Journal of Electrocardiology - Articles in Press

Pacemaker-mediated tachycardia initiated by an atrioventricular search algorithm to minimize right ventricular pacing - Corrected Proof

S. Serge Barold, Roland X. Stroobandt — 2012-01-27

Abstract: We report the initiation of pacemaker-mediated tachycardia by a St Jude implantable cardioverter-defibrillator with a programmed Ventricular Intrinsic Preference algorithm used for minimizing or inhibiting right ventricular pacing. This feature prolongs the atrioventricular (AV) delay periodically to determine if ventricular sensed events follow atrial events. Retrograde ventriculoatrial conduction and pacemaker-mediated tachycardia were initiated by long extended AV delays of 300 and 400 milliseconds. The 400-millisecond AV delay consisted of the programmed sensed AV delay (100 milliseconds) plus the Ventricular Intrinsic Preference increment (200 milliseconds) plus 100 milliseconds imposed by the AutoCapture algorithm when it detected loss of ventricular capture.

Correlations among the frequencies of atrial activity on the surface electrocardiogram, intracardiac atrial electrograms, and the atrial effective refractory period in patients with atrial fibrillation - Corrected Proof

Merritt H. Raitt, Walter Kusumoto — 2012-01-27

Abstract: Background: The frequency of surface atrial electrocardiogram (ECG) depolarization has been postulated to reflect the atrial effective refractory period (AERP).Methods: Frequency analysis of surface ECGs after QRST subtraction and of electrograms from 4 right atrium and 4 coronary sinus electrode pairs was performed in 38 patients in atrial fibrillation. The AERP was measured in the right atrium and coronary sinus 10 minutes after cardioversion.Results: The correlation between the dominant frequencies of intracardiac electrograms and atrial activity in leads I, II, and V1 were 0.89, 0.85, and 0.88, respectively (all P < .001). The correlation between the average AERP and the frequency of atrial activity in the surface leads was 0.50, 0.45, and 0.47 (all P < .005).Conclusion: In atrial fibrillation, the frequency of atrial depolarization measured from the surface ECG is highly correlated with intracardiac atrial frequency. However, the correlation between the frequency of surface atrial activity and atrial refractoriness, although significant, is not strong.

Diagnosis and mortality prediction in pulmonary hypertension: The value of the electrocardiogram-derived ventricular gradient - Corrected Proof

2012-01-24

Abstract: Purpose: The aim of this study was to investigate the use of the electrocardiogram-derived ventricular gradient, projected on the x-axis (VGx), for detection of pulmonary hypertension (PH) and for prediction of all-cause mortality in PH patients.Methods: In patients referred for PH screening (n = 216), the VGx was calculated semiautomatically from the electrocardiogram and was defined as abnormal when less than 24 mV·ms. The VGx of PH patients was compared with the VGx of patients without PH. The association between a reduced VGx and mortality was investigated in PH patients.Results: Patients with PH (n = 117) had a significantly reduced VGx: 14 ± 27 vs 45 ± 23 mV·ms, P < .001. Furthermore, a severely reduced VGx (<0 mV·ms) was associated with increased mortality in PH patients: hazard ratio, 1.025 (95% confidence interval, 1.006-1.045; P = .012) per mV·ms VGx decrease.Conclusion: Reduced VGx is associated with the presence of PH and, more importantly, within PH patients, a severely reduced VGx predicts mortality.

T-wave alternans and the confounding role of the T-wave amplitude - Corrected Proof

John E. Madias — 2012-01-20

Abstract: The interpretation of the electrocardiogram (ECG) T-wave alternans (TWA) as positive or negative depends on its magnitude, regardless whether the frequency domain or the time domain analysis is employed. The author argues that a number of cardiac and extracardiac influences can confound the magnitude of TWA. The amplitude of the ECG T waves, considered in the measurement/calculation of TWA, and possibly myocardial edema are examples of cardiac influences. Peripheral edema with its effect in attenuating the amplitude of all components of the ECG, including the T waves, is an example of extracardiac influence. Another concern is the variation in the evolution of the T-wave amplitudes during the 3- to 6-month period after an acute myocardial infarction, and whether such variation confounds the results of the TWA testing, which often is undertaken at that time bracket. The T-wave amplitude changes may impact the sensitivity and specificity of TWA testing after an acute myocardial infarction. Perhaps the measured TWA magnitude should be adjusted to the amplitude of the T waves or voltage-time integral of the J-T interval, depending on the method used for the calculation of TWA. These issues need to be considered and investigated in an effort to render TWA testing more reliable in predicting sudden cardiac death.

Long-term results of slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: simple approach - Corrected Proof

Francisco Femenía, Mauricio Arce, Martín Arrieta, Jorge Palazzolo, Emilce Trucco — 2012-01-19

Abstract: Aims: The aim of this study was to report the short- and long-term results of slow pathway radiofrequency (RF) ablation in patients with atrioventricular (AV) nodal reentrant tachycardia (AVNRT) using a simplified approach (2 catheters and short applications of RF).Materials and Methods: This was a retrospective study that included consecutive patients with AVNRT. We used an anatomical approach with only 2 catheters. Decremental AV nodal conduction and atrial-His conduction interval jump were measured. To detect the onset of the QRS, we used surface lead II. During the stimulation protocol, we performed S2-QRS and S3-QRS measurements. An increase in the S3-QRS3 interval of 50 milliseconds or greater in response to a decrease in the S2-QRS2 coupling interval of 10 milliseconds was defined as a discontinuous AV nodal function curve and taken as evidence of dual antegrade AV pathways. Atrioventricular nodal reentrant tachycardia was demonstrated by the presence of dual AV nodal physiology, atrial echoes, and tachycardia induction with a 1:1 AV relationship and a VA interval of less than 70 milliseconds. Short RF applications (10-15 seconds) were delivered at an intermediate point between the posteroseptal and medioseptal regions of the Koch triangle. The applications were considered effective when junctional rhythm appeared. The end point was the demonstration of slow pathway modification without AVNRT induction.Results: Three hundred forty-four patients (age, 49.22 ± 17.47 years; 254 were female) were included. Discontinuous AV nodal function curves were found in 271 patients (78.77%), and short-term success was achieved in all patients. The anterograde jump in AV nodal conduction was abolished after RF in 222 patients (81.91%), and discontinuous AV nodal conduction and single AV nodal echo beats persisted in 49 cases (18%). The mean number of RF application was 7.79 ± 2.23, the mean number of effective applications was 4.63 ± 0.62, and the mean RF application time was 54.92 ± 8.03 seconds. The total procedure and fluoroscopy time was 29.45 ± 9.6 and 10.87 ± 2.36 minutes, respectively. After the procedure, all patients were followed up for a mean of 46.44 ± 18.89 months, and 7 patients (2%) presented AVNRT recurrences. Complications were observed in 4 patients (1.16%); no permanent AV block was observed.Conclusion: In this study, slow pathway RF ablation using a simplified approach technique is an effective and safe approach for the treatment of AVNRT.

Prediction of sinus node dysfunction in patients with long-standing persistent atrial fibrillation using the atrial fibrillatory cycle length - Corrected Proof

2012-01-19

Abstract: Background: Sinus node dysfunction (SND) occasionally coexists with long-standing atrial fibrillation (AF) but is unidentifiable during AF. We aimed to identify the predictors of underlying SND when deciding the indications for long-standing persistent AF ablation.Methods: We included 105 patients undergoing ablation of long-standing persistent AF to assess the frequency of a permanent pacemaker implantation (PMI) for SND that manifested after sinus conversion and to determine the relationship between the corrected sinus node recovery time (CSNRT) and other clinical parameters obtained before the ablation including the atrial fibrillatory cycle length (AFCL).Results: We identified 7 patients (7%) requiring a PMI for SND after AF termination. The patients with a PMI were nearly all females (6/7) and had a significantly longer CSNRT (1197 ± 647 vs 612 ± 349 milliseconds; P = .0046) and more prolonged AFCL (179 ± 19 vs 153 ± 22 milliseconds; P = .0028) than those without. The age (r = 0.26; P = .011), female sex (r = 0.25; P = .012), hypertension (r = 0.22; P = .038), and AFCL (r = 0.4; P < .0001) were significantly correlated with the CSNRT. A stepwise multivariate linear regression analysis including these parameters revealed that the AFCL was the only independent determinant of the CSNRT (β = 0.38; P = .0012). A receiver operating characteristic curve identified an AFCL of more than 162 milliseconds as the optimal cutoff value for predicting SND requiring a PMI (area under the curve, 0.84; sensitivity, 86%; specificity, 74%; P = .0066).Conclusions: A prolonged AFCL was significantly associated with SND. Thus, assessing the AFCL in the patients with long-standing persistent AF may be helpful for the risk stratification of underlying SND.

Electrocardiographic patterns of proximal left anterior descending artery occlusion in ST-elevation myocardial infarction may be modified by 3-vessel coronary artery disease - Corrected Proof

2012-01-16

Abstract: Background: The electrocardiographic (ECG) pattern of ST-segment deviation in myocardial infarction is integral to the proper assessment of the location, extent, and functional significance of the infarct but may be modified by the underlying coronary artery anatomy.Methods: We describe the ECG findings in 2 cases of proximal left anterior descending (LAD) artery occlusion in ST-elevation myocardial infarction (STEMI) associated with 3-vessel coronary artery disease.Results: Both patients had atypical ECG patterns of ST-segment elevation in leads V2, I, and aVL and ST-segment depression with positive T waves suggestive of extensive subendocardial ischemia in leads II, III, aVF, and V3 through V6; acute proximal LAD occlusion and concomitant 3-vessel coronary artery disease were observed angiographically.Conclusion: Electrocardiographic changes in proximal LAD STEMI may be modified by the presence of significant atherosclerotic disease elsewhere in the coronary vasculature. Recognition of this ECG pattern may aid the clinician in the rapid identification of high-risk STEMI.

Visual computed tomographic scoring of emphysema and its correlation with its diagnostic electrocardiographic sign: the frontal P vector - Corrected Proof

Lovely Chhabra, Pooja Sareen, Amit Gandagule, David H. Spodick — 2012-01-16

Abstract: Background: Verticalization of the frontal P vector in patients older than 45 years is virtually diagnostic of pulmonary emphysema (sensitivity, 96%; specificity, 87%). We investigated the correlation of P vector and the computed tomographic visual score of emphysema (VSE) in patients with established diagnosis of chronic obstructive pulmonary disease/emphysema.Methods: High-resolution computed tomographic scans of 26 patients with emphysema (age, >45 years) were reviewed to assess the type and extent of emphysema using the subjective visual scoring. Electrocardiograms were independently reviewed to determine the frontal P vector. The P vector and VSE were compared for statistical correlation. Both P vector and VSE were also directly compared with the forced expiratory volume at 1 second.Results: The VSE and the orientation of the P vector (ÂP) had an overall significant positive correlation (r = +0.68; P = .0001) in all patients, but the correlation was very strong in patients with predominant lower-lobe emphysema (r = +0.88; P = .0004). Forced expiratory volume at 1 second and ÂP had almost a linear inverse correlation in predominant lower-lobe emphysema (r = −0.92; P < .0001).Conclusion: Orientation of the P vector positively correlates with visually scored emphysema. Both ÂP and VSE are strong reflectors of qualitative lung function in patients with predominant lower-lobe emphysema. A combination of more vertical ÂP and predominant lower-lobe emphysema reflects severe obstructive lung dysfunction.

Characteristics of electrocardiographic repolarization in acute myocardial infarction complicated by ventricular fibrillation - Corrected Proof

2012-01-12

Abstract: Background and Purpose: Some de- and re-polarization patterns can reflect an increased risk of ventricular tachyarrhythmias. We studied whether some electrocardiographic (ECG) patterns are able to predict the development of ventricular fibrillation (VF) during acute myocardial infarction (MI).Methods: We compared the patterns of ST-T segment of 78 patients who developed VF during acute MI (patient with VF) vs 170 comparable patients with acute MI but with no VF complications.Results: Of the VF group, 47 developed out-of-hospital VF and 31 developed VF after their admission to the hospital. A steep downsloping ST segment toward a negative T wave with or without a short, flat, or rising portion at the initial portion was observed in 69.2% of the 78 patients: 61.3% in patients with pre-VF and 74.5% in patients with post-VF, vs 9.4% of patients who did not develop VF (P < .0001). In 90.6% of the latter, a typical upward-concave or convex “ischemic” pattern of the ST segment was observed. Thus, the characteristic ST-T patterns were highly associated with VF with a specificity greater than 90%.Conclusions: A steep downsloping ST segment may characterize the ECGs of patients who develop VF during acute MI.

Escape-echo bigeminy - Corrected Proof

S. Serge Barold, Roland Stroobandt, Bengt Herweg — 2012-01-09

Abstract: Escape-capture bigeminy is a well-known arrhythmia characterized by group beating of a junctional beat followed by a conducted sinus beat. We report a variant of this arrangement where a junctional beat gives rise to a retrograde P wave, which is then conducted back to the ventricles producing a hitherto undescribed combination (escape-echo bigeminy) resembling escape-capture bigeminy. The clinical significance of escape-echo bigeminy appears similar to that of classic escape-capture bigeminy.

Optimized electrocardiographic criteria for prior inferior and anterior myocardial infarction - Corrected Proof

Robert A. Warner, Norma E. Hill — 2012-01-04

Abstract: Background and Purpose: The first purpose of the study was to optimize empirically the detection of prior inferior myocardial infarction (IMI) and prior anterior myocardial infarction (AMI) by electrocardiogram (ECG). The second purpose was to compare the diagnostic performances of the new criteria with those of 3 widely used commercial diagnostic ECG algorithms.Materials and Methods: We analyzed the digital ECG data from 1138 subjects with suspected coronary artery disease in whom the presence or absence of prior IMI or AMI was documented by coronary angiography and left ventriculography. We used receiver operating characteristic curves to develop the new criteria for prior IMI and AMI using a training set of 562 subjects and then tested their diagnostic performances using a separate test set of 576 subjects. In both the training and test sets, we used χ2 test to compare the performances of the new criteria with those of 3 commercial computerized diagnostic algorithms.Results: The best criterion for prior IMI was the algebraic sum of the Q and T amplitudes in leads III and aVF. Its sensitivities/specificities were 71%/98% and 74%/98% in the training and test sets, respectively. The best criterion for prior AMI was the algebraic sum of the Q, R, and T amplitudes minus the Q duration in leads V2, V3, and V4. Its sensitivities/specificities were 68%/98% and 65%/98% in the training and test sets, respectively. In both the training and test sets, these diagnostic performances were generally superior to those of the 3 commercial algorithms.Conclusions: Using digital ECG data, we developed and tested new criteria for prior IMI and AMI whose diagnostic performances are generally superior to each of 3 widely used commercial ECG diagnostic algorithms.

Prognostic value of high sensitive C-reactive protein in subjects with silent myocardial ischemia - Corrected Proof

2012-01-04

Abstract: Objectives: The aim of this study was to evaluate the prognostic value of high sensitive C-reactive protein (CRP) in subjects with silent myocardial ischemia (SMI).Design: In total, 678 healthy men and women aged 55 to 75 years with no history of cardiovascular disease or stroke were included. High-sensitive CRP and 48-hour ambulatory ECG monitoring were performed. The primary endpoint was the combined endpoint of death and myocardial infarction.Results: The median follow-up time was 76 months. Seventy-seven subjects (11.4%) had SMI. The combined endpoint occurred in 26% of the subjects with SMI and 14% of the subjects without SMI (P = .005). SMI had a poor prognosis in the group with an elevated CRP ≥3.0 μg/mL (hazard ratio, 3.46; 95% confidence interval, 1.67-7.16; P = .001) compared with the group of subjects with SMI and a low CRP <3.0 μg/mL (hazard ratio, 1.37; 95% confidence interval, 0.63-2.98; P = .54).Conclusions: In apparently healthy subjects, a low level of CRP <3.0 μg/mL selects a low-risk subgroup, despite the presence of SMI.

Acute myocardial infarction with isolated conus branch occlusion - Corrected Proof

2012-01-04

Abstract: There are few reports of acute myocardial infarction (AMI) relating to the occlusion of the conus branch, most of which are iatrogenic in nature. So far as we are concerned, this is the first case of spontaneous AMI with isolated conus branch occlusion. Electrocardiogram (ECG) showed mild elevation of ST segment in leads V1 through V3. Cardiac makers of myocardial infarction were positive. Right coronary angiography revealed an isolated occlusion of the conus branch. Penetration of the guidewire in the occluded lesion was attempted, and recanalization was successfully achieved. The patient was discharged without any adverse events.

Factors associated with development of prolonged QRS duration over 20 years in healthy young adults: the Coronary Artery Risk Development in Young Adults study - Corrected Proof

2011-12-26

Abstract: Background: Data describing factors associated with the development of a prolonged QRS duration (QRSd) from young adulthood to middle age are sparse.Methods: We analyzed 12-lead electrocardiograms (ECGs) from the Coronary Artery Risk Development in Young Adults study over 20 years. We performed logistic regression to examine the associations of baseline (year 0) or average (years 0-20) risk factors with incident prolonged QRSd (QRS >100 milliseconds).Results: We included 2537 participants (57.2% women, 44.7% black; mean age, 25 years); 292 (11.5%) developed incident QRSd greater than 100 milliseconds by year 20. In univariate analyses, baseline covariates associated with incident QRSd prolongation included white race, male sex, ECG–left ventricular mass index, and baseline QRSd. Similar results were observed after multivariable adjustment.Conclusion: We found no long-term associations of modifiable risk factors with incident QRSd >100 milliseconds. Men, whites, and those with higher ECG–left ventricular mass index and QRSd in young adulthood are at an increased risk for incident prolonged QRSd by middle age.

Very late stent thrombosis immediately after recurrent inappropriate shock delivery by an implantable cardioverter defibrillator - Corrected Proof

John Groarke, Dermot Phelan, David Burke, Peter Crean, Brendan Foley — 2011-12-26

Abstract: The case of a 49-year-old man who developed an ST segment elevation myocardial infarction because of very late stent thrombosis occurring in the immediate aftermath of a “storm” of recurrent inappropriate implantable cardioverter defibrillator (ICD) shocks caused by a fracture of a Medtronic Sprint Fidelis (Medtronic Inc., Minneapolis, MN) right ventricular lead is described. A causal relationship between recurrent ICD shocks and stent thrombosis is proposed. This deleterious association is an important observation given the increasing population of patients who receive both coronary stents and ICDs.

Coexisting early repolarization pattern and Brugada syndrome: recognition of potentially overlapping entities - Corrected Proof

2011-12-19

Abstract: The Brugada type 1 electrocardiographic (ECG) pattern and the early repolarization pattern (ERP) are 2 ECG patterns characterized by the appearance of J waves. Although Brugada type 1 ECG pattern in the context of the Brugada syndrome (BrS) is well known for predisposing to life-threatening ventricular arrhythmias, it has only recently come to light that ERP, which was previously believed to be benign, may also be a marker for arrhythmogenic potential. ERP and BrS share many remarkable cellular, ionic, and ECG similarities and behave comparably in terms of their response to heart rate, pharmacologic agents, and neuromodulation. The extent to which ERP and BrS may overlap remains unclear.Here, we present an illustrated case of a symptomatic patient whose ECG signature evolved spontaneously from ERP alone to ERP with a concomitant Brugada type 1 ECG pattern over a short number of days. This case lends further strength to the notion that these 2 ECG patterns may be more closely related than had been initially thought.

Overly excited over preexcitation - Corrected Proof

Sanjiv M. Baxi, Nora Goldschlager — 2011-12-15

Non–ST-segment elevation acute coronary syndrome presenting with ST-segment elevation in aVR and dual antiplatelet therapy - Corrected Proof

2011-12-08

A 74-year-old woman was admitted to our emergency department because of severe chest pain lasting more than 2 hours. The initial triage included a ph ysical examination and a 12-lead electrocardiogram, which showed ST-segment elevation (>2.0 mm) in the aVR lead and diffuse ST-segment depression (>2.0 mm) in leads I, II, III, aVF, and V2 through V6 (A).

A user-friendly integrated monitor-adhesive patch for long-term ambulatory electrocardiogram monitoring - Corrected Proof

2011-12-08

Abstract: Background: Compliance to long-term ambulatory electrocardiogram monitoring is important for diagnosis in patients with cardiac arrhythmia. This requires a system with a minimal impact on daily activities.Objective: The aim of this study was to investigate if a lightweight integrated adhesive monitor for long-term use without unacceptable adverse effects is feasible.Methods: The participants wore either a prototype lightweight monitor or a control system for a total of up to 30 days, changing patches once (investigational device) or twice (control) weekly. Comfort, skin irritation, and impact on quality of life were recorded.Results: The new monitor can be worn by most participants for periods of at least 6 days. Skin irritation and comfort rating were comparable, and impact on the quality of life was low compared with the control. Patients considered the device comfortable.Conclusion: An integrated adhesive monitor that can be worn on the skin up to 7 days with minimal side effects is feasible.

Electrocardiographic, electrophysiologic, and anatomical features of ventricular tachycardia originating from noncoronary cusp - Corrected Proof

Sima Sayah, Shahab Shahrzad, Mehdi Moradi, Majid Haghjoo — 2011-12-08

Abstract: In this article, we report 2 young patients (a 15-year-old adolescent girl and a 25-year-old man) with drug-refractory palpitations. Admission electrocardiograms showed runs of ventricular tachycardia with left bundle-branch block morphology, left inferior axis, early precordial QRS transition, and positive QRS complex in lead I. In right ventricular mapping, the earliest activation site was found in the His bundle region. Aortic root mapping showed a very early fractionated ventricular signal with large atrial potential and no His potential in the noncoronary cusp region. Radiofrequency energy application in this region resulted in tachycardia termination within 5 to 10 seconds. During a 3- to 6-month follow-up period, the patients remained asymptomatic, and the electrocardiogram showed no ventricular arrhythmias.

Prehospital 12-lead ST-segment monitoring improves the early diagnosis of acute coronary syndrome - Corrected Proof

2011-11-24

Abstract: Aims/Methods: We studied 620 patients who activated “911” for chest pain symptoms to determine the sensitivity and specificity of 12-lead electrocardiogram (ECG) ST-segment monitoring in the prehospital period (PH ECG) for diagnosing acute coronary syndrome (ACS) and to assess whether the addition of PH ECG signs of ischemia/injury to the initial hospital 12-lead ECG obtained in the emergency department would improve the diagnosis of ACS.Results: The sensitivity and specificity of the PH ECG were 65.4% and 66.4%. There was a significant increase in sensitivity (79.9%) and decrease in specificity (61.2%) when considered in conjunction with the initial hospital ECG (P < .001). Those with PH ECG ischemia/injury were more than 2.5 times likely to have an ACS diagnosis than those who had no PH ECG ischemia/injury (P < .001).Conclusions: Prehospital ECG data obtained with 12-lead ST-segment monitoring provides diagnostic information about ACS above and beyond the initial hospital ECG.

Wireless remote monitoring of reconstructed 12-lead ECGs after ablation for atrial fibrillation using a hand-held device - Corrected Proof

2011-11-11

Abstract: Objective: Atrial fibrillation (AF) surveillance using a wireless handheld monitor capable of 12-lead electrocardiogram reconstruction was performed, and arrhythmia detection rate was compared with serial Holter monitoring.Methods: Twenty-five patients were monitored after an AF ablation procedure using the hand-held monitor for 2 months immediately after and then for 1 month approximately 6 months postablation. All patients underwent 12-lead 24-hour Holter monitoring at 1, 2, and 6 months postablation.Results: During months 1-2, 425 of 2942 hand-held monitor transmissions from 21 of 25 patients showed AF/atrial flutter (Afl). The frequency of detected arrhythmias decreased by month 6 to 85/1128 (P < .01) in 15 of 23 patients. Holter monitoring diagnosed AF/Afl in 8 of 25 and 7 of 23 patients at months 1-2 and month 6, respectively (P < .01 compared with wireless hand-held monitor). Af/Afl diagnosis by wireless monitoring preceded Holter detection by an average of 24 days.Conclusions: Wireless monitoring with 12-lead electrocardiogram reconstruction demonstrated reliable AF/Afl detection that was more sensitive than serial 12-lead 24-hour Holter monitoring.

Role of the vectorcardiogram-derived spatial QRS-T angle in diagnosing left ventricular hypertrophy - Corrected Proof

2011-11-11

Abstract: Introduction: Current criteria for electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH) have a low diagnostic accuracy. Addition of demographic, anthropomorphic, and additional ECG variables may improve accuracy. As hypertrophy affects action potential morphology and intraventricular conduction, QRS prolongation and T-wave morphology may occur and become manifest in the vectorcardiographic variables spatial QRS-T angle (SA) and spatial ventricular gradient. In this study, we attempted to improve the diagnostic accuracy for LVH by using a combination of demographic, anthropomorphic, ECG, and vectorcardiographic variables.Methods: The study group (n = 196) was divided in 4 subgroups with, on one hand, echocardiographically diagnosed LVH or a normal echocardiogram and, on the other hand, with any of the conventional ECG signs for LVH or with normal ECGs. Each subgroup was randomly split into halves, yielding 2 equally-sized (n = 98) data sets A and B. Age, sex, height, weight, body mass index, body surface area (BSA), frontal QRS axis, QRS duration, QT duration, maximal QRS vector magnitude, SA, and ventricular gradient magnitude and orientation were univariate studied by receiver operating characteristic analysis and were used to build a stepwise linear discriminant model using P < .05 as entry and P > .10 as removal criterion. The discriminant model was built in set A (model A) and tested on set B. Stability checks were done by building a discriminant model on set B and testing on set A and by cross-validation analysis in the complete study group.Results: The discriminant model equation was D = 5.130 × BSA − 0.014 × SA − 8.74, wherein D greater than or equal to 0 predicts a normal echocardiogram and D less than 0 predicts LVH. The diagnostic accuracy (79%) was better than the diagnostic accuracy of conventional ECG criteria for LVH (57%).Conclusion: The combination of BSA and SA yields a diagnostic accuracy of LVH that is superior to that of the conventional ECG criteria.

Outcome after implantable cardioverter-defibrillator in patients with Brugada syndrome: the Gulf Brugada syndrome registry - Corrected Proof

2011-11-11

Abstract: Background and Objective: Among patients with Brugada syndrome (BS) and aborted cardiac arrest, syncope, or inducible ventricular fibrillation at electrophysiologic study (EPS), the only currently recommended therapy is an implantable cardioverter-defibrillator (ICD), but these are not without complications. We assessed the total number of shocks (appropriate and inappropriate) and complications related to ICD in patients with BS.Methods and Results: Twenty-five patients implanted with ICD for BS in 6 Gulf centers between January 1, 2002, and December 31, 2010, were reviewed. Implantable cardioverter-defibrillator indication was based on aborted cardiac arrest (24%), syncope (56%), or in asymptomatic patients with positive EPS (20%). During a follow-up of 41.2 ± 17.6 months, 3 patients (all with prior cardiac arrest) had appropriate device therapy. Four patients developed complications; 3 of them had inappropriate shocks.Conclusion: In our cohort, appropriate device therapy was limited to cardiac arrest survivors, whereas none of those with syncope and/or positive EPS had arrhythmias. Overall complication rate was relatively high, including inappropriate ICD shocks.

Multidimensional ECG-based analysis of cardiac autonomic regulation predicts early AF recurrence after electrical cardioversion - Corrected Proof

2011-10-26

Abstract: Background: Heart rate turbulence, deceleration capacity (DC), and symbolic dynamics (SD) are promising novel domains of autonomic indices representing the multidimensional qualities of autonomic heart rate dynamics.Purpose: The aim of this study was to test the impact of these novel indices in predicting early AF recurrence within the first month after electrical cardioversion (CV).Methods: In 45 patients with AF, standard Holter recordings were commenced immediately after CV. Holter-based indices were retrospectively analyzed using computerized algorithms. The best indices were applied in a multivariate model to select the optimal combination set that correctly classified patients who developed early AF recurrence.Results: Early AF recurrence occurred in 25 vs 20 patients with stable sinus rhythm. The set with the highest predictive power consisted of DC, turbulence onset, VLF/P, and PTH19 as a parameter of SD. The receiver operating curve analysis applied to this optimum set produced an area under the curve of 0.86, thus correctly classifying patients with 95.0% specificity and 76.0% sensitivity.Conclusion: The analysis of novel multidimensional Holter-based autonomic indices after CV appears of clinical value because the procedure identifies patients with high risk of early AF recurrence. Furthermore, it indicates a substantial alteration of autonomic regulation.

Telmisartan decreases atrial electromechanical delay in patients with newly diagnosed essential hypertension - Corrected Proof

2011-10-21

Abstract: Background: Atrial electromechanical delay (EMD) parameters predict the development of atrial fibrillation. We investigated the effect of telmisartan treatment on atrial EMD parameters in patients with newly diagnosed essential hypertension.Methods: Thirty-six patients with essential hypertension were treated with telmisartan (80 mg/day) for 6 months. Baseline electrocardiographic P-wave measurements and echocardiographic atrial EMD parameters were compared with the 6-month follow-up.Results: Pmax and Pd were significantly decreased (108.4 ± 6.1 vs 93.9 ± 6.2 milliseconds, 33.4 ± 8.6 vs 19.5 ± 7.0 milliseconds, respectively, P = .0001 for each) after 6-month telmisartan therapy. The atrial EMD parameters were decreased from baseline (mitral EMD, 68.9 ± 4.9 vs 53.8 ± 4.9 milliseconds; septum EMD, 51.6 ± 7.1 vs 42.6 ± 7. milliseconds1; tricuspid EMD, 48 ± 6.9 vs 39 ± 6.9 milliseconds; interatrial EMD, 20.9 ± 5.5 vs 14.8 ± 5.7 milliseconds; P = .0001 for each parameter). The reduction of interatrial EMD was correlated with the reduction in systolic BP nighttime and the increase in mitral E wave velocity/mitral A wave velocity ratio.Conclusion: Telmisartan decreased the atrial EMD parameters in patients with newly diagnosed essential hypertension.

Specificity of the wide QRS complex tachycardia algorithms in recipients of cardiac resynchronization therapy - Corrected Proof

Marek Jastrzebski, Piotr Kukla, Danuta Czarnecka, Kalina Kawecka-Jaszcz — 2011-10-10

Abstract: Background: We assessed the specificity of wide QRS complex tachycardia (WCT) differentiating algorithms in patients with preexistent left bundle branch block (LBBB) and heart failure.Methods: Three hundred fourteen patients with resynchronization devices were retrospectively screened. electrocardiograms with supraventricular LBBB rhythm were used as a surrogate for supraventricular tachycardia QRS morphology. The Pava lead II criterion, ventricular activation velocity ratio (Vi/Vt) ratio in V2, Vereckei aVR, Brugada, Griffith, and Bayesian algorithms were investigated.Results: The WCT algorithms had a lower specificity (33%-69%) in patients with LBBB than in general WCT populations. The Pava lead II criterion and Brugada algorithm had higher specificity than other algorithms (P < .05). Several of the single criteria (absence of an RS complex in V1 through V6, initial R wave in aVR, Vi/Vt < 1 in V2) had specificities of 92% to 99%.Conclusions: In patients with heart failure and LBBB, an electrocardiographic diagnosis of ventricular tachycardia should be based on selected, specific criteria rather than on WCT algorithms.

A noninvasive index of atrial remodeling in patients with paroxysmal and persistent atrial fibrillation: a pilot study - Corrected Proof

2011-09-16

Abstract: Purpose: This study aims to develop a noninvasive atrial remodeling index (RI) to separate patients presenting paroxysmal atrial fibrillation (ParAF) from those with sustained persistent atrial fibrillation (PerAF), that is, AF episodes interrupted 7 days or more after the onset.Methods: Signal-averaged P-wave duration (SAPWd) and left atrial anteroposterior diameter (LADd) were measured in 33 ParAF patients, in 26 sustained PerAF patients, and in 18 control subjects. By using SAPWd and LADd, a dichotomous (0/1) RI was created. A logistic regression model on the probability of having a sustained PerAF vs a ParAF episode was estimated, including the RI, sex, age, and cardiac comorbidities as covariates.Results: Signal-averaged P-wave duration was significantly longer in sustained PerAF (153 ± 15 milliseconds) than in ParAF patients (142 ± 13 milliseconds, P < .001) and in both ParAF and sustained PerAF groups vs control group (123 ± 7 milliseconds, P < .001). Left atrial anteroposterior diameter was larger both in sustained PerAF (43 ± 6 mm) vs ParAF patients (38 ± 5 mm, P = .002) and in sustained PerAF group vs control group (38 ± 2 mm, P = .004), but no differences were observed between ParAF patients and controls (P = .6). A 12-fold increase (odds ratio, 11.8; 95% confidence interval, 2.2-63.5) in the odds of having a sustained PerAF vs a ParAF episode was observed in patients with RI equal to 1.Conclusions: P-wave duration and left atrium diameter enabled to define a noninvasive atrial RI to separate patients with ParAF from those with sustained PerAF. This could be a useful tool to select a suitable strategy for AF treatment.

Isolated spontaneous septal myocardial infarction - Corrected Proof

Janos Tomcsanyi, Bela Bozsik, Andras Zsoldos, Tamas Simor — 2011-09-12

Abstract: Isolated occlusion of the septal perforating branch of the left anterior descending coronary artery is extremely rare. As a result, little is known about its electrocardiographic manifestations compared with those of an anteroseptal myocardial infarction. We present the case of an isolated septal myocardial infarction with ST-segment elevation.

Inducible atrial tachycardias with multiple circuits in a stepwise approach are associated with increased episodes of atrial tachycardias after catheter ablation - Corrected Proof

2011-08-29

Abstract: Background: Atrial tachycardia (AT) is commonly observed during catheter ablation (CA) in patients with atrial fibrillation (AF) undergoing a stepwise extensive CA. In this study, we examined the hypothesis that the presence of multiple inducible ATs (multiple-ATs), which allow for latent multiple reentrant circuits, might increase the potential for following AT episodes after CA.Methods and Results: The study population consisted of 347 consecutive AF patients undergoing CA with a stepwise approach. A total of 366 ATs (tricuspid isthmus dependent, 101; mitral annulus, 62; septal, 26; roof dependent, 22; left atrial anterior wall, 13; upper loop, 8; surrounding the left pulmonary veins, 6; surrounding the right pulmonary veins, 6; left atrial appendage, 4; and Cs ostium, 3) occurring during the CA were found in 216 (62.2%) of 347 patients. Multiple-ATs (≥2) during the CA were observed in 93 (26.8%) of 347 patients. The incidence of AT episodes significantly increased as the number of inducible ATs increased (no AT, 7.8%; single AT, 13.7%; and multiple-ATs, 24.2%; P < .001), and multiple-ATs were an independent risk factor for AT episodes (3.07 [1.39-6.78]; P = .005). The impact of the multiple-ATs on the AT episodes was pronounced especially in the patients with coinducible residual AF (with coresidual AF vs without coresidual AF, 8.1% vs 47.7%; P < .001).Conclusions: The presence of an atrial substrate allowing for multiple-ATs was associated with increased AT episodes during follow-up.

Acute ischemia manifestation in a patient with coronary slow flow phenomenon - Corrected Proof

Blendi Horjeti, Artan Goda — 2011-08-16

Abstract: A patient with anginal chest pain and electrocardiographic changes suggesting ischemia was referred to our hospital. Coronary angiography revealed no significant stenosis or ectasia but only slow flow in all 3 coronary arteries. After infusion of unfractionated heparin for 24 hours, negative T waves became less deep, and repeated coronary angiography showed significant improvement of the coronary flow. The coronary slow flow phenomenon, together with the associated ischemic electrocardiographic changes, should be considered as a separate entity in the differential diagnosis of acute coronary syndromes. Additional clinical research is required to better understand the syndromes of chest pain with normal coronary arteries.

Cardiac magnetic resonance imaging as a tool to link cardiac conduction disease to myocarditis with minimal left ventricular impairment - Corrected Proof

Dirk Prochnau, Helmut Kühnert, Jens-Peter Heyne, Hans R. Figulla, Ralf Surber — 2011-07-11

Abstract: Myocarditis is an injury of the myocardium caused by a variety of agents. Conduction disturbances such as complete atrioventricular block (AV block) may occur as an infrequent but serious complication of myocarditis. Early detection and accurate diagnosis of myocarditis are still unresolved challenges. We present 2 cases of otherwise mild myocarditis complicated by high-degree AV block in combination with isolated delayed uptake of contrast at the septal regions in the cardiac magnetic resonance imaging. Because the AV block was persistent in both cases, permanent pacemaker implantation was necessary. Delayed enhancement in the septal area in myocarditis might be predictive of infra-Hisian AV block.

Initial experience with robotic navigation for catheter ablation of paroxysmal and persistent atrial fibrillation - Corrected Proof

2011-06-29

Abstract: Background and Purpose: Remote robotic navigation (RRN) technology has been developed to facilitate catheter ablation of symptomatic atrial fibrillation (AF). Here, we assess procedural parameters of AF ablation obtained during initial use of RRN compared with a control group treated with a manual ablation approach.Methods: Consecutive patients with symptomatic paroxysmal or persistent AF were subjected to radiofrequency catheter ablation with RRN (Sensei X [Hansen Medical, Mountain View, CA]; n = 25; mean age, 60 ± 2.3 years) or using the standard manual technique (n = 61; mean age, 62 ± 1.4 years). A circumferential pulmonary vein isolation approach guided by 3-dimensional electroanatomical mapping was followed.Results: Remote robotic navigation was associated with reduction of overall fluoroscopy time by 26%. In a case-control subgroup analysis comparing 25 patients with similar clinical characteristics from each group, mean fluoroscopy time was reduced by 22%. Acute isolation of pulmonary veins was achieved in 97% (RRN) and 96% (conventional ablation), respectively. Ablation times and frequency of adverse events were not significantly different among study groups.Conclusions: The early use of RRN resulted in a significant reduction of overall fluoroscopy time and was equally effective and safe compared with manual catheter ablation.

Electrocardiogram quiz - Corrected Proof

Sivakumar Ardhanari, Greg Flaker, Mary Dohrmann — 2011-06-27

Ventricular fibrillation after exposure to air freshener—death just a breath away - Corrected Proof

2011-06-22

Abstract: A case of ventricular fibrillation due to butane toxicity after unintentional inhalation of air freshener is reported for its rarity and to create awareness among practitioners and the public. A 25-year-old woman collapsed in the supermarket after unintended exposure to air freshener sprayed into her nostrils. Her husband started cardiopulmonary resuscitation immediately, and she was brought to the hospital. She had coarse ventricular fibrillation. Defibrillation with 360 J was given, and the rhythm reverted to normal sinus rhythm after the third shock. Epinephrine was not administered, and she was treated with esmolol infusion for ventricular ectopy. The patient recovered completely without any sequelae and was discharged on the fifth hospital day. On thin layer chromatography, the chemical content of the spray was identified to be isobutane. Avoiding epinephrine and administering β-adrenergic blockers may protect the catecholamine-sensitized heart early during resuscitation in butane exposure cases.

Mason-Likar electrode configuration can confound the recognition of electrode cable interchange - Corrected Proof

Velislav N. Batchvarov, Dilshat Djumanov, Jorg Taubel, A. John Camm — 2011-03-02

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.