektrophysiologie
Cira R T di Gioia, Carla Giordano, Bruna Cerbelli, Annalinda Pisano, Elena Perli, Enrico De Dominicis, Barbara Poscolieri, Vincenzo Palmieri, Costantino Ciallella, Paolo Zeppilli, Giulia d'Amati
Nonischemic Left Ventricular Scar (NLVS) is a pattern of myocardial injury characterized by midventricular and/or subepicardial gadolinium hyper enhancement at cardiac magnetic resonance, in absence of significant coronary artery disease. We aimed to evaluate the prevalence of NLVS in juvenile sudden cardiac death and to ascertain its aetiology at autopsy. We examined 281 consecutive cases of sudden death of subjects aged 1 to 35 years of age. NLVS was defined as a thin, grey rim of subepicardial and/or midmyocardial scar in the left ventricular free wall and/or the septum, in absence of significant stenosis of coronary arteries...
August 25, 2016: Human Pathology
Philippe Maury, Anne Rollin, Jean-Marc Sellal, Alexandre Duparc, Pierre Mondoly, Christelle Cardin, Christian De Chillou
We present an example of sudden modification in QRS morphology during ventricular pacing inside a scar-related isthmus. This is explained by a "concealed" sudden block in both the orthodromic and antidromic wavefront directions, allowing then the activation to proceed through a now overt antidromic conduction.
August 4, 2016: Journal of Electrocardiology
Ljuba Bacharova, Vavrinec Szathmary, Jana Svehlikova, Anton Mateasik, Milan Tysler
Diffuse or regional activation slowing in ventricular myocardium can result from different cardiac pathologies, such as left ventricular hypertrophy, ischemia or fibrosis. Altered ventricular activation sequence leads to deformations of the activation front and consequently to the changes in the QRS complex. Using a computer model we simulated the effect of slowed ventricular activation on the QRS waveform with a special interest in ECG changes which reproduce the ECG criteria of left ventricular hypertrophy (ECG-LVH)...
August 5, 2016: Journal of Electrocardiology
Jeffrey Luebbert, Denise Auberson, Francis Marchlinski
Premature ventricular complexes (PVCs) are consistently associated with worse prognosis and higher morbidity and mortality. This article reviews PVCs and their presentation in patients with an apparently normal heart. Patients with PVCs may be completely asymptomatic, whereas others may note severely disabling symptoms. Cardiomyopathy may occur with frequent PVCs. Diagnostic work-up is directed at obtaining 12-lead ECG to characterize QRS morphology, Holter monitor to assess frequency, and echo and advanced imaging to assess for early cardiomyopathy and exclude structural heart disease...
September 2016: Cardiac Electrophysiology Clinics
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
Danilo Ricciardi, Ilaria Cavallari, Antonio Creta, Giacomo Di Giovanni, Vito Calabrese, Natale Di Belardino, Simona Mega, Iginio Colaiori, Laura Ragni, Claudio Proscia, Antonio Nenna, Germano Di Sciascio
BACKGROUND: In 1990 the American Heart Association (AHA) established a standard 0.05 to 150Hz bandwidth for the routine recording of 12-lead electrocardiograms (ECGs). However, subsequent studies have indicated a very high prevalence of deviations from the recommended cutoffs. OBJECTIVE: This prospective observational study investigates the impact of 40Hz compared to 150Hz high-frequency cutoffs on ECG quality and clinical interpretation in a single-center surgical outpatient population...
September 2016: Journal of Electrocardiology
C Daluwatte, L Johannesen, L Galeotti, J Vicente, D G Strauss, C G Scully
False and non-actionable alarms in critical care can be reduced by developing algorithms which assess the trueness of an arrhythmia alarm from a bedside monitor. Computational approaches that automatically identify artefacts in ECG signals are an important branch of physiological signal processing which tries to address this issue. Signal quality indices (SQIs) derived considering differences between artefacts which occur in ECG signals and normal QRS morphology have the potential to discriminate pathologically different arrhythmic ECG segments as artefacts...
August 2016: Physiological Measurement
Michael A Valentino, Andrew Panakos, Loheetha Ragupathi, Janna Williams, Behzad B Pavri
In the setting of flecainide toxicity, supraventricular tachycardia can manifest as a bizarre right or left bundle branch block, sometimes with a northwest axis, and can easily be mistaken for ventricular tachycardia leading to inappropriate therapy. We conducted a comprehensive literature review for cases of flecainide toxicity. We found 21 articles of flecainide toxicity in adult patients in which 22 ECG tracings were published. In patients with flecainide toxicity and QRS duration ≤ 200 ms, the ECGs were more likely to show RBBB, visible P waves (p = 0...
July 19, 2016: Cardiovascular Toxicology
Krishna Kumar Mohanan Nair, Narayanan Namboodiri, Bharatraj Banavalikar, Ajitkumar Valaparambil, Anees Thajudeen, Jaganmohan Tharakan
No abstract text is available yet for this article.
July 16, 2016: Journal of Cardiovascular Electrophysiology
Stuart Mealing, Beth Woods, Neil Hawkins, Martin R Cowie, Christopher J Plummer, William T Abraham, John F Beshai, Helmut Klein, Mark Sculpher
OBJECTIVE: To evaluate the cost-effectiveness of implantable cardioverter defibrillators (ICDs), cardiac resynchronisation therapy pacemakers (CRT-Ps) and combination therapy (CRT-D) in patients with heart failure with reduced ejection fraction based on a range of clinical characteristics. METHODS: Individual patient data from 13 randomised trials were used to inform a decision analytical model. A series of regression equations were used to predict baseline all-cause mortality, hospitalisation rates and health-related quality of life and device-related treatment effects...
July 13, 2016: Heart: Official Journal of the British Cardiac Society
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