RBBB Morphology Research Articles

Feasibility and effectiveness of left bundle branch area pacing after TAVR: the single center experience

Abstract Introduction Transcatheter aortic valve replacement (TAVR) is a safe alternative to open-heart surgery in patients with symptomatic severe aortic stenosis and high surgical risk due to multiple comorbidities, advanced age, and severe left ventricle dysfunction. Due to anatomical considerations of the atrioventricular node, conduction abnormalities requiring the implantation of a pacemaker are common findings after TAVR. High-grade atrioventricular block and new-onset left bundle branch block (LBBB) are the most commonly reported conduction abnormalities after TAVR. Purpose The aim of our study was to assess the feasibility, success rates, and effectiveness of LBBAP in patients requiring pacing after TAVR. Methods A total of 302 patients underwent the TAVR procedure in our institution in the period from January 2022 to November 2023. In this cohort, 38 patients required ventricular pacing in the postoperative period. 16 patients who underwent permanent pacing using LBBAP were included in this observational study. Patients undergoing traditional right ventricular pacing biventricular pacing or leadless pacemaker implantation were excluded from the study. Results LBBAP was successfully performed in 16 patients (89%). 2 patients underwent conventional CRT implantation (1 cardiac resynchronization therapy pacemaker and 1 cardiac resynchronization therapy defibrillator) in order to severe calcification and presence of fibrotic tissue in the target area. The mean age was 60.5±2.74 years, and 10 patients (62.5%) were women. According to the patient’s medical history, 14 patients (84%) had hypertension; coronary artery disease – 2 (12.5%), 2 (12.5%) patients had atrial fibrillation and atrial flutter, and 7 (43.5%) patients had diabetes mellitus. The mean left ventricle ejection fraction (LVEF) was 46.2±14.7%. Interventricular septal thickness 11.8 ± 1.9 mm. Type of conduction diseases: Infranodal AV block and LBBB were present in 9 (56.5%) patients. 5 (31,25%) patients had persistent complete AV block and 2 (12,25%) had Mobitz II AV block. In 2 patients we observed congestive heart failure combined with LBBB. Pre-TAVR QRS morphology was normal in 15 (93%), and RBBB morphology in 1 (7%). The mean QRS duration at baseline was 105±20 ms. Pre-implant QRS duration 135±52 ms. The single-chamber pacemaker was implanted in 1 patient, dual-chamber pacemaker - 13 patients, and cardiac resynchronization therapy defibrillators in 2 patients. Procedural duration and fluoroscopy times were 105. ± 31.9 min and 18 ± 11 min, respectively. Conclusion Complete AV block and new-onset LBBB after TAVR is still an important issue. LBBB correction using conduction system pacing technology is an effective strategy for this type of patient. LBBAP is one of the most exciting developments in pacing therapy over the last few years. Long-term clinical outcomes and safety of physiological pacing data are limited and require further investigations

Association of ventricular tachycardia morphology induced on electrophysiology study after myocardial infarction: long-term survival and ventricular tachyarrhythmia recurrence

Abstract Background Electrophysiology study (EPS) presents a valuable risk stratification tool to facilitate the implantation of implantable cardioverter-defibrillators (ICDs) to prevent sudden cardiac death from ventricular tachyarrhythmia early after myocardial infarction. Purpose To investigate long-term survival of patients with inducible ventricular tachycardia (VT) at electrophysiology study (EPS) early after ST elevation myocardial infarction (MI) and possible association with site of origin of the induced VT. Methods Consecutive patients with LVEF ≤40% on day 3–5 after MI who underwent EPS were prospectively recruited. Positive EPS was defined as sustained monomorphic VT cycle length ≥200ms for >10 seconds, or shorter duration if hemodynamic compromise occurred. The primary outcome was time to death from any cause. The secondary outcome was time to the composite endpoint of first activation of ICD for ventricular tachyarrhythmia or death. Results A total of 126 patients with inducible VT on EPS early after MI were included with median follow up 6.7 years. 54% had LBBB and 46% had RBBB morphologies during induced VT. The distributions of age, sex, left ventricle ejection fraction, cardiovascular risk factors, infarct artery and EPS characteristics did not differ significantly by induced VT morphology. The estimated risk of death was independently associated with RBBB morphology of VT induced at EPS (adjusted HR 3.2, 95%CI 1.0-10.0, p=0.044). The estimated risk of the composite end-point of spontaneous ventricular tachyarrhythmia recurrence or death was also independently associated with RBBB morphology of VT induced at EPS (HR 1.8, 95%CI 1.0-3.2, p=0.043). Conclusion There is an increased risk of death and spontaneous ventricular tachyarrhythmia recurrence at median follow up of 6.7 years, associated with RBBB morphology of VT (likely origin from left ventricle) induced at EPS early after MI, in those with LVEF <40%. This study is the first to characterise the association between site of origin of VT induced at EPS after myocardial infarction, indicated by RBBB or LBBB morphology, and overall survival as well as activation free survival. The results could help to identify a group of patients that could benefit from closer monitoring post MI and more intense preventative management to improve long-term outcomes.

The pivotal role of ECG in cardiomyopathies.

Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Recent technological advances in cardiovascular imaging offer an opportunity for deep phenotypic and etiological definition. Electrocardiogram (ECG) is the first-line diagnostic tool in the evaluation of both asymptomatic and symptomatic individuals. Some electrocardiographic signs are pathognomonic or fall within validated diagnostic criteria of individual cardiomyopathy such as the inverted T waves in right precordial leads (V1-V3) or beyond in individuals with complete pubertal development in the absence of complete right bundle branch block for the diagnosis of arrhythmogenic cardiomyopathy of the right ventricle (ARVC) or the presence of low voltages typically seen in more than 60% of patients with amyloidosis. Most other electrocardiographic findings such as the presence of depolarization changes including QRS fragmentation, the presence of epsilon wave, the presence of reduced or increased voltages as well as alterations in the repolarization phase including the negative T waves in the lateral leads, or the profound inversion of the T waves or downsloping of the ST tract are more non-specific signs which can however raise the clinical suspicion of cardiomyopathy in order to initiate a diagnostic procedure especially using imaging techniques for diagnostic confirmation. Such electrocardiographic alterations not only have a counterpart in imaging investigations such as evidence of late gadolinium enhancement on magnetic resonance imaging, but may also have an important prognostic value once a definite diagnosis has been made. In addition, the presence of electrical stimulus conduction disturbances or advanced atrioventricular blocks that can be seen especially in conditions such as cardiac amyloidosis or sarcoidosis, or the presence of left bundle branch block or posterior fascicular block in dilated or arrhythmogenic left ventricular cardiomyopathies are recognized as a possible expression of advanced pathology. Similarly, the presence of ventricular arrhythmias with typical patterns such as non-sustained or sustained ventricular tachycardia of LBBB morphology in ARVC or non-sustained or sustained ventricular tachycardia with an RBBB morphology (excluding the "fascicular pattern") in arrhythmogenic left ventricle cardiomyopathy could have a significant impact on the course of each disease. It is therefore clear that a learned and careful interpretation of ECG features can raise suspicion of the presence of a cardiomyopathy, identify diagnostic "red flags" useful for orienting the diagnosis toward specific forms, and provide useful tools for risk stratification. The purpose of this review is to emphasize the important role of the ECG in the diagnostic workup, describing the main ECG findings of different cardiomyopathies.

P256 AN UNUSUAL CASE OF PACEMAKER MALFUNCTION WITH NON COMMON ELCTROCARDIOGRAPHIC PRESENTATION AND UNEXPECTED ECHOCARDIOGRAPHIC FINDING

Abstract This clinical case shows the diagnostic challenge and the management of a 79 y–o male with recent hospitalization for infero–lateral STEMI undergoing primary PCI of Right Coronary Artery with 2 DES and following DDDR MRI PM (pacemaker) implantation due to the development of persistent 2:1 Atrio–Ventricular Block. One month later, admission at Emergency Department for syncope. Normal parameters were found at laboratory analyses. The electro–stimulator activity evaluation showed a PM malfunction with ventricular capture failure. Thus, the increase of PM output up to electric ventricular capture (8 Volt/120 msec) was performed, but the following Electrocardiogram showed a PM–induced rhythm with RBBB–morphology. Then, the bedside Echocardiogram showed an apparent presence of a linear hyper–echogenic image into left ventricle with no inter–ventricular septal defect neither inter–ventricular shunt, inter–atrial septal hypermobility with no evident inter–atrial shunt at rest; while a chest Radiography identified the atrial and ventricular leads with no accurate individuation of their position. The patient was admitted in Intensive Cardiac Care Unit with confirmation of intermittent failure to ventricular capture and RBBB–morphology during PM–induced rhythm at telemetry monitoring. Due to Electrocardiographic and Echocardiographic findings, a strong suspect of abnormal position of the ventricular lead into left ventricle through a possible PFO has been raised. A chest Computed Tomography was performed confirming the anomalous position of the ventricular lead: it reached the left atrium through an inter–atrial defect/patent foramen ovale (PFO), then crossing the mitral valve up to left ventricle. The PM–lead repositioning was scheduled two days after. After positioning of temporary stimulator lead in right ventricle, the ventricular lead has been withdrawn from left–side chambers and positioned into septal–apical right ventricle; furthermore, the position of right atrial lead has been optimized (because of frequent spontaneous passage to the left atrium through the PFO, during manual maneuvers) thus obtaining good stability of the device. During the following days, the telemetry monitoring showed a PM–induced rhythm, without capture nor sensing failure. The chest Radiography confirmed the correct position of leads and the pre–discharge Echocardiography showed a LVEF 57% with no valvular pathology and with atrial and ventricular leads into right–side chambers.

Endocardial, epicardial, and right atrial approach for catheter ablation of premature ventricular contractions from the inferoseptal process of the left ventricle.

Inferoseptal process of the left ventricle (ISP-LV) might be a source of idiopathic ventricular arrhythmias. In these cases, ectopic foci are accessible from the LV endocardium, epicardially from the middle cardiac vein as well as from the right atrium (RA). This study reports a series of patients with premature ventricular contractions (PVCs) arising from the ISP-LV that were successfully ablated following access from different structures. Five patients (4 males, age 61 ± 12.8 years) with PVCs arising from the ISP-LV were successfully ablated using three different approaches for ablation-endocardial, epicardial (through coronary sinus or its branches), and RA approaches. Endocardial LV mapping, RA, and coronary sinus (CS) mapping were performed in all five cases. PVCs demonstrated RBBB or LBBB-like morphology and left superior axis. The three patients ablated endocardially had a maximum deflection index (MDI) of 0.36, 0.43, and 0.54, whereas in the remaining 2 patients, MDI was 0.57 and both demonstrated QS morphology in the inferior leads. Local activation time at the successful ablation site was 35 ± 8.9 (26-55) msec pre-QRS. Pacemapping at the successful ablation site resulted in a good (11/12) or perfect (12/12) QRS match in all cases. Three of the patients demonstrated frequent monomorphic PVCs of another morphology suggesting a remote exit site. All patients remained arrhythmia-free after a mean follow-up of 21 ± 15 (6-36) months. Successful ablation of PVCs from ISP-LV may require access from the CS or even RA apart from LV endocardial approach. Not infrequently patients demonstrate additional PVC foci.

PO-05-102 CHARACTERISTICS AND ABLATION OF VENTRICULAR ARRHYTHMIAS FROM THE POSTERIOR SUPERIOR PROCESS OF THE LEFT VENTRICLE

Ventricular arrhythmias (VA) have been noted to arise from the basal inferoseptal portion of the LV, also known as the posterior-superior process of the LV (PSP). Data regarding ablation in this patient group are sparse. This study sought to determine the incidence of PSP VAs and to describe ablation characteristics and outcomes. A retrospective cohort study including all patients undergoing VA ablation for PVCs and/or focal NSVT/VT from January 2017 to February 2022 was conducted at a single center. Patients undergoing ablation for scar-related reentrant VT were excluded. Clinical data and outcomes were analyzed for those patients with PSP VAs. A total of 267 patients underwent VA ablation. Twenty (7.5%) had VAs ablated from the PSP (90% male, age 60.6 ± 15.8 years, LVEF 45 ± 13%). Of these, 11 were idiopathic (5.1% of all idiopathic VAs) and 9 were associated with structural heart disease. In the idiopathic group, 3 had PVC-induced cardiomyopathy. ECG predominantly showed RBBB morphology with positive concordance, small s wave in V6, and left superior axis. In two patients, a LBBB morphology was seen with early transition in V2. Four had a second, infrequent PVC with LBBB morphology, left superior axis, and “reverse V2 pattern break.” (Figure, top) All 20 patients were ablated in the PSP. Two required additional ablation in the right atrium (RA), and both had the two PVC morphologies described above. In 1 patient, after ablation in the PSP, the PVC morphology changed from RBBB to LBBB in V1 and was terminated after ablation in the coronary sinus and middle cardiac vein (CS/MCV). Four patients developed transient junctional rhythm during the procedure (3 with ablation in the PSP, 1 with ablation in the RA). AV block was not observed, but cryoablation of the RA was required in 1 patient. Ablation was acutely successful in all patients. In the 18 patients with follow-up, 14 (78%) had long-term PVC suppression. In 3 patients with recurrence, the recurrent PVC had a different morphology than the targeted PVC (Figure, top: 2-7) In patient 4, the recurrent PVC was only seen after ablation. PSP VAs may be more prevalent than previously reported. Multiple PVC morphologies with a left superior axis were seen in a large proportion of patients, suggesting an intramural focus with variable exits in the region. The PSP has anatomic relationships to the RA, cardiac crux/CS/MCV, and the AV node (Figure, bottom), and a multifocal approach may be needed for ablation success.

112 A CASE OF INCESSANT SLOW-FAST AVNRT TREATED WITH HIS BUNDLE PACING

Abstract Introduction Slow-fast AVNRT can rarely present as incessant SVT, particularly in patients with increased HV interval. We describe a case of incessant typical AVNRT, treated without transcatheter ablation. Case Presentation An 83-year-old man, with history of PAF, was admitted to our ICU complaining of dyspnea, dizziness and amaurosis. His ECG at presentation depicted sinus bradycardia, first degree AVB (PQ=400 ms) and RBBB (Fig 1A). After betablocker wash-out period, we decided to perform CSP using HBP to ensure AV synchrony and restore physiological pacing. During wash-out period, an incessant regular wide complex tachycardia with RBBB morphology and ventricular rate of 110 bpm occurred: the tracing showed a P wave immediately after the QRS, with RP < PR (Fig 1B). The tachycardia was incessant also in the EP lab. By means of 2 pacing leads (RV lead in the apical septum and RA lead in right appendage) and one diagnostic decapolar catheter (Inquiry, 2-2-2 Abbott) in His region, all connected to the polygraph, we performed an EPS. HV interval in sinus rhythm was 60 ms, AH 340 ms. The electrograms during tachycardia showed HVA sequence and 1:1 VA association, VA< 70 ms, cycle length 520 ms. Pacing from RV lead, we performed the ventricular overdrive pacing maneuver obtaining a VAV response; PPI-TCL was 280 ms and SA-VA difference was 205 ms (Fig 2A). We also noted a VA linking response to atrial overdrive pacing, and AHA response at the end of maneuver excluding JT (Fig 2B). In addition, pacing by the His catheter during tachycardia, we interrupted the arrythmia: the V signal after the last paced beat was not followed by retro-conducted A signal (Fig 2C). Finally, by administrating adenosine 12 mg the tachycardia interrupted with A as last signal recorded (Fig 2D). All these findings were consistent with an incessant typical AVNRT. We chose to treat AVRNT with sequential atrial-His pacing, placing a third lead in His region and programming the device in DDD 70-120, with selective His bundle capture, not correcting the RBBB (Fig 1C, D). Discussion In patients with poor anterograde AV nodal conduction, also slow-fast AVNRT can present as incessant tachycardia. In fact, a shorter sinus cycle length or atrial extrasystole could initiate sufficient delay in anterograde conduction to allow for recovery in conduction in the retrograde direction led to a persistent tachycardia. This case highlights the value of performing EPS diagnostic maneuvers also during PM implantations in order to personalize therapy and programming.

Enormous Pulmonary Arteries and a Late Diagnosis of a Common Congenital Cardiac Issue: A Case Report

Background: Noonan’s syndrome is the second most common congenital cardiac syndrome after Down syndrome. Classically it is associated with pulmonary stenosis, Hypertrophic Cardiomyopathy (HCM), and Atrial Septal Defects (ASD). Late presentations, milder phenotypes and atypical presentations can occur in adult life and have cardiovascular implications. Case Summary: A 62-year-old presented to the emergency department with chest pain and atrial fibrillation with fast ventricular rate and RBBB morphology. A transthoracic echocardiogram demonstrated a massive Pulmonary Artery (PA), concerning for pulmonary hypertension and an atrial septal defect (ASD). Right heart catheterization indicated enormous coronary artery ectasia but normal PA pressures and wedge pressures. He was identified as a late presentation of Noonan’s syndrome on subsequent genetic testing. Discussion: Some series indicate a prevalence of 1 in 100 for mild Noonan’s syndrome phenotypes, highlighting the importance of understanding its cardiac presentations. In this case, we present a man with minimal symptoms but gross pathologies of his pulmonary and coronary arteries. Furthermore, pulmonary artery dilatation without pulmonary valve pathology has not been reported in the literature, and only a few reports of coronary artery ectasia are reported.

ELECTROCARDIOGRAPHIC CHARACTERISTICS WITH LEFT BUNDLE BRANCH AREA PACING: A SINGLE CENTER PROSPECTIVE STUDY

<h3>BACKGROUND</h3> Pure left bundle branch (LBB) capture should result in typical RBBB (rsR') morphology. However, numerous paced QRS morphologies are observed during LBB area pacing (LBBAP). There are limited papers describing the various electrocardiographic (ECG) morphologies seen with LBBAP. Objective: To evaluate the various ECG characteristics encountered in LBBAP. <h3>METHODS AND RESULTS</h3> Patients referred for pacemaker implantation between 08/2019-01/2021 were considered for LBBAP. LBBAP was performed by implantation of a Medtronic 3830 lead 2 cms distal to His and confirmed by previously published criteria. Paced QRS morphology and QRS axis was analyzed. Baseline, ECG, and implantation characteristics are summarized in table 1. Of 264 LBBAP ECGs, the most common morphology seen during unipolar tip pacing was an incomplete RBBB pattern (qR) in V1 in 165 (69.9%) patients. rSR' pattern was seen in 9 (3.2%) and a narrow QS pattern in 60 (21.5%) patients. <h3>CONCLUSION</h3> Various ECG morphologies may be encountered during successful LBB area capture and are associated with similar QRSd, pacing characteristics and short-term lead performance. These morphologies are due to capture of various structures (RV or LV septum, capture of LBB, LPF +/- RBB) and are likely due to virtual-electrode effect.

B-PO05-037 ELECTROCARDIOGRAPHIC CHARACTERISTICS WITH LEFT BUNDLE BRANCH AREA PACING: A SINGLE CENTER PROSPECTIVE STUDY

Pure left bundle branch (LBB) capture should result in typical RBBB (rsR’) morphology. However, numerous paced QRS morphologies are observed during LBB area pacing (LBBAP). There are limited papers describing the various electrocardiographic (ECG) morphologies seen with LBBAP. To evaluate the various ECG characteristics encountered in LBBAP. Patients referred for pacemaker implantation between 02/2019-02/2021 were considered for LBBAP. LBBAP was performed by implantation of a Medtronic 3830 lead 2 cms distal to His and confirmed by previously published criteria. If unsuccessful, lead was repositioned distally and inferiorly on the septum to capture the left posterior fascicle (LPF). Paced QRS morphology and QRS axis was analyzed. Baseline, ECG, and implantation characteristics are summarized in table 1. Of 274 LBBAP ECGs, the most common morphology seen during unipolar tip pacing was an incomplete RBBB pattern (qR) in V1 in 131 (48%) patients. rSR’ pattern was seen in 38 (14%) and a narrow QS pattern in 34 (12.5%) patients. qR or rsR’ with left axis deviation, i.e., LPF capture was noted in 69 (25%) patients. One patient exhibited monophasic R in lead V1. Unipolar ring pacing resulted in wide QS in all patients due to RV septal capture only. Various ECG morphologies may be encountered during successful LBB area capture and are associated with similar QRSd, pacing characteristics and short-term lead performance. These morphologies are due to capture of various structures (RV or LV septum, capture of LBB, LPF +/- RBB) and are likely due to virtual-electrode effect.

Prognostic value of non-ischemic ring-like left ventricular scar pattern in patients with apparently idiopathic ventricular arrhythmias: a CMR imaging study

Abstract Background The presence of left ventricular (LV) late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has been correlated to life-threatening arrhythmic events in patients with apparently idiopathic ventricular arrhythmias (VAs). Aim of the present study was to investigate the prognostic significance of a specific LV-LGE phenotype characterized by a subepicardial/midmyocardial “ring-like” pattern of fibrosis. Methods Out of a total of 518 consecutive patients with apparently idiopathic VAs who underwent CMR study, 79 (15%) had evidence of LV-LGE. Of these, 23 (4%) patients had LV LGE with ring-like pattern, defined as subepicardial or midmyocardial LGE involving at least 3 contiguous segments in the same slice (group A), while 56 (11%) patients had LV LGE with no ring-like pattern (group B). The remaining 439 patients had no LGE (group C). The end-point of the study was a composite SCD, resuscitated cardiac arrest and nonfatal episodes of ventricular fibrillation or documented sustained ventricular tachycardia. Results Group A patients were more frequently males compared to groups B and C (96% vs. 79% vs. 52%; p&amp;lt;0.01) and had more frequently a family history of SCD and/or cardiomyopathy (30% vs. 11% vs. 5%; p&amp;lt;0.01). All patients in Group A showed VAs with a predominant RBBB morphology vs. 38 (68%) patients in Group B and 65 (15%) in Group C (p&amp;lt;0.01). During a follow-up of 63±39 months, the composite outcome occurred in 13 patients (57%) in Group A vs. 11 (20%) in Group B and 2 (1%) in Group C (p&amp;lt;0.01). Conclusion In patients with apparently idiopathic VAs, a nonischemic LV-LGE with a ring-like pattern at CMR is associated with a high rate of malignant arrhythmic events during follow-up. Funding Acknowledgement Type of funding source: None

CARDIAC SARCOIDOSIS PRESENTING WITH VENTRICULAR ARRHYTHMIAS

Background: Clinically manifest cardiac involvement occurs in perhaps 5% of patients with sarcoidosis. The three principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. We report a patient whose initial manifestation of cardiovascular involvement was sudden cardiac arrest due to sustained ventricular tachycardia. Presentation: A 40 year old lady with a history with no significant past medical history presented one year ago with haemodynamically stable RBBB morphology with inferior axis wide complex tachycardia consistent with VT which reverted to sinus rhythm with intravenous metoprolol. Echo revealed normal LV function. She was then discharged on beta blockers and advised to get CT chest on follow up. CT chest revealed bilateral hilar lymphadenopathy and she was referred to pulmonologist. Diagnosis and Management: 6 months later she presented with incessant hemodynamically stable ventricular tachycardia that remained sustained for 24 hours despite intravenous beta blockers, amiodarone and verapamil requiring multiple cardioversions. She was sedated, mechanically ventilated and started on oral Propranolol and intravenous methylprednisolone with the suspicion of CS. Patient reverted to sinus rhythm within 24 hours of intravenous steroids. Patient’s PET scan confirmed the diagnosis CS. Follow-up and Outcomes: Though the diagnosis of early CS is difficult, detection and initiation of specific treatment is vital. Although the present case lacks a definitive tissue diagnosis, the patient meets accepted criteria for CS. ICD was implanted in this patient. Keywords: Wide Complex Tachycardia 1, Cardiac Sarcoidosis 2, Incessent 3, ICD 4, PET 5

P4600Intraventricular conduction disturbance and ventricular paced rhythms in patients with acute coronary syndromes

Abstract Introduction Left or right bundle branch block (LBBB or RBBB) and ventricular paced rhythms (PM) difficult the diagnosis and often delay adequate treatment in patients with acute coronary syndromes (ACS). In the past few years, guidelines have placed a greater emphasis on the need for considering urgent revascularization in these patients. Purpose Evaluate initial revascularization strategy and short-term prognostic impact of LBBB, RBBB and PM in patients with ACS. Methods Multicentric observational study of consecutive patients with ACS recorded in the Portuguese Registry of Acute Coronary Syndromes (ProACS) between October 2010 and January 2019. Patients were categorized according to the ECG at admission: LBBB, RBBB, PM and normal QRS morphology. Patients with missing data on the ECG or the primary outcome were excluded. Demographic, clinical data and in-hospital outcomes were analyzed. The association between LBBB, RBBB, PM and in-hospital adverse outcomes was assessed using a logistic regression model. The primary and secondary outcomes were in-hospital mortality and a composite of in-hospital adverse events (heart failure, re-infarction or cardiac arrest), respectively. Results Of the original cohort, 18314 (94.3%) patients were included (mean age 66±13 years, 73.2% male): 243 (1.3%) had PM, 846 (4.6%) had LBBB, 1195 (6.5%) had RBBB and 16030 (87.5%) had normal QRS. Patients with abnormal QRS were significantly older, had more comorbidities, were less frequently diagnosed as ST-elevation MI (LBBB 18%; RBBB 35.1%; PM 7.8%; Normal 44.2%, p&lt;0.001) and considered for urgent reperfusion (LBBB 13%; RBBB 33.6%; PM 5.8%; Normal 41.6%, p&lt;0.001). Among patients who underwent non-urgent coronary angiography, the finding of an occluded culprit coronary artery was not higher compared to patients with normal QRS (Normal 15.2% vs LBBB 14.3%; RBBB 17.4%; PM 11.4%, p&gt;0.05 for difference). Overall in-hospital mortality was 3.4% (LBBB 6.6%; RBBB 8.1%; PM 5.3%; Normal 3.4%; p&lt;0.001) and the composite endpoint of in-hospital adverse events was 17.4% (LBBB 35.6%; RBBB 27.3%; PM 23.5%; Normal 15.6%, p&lt;0.001). After adjusting for cofounding variables, and using normal QRS as reference, only RBBB was shown to be significantly associated with increased in-hospital mortality (OR 1.94; 95% CI 1.43–2.66), p&lt;0.001); and both RBBB (OR 1.75; 95% CI 1.5–2, p&lt;0.001) and LBBB (OR 1.8; 95% CI 1.4–2.3, p&lt;0.001), but not PM, were significantly associated with the composite endpoint of heart failure, re-infarction or cardiac arrest. Conclusion Compared to patients with normal QRS, those with LBBB, RBBB or PM less often undergo urgent revascularization and have higher rates of in-hospital adverse outcomes. In multivariate analysis, RBBB patients are almost two times more likely to die compared to those with normal QRS. LBBB and RBBB were independently associated with increased rates of in-hospital adverse events. PM was not associated with worse in-hospital outcomes.

GIANT CELL MYOCARDITIS: STILL A CONUNDRUM

Giant cell myocarditis is a rare, life-threatening disease affecting young adults. To date, no standard therapy has been defined. A 51-year-old male with Crohn's disease was admitted with palpitations and shortness of breath. EKG showed ventricular tachycardia (RBBB morphology, heart rate of 122

81 Suitability of cardiac resynchronisation therapy in patients with univentricular and systemic right ventricular hearts

IntroductionCardiac resynchronisation therapy (CRT) is a well-recognised treatment in patients with systolic heart failure complicated by ventricular dyssychrony. However, there is limited evidence to support its use in patients with...

Evaluation of Morphology of Premature Ventricular Contraction on 12-Lead Electrocardiogram

Background-Evaluation of different morphology of premature ventricular contraction (PVC) in 12-lead ECG might reflect the presence or absence of myocardial diseases and determine PVC foci. It is important for ablation procedure and it can help in pre-procedural planning and potentially may improve ablation outcome.Methods and Results-In this study, 12-lead Electrocardiogram (ECG) of 50 patients with or without structural cardiac diseases, who had experienced PVC, were obtained. PVC QRS duration, contour, pattern, unifocal or multifocaland different morphology in various lead were evaluated. PVC-QRS morphology of 50 ECGs showed QRSd d” 140ms was 60%, &gt;140ms was 24%, &gt;160ms was 16%. QRS notching &lt;40ms was 42%, &gt;40ms was 16%, smooth contour was 42%. The morphology of PVCs in lead V1, RBBB morphology was 36%, LBBB morphology was 64%; in lead V1 &amp; V2, high r 8%, low r 4%. QRS wave polarity in lead I negative (QS, Qr, or rS wave pattern) 28%, positive (R-wave pattern) 52%; in lead II, III, avF, positive 76%. Of these RR’ or Rr’ pattern 20%, R pattern 56%. Negative 24%. QRS transition in chest lead, 16% transition occur at V4 –V5, 48% at V3-V4, 4% at V2-V3, 36% at V1-V2 level. The pattern of PVCs were bigeminy 24%, trigeminy 6%, couplet 4%, salvos 12%, R on T 2%, VT 6%. Of the 32 PVCs originating from the RVOT, 8 were classified as of free-wall origin, 24 of septal, 14 of left, 26 of right, 4 of proximal, and 2 of distal origin. Of the 6 PVCs originating from the LVOT, 4 were originated from the LVOT close to the left coronary cusp and 2 were originated from the LVOT close to the right coronary cusp. Of the 12 PVCs originated from LV fascicle, 12 of posterior fascicle origin and none from anterior fascicle origin.Conclusion-12-lead ECG is a simple, inexpensive and noninvasive tool to detect PVCs and facilitate their localization. By evaluating morphology of PVC, we can also predict the structural and functional state of heart.Bangladesh Heart Journal 2016; 31(2) : 75-79

New mutation in prkag2 syndrome and sudden cardiac death

Background: Mutations in PRKAG2 have been described in patients (PT) with familial WPW syndrome and hypertrophic cardiomyopathy (HC). Conduction system disease, embolic stroke and heart failure can happen Tachyarrhythmias are frequent and can cause sudden cardiac death (SCD) and the predictive factors remain unknown. Objective: The purpose of this study is to describe the mechanism of aborted SCD in individuals affected by WPW in association with HC. Methods: A total of 18 (21%) PT selected from an 84-member family cohort were included retrospectively from March 2005 to March 2012 and submitted to ECG, 2D ECHO and 24h Holter. For a genetic analysis, it was collected blood samples (3ml) and used a commercial kit (Gentra System, Puregene), ExoSAP-IT, USB and directly sequenced in both directions using an ABI PRISM Automatic DNA Sequencer in a subgroup of 8 PT. Diagnosis of WPW was based on ECG with a shortened PR interval and a slurred upstroke to the QRS complex (delta wave). Diagnosis of HC was based on ECHO by demonstrating evidence of LVH, asymmetric in distribution, and with any diffuse or segmental pattern of left ventricular [LV] wall thickening ≥ 15 mm. Results: Eleven PT (61%) were female, with a mean age of 27±16. HC was detected in association with WPW in 11 (61.1%) PT, isolated WPW in 6 (33%) PT and HC only in one PT (5.6%). Main clinical findings: TIA (16.7%), spontaneous abortion (16.7%). Palpitations occurred in 12 (67%), chest pain in six (33.3%) and syncope in five (28%). Learning disabilities, retarded growth development were also observed in 3 males (16.7%). Five PT were submitted to pacemaker implantation due to total AV block. Main ECG findings: RBBB morphology (55.5%), LBBB (27.7%), atrial fibrillation (AF) (33.3%), atrial flutter (AFL) (16.7%), atrial tachycardia (11.1%), non-sustained VT (5.5%) and SVT in 12 (67%). ECHO showed generalized and diffuse LVH with septal thickness ≥15 mm and good contractility. Mitral valve insufficiency (50%) and diastolic dysfunction (61.1%). SCD occurred in 4=22% PT. Two PT had SCD at age 37 (♀) and 27 (♂). Three episodes of aborted SCD were documented in two PT with WPW in association with HC due to AF and AFL with anterograde conduction through the accessory pathway Direct sequencing of PRKAG2 revealed a missense mutation in exon 7 of PRKAG2, A869T (K290I).This mutation has not been previously described Conclusion: SCD had a high incidence in this cohort and the documented mechanism was AF and AFL with anterograde conduction through the accessory pathway. A new mutation in PRKAG2 was found in an initial study of subgroup.

Myocardial delayed enhancement by magnetic resonance imaging in a patient with Duchenne muscular dystrophy and ventricular tachycardia

Received 17 December 2012; revision accepted for publication 27 February 2013. Cardiomyopathy is a significant component in Duchenne muscular dystrophy (DMD), and it is not necessarily related to the degree of skeletal myopathy. Cardiac death can result from progressive heart failure, due to ventricular dysfunction, or from sudden death, presumably caused by heart block or malignant arrhythmias. Although electrical abnormalities may occur in the absence of overt cardiac histopathology, electrical and functional abnormalities have been attributed to cardiac fibrosis1. As a representative example of this, we present the cardiovascular magnetic resonance (CMR) finding in a 19-year-old patient with DMD. Myocardial delayed enhancement showed multifocal fibrosis in the septal and lateral wall of the mid left ventricle. This patient had presented several syncopes and spells, with electrocardiographic documentation of repetitive episodes of ventricular tachycardia (VT). The ECG shows a monomorphic wide QRS tachycardia (240 bpm), with RBBB morphology, inferior axis and QS complex in lead I and aVL, suggestive of a basal lateral LV exit site, with, possibly, epicardial origin, compatible with the CMR findings mentioned above. Baseline ECG was representative of cardiac involvement, showing a short PR interval, R/S ratio > 1 in lead V1 V2 and Q waves in the lateral leads2. Myocardial delayed enhancement by magnetic resonance imaging in a patient with Duchenne muscular dystrophy and ventricular tachycardia

Reverse BBRVT in a structurally normal heart

We present a case of bundle-branch reentry ventricular tachycardia with RBBB morphology (reverse BBRVT) in a patient with preexisting right bundle-branch block and without apparent structural heart disease. The diagnosis of BBRVT may be very challenging due to the similar wide QRS morphology during tachycardia and in sinus rhythm, rather suggesting a supraventricular origin. BBRVT should be suspected even in the absence of structural heart disease, but especially in patients with extensive underlying His-Purkinje conduction disorders. The aetiology, mechanism, diagnostic issues and treatment are briefl y reviewed.

Successful Ablation for the Ventricular Tachycardia Storm Arising from the Peri-Aortomitral Continuity in a Patient with Ischemic Cardiomyopathy

Ventricular tachycardia arising from the peri-aortomitral continuity (peri-AMC) region in structural heart disease is uncommon. A 70-year-old of post-CABG patient with biventricular ICD was admitted for drug-resistant VT storm. Four inducible VTs (VT1–4) demonstrated RBBB morphology with inferior axis. Mechanism of VT was reentry based on the entrainment study but the identification of circuit was difficult. Pacemapping suggested that the exit of VT1 and 2 be in the vicinity of the peri-AMC but perfect pacemaps were not gained, whereas perfect pacemaps for VT3 and 4 were yielded at the LV basal-anterior wall where the islet of low voltage area (LVA) was elucidated with substrate mapping. In order to confine the putative origins of VT1 and 2, radiofrequency applications were given along the peri-AMC to the anterior mitral annulus (AMA). Subsequently, the linear lesion was made from the AMA to the septal LVA across the LVA-islet of basal-anterior wall. After the procedure, no VT could be induced and demonstrated. Interestingly, origins of VT1 and 2 were concentrated nearby the peri-AMC in which did not correspond to the ischemic area. We suppose that the arrhythmogenicity in the peri-AMC contributed to the VT storm in conjunction with the ischemic scars. The substrate modification of the peri-AMC was effective for the bail-out of VT storm.