Increased QRS Voltage Research Articles

Electrocardiographic and morphological cardiac remodeling in competitive female athletes - a scoping review.

To quantitatively analyse exercise-induced cardiac remodeling (EICR) data in female athletes. This scoping review included from the databases Medline, Embase, and Google Scholar, peer-reviewed original English-language articles on female athlete-populations aged ≥18 years containing data on electrocardiography (ECG), echocardiography or cardiac magnetic resonance (CMR), and excluded athletes with cardiovascular conditions. From the extracted ECG data, we calculated prevalence percentages, and from the imaging data we compared the results with the upper reference limits of the general female population (URL). We included 31 articles comprising 4,896 female athletes, aged mean 22.2±4.6 years. On ECG (n=889), most prevalent findings were increased QRS voltages for LV hypertrophy (LVH, n=97), J-point elevation (JPE, n=108), and T-wave inversion (TWI, n=104). On echocardiography (n=4,644), we found increased mean of means BSA-indexed volumes for the LV 67.3 mL/m2 (95%CI 66.8-67.8; URL=61) and right ventricle (RV) 82.7 mL/m2 (95%CI 79.5-86.0; URL=74), while atrial volumes, septal wall thickness and LV mass were within the upper reference limits of the general population (URL). On CMR (n=309), the mean of means volumes of LA (62.0 mL/m2, 95%CI 58.8-65.2; URL=61), LV (103.4 mL/m2, 95%Ci 101.8-105.0; URL=96), and RV (105.3 mL/m2, 95%CI 103.3-110.6; URL=107.2) were >URL. Female athletes demonstrate distinct features of electrical (increased QRS voltages for LVH, JPE and TWI) and morphological EICR (biventricular dilatation). On CMR, LA was borderline dilated. Extensive studies on female athletes are needed to understand sex specific EICR.

Early repolarization in adolescent athletes: A gender comparison of ECG and echocardiographic characteristics.

The early repolarization pattern (ERp) is an electrocardiographic finding previously associated with arrhythmic risk in adults. The purpose of this study is to evaluate the prevalence and characteristics of ERp in a group of adolescent athletes according to gender. Furthermore, potential associations with clinical, electrocardiographic, and echocardiographic parameters are explored. In this cross-sectional study young athletes (age < 18 years) were consecutively enrolled during the annual pre-participation evaluation, undergoing also transthoracic echocardiography assessment from January 2015 to March 2020. The prevalence of ERp was 27% in the whole population. Athletes with ERp were more frequently men practicing endurance sports. Women with ERp showed lower heart rate at rest, greater posterior, and relative ventricular wall thickness than those without ERp. Men with ERp presented higher systolic blood pressure at peak exercise, greater septal wall thickness, and indexed left ventricular mass than those without ERp. Both genders with ERp showed increased QRS voltage and narrower QRS duration. The ERp phenotype in men was more frequently notched with higher amplitude and ascending ST segment. Women's ERp presented more frequently a slurred morphology, especially in the inferior leads, and horizontal ST slope. No differences emerged in the occurrence of arrhythmias at rest and during maximal exercise test between groups, even considering higher risk phenotypes. ERp is an ECG finding compatible with normal cardiac adaptations to training in young athletes. ERp demonstrated gender differences regarding phenotypes previously associated with increased cardiovascular risk, not showing any differences in arrhythmias during maximal exercise test.

Inter-relationships of different electrocardiographic indicators of left ventricular hypertrophy in 25,000 Chinese adults

Abstract Background Several electrocardiographic (ECG) indices have previously been proposed to diagnose left ventricular hypertrophy (LVH). Such indices utilize different criteria, including increased QRS voltage, prolonged QRS duration, left axis deviation, and LAFB and LBBB-like patterns in varying combinations. However, the inter-relationships of these different electrocardiographic indices of LVH with each otherare not fully understood. The purpose of this study is to estimate the relationships between the different LVH indices. Methods Electronic tracings of 12-lead ECGs recorded in 24,786 adult participants in the China Kadoorie Biobank recorded in 2014 were accessed to detect presence of LVH. ECG parameters of LVH, including individual and combinations of such parameters (voltage-only criteria such as Sokolov-Lyon, Cornell, Gubner as well as scores such as Romhilt-Estes point score) were estimated using customized computer software (Cardiolyse Oy, Finland) and compared proprietary LVH point score algorithms (Mortara, USA). Relationships between the different indices were assessed using a correlation matrix to explore associations between individual parameters and combined indices of such parameters. The matrices were used to construct heat maps and identify clustering of individual parameters. Results Overall, approximately 10% of the population had LVH assessed by Mortara algorithms. This graph shows that along with the free standing peaks, the rest are divided into two clusters of interconnected individual parameters. In the center of the largest cluster is the parameter, reflecting R-peak magnitude in aVL lead. In the center of another cluster was the left ventricular strain pattern, as described in Romhilt-Estes point score system. Overall, the Sokolov-Lyon index and LVH point score in Veritas algorithm had the strongest relationships with each other, but the Gubner and Cornell indices had relatively weak correlations with the other indices (Table 1). The mean correlation coefficient between five combined LVH indices was as follows: Veritas (Mortara) – 0.58, Sokolov-Lyon – 0.56, Romhilt-Estes – 0.45, Gubner – 0,32, Cornell – 0,3. Conclusions Parameters such as R-peak magnitude in aVL and left ventricular strain pattern were the most strongly related with each other. Aggregate indices, such as the Sokolov-Lyon index and LVH point score in Veritas algorithm were the most strongly related with all other indices, but the Gubner and Cornell indices were only weakly correlated. The results reinforce the utility of Sokolov-Lyon index and Mortara algorithms as the optimum measures of LVH. Funding Acknowledgement Type of funding sources: None.

Electrocardiographic changes after completion of a triathlon

ABSTRACT Objectives Given the increasing popularity of long-distance triathlon events amongst amateur athlete and the difficulty for emergency physician to address cardiovascular complaints in the context of exercise, this study aims to: -Identify the prevalence of electrocardiographic abnormalities before and after a long distance triathlon in a cohort of participants using the Seattle criteria. -Identify the acute changes that occur on their ECGs at the finish line of a long-distance triathlon. Methods This prospective observational study examines the prevalence of selected standard 12-lead ECG findings, the Seattle criteria, in asymptomatic athletes before and after the completion of a long-distance triathlon. Results Of 99 ECGs obtained prior to the race, 28 were abnormal, for a pre-race prevalence of 28.3% (95% CI (20.4, 37.8)). Of the 72 ECGs post-race, 12 were abnormal, for a post-race prevalence of 16.7% (95% CI (9.8, 26.9)). We did not observe any athletes with marked repolarization abnormalities. Common findings were increased QRS voltage significant for left ventricular hypertrophy (LVH) (24 (24.2%) pre-race, 10 (14.1%) post-race), early repolarization (21 (21.2%) pre-race, 19 (26.8%) post-race) and incomplete right bundle branch block (RBBB) (8 (8.1%) pre-race, 11 (15.5%) post-race). McNemar’s test showed no agreement between the ECG pre and post results (Chi-square =6.54, p = 0.01), suggesting a possible effect of the race on ECG findings. We observed a trend to normalization of athlete’s ECGs with acute exercise. Conclusion Long-distance endurance exercise might acutely affect the ECGs findings in asymptomatic athletes and abnormal ECG findings were common in our cohort of athletes. Physicians providing care to long-distance athletes should interpret ECGs in this population prudently. SUMMARY BOX The acute effect of exercises on athlete’s electrocardiograms has not been well studied. In our cohort of long-distance triathlon finishers, 28.3% of athletes had abnormal ECGs pre-race and 16.7% had abnormal ECGs post-race according to the Seattle Criteria. We observed a trend toward normalization of athlete’s ECGs with acute exercise. Common ECGs abnormalities found in those asymptomatic athletes were left ventricular hypertrophy, early repolarization and right bundle branch block. Physicians involved in the care of athletes should be prudent when interpreting ECGs in this population.

Abnormal ECG findings in athletes

Athlete's heart, as a consequence of exercise training, is characterized by hypervagotonia and enlargement of cardiac chambers. Such modifications influence the electrocardiogram. In fact, athletes frequently present with common cardiac alterations, including sinus bradycardia, first and second degree atrioventricular block, increased QRS voltage, and early repolarization. In addition, uncommon alterations (borderline or abnormal) may be discovered incidentally during screening, which may underline cardiac disease in a preclinical phase. The challenge of sports cardiology, which daily engages sports medicine physicians, is to differentiate in athletes benign alterations from those that may be due to dangerous heart diseases.

A Population‐wide study of electrocardiographic (ECG) norms and the effect of demographic and anthropometric factors on selected ECG characteristics in young, Southeast Asian males—results from the Singapore Armed Forces ECG (SAFE) study

Routine use of pre-participation electrocardiograms (ECGs) has been used by the Singapore Armed Forces, targeting early detection of significant cardiac diseases. We aim to describe the impact of demographic and anthropometric factors on ECG variables and establish a set of electrocardiographic reference ranges specific to a young male multiethnic Southeast Asian cohort. Between November 1, 2009, and December 31, 2014, 144,346 young male conscripts underwent pre-participation screening that included a 12-lead ECG, demographic and anthropometric measurements. The Chinese population had the longest PR interval (146.7±19.7 vs. 145.21±19.2 in Malays vs. 141.2±18.8ms in Indians), QRS duration (94.5±9.8 vs. 92.6±9.7 in Malays vs. 92.5±9.4ms in Indians) and QTcB interval (408.3±21.3 vs. 403.5±21.6 in Malays vs. 401.2±21.4ms in Indians) (all p<0.001). Body mass index (BMI) >25kg/m2 and body fat >25% were independently associated with lower prevalence of increased QRS voltage on ECG. Systolic blood pressure of >140mmHg or diastolic blood pressure of >90mmHg independently increased the prevalence of increased QRS voltage on ECG. Electrocardiographic parameters vary across different ethnicities and in comparison with international norms. In our population, diagnosis of increased QRS voltage by ECG is less prevalent with obesity and increased body fat. Further analysis of gold standard measurements for the diagnosis of LVH in our population is ongoing, to improve the accuracy of the ECG screening process.

Findings relevant to the QRS wave in the resting electrocardiogram are associated with circulating concentrations of high-sensitivity cardiac troponin I in the general population

Myocardial damage could develop asymptomatically through nonischemic mechanisms such as cardiac overload. This study investigated possible associations between electrocardiogram (ECG) findings relevant to the QRS wave and high-sensitivity cardiac troponin I (hs-cTnI) in the general population. Subjects undergoing their annual health checkup were enrolled in the study (n = 1258). ECG features relevant to the QRS wave that were investigated included PQ interval, QRS voltage (Sokolow–Lyon voltage), QRS duration, product of QRS duration and voltage (Cornell product), corrected QT interval, and QRS axis. Laboratory measurements included hs-cTnI and B-type natriuretic peptide. hs-cTnI was significantly higher in subjects with a long PQ interval, high Sokolow–Lyon voltage, wide QRS duration, increased Cornell product, long corrected QT interval, or left QRS axis deviation. Univariate and multivariate regression analysis showed that Sokolow–Lyon voltage, QRS duration, and Cornell product were significantly associated with hs-cTnI after adjustment for possible confounding factors, including B-type natriuretic peptide. Logistic regression analysis with the endpoint of higher hs-cTnI than the median value showed that Sokolow–Lyon voltage and Cornell product were independently associated with increased hs-cTnI concentrations. ECG findings relevant to the QRS wave, especially increased QRS voltage, are associated with hs-cTnI in the general population.

Fatigue And Leg Heaviness

HISTORY: 18 year old college freshman cross country runner presents with bilateral leg weakness/heaviness. In the past 6 years have had 10 separate incidences of bilateral leg weakness/heaviness few minutes into running. But since the symptoms always resolve after resting and the incidences are few and far in between, the patient never thought much about it. However, since starting college running, had the same symptoms on two consecutive days. During the episode, patient states he also has normal breathing, but can’t seem to “utilize the oxygen”. Denies any chest pain but just a twinge in his upper chest. No past medical history, no surgical history, not on any medications, no allergies. Family history of father and paternal grandfather with A-fib. PHYSICAL EXAM: VSS Gen: Well appearing, NAD HEENT: NC/AT, EOMI Resp: CTABL, no w/r/r Card: S1, S2 appreciated, no additional heart sounds, no m/r/g, RRR GI: BS+, no HSM Neuro: CN 2–12 intact, sensation intact, 5/5 strength bilaterally to upper and lower extremitySkin: intact, no rashes or signs of infection DIFFERENTIAL DIAGNOSIS: 1. Over training 2. Iron deficiency 3. Anemia 4. Hypothyroid TESTS AND RESULTS: - In office EKG: ST segment elevation, T wave inversion, increased QRS voltage, Q waves - In the ER the same night: normal blood work with 3 sets of negative troponins - In office Echo in cardiology office one week later: thickened ventricles consistent of HCM FINAL/WORKING DIAGNOSIS: Hypertrophic Cardiomyopathy TREATMENT AND OUTCOMES: 1. Restriction from sports 2. Repeat echo in 6 months to rule out athletic heart

Clinical significance of J-wave in elite athletes

The J-wave pattern on 12-lead ECG is traditionally defined as a positive deflection at junction between the end of the QRS and the beginning of the ST-segment. This pattern has recently been associated with increased risk for idiopathic ventricular fibrillation in the absence of cardiovascular disease.The interest for the clinical significance of J-wave pattern as a potential ECG hallmark of high risk for cardiac arrest has recently been reinforced by the growing practice of ECG screening, such as occurs in large population of young competitive athletes.The available scientific evidence shows that the J-wave pattern is relatively common in trained athletes (ranging from 14% to 44%) and, differently from subjects who suffered from ventricular fibrillation, commonly localized in lateral leads while it is relatively rare to be found in inferior leads. Furthermore the J-wave pattern has been demonstrated to be a dynamic phenomenon related to the training status, with the larger prominence at the peak of training and with an inverse relation between magnitude of J-wave and heart rate. In addition the J-wave pattern is usually associated with other ECG changes, such as increased QRS voltages and ST-segment elevation, as well as LV remodeling, suggesting that it likely represents another expression of the physiologic athlete's heart.Finally the scientific data available demonstrated that during a medium follow-up period the J-wave pattern does not convey risk for adverse cardiac events, including sudden death or ventricular tachyarrhythmias.

Benign clinical significance of J-wave pattern (early repolarization) in highly trained athletes.

J wave/QRS slurring (early repolarization) on 12-lead ECG has been associated with increased risk for ventricular fibrillation in the absence of cardiovascular (CV) disease. The purpose of this study was to assess the prevalence and clinical significance of J wave/QRS slurring in a large population of competitive athletes. Seven hundred four athletes (436 males [62%], age 25 ± 5 years) free of CV disease who had engaged in 30 different sports were examined. Serial clinical, ECG, and echocardiographic evaluations were available over 1 to 18 years of follow-up (mean 6 ± 4 years). J wave was found in 102 athletes (14%) and was associated with QRS slurring in 32 (4%). It was found most commonly in anterior, lateral, and inferior leads (n = 73 [72%]), occasionally in lateral leads (n = 26 [25%]), and rarely in inferior leads (n = 3 [3%]). Most of 102 athletes (n = 86 [84%]) also showed ST-segment elevation. J wave/QRS slurring was associated with other training-related ECG changes (ie, increased R/S-wave voltages in 76%) and left ventricular (LV) morphologic remodeling (LV mass 199 ± 48 g vs 188 ± 56 g, P <.05). During follow-up, no athlete with J wave experienced cardiac event or ventricular tachyarrhythmias, or developed structural CV disease. In athletes, early repolarization pattern usually is associated with other ECG changes, such as increased QRS voltages and ST-segment elevation, as well as LV remodeling, suggesting that it likely represents another benign expression of the physiologic athlete's heart. J wave (early repolarization) is common in highly trained athletes and does not convey risk for adverse cardiac events, including sudden death or tachyarrhythmias.

Electrocardiographic specificities in athletes

The use of electrocardiogram in athletes as a routine screening method for diagnosing potentially dangerous cardiovascular diseases is still an issue of debate. According to the guidelines of the European Society of Cardiology, the recording of electrocardiogram is necessary in all athletes as a screening method, whereas the guidelines of the American Heart Association do not necessitate an electrocardiogram as a screening method and they insist on detailed personal and family history and clinical examination. CLASSIFICATION OF ELECTROCARDIOGRAM CHANGES IN ATHLETES: According to the classification of the European Society of Cardiology, electrocardiogram changes in athletes are divided into two groups: a) usual (physiological) that are connected with training; b) unusual (potentially clinically relevant) that are not connected with training. SUDDEN CARDIAC DEATH IN ATHLETES: The most frequent causes include hypertrophic cardiomyopathy and congenital coronary artery anomalies, while others may be found only sporadically at autopsy. Physiological electrocardiogram changes are frequent in asymptomatic athletes and they do not require further assessment. They include sinus bradycardia, atrioventricular blocks of I and II degree--Wenkebach, isolated increased QRS voltage, incomplete right bundle branch block and early repolarization. Potentially pathological electrocardiogram changes in athletes are not frequent but they are alarming and they urge further assessment to diagnose the underlying cardiovascular disease as well as the prevention of sudden cardiac death. They include: T wave inversion, ST segment depression, complete right or left bundle branch block, atrial pre-excitation syndrome-WPW, long QT interval, short QT interval, Brugada like electrocardiogram finding. Introduction of electrocardiogram recording into the screening protocol in athletes increases the sensitivity of evaluation and may help to discover asymptomatic cardiovascular diseases that may cause sudden cardiac death. Special attention and further assessment are required when the above potentially pathological electrocardiogram changes are found in athletes.

Computer simulation of ECG manifestations of left ventricular electrical remodeling

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–like patterns, as well as pseudo-normal QRS patterns.The classical interpretation of the QRS patterns in LVH relates these changes to increased left ventricular mass (LVM) per se, while tending to neglect the modified active and passive electrical properties of the myocardium. However, it has been well documented that both active and passive electrical properties in LVH are altered.Using computer simulations, we have shown that an increased LVM is not the only determinant of QRS complex changes in LVH, as these changes could also be produced without changing the left ventricular mass, implying that these QRS patterns can be present in patients before their LVM exceeds the arbitrary upper normal limits.Our results link the experimental evidence on electrical remodeling with clinical interpretation of ECG changes in patients with LVH and stress the necessity of a complex interpretation of the QRS patterns considering both spatial and nonspatial determinants in terms of the spatial angle theory. We assume that hypertrophic electrical remodeling in combination with changes in left ventricular size and shape explains the variety of ECG patterns as well as the discrepancies between ECG and left ventricular mass.

EKG-Diagnostik bei Leistungssportlern

In young competitive athletes sudden cardiac death frequently occurs as a tragic first manifestation of clinically inapparent underlying structural or electrical cardiac disorders. An increased risk may be reflected by typical electrocardiogram (ECG) alterations preceding symptoms but a correct interpretation is often challenging due to a high prevalence of training-related ECG alterations in competitive athletes mimicking such disorders. Misinterpretation may thus result in either unnecessary disqualification from competitive sports or continuation despite an increased risk or extensive diagnostic work-ups yielding additional equivocal findings. However, as observed in large athlete cohorts in recent years a variety of ECG alterations, such as isolated increased QRS voltage, early repolarization, sinus bradycardia, first degree AV block or incomplete right bundle branch block, represent common variants of ECGs of athletes reflecting physiological and training-related cardiac adaptations. These alterations do not usually require further diagnostic evaluation. In contrast, alterations such as repolarization abnormalities, complete bundle branch block, prolonged QT intervals or pathological Q waves, are strongly suggestive of underlying disorders and require further evaluation even in asymptomatic athletes. Thus, the ECG plays a pivotal role in the prevention of sudden cardiac death in competitive athletes. The present article summarizes current recommendations for the interpretation of athlete ECGs regarding the differentiation between physiological or pathological cardiac adaptation.

Early Repolarization Pattern in Competitive Athletes

Background— Inferior lead early repolarization pattern (ERP) recently has been associated with sudden cardiac death. Although ERP is common among athletes, prevalence, ECG lead distribution, clinical characteristics, and effects of physical training remain uncertain. We sought to examine the nonanterior ERP in competitive athletes. Methods and Results— ERP was assessed in a cross-sectional cohort of collegiate athletes (n=879). The relationship between ERP and cardiac structure were then examined in a longitudinal subgroup (n=146) before and after a 90-day period of exercise training. ERP was defined as J-point elevation ≥0.1 mV in at least 2 leads within a nonanterior territory (inferior [II, III, aVF] or lateral territory [I, aVL, V4-V6]). Nonanterior ERP was present in 25.1% (221/879) of athletes, including the inferior subtype in 3.8% (33/879). Exercise training led to significant increases in the prevalence of ERP and the inferior subtype, but there were no associations between ERP and echocardiographic measures of left ventricular remodeling. In a multivariable model, ERP was associated with black race (odds ratio [OR], 5.84; 95% CI, 3.54 to 9.61; P &lt;0.001), increased QRS voltage (OR, 2.08; 95% CI, 1.71 to 2.52; P &lt;0.001), and slower heart rate (OR, 1.54; 95% CI, 1.26 to 1.87; P &lt;0.001). Conclusions— Nonanterior ERP, including the inferior subtype, is common and has strong clinical associations among competitive athletes. The finding of increased ERP prevalence after intense physical training establishes a strong association between exercise and ERP.

The effect of reduced intercellular coupling on electrocardiographic signs of left ventricular hypertrophy

Background The electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH) is based on the assumption that QRS voltage increases with left ventricular mass. However, most of patients with echocardiographically detected LVH do not have increased QRS voltage. Reduced intercellular coupling has been observed in LVH patients and animal models. The purpose of this study was to show that this uncoupling can explain relatively low QRS voltage in LVH patients. Methods Electrocardiograms and vectorcardiograms (VCG) were simulated with a realistic large-scale computer model of the human heart and torso that reliably represented the effects of reduced coupling on both propagation and ECG voltage. Results Uncoupling reduced QRS voltage in all leads except aVL, reflecting a decrease in vector amplitude as well as a leftward axis deviation that suggested left anterior fascicular block. Conclusions Low QRS voltage does not necessarily contradict a diagnosis of LVH but may be an indication for electrical uncoupling. The diagnostic value of this “relative voltage deficit” needs to be demonstrated in clinical studies.

Electrocardiogram in Athletes

Changes in the resting electrocardiogram(ECG) as a result of training are common and can cause difficulties for the differential diagnosis. Recently updated guidelines from the European Society of Cardiology (ESC) differentiate between common, training-related and rare, potentially pathological changes (1). These new international recommendations were omitted from the article on the pre-participation examination for leisure time physical activity (2), presumably because they were not yet available at the time the manuscript was accepted. I wish to add them at this point. The following changes on ECG are classed as training-related in the absence of other distinctive features: sinus bradycardia, 1st degree atrioventricular block, incomplete right bundle block, early repolarization, isolated increased QRS voltages (increased Sokolow-Lyon index). These changes may occur in up to 80% of athletes. The prevalence is highest in endurance athletes with physiological remodeling of the heart, but the changes may also be found in other athletes and are notably more common in men than in women, and in black people than in white (Caucasian) people (3, 4). Isolated increased QRS voltages are responsible for 60% of training-related changes in athletes (4). In addition to cardiac adaptations, athletes often have favorable conditions for ECG leads owing to a lower proportion of body fat. Early repolarization of at least 0.1 mV, mostly located in the precordial leads (V2)V3–V4, is also common. In athletes of Afro-Caribbean origin, these ST elevations may be followed by negative T waves (3). As far as AV blocks are concerned, I would, by contrast to the authors, be very reticent to classify a 3rd degree AV block in elite athletes as normal (Box 3). I am not familiar with any such findings in athletes who are proven to be healthy. It is to be expected that the current ESC recommendations will notably lower the rate of false positive findings on athletes’ ECGs.

Right Ventricular Late Enhancement as a Magnetic Resonance Marker of Glycogen Storage Disease

Glycogen storage disease may affect the heart, particularly as result of a mutation of the LAMP2 and PRKAG2 genes encoding for structural proteins of cardiomyocytes.1 Its recognition and differentiation from hypertrophic cardiomyopathy and other infiltrative and storage diseases may influence treatment and prognosis but are difficult to obtain by conventional noninvasive imaging. A 26-year-old man with family history of sudden cardiac death at a young age (an aunt and grandfather died before 40 years of age) was referred for cardiac magnetic resonance examination because of unexplained increased left ventricular wall thickness at echocardiography (maximal wall thickness, 17 mm) associated with reduced left ventricular function. The ECG (the Figure, A) showed sinus rhythm with increased QRS voltages and abnormalities of ST segment and T wave. Figure. A, A 12-lead ECG showing increased QRS voltages associated …

Effect of changes in left ventricular anatomy and conduction velocity on the QRS voltage and morphology in left ventricular hypertrophy: a model study

The increased QRS voltage is considered to be a specific electrocardiogram (ECG) sign of left ventricular hypertrophy (LVH), and it is expected that the QRS voltage reflects the increase in left ventricular mass (LVM). However, the increased QRS voltage is only one of QRS patterns observed in patients with LVH. According to the solid angle theory, the resultant QRS voltage is influenced not only by spatial (anatomic) but also by nonspatial (electrophysiologic) determinants. In this study, we used a computer model to evaluate the effect of changes in anatomy and conduction velocity of the left ventricle on QRS complex characteristics. Material and Methods The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids and allows to change dimensions of the ventricles, as well as the conduction velocity in the individual layers of myocardium. Three types of anatomic changes were simulated: concentric hypertrophy, eccentric hypertrophy, and dilatation. The conduction velocity was slowed in the inner layer of the left ventricle representing the Purkinje fiber mesh and in the layers representing the working myocardium. The outcomes of the model are presented as the time course of the spatial QRS vector magnitude, the vectorcardiographic QRS loops (VCGs) in horizontal, left sagittal, and frontal planes, as well as derived 12-lead ECGs. The following indicators of the 12-lead ECG were evaluated: the left axis deviation, the intrinsicoid deflection in V6, Cornell voltage, Cornell voltage-duration product, and Sokolow-Lyon index. Results The increase in LVM did not affect the QRS voltage proportionally, and the LVM and type of hypertrophy were not the only determinants of the QRS patterns. The conduction velocity slowing resulted in a spectrum of QRS patterns including increased QRS voltage and duration, left axis deviation, prolonged intrinsicoid deflection, VCG patterns of left bundle branch block, as well as pseudo-normal VCG/ECG patterns. The anatomic changes and conduction velocity slowing affected differently Sokolow-Lyon index and Cornell criteria. Conclusion We showed that the LVM is not the only determinant of the QRS complex changes in LVH, but it is rather a combination of anatomic and electric remodeling that creates the whole spectrum of the QRS complex changes seen in LVH patients. The slowed conduction velocity in the model heart produced QRS patterns consistent with changes described in LVH, even if the LVM was not changed.

Electrocardiographic diagnosis of left ventricular hypertrophy: depolarization changes

Electrocardiographic signs of left ventricular hypertrophy (LVH) are on one hand accepted as independent cardiovascular risk factors and indicators of target organ damage in hypertensive patients, but, on the other hand they are strongly criticized for their low sensitivity. In this paper, a historic perspective on the ECG dignosis of LVH is presented, showing the development of current views on the role of ECG in LVH detection. Based on the fact that ECG provides information on the electrical properties of myocardium and on new knowledge about electrical remodeling in LVH, a shift of paradigm in our consideration of the diagnosis of left ventricular hypertrophy is proposed, based on changes in the electrical properties of hypertrophied myocardium. This new paradigm could explain the broad spectrum of QRS patterns seen in LVH, including increased QRS voltage, prolonged duration of QRS complex, left axis deviation, prolonged intrinsicoid deflection, LBBB and LAFB patterns, as well as pseudo-normal ECG findings.

Clinical Use of Electrocardiography in Adults With Congenital Heart Disease

The prevalence of adult congenital heart disease (ACHD) has risen markedly over the past 2 decades, with the number of adults now rivaling the number of children with severe defects.1 This is, perhaps, not surprising given that current care allows nearly 90% of infants born with heart defects to thrive into their adult years.1,2 This remarkable triumph is tempered, however, by the realization that early interventions were reparative and not curative. Numerous complications may surface years after uneventful childhood courses, justifying vigilant clinical follow-up throughout adulthood. The 12-lead ECG remains an invaluable cornerstone in the clinical appraisal of adults with congenital heart disease that, in certain circumstances, provides diagnostic and/or prognostic information. The present review imparts a clinical perspective to ECG interpretation in ACHD, emphasizing practical and pathogenomonic findings in the more frequently encountered congenital defects in adults. Anatomic features of the conduction system relevant to ECG findings in ACHD are summarized, including variations in the location of the sinus node, atrioventricular (AV) node, and His-Purkinje system. Thereafter, pertinent ECG features are highlighted for common subtypes of ACHD (Table). Examples are provided throughout for illustration. View this table: Table. Typical ECG Features in Common Forms of ACHD ### Sinus Node In the morphologically normal heart, a crescent-shaped sinus node is characteristically located epicardially along the lateral aspect of the superior cavoatrial junction. It generates a P-wave axis typically between 15° and 75°. Most patients with ACHD have normally positioned atrial chambers, called atrial situs solitus, with normal sinus node location. The position of the sinus node may, however, vary with the atrial chambers and their appendages. #### Juxtaposition of the Atrial Appendages In juxtaposition of the atrial appendages, both appendages are on the same side of the arterial pedicle rather than each being ipsilateral to its respective atrium. Left juxtaposition, with left-sided atrial appendages, frequently accompanies tricuspid atresia and has …