Ljuba Bacharova

International Laser Centre · Biophotonics

The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria. The classical paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces, reflected in the augmented QRS amplitude. However, the low sensitivity of voltage criteria has been repeatedl...

The International Research Interdisciplinary School (IRIS) program is a training for young researchers with a biomedical background who are interested in acquiring the methodological knowledge and experience in preparing a study protocol for a project. The IRIS program is an outcome-oriented problem-solving workshop designed to promote team collabo...

The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria, i.e. the increased QRS complex amplitude in defined leads. The classical ECG diagnostic paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces. These increased forces are reflecte...

Left ventricular hypertrophy (LVH) refers to a complex rebuilding of the left ventricle that can gradually lead to serious complications—heart failure and life-threatening ventricular arrhythmias. LVH is defined as an increase in the size of the left ventricle (i.e., anatomically), therefore the basic diagnosis detecting the increase in the LV size...

Intraventricular conduction disturbances (IVCD) are currently generally accepted as ECG diagnostic categories. They are characterized by defined QRS complex patterns that reflect the abnormalities in the intraventricular sequence of activation that can be caused by pathology in the His-Purkinje conduction system (HP) or ventricular myocardium. Howe...

The electrocardiogram (ECG) and cardiovascular magnetic resonance imaging (CMR) provide powerful prognostic information. The aim was to determine their relative prognostic value. Patients (n = 783) undergoing CMR and 12-lead ECG with a QRS duration < 120 ms were included. Prognosis scores for one-year event-free survival from hospitalization for he...

Electrocardiographic (ECG) signs of left ventricular hypertrophy (LVH) lack sensitivity. The aim was to identify LVH based on an abnormal spatial peaks QRS-T angle, evaluate its diagnostic performance compared to conventional ECG criteria for LVH, and its prognostic performance. This was an observational study with four cohorts with a QRS duration...

Purpose Oxidative stress is an important contributor to the etiology of atrial fibrillation (AF). Our aim was to study oxidative stress biomarkers in patients undergoing pulmonary vein isolation (PVI) for paroxysmal AF with radiofrequency catheter ablation and to assess its prognostic value in predicting long-term PVI outcome. Methods In this pros...

Left ventricular hypertrophy (LVH) detected electrocardiographically is documented as an independent cardiovascular risk factor. However, the reasoning for using electrocardiography (ECG) for LVH detection is frequently referring to its low cost and availability, which should compensate for the main problem of the ECG criteria for LVH detection (EC...

Background: Conventional electrocardiographic (ECG) signs of left ventricular hypertrophy lack sensitivity, The aim was to identify LVH based on an abnormal spatial peaks QRS-T angle, and evaluate its diagnostic and prognostic performance compared to that of conventional ECG criteria for LVH. Methods: This was an observational study with four cohor...

Background: The electrocardiogram (ECG) and cardiovascular magnetic resonance imaging (CMR) both provide powerful prognostic information. The aim was to determine the relative prognostic value of ECG and CMR, respectively. Methods: Consecutive patients (n=783) undergoing CMR and resting 12-lead ECG with a QRS duration <120 ms were included. CMR mea...

The Fourth Universal Definition of Myocardial Infarction (FUDMI) focuses on the distinction between nonischemic myocardial injury and myocardial infarction (MI), along with the role of cardiovascular magnetic resonance, in order to define the etiology of myocardial injury. As a consequence, there is less emphasis on updating the parts of the defini...

Micro ribonucleic acids (miRNAs) are short non-coding RNA molecules responsible for regulation of gene expression. They are involved in many pathophysiological processes of a wide spectrum of diseases. Recent studies showed their involvement in atrial fibrillation. They seem to become potential screening biomarkers for atrial fibrillation and even...

The Fourth Universal Definition of Myocardial Infarction (FUDMI) [published simultaneously in 2018 in numerous journals including Circulation, Journal of the American College of Cardiology and European Heart Journal] focuses mainly on the distinction between non-ischemic myocardial injury and myocardial infarction (MI), along with the role of cardi...

Background: Previous studies showed an association between apelin and atrial fibrillation (AF). The aim of this study was to analyse the effect of pulmonary vein isolation (PVI) in patients with paroxysmal AF on plasmatic apelin concentrations. Methods: Nine consecutive patients (aged from 43 to 69 years, 3 females and 6 males) with documented p...

The sex differences in ventricular structure and electrophysiological characteristics under normal/physiological conditions are well described. These differences are more pronounced in cardiac pathology associated with structural changes of myocardium that can consequently create a substrate for initiating and maintaining ventricular arrhythmias. T...

The aim of this opinion paper is to point out the knowledge gap between evidence on the molecular level and clinical diagnostic possibilities in left ventricular hypertrophy (LVH) regarding the prediction of ventricular arrhythmias and monitoring the effect of therapy. LVH is defined as an increase in left ventricular size and is associated with in...

In the year 2019, two IRIS courses were held, one in Ukraine and one in Slovakia, completing the total number of 25 courses since the year 2006. The IRIS courses (International Research Interdisciplinary Schools, previously International Scientific Summer Schools) are organized already 14 years, aiming to satisfy the needs in training young researc...

Background: According to current guidelines, the main indications for PCI in patients with STEMI are ST-segment deviations and defined time from the onset of symptoms. Negative T wave at admission can be a sign of prolonged ischemia or spontaneous reperfusion. In both situations, the urgent intervention is questionable. We evaluated the infarct si...

The term ‘ventricular hypertrophy’ encompasses changes seen in a variety of cardiac pathological processes as well as in some physiological ones. The traditional concept involved in the electrocardiographic (ECG) diagnosis of ventricular hypertrophy assumes that an enlarged ventricular mass generates a stronger electrical field: in left ventricular...

The term ‘ventricular hypertrophy’ encompasses changes seen in a variety of cardiac pathological processes as well as in some physiological ones. The traditional concept involved in the electrocardiographic (ECG) diagnosis of ventricular hypertrophy assumes that an enlarged ventricular mass generates a stronger electrical field: in left ventricular...

Both obesity and menopause are significant cardiovascular risk factors. In postmenopausal women the protective effect of estrogens is reduced and menopause is frequently associated with occurrence of other significant cardiovascular factors including obesity. This study was focused on evaluating the effect of obesity on the QRS complex in pre- and...

Background: Eisenmenger syndrome represents severe, irreversible, and end-stage pulmonary arterial hypertension (PAH) associated with congenital heart defects. For long-term outcome optimal right ventricular (RV) adaptation is crucial with precise assessment of its hypertrophy, dilatation and function. Objectives: Associations of electrocardiogr...

Despite its importance in everyday clinical practice, the ability of physicians to interpret electrocardiograms (ECGs) is highly variable. ECG patterns are often misdiagnosed, and electrocardiographic emergencies are frequently missed, leading to adverse patient outcomes. Currently, many medical education programs lack an organized curriculum and c...

Background: Immune abnormalities are common in Fontan patients with protein-losing enteropathy. Limited data exist on immune function of other patients with single ventricle circulation. Methods: This prospective cohort study evaluated immunologic characteristics of children with single ventricle circulation from neonatal age up to early post-Fo...

Left ventricular hypertrophy (LVH) is defined as an increase in left ventricular mass (LVM) associated with structural changes of myocardium. The increase in LVM and associated changes are associated with changes in depolarization and repolarization, manifested as a variety of altered QRS and T patterns. Increased QRS voltage has been considered to...

Despite the increasing number of women entering the medical profession, senior positions and academic productivity in many fields of medicine remain to be men dominated. We explored gender equity in electrocardiology as perceived by recent academic productivity and also active participation (presidencies and board constituents) in both the Internat...

Background Myocardial fibrosis quantified by myocardial extracellular volume fraction (ECV) and left ventricular mass (LVM) index (LVMI) measured by cardiovascular magnetic resonance might represent independent and opposing contributors to ECG voltage measures of left ventricular hypertrophy (LVH). Diffuse myocardial fibrosis can occur in LVH and i...

The classical paradigm of the left ventricular hypertrophy (LVH) postulates the increased electrical dominance of the left ventricle, i.e. the increased QRS amplitude in leads that record resultant electrical forces directed leftward, downward and posteriorly. However, the ECG criteria based on this paradigm are characteristic by low sensitivity an...

The International Research Interdisciplinary School (IRIS) provides an interdisciplinary international environment for training skills required for preparing research study protocols, scientific manuscript and international collaboration. It is a common initiative of the Journal of Electrocardiology, Anatolian Journal of Cardiology, Monitor of Medi...

The 4th Report provides a brief review of publications focused on the electrocardiographic diagnosis of left ventricular hypertrophy published during the period of 201 to 2016 by the members of the Working Group on ECG diagnosis of Left Ventricular Hypertrophy. The Working Group recommended that ECG research and clinical attention be redirected fro...

This paper describes a substantial part of the international mentoring network of students and young investigators in electrocardiology that developed around Dr. Galen Wagner (1939–2016), including many experiences of his mentees and co-mentors. The paper is meant to stimulate thinking about international mentoring as a means to achieve important l...

A growing number of targeted anticancer agents has shown the unexpected ability to induce QT interval prolongation. In addition, standard chemotherapeutics and a variety of conditions such as electrolyte abnormalities, endocrine disorders, cardiac diseases, nutritional disturbances and other factors may be associated with long QT syndrome in cancer...

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...

Identification of the QRS-complex duration in acute myocardial infarction (MI) is of great importance, having diagnostic, therapeutic and prognostic consequences. In acute MI with ST- segment deviation, the terminal part of QRS complex is distorted, without a clear demarcation between QRS and ST segment, making the identification of the QRS-complex...

Activation wavefront propagation was computed and visualized in a geometrical heart model for pathological cases of reduced velocity of propagation, left ventricular hypertrophy and their combination. Selected parameters of a multiple dipole equivalent heart generator were computed and compared for three heart geometries and several degrees and ext...

Introduction: There is a well-known relation between oxidative stress and atrial fibrillation. The aim of our research was to study the relation between the percentage of time spent in atrial fibrillation (AF burden) and concentrations of oxidative stress biomarkers, before and after pulmonary veins isolation (PVI). Methodology: We included 19 pati...

Material and methods: The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids; the left ventricular wall is represented by five layers. The impulse propagation velocity was decreased by 50% in one and two midwall layers, respectively, in the whole left ventricle and in LV anterior region. The effects of slowed cond...

Obstructive sleep apnea (OSA) has been reported to be associated with an increased risk of ventricular arrhythmias and conduction disturbances. The aim of this study was to analyze the QRS complex morphology potentially indicative of intraventricular conduction impairment in patients with mild to severe OSA. One hundred ninety-three consecutive pat...

Despite the low sensitivity of the electrocardiogram (ECG) in detecting left ventricular hypertrophy (LVH), ECG-LVH is known to be a strong predictor of cardiovascular risk. Understanding reasons for the discrepancies in detection of LVH by ECG versus imaging could help improve the diagnostic ability of ECG. We examined factors associated with fals...

Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow–Lyon, Romhilt–Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging wi...

The classical paradigm of electrocardiographic diagnosis of left ventricular hypertrophy (LVH) is based on empirical finding of increased QRS voltage in cases of LVH and a continuous effort is devoted to finding ECG criteria that agree best with LVH classification according to an ECG-independent standard such as echocardiographic LVH (echo-LVH) bas...

Background Acute myocardial infarction creates regions of altered electrical properties of myocardium resulting in typical QRS patterns (pathological Q waves) and ST segment deviations observed in leads related to the MI location. The aim of this study was to present a graphical method for imaging the changes in the sequence of depolarization and t...

The traditional approach to the ECG diagnosis of left ventricular hypertrophy (LVH) is focused onthe best estimation of left ventricular mass (LVM) i.e. finding ECG criteria that agree with LVM as detected by imaging. However, it has been consistently reported that the magnitude of agreement is rather low as reflected in the low sensitivity of ECG...

Reduction or interruption of the blood supply to myocardium due to occlusion of coronary artery and consequent ischemia leads to changes of electrogenesis: changes in morphology and duration of action potentials and slowing of conduction velocity in the affected area. In this study we simulated the effects of localized changes in depolarization seq...

A left bundle-branch block (LBBB) electrocardiogram (ECG) type may be caused by either a block in the left branch of the ventricular conduction system or by uncoupling in the working myocardium. We used a realistic large-scale computer model to evaluate the effects of uncoupling with and without left-sided block and in combination with biventricula...

An increased QRS voltage is considered to be specific for the electrocardiogram (ECG) diagnosis of left ventricular hypertrophy (LVH). However, the QRS-complex patterns in patients with LVH cover a broader spectrum: increased QRS voltage, prolonged QRS duration, left axis deviation, and left anterior fascicular block- and left bundle branch block-l...

Impaired interatrial conduction or interatrial block is well documented but is not described as an individual electrocardiographic (ECG) pattern in most of ECG books, although the term atrial abnormalities to encompass both concepts, left atrial enlargement (LAE) and interatrial block, has been coined. In fact, LAE and interatrial block are often a...