Journal of Electrocardiology - Articles in Press

Electrocardiographic J waves as a hyperacute sign of Takotsubo syndrome - Corrected Proof

2012-05-14

Abstract: Typical electrocardiographic (ECG) signs of acute Takotsubo syndrome (TTS) consist of ST-segment elevation and/or T wave inversion. We report an unusual case of a 62-year-old woman with TTS who acutely exhibited on 12-lead ECG transient J waves preceding ST-T abnormalities. In the experimental model of myocardial ischemia, the appearance of J waves represents an early ECG abnormality and is followed by ST-segment elevation. Because of the similar ECG time course observed in TTS and myocardial ischemia, we speculate that common electrophysiologic mechanisms may account for J waves appearance in these 2 clinical conditions. Our case report shows that recording of ECG J waves in postmenopausal women presenting for acute chest pain may be a sign of an ongoing TTS and suggests a similarity to myocardial ischemia as the pathologic basis.

Prevalence and clinical correlates of early repolarization and J wave in a large cohort of subjects without overt heart disease - Corrected Proof

2012-05-10

Abstract: Background: Recent studies have suggested that early repolarization (ER) is associated with increased risk of ventricular tachyarrhythmias. Early repolarization in these studies, however, was defined as J-wave (terminal QRS slurring or notching) or J-point elevation rather than typical ST-segment elevation (STE). Prevalence and characteristics of these different findings in the general population are poorly known. In this study, we assessed prevalence and correlates of STE typical of ER and of J wave in a large population of noncardiac subjects.Methods: We prospectively collected electrocardiograms of 4176 consecutive subjects without heart disease at our hospital.Results: Early repolarization was found in 84 subjects (2.0%) and J wave in 663 (15.9%). Among ER subjects, a J wave was present in 60 (71.4%). Variables independently associated with both ER and J wave included young age, male sex, and lower heart rate. There was no increased history of symptoms (palpitations and syncope) possibly related to arrhythmias in STE or J-wave subjects.Conclusions: Typical ER pattern and J wave are common in noncardiac subjects, particularly in young people, and are not associated with symptoms potentially related to arrhythmias.

Prevalence of acute myocardial infarction in patients with presumably new left bundle-branch block - Corrected Proof

Nilay Mehta, Henry D. Huang, Salman Bandeali, James M. Wilson, Yochai Birnbaum — 2012-05-10

Abstract: Objectives: We assessed the prevalence of true acute myocardial infarction and the need for emergent revascularization among patients with new or presumably new left bundle branch block (nLBBB) for whom the primary percutaneous coronary intervention protocol was activated.Methods and Results: Among 802 patients, 69 (8.6%) had nLBBB. The chief presenting symptom was chest pain or cardiac arrest in 36 patients (52.2%) and shortness of breath in 15 (21.7%). Less than 30% of the patients had elevated cardiac troponin-I, and less than 10% had elevated creatine kinase–MB. Only 11.6% of the patients underwent emergent revascularization; the rate was higher for patients who presented with chest pain or cardiac arrest or shortness of breath than for patients who presented with other symptoms.Conclusions: Acute myocardial infarction and the need for emergent revascularization are relatively uncommon among patients who present with nLBBB, especially when symptoms are atypical. Current guidelines for primary percutaneous coronary intervention protocol activation for nLBBB should be reconsidered.

Automated discrimination of proximal right coronary artery occlusion from middle-to-distal right coronary artery occlusion and left circumflex occlusion in ST-elevation myocardial infarction - Corrected Proof

2012-05-07

Abstract: Background: Classifying the location of an occlusion in the culprit artery during ST-elevation myocardial infarction (STEMI) is important for risk stratification to optimize treatment. We developed a new logistic regression (LR) algorithm for 3-group classification of occlusion location as proximal right coronary artery (RCA), middle-to-distal RCA or left circumflex (LCx) coronary artery with inferior myocardial infarction. We compared the performance of the new LR algorithm with the recently introduced decision tree classifier of Fiol et al (Ann Noninvasive Electrocardiol. 2004;4:383-388) in the classification of the same 3 categories.Methods: The new algorithm was developed on a set of electrocardiograms from an emergency department setting (n = 64) and tested on a different set from a prehospital setting (n = 68). All patients met the current STEMI criteria with angiographic confirmation of culprit artery and occlusion location. Using LR, 4 ST-segment deviation features were chosen by forward stepwise selection. Final LR coefficients were obtained by averaging more than 200 bootstrap iterations on the training set. In addition, a separate 4-feature classifier was designed adding ST features of V4R and V8, only available in the training set.Results: The LR algorithm classified proximal RCA occlusion vs combined LCx occlusion and middle-to-distal RCA occlusion, with a sensitivity of 76% and specificity of 81% as compared with 71% and 62% for the Fiol classifier. The difference in specificity was statistically significant. The LR classifier trained with additional ST features of V4R and V8, but still limited to 4, improved the overall agreement in the training set from 65% to 70%.Conclusion: Discrimination of proximal RCA lesion location from LCx or middle-to-distal RCA using the new LR classifier shows improvement over decision tree–type classification criteria. Automated identification of proximal RCA occlusion could speed up the risk stratification of patients with STEMI. The addition of leads V4R and V8 should further improve the automated classification of the occlusion site in RCA and LCx.

The electrocardiographic diagnosis of intraventricular blocks coexisting with ventricular preexcitation - Corrected Proof

Pablo A. Chiale, Marcelo V. Elizari — 2012-05-07

Abstract: The electrocardiographic diagnosis of intraventricular conduction disturbances may be hindered by the coexistence of ventricular preexcitation. In fact, the premature depolarization of ventricular myocardium through an accessory pathway tends to conceal any electrocardiographic manifestation of a bundle-branch block. However, there are several conditions favoring the diagnosis of bundle-branch block associated with ventricular preexcitation: intermittency of ventricular preexcitation and/or bundle-branch block, fast atrioventricular (AV) nodal impulse propagation, slow conduction over the accessory pathway or between its ventricular insertion site and the remaining myocardium, and presence of atrioventricular junctional ectopic beats exposing the intraventricular conduction disturbance. This article reexamines the available data on preexcitation in patients with intraventricular blocks and presents clinical examples to emphasize the importance of a thorough examination of the electrocardiogram to attain the correct diagnosis of this association.

Pacemaker repetitive nonreentrant ventriculoatrial synchrony. Why did automatic mode switching occur? - Corrected Proof

S. Serge Barold, Roland X. Stroobandt, Frederic Van Heuverswyn — 2012-05-07

Abstract: Repetitive nonreentrant ventriculoatrial synchrony during dual-chamber pacing is characterized by long intervals alternating with short intervals. This arrangement activated automatic mode switching in a St Jude dual-chamber pacemaker in which the algorithm requires an atrial sensed event for automatic mode switching initiation. Automatic mode switching activation by an atrial sensed event (retrograde P wave) was puzzling because the programmed postventricular atrial period was longer than the retrograde ventriculoatrial conduction time. The explanation is presented in the form of questions and answers to facilitate the understanding of pacemaker function and complex timing cycles.

T-wave morphology after epinephrine bolus may reveal silent long QT syndrome mutation carriers - Corrected Proof

Anna-Mari Hekkala, Väänänen Heikki, Swan Heikki, Viitasalo Matti, Toivonen Lauri — 2012-05-07

Abstract: Background: Long QT syndrome (LQTS) gene mutation carriers with indeterminate electrocardiogram frequently escape clinical diagnosis. We assessed the use of epinephrine bolus injection in revealing T-wave abnormalities.Methods: We recruited 30 genotyped asymptomatic LQTS gene carriers with nondiagnostic QT interval and 15 controls. Electrocardiogram was recorded with body surface potential mapping after an intravenous epinephrine bolus. T-wave morphology was determined as normal, biphasic, inverted, bifid, or combined pattern.Results: Long QT syndrome carriers and healthy controls had different T-wave profiles (P = .027). Of controls, 12 (80%) of 15 had no change or biphasic appearance, whereas only 10 (33%) of 30 of LQTS carriers had so. Bifid or combined pattern occurred in 15 (50%) of 30 in LQTS and in 6 (60%) of 10 in the LQT3 subgroup but only in 1 (7%) of 15 of healthy.Conclusions: Modification of ventricular repolarization with low-dose epinephrine injection helps to distinguish silent LQTS mutation carriers. This concerns also the LQT3 subtype, which may escape tests.

Comparison of Selvester QRS score with magnetic resonance imaging measured infarct size in patients with ST elevation myocardial infarction - Corrected Proof

2012-05-03

Abstract: Background and Purpose: Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates well with MI size determined by DE-MRI in reperfused STEMI.Methods and Results: The relationship was evaluated retrospectively in 55 first-time STEMI patients 3 months after receiving primary percutaneous coronary intervention. Selvester QRS score and DE-MRI MI size were significantly correlated, r = 0.41 (P < .01). The difference between the Selvester QRS score and DE-MRI was 5.8% MI of the left ventricle (95% confidence interval, 2.9%-8.6%). Furthermore, increasing difference between Selvester QRS score and DE-MRI was observed with increasing MI size.Conclusion: Selvester QRS score correlated only moderately with DE-MRI MI size. Selvester QRS score overestimated MI size.

Characteristics of ventricular tachycardia arising from the inflow region of the right ventricle - Corrected Proof

2012-05-03

Abstract: Introduction: Ventricular tachycardia (VT) arising from the right ventricular inflow (RVI) region is uncommon. There is minimal literature on the clinical and electrocardiographic characteristics of RVI VT.Methods: A retrospective analysis of patients with RVI VT who underwent electrophysiology study between 2006 and 2011 was performed. Patients with structural heart disease (including arrhythmogenic right ventricular dysplasia) were excluded.Results: Seventy patients underwent an electrophysiology study for VT arising from the right ventricle during the study period. Nine patients (13%) met the inclusion criteria for RVI VT and were the subject of this analysis. The median age was 46 years (range, 14-71), and VT cycle length was 295 milliseconds (range, 279-400 milliseconds). All VTs had an left bundle-branch block morphology. An inferiorly directed QRS axis was noted in 7 (78%) of 9 patients and a left superior axis in 2 (22%) of 9 patients. A QS or rS pattern was noted in all patients in aVR and V1. A transition from S to R wave occurred in V3 to V5 in all patients, with 78% of the patients transitioning in V4 or V5. Ablation was attempted in 8 (89%) of 9 patients and was successful in 6 (67%) of 9 patients. Ablation was limited in all unsuccessful patients due to the proximity to the His and risk of complete heart block.Conclusions: Electrocardiographic findings of a left bundle-branch block with a normal QRS axis, QS or rS patterns in aVR and V1, and late S to R transition (V4/V5) are commonly found in RVI VT. Because of the proximity to the His, ablation of RVI VT may be more challenging than that of right ventricular outflow tract VT.

The role of pacing-induced dyssynchrony in left ventricular remodeling associated with long-term right ventricular pacing for atrioventricular block - Corrected Proof

2012-05-03

Abstract: Aims: Patients with atrioventricular (AV) block can develop left ventricular (LV) dysfunction with long-term right ventricular pacing (RVP). We investigated the role of RVP-induced LV dyssynchrony in this adverse remodeling.Methods and Results: Nineteen patients with normal LV function undergoing pacemaker implantation for AV block were included. Right ventricular pacing leads were positioned at the apex. Two-dimensional and tissue Doppler echocardiography was performed before and immediately after implantation and at the end of follow-up. The maximal delay between peak velocities of opposing basal LV walls was measured using tissue Doppler echocardiography, as an index of LV dyssynchrony. With the initiation of RVP, LV dyssynchrony increased in some patients and decreased in others, as compared with intrinsic rhythm. The RVP-induced change in dyssynchrony inversely correlated with baseline dyssynchrony (r = −0.686, P = .010). After 28 ± 3.6 months, LV end-systolic volume (ESV) increased, and ejection fraction decreased (from 34 ± 12 to 40 ± 20 mL, P = .010 and from 65% ± 6% to 56% ± 11%, P < .001, respectively). The change in LV ESV was greater in patients with 60% or greater cumulative RVP (9.9 vs 0.08 mL, P = .027). Within this frequently paced group, the RVP-induced change in dyssynchrony correlated with the increase in LV ESV (r = 0.727, P = .026). Patients who had a 15% or greater increase in LV ESV had greater RVP-induced change in dyssynchrony (28.4 vs −7.8 milliseconds, P = .037).Conclusion: Some patients with AV block experience an increase in LV dyssynchrony with RVP. Increased LV dyssynchrony predicts adverse LV remodeling during long-term follow-up.

Should the cardiac catheterization laboratory be activated? - Corrected Proof

Marc Solomon, Nora Goldschlager — 2012-04-25

Sleep apnea, cardiac arrhythmias, and conduction disorders - Corrected Proof

Adrian Baranchuk — 2012-04-23

Abstract: Sleep apnea (SA) is a common breathing disorder. It is associated with a myriad of medical conditions including increased cardiovascular morbidity and mortality. Recent studies have shown that cardiac arrhythmias and conduction disorders are common in patients with SA. Sleep apnea has also been also linked to heart failure, hypertension, coronary artery disease, and stroke.The purpose of this brief review is to analyze the available information that links SA with different cardiac arrhythmias and conduction disorders and the role of intracardiac devices for the diagnosis and management of this condition.

Ventriculoatrial conduction in complete atrioventricular block - Corrected Proof

2012-04-19

Abstract: The case of a patient with complete atrioventricular block with capability of rapid ventriculoatrial conduction with unusual behavior is presented. Potential mechanisms are discussed.

Hypothermia masquerading as pericarditis: an unusual electrocardiographic analogy - Corrected Proof

Lovely Chhabra, David H. Spodick — 2012-04-19

Abstract: Hypothermia is one of the most common environmental emergencies encountered by physicians that can be associated with a variety of electrocardiographic (ECG) abnormalities. The classic and well-known ECG manifestations of hypothermia include the presence of J (Osborne) waves, interval (PR, QRS, QT) prolongation, varied T-wave abnormalities, and atrial and ventricular arrhythmias. There are less well-defined and known ECG signs of hypothermia that, in fact, may simulate findings of acute coronary ischemia. We describe a case of hypothermia with associated ECG findings mimicking pericarditis. Especially interesting was the challenging presentation and several associated important learning points. Herewith, we also discuss some important ECG and clinical factors that may be used in differentiating the genesis of ST elevations.

Evolution of clinical and electrophysiologic data in patients with a preexcitation syndrome - Corrected Proof

Claire Lalevée, Béatrice Brembilla-Perrot — 2012-04-12

Abstract: The purpose of the study is to report the natural changes of preexcitation syndrome (PS).Methods: Electrophysiologic study was performed for syncope (n = 8), atrioventricular reentrant tachycardia (AVRT) (n = 42), atrial fibrillation (n = 3), adverse presentation (n = 4), or for asymptomatic PS (n = 22) and was repeated 1 to 21 years later.Results: Clinically, 12 patients initially asymptomatic became symptomatic (54.5%), and 12 symptomatic patients became asymptomatic (21%). At electrophysiologic study 2, maximal rate conducted over accessory pathway (AP) was slower. Anterograde conduction disappeared in 22 patients, but 10 of them had inducible AVRT. Among 27 patients with initially rapid conduction over AP, 7 had a benign form; 20 had always a rapid conduction over AP, and 3 of them initially asymptomatic developed rapid atrial fibrillation.Conclusions: Asymptomatic patients with a PS frequently became symptomatic (54.5%), whereas symptomatic patients rarely became asymptomatic (21%). Maximal rate conducted over AP decreased during life, but AVRT remained inducible.

Sensing of 2 atrial rhythms by a pacemaker in a transplanted heart - Corrected Proof

S. Serge Barold, Bengt Herweg — 2012-04-06

Abstract: A patient who had undergone orthotopic heart transplantation received a VDD pacemaker for AV block. The pacemaker sensed both the recipient and donor atrial rhythms. The atrial lead must be implanted in the donor atrium: a double atrial electrogram requires a different atrial site unless programmable atrial sensitivity can establish preferential sensing of donor P waves.

Brugada syndrome phenotype cardiac arrest in a young patient unmasked during the acute phase of amiodarone infusion: disclosure and aggravation of Brugada electrocardiographic pattern - Corrected Proof

2012-03-19

Abstract: We report a case of an outpatient cardiac arrest due to ventricular fibrillation and resuscitated with external automated defibrillator shocks in which acute amiodarone infusion unmasked a Brugada phenotype electrocardiographic pattern. Possible interferences by this drug and suitable therapeutic actions are discussed.

Ventricular allorhythmia during infarct-related ventricular tachycardia - Corrected Proof

2012-03-19

Abstract: Ventricular allorhythmia is an electrocardiogram feature leading to a pattern of “regularly irregular” arrhythmia mainly reported during non–life-threatening organized atrial tachycardia. We report the infrequent case of a patient presenting with ventricular allorhythmia during infarct-related ventricular tachycardia. The potential mechanisms of this tachycardia are discussed.

Arrhythmia-related workup in hereditary myopathies - Corrected Proof

Josef Finsterer, Claudia Stöllberger, Hans Keller — 2012-03-15

Abstract: Background: Arrhythmias determine life expectancy in patients with hereditary myopathies.Aims: The aim of this study was to summarize recent advances in the diagnosis and management of arrhythmias in hereditary myopathies.Methods: Literature search via PubMed and inclusion of own experiences were performed.Results: All types of arrhythmias can be found in patients with hereditary myopathies, but some are more prevalent than others. Arrhythmias reported in myopathies include atrial fibrillation, atrial flutter, sick-sinus syndrome, preexcitation syndromes, atrioventricular conduction delay, intraventricular conduction delay, and ventricular tachycardia. Sudden cardiac death is a common finding in certain myopathies, and patients at risk for ventricular arrhythmias and sudden cardiac death should be identified early enough to implant a cardioverter-defibrillator to prevent a fatal outcome. Myopathies associated with a high risk for arrhythmias include laminopathies, Emery-Dreifuss muscular dystrophy, myotonic dystrophy I, mitochondrial myopathies, fatty-acid oxidation defects, and dystrophinopathies. To detect arrhythmias with high risk for sudden cardiac death, patients require close follow-up investigations or an implantable loop recorder. Documentation of severe arrhythmias requires immediate treatment according to established guidelines.Conclusions: Patients with certain hereditary myopathies carry an increased risk for developing severe supraventricular or ventricular arrhythmias and for dying of sudden cardiac death. Close follow-up and long-term surveillance of the electrocardiogram may prevent fatal complications of arrhythmias in these patients.

Reappraisal of the electrographic manifestations of right ventricular apical pacing - Corrected Proof

S. Serge Barold, Michael C. Giudici, Bengt Herweg — 2012-03-14

A dominant R wave in V1 (R/S >1) during right ventricular (RV) pacing is often called a “right bundle-branch block” (“RBBB”) configuration, but this terminology is potentially misleading because it is not related to delayed RV activation. The dominant R wave is, therefore, not associated with an rSR' complex or a delayed R wave. The terms dominant or tall R wave in lead V1 are commonly used, but they do not reflect the underlying pathophysiology. Perhaps “pseudo-RBBB” may be more appropriate. When faced with an apparent “RBBB” pattern, a repeat electrocardiogram (ECG) should be done making sure that leads V1 and V2 are recorded from the correct intercostal space because a tall R wave V1 and V2 can sometimes be recorded during uncomplicated RV apical pacing at the level of the third or second intercostal space when it is absent in the fourth intercostal space. Then, ventricular fusion with the intrinsic rhythm must also be ruled out as the cause of a tall R wave in V1 by standard maneuvers such as increasing the ventricular paced rate and/or programming a very short atrioventricular delay.

An ectopic atrial rhythm? - Corrected Proof

Kurt S. Hoffmayer, Melvin Scheinman, Nora Goldschlager — 2012-03-09

WITHDRAWN: “Pseudo-high lateral leads Brugada pattern” due to lead reversal - Corrected Proof

2008-08-26

Available online August 26, 2008This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The publisher apologizes for any inconvenience this may cause.