Pre-existing Bundle Branch Block Research Articles

Ectopic Atrial Tachycardia in Children: A Literature Review

Introduction: Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result in left ventricular dysfunction if not properly managed. In adults, EAT is mainly caused by diseased atrial myocardium and responds poorly to antiarrhythmic drugs. The characteristics of EAT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characteristics of their conduction tissue. Purpose: To present the data on the natural history and treatment of EAT in children. Material and method: The study material consisted of reviewed articles on the topic found on the globally accepted electronic databases, PubMed, Medline and Google Scholar regarding the Ectopic atrial tachycardia in children and its treatment. Results: The diagnosis of atrial ectopic tachycardia is based on the presence of a narrow complex tachycardia (in the absence of aberrancy or pre-existing bundle branch block) with visible P waves at an inappropriately rapid rate. The rates range from 120 to 300 beats per minute (bpm) and are typically higher than 200 bpm, although physiologic rates may be observed. EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. Spontaneous resolution of EAT after medication in children was frequent (75%). Conclusion: EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. The results of studies suggest that a stepwise approach using digoxin, a beta-blocker, and a class I antiarrhythmic drug may be the most effective treatment for EAT

PO-03-110 NEW INSIGHTS FROM HIS VENTRICULAR INTERVALS IN PATIENTS UNDERGOING TAVR AND IMPLICATIONS FOR PERMANENT PACING

Trans catheter aortic valve replacement (TAVR) represents a revolutionary treatment for patients with severe symptomatic aortic stenosis who are at high surgical risk. The rate of periprocedural complications has decreased over time. However, the incidence of conduction disease requiring permanent pacemaker (PPM) implantation has failed to decrease. The decision for PPM for conduction disease post TAVR is usually made based on ECG. It’s not uncommon for patients with conduction disease without evidence for infra-nodal block to receive a PPM, and pacing has been shown to have deleterious effects. To assess the utility of His Ventricular Interval (HVI) studies in predicting the need for PPM implantation. We included patients who underwent assessment of the AV nodal (AH interval) and the HVI pre and/or post TAVR and were continuously monitored until discharge and after discharge for 2 weeks. Repeat EP study was performed in the presence of new conduction disease during in-hospital or as an outpatient. PPM was recommended in the presence of complete heart block (CHB), infra-Hisian block or with an HV > 70 ms (discretion of the physician). Patients receiving PPM before 30 days were documented. Total of 71 patients who had pre and post TAVR EP study had follow up for at least 30 days. The Cohort predominantly male with an average age of 77 years. Forty-six patients received Edwards and 25 Medtronic valve. A total of 6 patients received PPM, 5 out of 6 within the index hospitalization, and 1 patient 5 days post discharge. Four out of 6 patients with PPM had Edwards and 2 out of 6 had Medtronic valve. Four out of 6 patient who received PPM, developed CHB during TAVR and HVI post TAVR was not measured; in 1 patient HVI could not be measured reliably because of atrial fibrillation and the other had normal pre and post HVI. Ten of 71 patients had pre-existing Bundle Branch Block (BBB). Four had right bundle branch block (RBBB) of which 1 required PPM, and 6 had left bundle branch block (LBBB) of which 1 required PPM. Six of 71 patients had new BBB post TAVR. 5 developed LBBB of which 2 required PPM, and 1 developed RBBB of which none required PPM In patients undergoing TAVR, pre and post TAVR EP study is very useful in determining the need for PPM. In the absence of significant infra-Hisian disease, Pre-TAVR RBBB or LBBB and new RBBB or LBBB are not an indication for PPM.Tabled 1HVI in pre-existing (Old)and post TAVR (new) Bundle Branch block (PO-03-110)Pre-existing LBBBPre-existing RBBBPost-TAVR (new) LBBBPost-TAVR (new) RBBBPatientPre-HVI (ms)Post-HVI (ms)PPM (yes/no)PatientPre-HVI (ms)Post-HVI (ms)PPM (yes/no)PatientPre-HVI (ms)Post-HVI (ms)PPM (yes/no)PatientPre-HVI (ms)Post-HVI (ms)PPM (yes/no)16063no155CHByes15255no14043no25060no25053no24871no35558yes35055no35058yes44548no44045no46063no55560no54859yes66373no Open table in a new tab

The ECG in cardiac rehabilitation

The concept and the benefits of cardiac rehabilitation are well established and scientifically proven. In the context of shortened in-hospital stays and older patients receiving more complex interventions, complications of those procedures might occur during cardiac rehabilitation. This article discusses guideline-directed diagnosis and treatment of complications after transcatheter aortic valve replacement, especially delayed-onset heart block, post-operative atrial fibrillation, and acute coronary ischemia in the setting of pre-existent bundle branch block.

Prediction of conduction disturbances in patients undergoing transcatheter aortic valve replacement

AimTranscatheter aortic valve replacement (TAVR) can cause intraventricular conduction disturbances (ICA), particularly left bundle branch block (BBB) and high-degree atrioventricular block (HAVB). The aim of this study was to investigate clinical, anatomical, procedural, and electrophysiological parameters predicting ICA after TAVR.MethodsPatients with severe aortic stenosis (n = 203) without pacing devices undergoing TAVR with a self-expanding (n = 103) or balloon-expanding (n = 100) valve were enrolled. Clinical and anatomical parameters, such as length of the membranous septum (MS) and implantation depth, were assessed. His-ventricular interval (HVi) before and after implantation was determined. 12-lead-electrocardiograms (ECG) before, during and after 3 and 30 days after TAVR were analyzed for detection of any ICA.ResultsAmong 203 consecutive patients (aortic valve area 0.78 ± 0.18 cm2, age 80 ± 6 years, 54% male, left ventricular ejection fraction 52 ± 10%), TAVR led to a significant prolongation of infranodal conduction in all patients from 49 ± 10 ms to 59 ± 16 ms (p = 0.01). The HVi prolongation was independent of valve types, occurrence of HAVB or ICA. Fifteen patients (7%) developed HAVB requiring permanent pacemaker (PPM) implantation and 63 patients (31%) developed ICA within 30 days. Pre-existing BBB (OR 11.64; 95% CI 2.87–47.20; p = 0.001), new-onset left BBB (OR 15.72; 95% CI 3.05–81.03; p = 0.001), and diabetes mellitus (OR 3.88; 95% CI 1.30–15.99; p = 0.02) independently predicted HAVB requiring PPM. Neither pre-existing right BBB, a prolonged postHVi, increases in PR duration, any of the TAVR implantation procedural and anatomic nor echocardiographic characteristics were predictive for later HAVB.ConclusionsNew-onset left BBB and diabetes mellitus independently predicted HAVB requiring PPM after TAVR and helped to identify patients at risk. Electrophysiologic study (EPS) of atrioventricular conduction was neither specific nor predictive of HAVB and can be skipped.Trial registration numberNCT04128384 (https://www.clinicaltrials.gov).Graphical abstract

Delta Increment in Pacing QRS Duration Predicts Cardiovascular Mortality in Patients with Pre-Existing Bundle Branch Block Receiving Permanent Pacemakers.

The clinical implication of pre-existing intraventricular conduction disturbance (IVCD) in permanent pacemaker (PPM) recipients is unknown. To explore the clinical outcomes in patients with pre-existing IVCD after implantation of PPMs. A total of 1424 patients who received PPMs were categorized into three groups by pre-procedural electrocardiography: patients without IVCD (n = 1045), patients with right bundle branch block (RBBB) (n = 309), and patients with left bundle branch block (LBBB) (n = 70). The primary outcome was cardiovascular (CV) mortality. Receiver operating characteristic curve analysis was performed to determine the optimal cut-off values of variable in predicting CV mortality. During follow-up, there was no significant difference in CV mortality between patients with and without IVCD. In multivariate analysis, independent predictors of CV mortality were age [hazard ratio (HR): 1.03; 95% confidence interval (95% CI): 1.00-1.05; p = 0.026], history of heart failure [HR: 1.98; 95% CI: 1.19-3.29; p = 0.009], chronic kidney disease [HR: 1.75; 95% CI: 1.11-2.74; p = 0.015] and increment in pacing QRS duration [HR: 1.01; 95% CI: 1.00-1.04; p = 0.038]. Delta increments in pacing QRS duration ≥ 43 msec [HR: 2.91; 95% CI: 1.23-6.83; p = 0.014] in patients with pre-existing RBBB, and ≥ 33 msec [HR: 11.44; 95% CI: 2.03-64.30; p = 0.006] in patients with pre-existing LBBB were independent determinants of CV mortality. There was no difference in CV mortality between patients with or without IVCD. However, wider pacing QRS duration increased the risk of CV mortality in PPM recipients, and delta increment in pacing QRS duration increased the risk of CV mortality in patients with pre-existing IVCD.

Impact of pre-existing right or left bundle branch block on patients undergoing surgical aortic valve replacement.

Contemporary data on the prognostic impact of pre-existing left or right bundle branch block on clinical outcomes after aortic valve (AV) replacement are limited. The aim of this study was to evaluate the impact of pre-existing bundle branch block on clinical outcomes in patients undergoing AV replacement. Data from patients who underwent AV replacement surgery between 2004 and 2020 were obtained from our departmental database. Of the 2704 study patients, 203 (7.5%) had pre-existing bundle branch block and 2501 (92.5%) had normal atrioventricular conduction. The mean age was 68 (13) years, 1697 (63%) were male and 683 (25%) had a unicuspid or bicuspid AV. The in-hospital mortality rate was higher in patients with pre-existing bundle branch block compared to those without on admission (5.9% vs 2.9%, P = 0.032), and more frequent in patients with left compared with right bundle branch block (11.9% vs 4.3%, P = 0.003). New pacemaker implantation was most frequent in those patients with pre-existing left bundle branch block, followed by right and no bundle branch block on admission (28.6% vs 7.5% vs 2.8% respectively, P < 0.001; odds ratio 4.96 95% confidence interval 2.96-8.08, P < 0.001). The 10-year cumulative survival rate was lower in patients with bundle branch block compared with patients with no bundle branch block (76.8% vs 82.8%, log-rank P < 0.001; hazard ratio 0.73, confidence interval 0.54-0.99, P = 0.042). This study indicates that patients with pre-existing bundle branch block have a higher incidence of pacemaker implantation and all-cause mortality after AV replacement compared with patients without a conduction disturbance.

Abstract 17261: Maintenance of Sinus Rhythm After His Bundle Pacing and AV Nodal Ablation in Patients With Recurrent Atrial Fibrillation After Catheter Ablation

Background: Catheter ablation (CA) is the most effective means of rhythm control for atrial fibrillation (AF) but is not curative. Irregular and rapid ventricular activation by AF begets AF. Cardiac resynchronization and atrioventricular nodal (AVN) ablation have been associated with favorable atrial remodeling and spontaneous reversion to sinus rhythm in patients with longstanding atrial fibrillation. Hypothesis: We hypothesized that in patients with longstanding persistent AF who had failed CA, AVN ablation and His bundle pacing (HBP) may improve maintenance of sinus rhythm. Methods and Results: A total of 13 patients (5 female, age 69±8.7 years, 8 with HFrEF, BMI 29 ±5 kg/m 2 ,LVEF 38±15%, NYHA 3±0.6) underwent simultaneous AVN ablation and HBP an average of 531 days (Range 1-2158 days) after CA for AF with recurrent AF. Prior to AVN ablation and HBP these patients had a median 9-year history of AF (IQR: 5-15 years) with a median of 2 prior cardioversions (IQR: 1-4) and 2 prior CA. All patients had failed at least 1 antiarrhythmic drug. In 3 patients HBP induced cardiac resynchronization of pre-existing bundle branch block and in 8 patients HBP was fused with ventricular pacing to optimize QRS duration. 12 of 13 patients had an atrial lead. All patients underwent cardioversion at the time of the procedure. In a median of follow up of 21 months (IQR:4-74 months), 7 of the 13 patients (54%) had no device detected or clinical recurrence of AF. In follow up LVEF increased to 46±12.7% and NYHA class to 2 ±0.2. Of patients with recurrence, 3 underwent CA and had no recurrence of AF in subsequent follow up. Conclusion: In patients with advanced longstanding persistent AF, a strategy of AVN ablation and HBP allowed for ventricular rate control with a narrow QRS. This approach resulted in a lower than expected rate of AF recurrence.

Effects of antiarrhythmic drugs on atrioventricular conduction in patients with preexisting bundle branch block

Abstract Background Theoretical concern exists regarding AV block (AVB) with class I antiarrhythmics (AADs) when bundle branch block (BBB) is present. Whether this is substantiated in real-world populations is unknown. Purpose To determine the relationship between type of AAD and incidence of AVB in patients with preexisting BBB. Methods We retrospectively studied all patients with BBB who received class I and III AADs between 1997–2019 to compare incidence of AVB. We defined index time as first exposure to either drug class and excluded patients with prior AVB or exposed to both classes. Time-at-risk window ended at first outcome occurrence or when patients were no longer observed in the database. We estimated hazard ratios for incident AVB using Cox proportional hazards models with propensity score stratification, adjusting for over 32,000 covariates from the electronic health record. Kaplan-Meier methods were used to determine treatment effects over time. Results Of 40,120 individuals with BBB, 148 were exposed to a class I AAD and 2401 to a class III AAD. Over nearly 4,200 person-years of follow up, there were 22 and 620 outcome events in the class I and class III cohorts, respectively (Figure). In adjusted analyses, AVB risk was markedly lower in patients exposed to class I AADs compared with class III (HR 0.48 [95% CI 0.30–0.75]). Conclusion Among patients with BBB, exposure to class III AADs was strongly associated with greater risk of incident AVB. This likely reflects differences in natural history of patients receiving class I vs class III AADs rather than adverse class III effects, however, the lack of worse outcomes acutely with class I AADs suggests that they may be safer in BBB than suspected. Funding Acknowledgement Type of funding source: None

Impact of tapered-shaped left ventricular outflow tract on permanent pacemaker implantation after the third-generation balloon-expandable valve implantation

Abstract Background In the era of transcatheter aortic valve implantation (TAVI) for patients with lower surgical risk, conduction disturbances requiring permanent pacemaker implantation (PPI) after TAVI remain a serious concern. The association between tapered-shaped left ventricular outflow tract (LVOT) and PPI after TAVI has not been elucidated. Purposes This study sought to identify predictors for PPI after TAVI with the third-generation balloon-expandable valve, with focus on LVOT morphology. Methods Of 272 consecutive patients treated with the third-generation balloon-expandable valve, 256 patients without previous PPI or bicuspid valve were retrospectively analyzed. Results PPI was implanted after TAVI in 20 (7.8%) patients. Patients requiring PPI had smaller LVOT area (356.3 mm2 vs. 399.4 mm2, p=0.011). Moreover, receiver-operating characteristic (ROC) statistics showed that LVOT area /annulus area possessed significantly higher predictive ability than LVOT area (area under the curve: 0.91 [95% confidence interval [CI]: 0.84 to 0.95] vs. 0.67 [95% CI: 0.57 to 0.77], p&amp;lt;0.001). Multivariable analysis revealed LVOT area /annulus area (odds ratio [OR]: 1.93 [95% CI: 1.38–2.71]; p&amp;lt;0.001 per % of decreasing), the difference between membranous septum length and implantation depth (ΔMSID) (OR: 6.82 [95% CI 2.39–19.48]; p&amp;lt;0.001 per mm of decreasing) and pre-existing complete right bundle branch block (CRBBB) (OR: 32.38 [95% CI 2.30–455.63]; p=0.002) as independent predictors of PPI. Further analysis using ROC statistics revealed LVOT area / annulus area of 88.5% and ΔMSID of 1.8 mm as the optimal cutoff points for prediction of PPI after the third-generation balloon-expandable valve implantation, with high negative predictive values of 98.1% and 99.0%, respectively. Figure shows the PPI rates stratified by the number of following predictors: LVOT area /annulus area &amp;lt;88.5%, ΔMSID &amp;lt;1.8 mm and pre-existing CRBBB. Patients with 2 or more predictors had significantly higher PPI rates than those with 1 or less predictor (67% [18 of 27 patients] vs. 1% [2 of 229 patients], p&amp;lt;0.001). Conclusions LVOT area /annulus area, ΔMSID and pre-existing CRBBB were identified as powerful independent predictors for PPI after TAVI. Higher valve implantation is important to prevent excessive PPI especially for patients with pre-procedural tapered-shaped LVOT, short membranous septum or pre-existing CRBBB. PPI rates stratified by predictors Funding Acknowledgement Type of funding source: None

Etiology of syncope in patients with preexisting atrioventricular conduction disorders.

The discussion about the feasibility of empiric pacemaker implantation in patients with preexisting atrioventricular (AV) conduction disorders continues. The aim of the study was to determine the etiology of syncope and the need for pacemaker insertion in patients with AV conduction impairment using implantable loop recorder (ILR). ILR was implanted after negative diagnostic workup in 37 patients with syncope (24 men, 13 women, age 72±10 years) and preexisting impairment of AV conduction. First-degree AV block (AVB I) was present in 26 patients, and bundle branch block (BBB) in 17 patients. ILR-based diagnosis was made in 28 patients (75%)-sinus arrest in 13 patients, complete AVB in 10 patients, and vasodepressor syncope in five patients. In patients with preexisting BBB, sinus arrest occurred during ILR monitoring significantly more frequently than in patients without BBB (53%vs 20%, P = .03). Complete AVB was significantly less common in patients with preexisting BBB than in patients without BBB (12%vs 40%, P=.04). On multivariate regression analysis, the only independent predictor of AVB occurrence during ILR monitoring was preexisting AVB I (P=.03). The only independent predictor of sinus arrest during ILR monitoring was preexisting BBB (P=.03). In patients with preexisting AV conduction disorders, prevailing syncopal mechanism during ILR monitoring was asystole. However, sinus arrest occurred more often than complete AVB and was predicted by preexisting BBB. Preexisting AVB wasa predictor of complete AVB during ILR monitoring.

Severe conduction defects requiring permanent pacemaker implantation in patients with a new-onset left bundle branch block after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is frequently associated with cardiac conduction defects (CCD) requiring permanent pacemaker implantation (PPI). Although new-onset left bundle branch block (LBBB) is often seen, the rate of progression to severe CCD is unclear. We aimed to find clinical and electrocardiographic (ECG) parameters associated with severe CCD requiring PPI in patients with a new-onset LBBB after TAVI and assess its effect on clinical outcome. All consecutive patients undergoing TAVI who developed a new-onset LBBB were retrospectively analysed. We excluded patients with pre-existing bundle branch block or pacemaker. Patients were divided into two groups: with or without PPI after TAVI. We included 155 patients (50% female, 80 ± 7 years), of which 37 (24%) developed CCD requiring PPI, mainly due to a total atrioventricular block (n = 17; 46%). Cardiac conduction defects requiring PPI were associated with the following pre-existing parameters: atrial fibrillation (AF), the use of digoxin, CoreValve implantation, and left heart axis. Furthermore, it was associated with the following post-procedural parameters: left heart axis, lower mean heart rate, and prolonged PQ and QRS times. During follow-up, patients with PPI showed a lower mortality rate (11 vs. 29%, P = 0.03). In patients without PPI, mortality was lower in those with narrower QRS complex and transient LBBB. The severity and persistence of a new-onset LBBB after TAVI is associated with mortality. Cardiac conduction defects requiring PPI are associated with prior AF, the use of digoxin, CoreValve implantation, and a left heart axis. In these patients, PPI portends a better prognosis than no PPI.

Management of Coronary Artery Disease and Conduction Abnormalities in Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve replacement (TAVR) is an expanding, catheter-based technology that allows the implantation of a prosthetic valve without requiring open heart surgery for the treatment of severe aortic stenosis (AS). The frequency of coronary artery disease (CAD) in patients (pts) with severe AS undergoing surgical treatment ranges from 30 to 50%. This tends to be higher in pts undergoing TAVR with a prevalence of 49-76% and is more prevalent with older age and the fact that TAVR is commonly performed in high-risk groups with more advanced cardiovascular disease. The overall influence of CAD on TAVR procedural outcomes remains controversial, and the management of concomitant artery disease is still under discussion. There are three major issues that must be addressed: the impact of CAD, optimal timing of percutaneous coronary intervention (PCI) and TAVR, and extent of revascularization. Today, TAVR is commonly performed as a stand-alone procedure with variable degrees of concomitant CAD tolerated without intervention. One of the major potential complications with TAVR is the damage to the conduction system. The requirement of permanent pacemaker (PM) implantation ranges from 9 to 49% of cases with a mean of ~20%, whereas surgical aortic valve replacement (sAVR) is associated with a complete heart block that requires permanent PM in 3-12% of cases. Reports have demonstrated an increased incidence of conduction damage in patients undergoing TAVR with the CoreValve (Medtronic Minneapolis, MN, USA) prosthesis (mean 20.8%, range 9.3-30.0%) compared with the Edwards SAPIEN (Edwards Lifesciences LLC; Irvine, CA, USA) prosthesis (mean 5.4%, range 0-10.1%). Factors predicting PM implantation include preexisting bundle branch block (BB) or conduction abnormalities. The prognostic significance of new left bundle branch block (LBBB) after TAVR is unclear. In the future, new valve designs may improve the incidence of permanent PM implantation after TAVR.

Short-term pacemaker dependency after transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is a less invasive technique for the treatment of severe aortic stenosis in high-risk patients. Occurrence of conduction disturbances requiring permanent pacemaker (PPM) implantation after TAVI is frequently observed. The retrospective analysis comprised 153 patients (96 women, aged from 65 to 97 years) who underwent TAVI due to high-grade aortic stenosis. The aim was to evaluate the incidence of high-grade atrioventricular (AV) block after TAVI and the percentage of ventricular pacing and pacemaker (PM)-dependency at the first follow-up 6-8 weeks after implantation. Out of the 153 patients (age 81 ± 6 years) who underwent TAVI, 144 (94 %) had a transfemoral and 9 (6 %) patients a transapical approach. A PPM was implanted in 31 (20 %) patients, 24 (16 %) were implanted with the Medtronic CoreValve® and 7 (5 %) with the Edwards Sapien® valve (p = n.s.). Complete AV block was the indication in 21 patients (68 %), second-degree AV block in 1 patient (3 %), slow atrial fibrillation in 3 patients (10 %), new left bundle branch block (LBBB) plus sustained ventricular tachycardia (VT) in 1 patient (3 %), sick sinus syndrome in 2 patients (7 %), whereas in 3 patients (10 %) a PPM was inserted for safety reasons because of new LBBB and first-grade AV block. All of the nine patients (6 %) with a preexisting bundle branch block developed total AV block after TAVI. At follow-up PM-dependency (intrinsic rhythm < 30 bpm) occurred in 11/30 patients (37 %), whereas an intrinsic rhythm > 50 bpm was seen in 17 patients (57 %). At nominal device programming the percentage of ventricular stimulation (VP) during the short-term observation period was 60 ± 44 % in dual-chamber devices (N = 18), and 70 ± 36 % in single-chamber PPM (N = 5). The PPM implantation rate of about 20 % after TAVI is comparable to previously published data. The need for permanent pacing is linked to the valve type and preexistence of a right bundle branch block. At short-term more than half of the patients implanted with a device were not strictly PM-dependent, but presented an underlying intrinsic rhythm, indicating that temporary AV conduction disturbances may recover over time. This might justify a more conservative approach in some patients under watchful waiting. From another point of view, ventricular pacing at a regular or sensor-modulated rate may provide rhythm stability and chronotropy during the short-term period post-TAVI.

Incidence of strict versus nonstrict left bundle branch block after transcatheter aortic valve replacement

Up to one-third of patients diagnosed with left bundle branch block (LBBB) by conventional electrocardiographic (ECG) criteria are misdiagnosed. Strict LBBB shows decreased left ventricular pumping efficiency compared with nonstrict LBBB. However, no previous study has evaluated the frequency of strict LBBB after transcatheter aortic valve replacement (TAVR). The aim of this study was to determine the incidence of developing strict versus nonstrict LBBB after TAVR and test the hypothesis that preprocedure QRS duration does not predict strict LBBB but predicts development of nonstrict LBBB. All patients receiving TAVR between 4/2011 and 2/2013 (n = 71) with no preexisting bundle branch block or permanent pacemaker were included. Twelve-lead ECGs were acquired preprocedure and both 1-day and 1-month postprocedure. All ECGs were classified as strict LBBB, nonstrict LBBB, or no LBBB. Sixty-eight patients had ECGs eligible for final analysis. On postprocedure day 1, 25 (37%) of 68 patients developed strict LBBB, and 2 patients (3%) developed nonstrict LBBB. At 1-month follow-up, the 2 patients diagnosed with nonstrict LBBB had resolved to normal, and 5 (20%) of 25 patients with strict LBBB had resolved to normal. Preprocedure QRS duration did not predict strict LBBB (P = .51). Because of the low incidence of nonstrict LBBB, QRS duration as a predictor of nonstrict LBBB could not be tested. Almost all patients who developed evidence of LBBB after TAVR met the new strict criteria, indicating probable procedural injury to the left bundle branch. Preprocedural QRS duration did not predict the development of strict LBBB.

Broad QRS complex tachycardias in the emergency department: a review of distinguishing features

The differentiation of Broad QRS complex tachycar dias is a commonly encountered diagnostic dilemma in the emergency department. Patients presently with Broad QRS complex tachycardias are usually uncomfortable or have some form of hemodynamic distress requiring urgent attention. The electrocardiographic differential diagnosis includes ventricular tachycardia, supraventricular tachycardia with functional aberration, preexisti ng bundle branch block, intraventricular conduction disturbances, pre-excitation and effect of medicatio ns. Despite all available criteria, Broad complex tachycardias are still misdiagnosed or under diagnosed. With the rising prevalen ce of coronary artery disease in developing countries this diagnostic dilemma will be more frequently encountered in sub- Saharan African countries than previously. This paper will review some of the distinguishing features and recognized criteria.

High-degree atrioventricular block in patients with preexisting bundle branch block or bundle branch block occurring during transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) has become the standard therapy for high-risk and non-operable patients with severe aortic stenosis. However, the procedure involves several adverse effects, such as rhythm and conduction disturbances. Patients with postprocedural left bundle branch block may have an increased mortality risk, whereas patients with preprocedural right bundle branch block display a higher rate of postinterventional bradyarrhythmias. The purpose of this study was to investigate the occurrence of high-degree atrioventricular block (AVB) in patients with preexisting bundle branch block (BBB) or BBB occurring during TAVI. In this prospective single-center study, 50 consecutive patients undergoing TAVI with the Medtronic CoreValve Revalving System were included. Of these patients, 17 with preexisting BBB or BBB occurring during TAVI received a primary prophylactic permanent DDD pacemaker, programmed to the SafeR-mode and featuring dual-channel event counters as well as stored intracardiac electrograms. Pacemaker readouts and intracardiac electrograms were analyzed for the occurrence of high-degree AVB. Ten of 17 patients (58.8%) with preexisting BBB or BBB occurring during TAVI developed episodes of high-degree AVB that were immediately terminated due to switch into DDD backup pacing. In 5 of the cases (29.4%), the first documented episode of high-degree AVB occurred after hospital discharge. Mean follow-up period was 578.1 ± 294.9 days. Development of high-degree AVB is a common complication in patients with preexisting BBB or BBB occurring during TAVI. Accordingly, intensified monitoring might be reasonable, especially in patients treated with the self-expandable Medtronic CoreValve Revalving System.

Supraventricular tachycardia and sinus rhythm with contralateral bundle branch block patterns.

A contralateral bundle branch block (BBB) aberration during tachycardia with a preexisting BBB strongly suggests the presence of ventricular tachycardia. We report on a middle-aged, female patient presented with wide QRS tachycardia. The patient had orthodromic atrioventricular tachycardia with a left BBB aberration in the presence of a preexisting right BBB due to an abnormal His-Purkinje system. We learned that the contralateral BBB aberration with supraventricular tachycardia could be seen when the His-Purkinje system was abnormal.

Comparison of the “Real-life” Diagnostic Value of Two Recently Published Electrocardiogram Methods for the Differential Diagnosis of Wide QRS Complex Tachycardias

The diagnostic values of the aVR lead or "Vereckei algorithm," and the lead II R-wave peak time (RWPT) criterion, recently devised for the differential diagnosis of wide QRS complex tachycardias (WCTs), were compared. A total of 212 WCTs (142 ventricular tachycardias [VTs], 62 supraventricular tachycardias [SVT], and eight preexcitation SVTs) from 145 patients with proven electrophysiologic diagnoses were retrospectively analyzed by seven examiners blinded to the electrophysiologic diagnoses. The overall test accuracy of the Vereckei algorithm was superior to that of the RWPT criterion (84.3% vs. 79.6%; p = 0.0003). The sensitivity of the Vereckei algorithm for VT diagnosis was greater than that of RWPT criterion (92.4% vs. 79.1%; p < 0.0001). The negative predictive value (NPV) for the Vereckei algorithm was also greater (77.8%; 95% confidence interval [CI] = 73.6% to 82.1%) than that of the RWPT criterion (61.6%; 95% CI = 57.6% to 65.6%). The specificity of the Vereckei algorithm was lower than that of the RWPT criterion (64.7% vs. 80.9%; p < 0.0001). The positive predictive value (PPV) was also lower for the Vereckei algorithm (86.4%; 95% CI = 84.4% to 88.4%) than for the RWPT criterion (90.9%; 95% CI = 89.1% to 92.8%). Incorrect diagnoses made by the Vereckei algorithm were mainly due to misdiagnosis of SVT as VT (65.7% of cases), and those made by the RWPT criterion were due to the more dangerous misdiagnosis of VT as SVT (72.5% of cases). The Vereckei algorithm was superior in overall test accuracy, sensitivity, and NPV for VT diagnosis and inferior in specificity and PPV to the RWPT criterion. All of these parameters were lower in "real life" than those reported by the original authors for each of the particular electrocardiographic methods.

043 Low pacing rate achieved in CoreValve transcatheter aortic valve implantation (TAVI): comparison of pacing rate pre and post new delivery catheter

IntroductionPermanent pacemaker implantation (PPM) following transcatheter aortic valve implantation (TAVI) is a recognised complication. However, the higher pacing rate post CoreValve TAVI compared to SAVR (33% vs 8%) is a...

107 New-onset permanent pacemaker implantation following isolated aortic valve replacement for aortic stenosis in elderly patients

107 New-onset permanent pacemaker implantation following isolated aortic valve replacement for aortic stenosis in elderly patients