Read by QxMD icon Read


Paolo Bifulco, Gaetano Dario Gargiulo, Maria Romano, Mario Cesarelli
Reliable detection of pacemaker pulses is getting more and more important in electrocardiography (ECG) diagnosis. Many studies recommend ECG amplifiers with higher bandwidth to prevent errors. In the past, few pilot studies showed that analysis of pacemaker pulses waveform can enhance diagnosis (eg, lead failure and fractured wire), but they were carried out with inadequate instrumentations for clinical practice. Typically, pacemaker pulses last hundreds of microseconds, edges of pulses elapse in few microseconds, and amplitude may exhibit large variations from few millivolts to volts...
2016: Medical Devices: Evidence and Research
Markus Lingman, Marianne Hartford, Thomas Karlsson, Johan Herlitz, Aigars Rubulis, Kenneth Caidahl, Lennart Bergfeldt
BACKGROUND: Prediction of sudden cardiac death (SCD) after acute coronary syndromes (ACS) remains a challenge. Although electrophysiology measures obtained by 3-D vectorcardiography (VCG) shortly after ACS may be useful predictors of SCD, they have not been adopted into clinical practice. The main objective of our study was to assess whether the VCG-derived QRS-T area angle (between area vectors) and the QRS-T angle (between maximum vectors) have additional value beyond standard risk factors in predicting SCD after ACS...
September 1, 2016: International Journal of Cardiology
Tobias Reichlin, Roger Abächerli, Raphael Twerenbold, Michael Kühne, Beat Schaer, Christian Müller, Christian Sticherling, Stefan Osswald
The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is critical for evidence-based management of patients with most cardiovascular conditions, including patients with acute myocardial infarction, suspected chronic cardiac ischaemia, cardiac arrhythmias, heart failure and implantable cardiac devices. In contrast to many other techniques in cardiology, the ECG is simple, small, mobile, universally available and cheap, and therefore particularly attractive. Standard ECG interpretation mainly relies on direct visual assessment...
2016: Swiss Medical Weekly
Raúl Correa, Pedro D Arini, Lorena S Correa, Max Valentinuzzi, Eric Laciar
BACKGROUND: The largest morbidity and mortality group worldwide continues to be that suffering Myocardial Infarction (MI). The use of vectorcardiography (VCG) and electrocardiography (ECG) has improved the diagnosis and characterization of this cardiac condition. OBJECTIVES: Herein, we applied a novel ECG-VCG combination technique to identifying 95 patients with MI and to differentiating them from 52 healthy reference subjects. Subsequently, and with a similar method, the location of the infarcted area permitted patient classification...
May 17, 2016: Methods of Information in Medicine
Golriz Sedaghat, Elyar Ghafoori, Jonathan W Waks, Muammar M Kabir, Alexei Shvilkin, Mark E Josephson, Larisa G Tereshchenko
Vectorcardiography (VCG), developed 100years ago, characterizes clinically important electrophysiological properties of the heart. In this study, VCG QRS loop roundness, planarity, thickness, rotational angle, and dihedral angle were measured in 81 healthy control subjects (39.0±14.2y; 51.8% male; 94% white), and 8 patients with infarct-cardiomyopathy and sustained monomorphic ventricular tachycardia (VT) (68.0±7.8y, 37.5% male). The angle between two consecutive QRS vectors was defined as the rotational angle, while dihedral angle quantified planar alteration over the QRS loop...
March 2016: Journal of Electrocardiology
Daniel Cortez, Sonali S Patel, Nandita Sharma, Bruce F Landeck, Anthony C McCanta, Pei-Ni Jone
INTRODUCTION: Kawasaki disease (KD) is the leading cause of acquired heart disease in children. The 12-lead electrocardiogram (ECG) changes in patients during the acute phase of KD include flattened T waves and prolonged corrected QT intervals (QTc). We set out to determine the 12-lead ECG and vectorcardiography predictors for identification of patients with KD and which of these predictors would be clinically useful for early identification of those with coronary artery anomalies (CAA)...
September 2016: Annals of Noninvasive Electrocardiology
Eszter M Végh, Elien B Engels, Caroline J M van Deursen, Béla Merkely, Kevin Vernooy, Jagmeet P Singh, Frits W Prinzen
AIMS: There is increasing evidence that left bundle branch block (LBBB) morphology on the electrocardiogram is a positive predictor for response to cardiac resynchronization therapy (CRT). We previously demonstrated that the vectorcardiography (VCG)-derived T-wave area predicts echocardiographic CRT response in LBBB patients. In the present study, we investigate whether the T-wave area also predicts long-term clinical outcome to CRT. METHODS AND RESULTS: This is a retrospective study consisting of 335 CRT recipients...
July 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Sumche Man, Arie C Maan, Martin J Schalij, Cees A Swenne
In the course of time, electrocardiography has assumed several modalities with varying electrode numbers, electrode positions and lead systems. 12-lead electrocardiography and 3-lead vectorcardiography have become particularly popular. These modalities developed in parallel through the mid-twentieth century. In the same time interval, the physical concepts underlying electrocardiography were defined and worked out. In particular, the vector concept (heart vector, lead vector, volume conductor) appeared to be essential to understanding the manifestations of electrical heart activity, both in the 12-lead electrocardiogram (ECG) and in the 3-lead vectorcardiogram (VCG)...
July 2015: Journal of Electrocardiology
Muhammad A Hasan, Derek Abbott
Elevated ventricular repolarization lability is believed to be linked to the risk of ventricular tachycardia/ventricular fibrillation. However, ventricular repolarization is a complex electrical phenomenon, and abnormalities in ventricular repolarization are not completely understood. To evaluate repolarization lability, vectorcardiography (VCG) is an alternative approach where the electrocardiographic (ECG) signal can be considered as possessing both magnitude and direction. Recent research has shown that VCG is advantageous over ECG signal analysis for identification of repolarization abnormality...
February 2016: Biomedizinische Technik. Biomedical Engineering
Laura Perrotta, Giuseppe Ricciardi, Paolo Pieragnoli, Martina Nesti, Giulia Pontecorboli, Fabio Fantini, Luigi Padeletti
INTRODUCTION: "Cardiac memory" (CM) refers to a change in repolarization induced by an altered pathway of activation, manifested after resumption of spontaneous ventricular activation (SVA). AIMS: To investigate for the first time in humans the effects of left ventricular (LV) pacing on CM development through vectorcardiography (VCG). METHODS: We studied 28 patients with heart failure (HF) and left bundle branch block (LBBB) treated with cardiac resynchronization therapy (CRT)...
July 2015: Journal of Electrocardiology
Elien B Engels, Salih Alshehri, Caroline J M van Deursen, Liliane Wecke, Lennart Bergfeldt, Kevin Vernooy, Frits W Prinzen
BACKGROUND: The use of vectorcardiography (VCG) has regained interest, however, original Frank-VCG equipment is rare. This study compares the measured VCGs with those synthesized from the 12-lead electrocardiogram (ECG) in patients with heart failure and conduction abnormalities, who are candidate for cardiac resynchronization therapy (CRT). METHODS: In 92 CRT candidates, Frank-VCG and 12-lead ECG were recorded before CRT implantation. The ECG was converted to a VCG using the Kors method (Kors-VCG) and the two methods were compared using correlation and Bland-Altman analyses...
July 2015: Journal of Electrocardiology
Stefan Peters
No abstract text is available yet for this article.
2015: International Journal of Cardiology
Caroline J M van Deursen, Liliane Wecke, Wouter M van Everdingen, Marcus Ståhlberg, Michel H G Janssen, Frieder Braunschweig, Lennart Bergfeldt, Harry J G M Crijns, Kevin Vernooy, Frits W Prinzen
Current optimization of atrioventricular (AV) and interventricular (VV) intervals in cardiac resynchronization therapy (CRT) is time consuming and subject to noise. We aimed to prove the principle that the best hemodynamic effect of CRT is achieved by cancelation of opposing electrical forces, detectable from the QRS morphology in the 3D vectorcardiogram (VCG). Different degrees of left (LV) and right ventricular (RV) pre-excitation were induced, using variation in AV intervals during LV pacing in 20 patients with left bundle branch block (LBBB) and variation in VV intervals during biventricular pacing in 18 patients with complete AV block or atrial fibrillation...
March 2015: Journal of Cardiovascular Translational Research
Daniel Cortez, Emily Ruckdeschel, Anthony C McCanta, Kathryn Collins, William Sauer, Joseph Kay, Duy Nguyen
INTRODUCTION: Vectorcardiography (VCG) may have predictive value in Tetralogy of Fallot (TOF) patients undergoing ventricular arrhythmia inducibility (VAI) electrophysiology studies (EPs). MATERIALS AND METHODS: Blinded, retrospective analyses of 37 adult TOF patients undergoing EPs prior to pulmonary valve replacements were performed (21 female, median age 37years). VAI was evaluated from EPs and resting 12-lead electrocardiograms, respectively using QRS and heart rate adjusted Q-T intervals, spatial QRS-T angles (peaks), T-wave and QRS-wave (QRSwave vc) component vector root mean squares...
March 2015: Journal of Electrocardiology
Caroline J M van Deursen, Kevin Vernooy, Elton Dudink, Lennart Bergfeldt, Harry J G M Crijns, Frits W Prinzen, Liliane Wecke
BACKGROUND: QRS duration and left bundle branch block (LBBB) morphology are used to select patients for cardiac resynchronization therapy (CRT). We investigated whether the area of the QRS complex (QRSAREA) on the 3-dimensional vectorcardiogram (VCG) can improve patient selection. METHODS: VCG (Frank orthogonal lead system) was recorded prior to CRT device implantation in 81 consecutive patients. VCG parameters, including QRSAREA, were assessed, and compared to QRS duration and morphology...
January 2015: Journal of Electrocardiology
Heidi Hintsala, Tuomas V Kenttä, Mikko Tulppo, Antti Kiviniemi, Heikki V Huikuri, Matti Mäntysaari, Sirkka Keinänen-Kiukaannemi, Risto Bloigu, Karl-Heinz Herzig, Riitta Antikainen, Hannu Rintamäki, Jouni J K Jaakkola, Tiina M Ikäheimo
OBJECTIVES: The aim of our study was to assess the effect of short-term cold exposure, typical in subarctic climate, on cardiac electrical function among untreated middle-aged hypertensive men. METHODS: We conducted a population-based recruitment of 51 hypertensive men and a control group of 32 men without hypertension (age 55-65 years) who underwent whole-body cold exposure (15 min exposure to temperature -10°C, wind 3 m/s, winter clothes). Conduction times and amplitudes, vectorcardiography, arrhythmias, and heart rate variability (autonomic nervous function) were assessed...
2014: PloS One
Markus Lingman, Marianne Hartford, Thomas Karlsson, Johan Herlitz, Aigars Rubulis, Kenneth Caidahl, Lennart Bergfeldt
OBJECTIVE: To study effects of ischemia-reperfusion on ventricular electrophysiology in humans by three-dimensional electrocardiography. METHODS: Fifty-seven patients with first-time acute anterior ST elevation myocardial infarction were monitored from admission and >24h after symptom onset with continuous vectorcardiography (VCG; modified Frank orthogonal leads). Global ventricular depolarization and repolarization (VR) measures were compared at maximum vs. minimum ST vector magnitude (STVM) (median 208; 111-303 vs...
July 2014: Journal of Electrocardiology
Raúl Correa, Pedro David Arini, Lorena Sabrina Correa, Max Valentinuzzi, Eric Laciar
BACKGROUND: The novel signal processing techniques have allowed and improved the use of vectorcardiography (VCG) to diagnose and characterize myocardial ischemia. Herein, we studied vectorcardiographic dynamic changes of ventricular repolarization in 80 patients before (control) and during Percutaneous Transluminal Coronary Angioplasty (PTCA). METHODS: We propose four vectorcardiographic ST-T parameters, i.e., (a) ST Vector Magnitude Area (aSTVM); (b) T-wave Vector Magnitude Area (aTVM); (c) ST-T Vector Magnitude Difference (ST-TVD), and (d) T-wave Vector Magnitude Difference (TVD)...
July 2014: Computers in Biology and Medicine
Alfredo de Micheli Serra, Pedro Iturralde Torres
The history of the investigations about of the so-called irritability of animal tissues showed by English physician Francis Glisson in the 17th century, is summarized. During the 18th century, reliable studies on the bioelectric properties of these tissues began, due to the Swiss scientist Albrecht von Haller and continuated by the Italian naturalist Felice Fontana. In the second half of this century, multiple controversies of the partisans of the animal electricity against the partisans of the contact electricity took place...
April 2014: Archivos de Cardiología de México
Gerard van Herpen
Einthoven not only designed a high quality instrument, the string galvanometer, for recording the ECG, he also shaped the conceptual framework to understand it. He reduced the body to an equilateral triangle and the cardiac electric activity to a dipole, represented by an arrow (i.e. a vector) in the triangle's center. Up to the present day the interpretation of the ECG is based on the model of a dipole vector being projected on the various leads. The model is practical but intuitive, not physically founded...
March 2014: Journal of Electrocardiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"