Management of patients with an electrical storm or clustered ventricular arrhythmias: a clinical consensus statement of the European Heart Rhythm Association of the ESC-endorsed by the Asia-Pacific Heart Rhythm Society, Heart Rhythm Society, and Latin-American Heart Rhythm Society.

Electrical storm (ES) is a state of electrical instability, manifesting as recurrent ventricular arrhythmias (VAs) over a short period of time (three or more episodes of sustained VA within 24 h, separated by at least 5 min, requiring termination by an intervention). The clinical presentation can vary, but ES is usually a cardiac emergency. Electrical storm mainly affects patients with structural or primary electrical heart disease, often with an implantable cardioverter-defibrillator (ICD). Management of ES requires a multi-faceted approach and the involvement of multi-disciplinary teams, but despite advanced treatment and often invasive procedures, it is associated with high morbidity and mortality. With an ageing population, longer survival of heart failure patients, and an increasing number of patients with ICD, the incidence of ES is expected to increase. This European Heart Rhythm Association clinical consensus statement focuses on pathophysiology, clinical presentation, diagnostic evaluation, and acute and long-term management of patients presenting with ES or clustered VA.

Three-dimensional electroanatomical mapping guided right bundle branch pacing in congenitally corrected transposition of great arteries.

AIMS: The ideal pacing strategy has been the Achilles' heel for patients with congenitally corrected transposition of great arteries (ccTGA) with bradycardia. Various pacing modalities were documented in the literature. This article describes a novel pacing strategy and its feasibility in ccTGA with an intact ventricular septum. METHODS AND RESULTS: We prospectively recruited three patients with ccTGA who presented with symptomatic complete heart block to our institute and were evaluated. All patients were planned for conduction system pacing. Those who had more than moderate or severe systemic atrioventricular regurgitation and systemic ventricular dysfunction were planned for conduction system pacing with an additional lead in the coronary sinus (CS) tributary, i.e. bundle branch pacing optimized cardiac resynchronization therapy with the intention to achieve incremental benefit. Since right bundle pacing is not described previously and in view of anatomical complexity in location, three-dimensional (3D) anatomical mapping was done with the EnSite system and later right bundle capture is identified conventionally as that of a left bundle in a normal heart. All three patients have stable lead positions and adequate thresholds at short-term follow-up. CONCLUSION: In this report, we demonstrated the feasibility of permanent physiological pacing of the systemic ventricle by capturing the right bundle with 3D anatomical mapping guidance, which results in physiological activation of the systemic ventricle.

Left cardiac sympathetic denervation in children with Jervell Lange-Nielsen syndrome and drug refractory torsades - A case series.

INTRODUCTION: Long QT syndrome is an inherited malignant channelopathy which leads to life-threatening arrhythmia, with multiple genotypes. Jervell and Lange-Nielsen syndrome (JLNS) is an autosomal recessive subtype of this disease, characterized by congenital sensorineural deafness and a high incidence of sudden cardiac death (SCD). METHODOLOGY: We prospectively followed up six children who underwent left cardiac sympathetic denervation (LCSD) for JLNS in view of high-risk features despite being on maximally tolerated doses of oral propranolol. RESULTS: Mean age at diagnosis was 2.75 ± 0.39 years, with a significant delay between onset of symptoms and diagnosis (mean 7.2 ± 3.5 months). All had sensorineural hearing loss, conforming to the JLNS phenotype. Mean QTc interval was 603 ± 93 ms, with T wave alternans (TWA) seen in all cases. All were started on propranolol and subsequently subjected to LCSD, and 3 underwent AAI permanent pacemaker implantation. Over a mean follow-up of 20 months, there was a significant reduction in QTc (603 ± 93 ms to 501 ± 33 ms, p = .04), which was persistent on follow-up (525 ± 41 ms) and only two out of six had persistent T wave alternans on ECG (p < .01). None of these children had presyncope, syncope, seizures, torsades de pointes, cardiac arrest or death on follow up following LCSD. CONCLUSION: Jervell Lange-Nielsen syndrome is a subtype of LQTS with high-risk features. LCSD, an effective therapeutic option for those having symptoms despite being on propranolol, results in significant reduction of QTc interval and amelioration of symptoms.

Clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in southern India.

BACKGROUND: Semi-permanent pacing (SPP) includes the placement of a permanent lead through the internal jugular vein and connection to a pulse generator on the skin outside the venous access site. AIM: To evaluate the clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in Southern India. METHODS: This is a retrospective observational study. All patients admitted and requiring management with semi-permanent pacing from January 2017 to June 2020 were included. RESULTS: From January 2017 to June 2020, 20 patients underwent semi-permanent pacing (SPP) with a median age of 54 (21-74) years. Males comprised a majority of the patients (55%). Hypertension was noted in 50% of patients and 30% were diabetic. The right internal jugular vein was the most common access in 95% of patients. The most common indication for semi-permanent pacing was pocket site infection in 30% of patients. There were no procedural complications. The median duration on SPP was 7 (5-14) days and the median duration of hospital stay was 13 (8-21) days. Permanent pacemaker implantation was done in 55% of patients. Mortality in our study group was 15% with 10% dying due to cardiogenic shock (post resuscitated cardiac arrest) and 5% dying due to non-cardiac cause (Epidural hematoma). CONCLUSION: In our study, semi-permanent pacing was noted to be a safe procedure and was more commonly indicated in emergent conditions with complete heart block secondary to underlying reversible causes and in the management of pocket site infection.

Interesting phenomenon during positioning of the 3830 lead deep inside the septum by rapid rotations. What is the mechanism?

A 66-year-old lady having complete AV block with narrow QRS escape had undergone left bundle branch pacing (LBB) with 4.1-F diameter 3830 Select SecureTM pacing lead (Medtronic Inc., Minneapolis, MN, USA). The pacing lead was placed with the inter-ventricular septum, 2 cm inferior to the distal His region towards the right ventricular apex, by 5 rapid turns. During the rapid turns, an interesting phenomenon was noted [Fig. 1A & B]. What is the mechanism?

Study of atrial arrhythmias after surgical or device closure of atrial septal defect.

Background Device closure of atrial septal defect (ASD) has emerged as a treatment modality for the past 3 decades and has changed the natural history of ASD compared to that of surgical closure. Early intervention in ASD retards the geometrical and electrical remodelling of the atrium that contributes to the development of atrial tachyarrhythmias. We studied the incidence of atrial arrhythmias in patients undergoing surgical and device closure of ASD. Methods We did this retrospective observational study at a tertiary referral centre, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala. Patients of all age groups undergoing surgical and device closure of ASD between 1 January 2003 and 31 December 2008 were included to compare the incidence and nature of atrial arrhythmias and also analyse the difference in new-onset atrial arrhythmias between the two arms. Results Of 277 patients, 144 with surgical closure and 133 with device closure were followed up for 10-15 years. A larger number of men underwent surgical closure (41.7%) compared to device closure (25.6%). The mean (SD) follow-up was 12.6 (3.7) years in the surgical closure group and 10.9 (2.6) years in the device closure arm. There were a larger number of patients with atrial tachyarrhythmias in the surgical closure group (6.3%) compared to the device closure group (0.8%) at baseline (p=0.02). A significantly larger number of patients had atrial fibrillation in the surgical closure group (5.6%) compared to the device closure group (0.7%) at baseline (p=0.003). Pulmonary hypertension at baseline was present in 38.9% of patients in the surgical closure group and in 23.3% of patients in the device closure group (p=0.006). New-onset atrial arrhythmias occurred in patients ≥30 years of age (p=0.006) and exclusively in patients with pulmonary hypertension in the surgical group (3.7%) and in the device closure group (6.6%). This was statistically significant in the device closure group (p=0.05) but not in the surgical closure group (p=0.13). The incidence of new-onset arrhythmias was not statistically significant in both groups. Conclusions Atrial arrhythmias were significantly more common in patients who underwent surgical or device closure at ≥ 30 years of age and in patients with pulmonary hypertension. There was no difference in new-onset atrial arrhythmias between the surgical and device closure groups. Our study results suggest that surgical or device closure before 30 years of age and before the development of atrial arrhythmias may be beneficial with respect to the development of atrial arrhythmias.

Two pacing spikes on the T wave in a single-chamber pacemaker: What is the mechanism?

We report a case of a 54-year-old female, known symptomatic sick sinus syndrome, who had undergone a single-chamber pacemaker (VVI, St. Jude Medical, VERITY ADxXL SC SN 2413520) implantation in 2011. Electrocardiography (ECG) performed on a recent visit to the pacemaker clinic showed intermittent double pacing spikes on top of the T wave (Fig. 1A). What is the mechanism?

Discordant responses to his refractory premature ventricular beats (PVBs) during a regular narrow QRS tachycardia. What is the mechanism.

A 32-year-old lady was evaluated for recurrent episodes of palpitation. During one of the palpitation episodes a regular narrow QRS tachycardia was documented, and it got terminated with the administration of IV adenosine. The baseline 12 lead electrocardiogram (ECG) did not show any manifest preexcitation. There was no evidence of structural heart disease by echocardiogram. Patient underwent an electrophysiology (EP) study after informed consent. Quadripolar catheters were placed at the His region and right ventricular (RV) apex. A decapolar catheter was placed in the coronary sinus (CS) with CS 9, 10 dipoles at CS OS region and CS 1, 2 dipoles at CS distal region. A mapping & ablation catheter was positioned at right atrial (RA) appendage. Baseline atrial and ventricular pacing protocols could not be performed as both atrial and ventricular pacing were easily inducing a regular narrow QRS tachycardia. His refractory premature ventricular beats [PVBs] were delivered from RVRV apex and left ventricular [LV] free wall. Discordant responses were obtained. What is the mechanism?

Regular narrow QRS tachycardia. What is the mechanism?

A 45-years-old lady with no structural heart disease on echocardiogram presented with recurrent episodes of palpitation. There was no baseline preexcitation. Twelve lead surface electrocardiograms (ECG) recorded during one of the episodes are provided. What is the likely mechanism of the tachycardia? [Figure: see text].

Transition during radiofrequency ablation of manifest preexcitation. What is the mechanism?

A 45-year-old lady was evaluated for recurrent episodes of palpitation. Her 12­lead electrocardiogram (ECG) showed manifest but incomplete pre-excitation consistent with left sided accessory pathway. There was no structural heart disease by echocardiogram. She underwent an electrophysiology (EP) study after informed consent. A narrow QRS tachycardia consistent with orthodromic AV re-entry got induced. The accessory pathway was mapped to 2 'O clock of the mitral annulus (MA). While radio frequency ablation (RFA) was being performed at that site, an interesting phenomenon was observed (Figs. 1 & 2). What is the mechanism?

Management of a complicated 'pacemaker pocket' site infection.

Pocket site infection after implantation of a pacemaker is a dreaded complication which requires removing the device and reimplanting it at a contralateral site. Difficulties arise when the patient is dependent on pacing and when there are issues with venous access at the contralateral site. We report a patient with pacemaker pocket site infection with congenital complete heart block managed with explantation of the device, semi-permanent pacing during antibiotic treatment, reimplantation of the device at the contralateral site and management of subtotal subclavian vein stenosis noted during reimplantation.

Tachycardiomyopathy managed by successful ablation of right ventricular outflow tract premature ventricular complexes.

Tachycardiomyopathy is a common reversible cause of left ventricular dysfunction. Prompt diagnosis and treatment of this condition is essential to ensure a good prognosis for the patient. We report a case of tachycardiomyopathy due to frequent premature ventricular complexes arising from the right ventricular outflow tract midseptum managed with successful ablation.

Tricuspid annular PVCS: Radiofrequency ablation by subtricuspid retrograde catheter approach.

Tricuspid annular PVCs constitute 8% of idiopathic PVCs and 5% of RV PVCs. Although a rare entity to encounter in routine clinical practice, it can be a prime culprit behind major arrhythmic burden in few individuals. Electroanatomic approach with sub tricuspid retrograde catheter technique can target those annular PVCs and decrease the arrhythmia burden to normal or near normal range. Although procedural approach for parahisian PVCs requires a close look to avoid injury to native conduction system, TA PVCs are a real challenge due to inherent catheter instability and contact issue in sub tricuspid retrograde approach.

A Novel pacing option in patients with endomyocardial fibrosis: A case series.

Endomyocardial fibrosis (EMF) is characterized by fibrous tissue deposition on the endocardial surface leading to impaired filling of one or both ventricles, resulting in either right or left heart failure or both. Although Sinus node dysfunction and tachyarrhythmia - atrial fibrillation, ventricular tachycardia, have been commonly reported, complete heart block (CHB) necessitating a pacemaker is rare in EMF. Transvenous pacing is technically limited by fibrotic obliteration of the affected ventricle that results in poor lead parameters, and alternative pacing strategy like epicardial pacing may be required in many. We report three cases of EMF, who were treated with an alternative pacing strategy.

Left bundle branch pacing: A comprehensive review.

Cardiac pacing is the only effective therapy for patients with symptomatic bradyarrhythmia. Traditional right ventricular apical pacing causes electrical and mechanical dyssynchrony resulting in left ventricular dysfunction, recurrent heart failure, and atrial arrhythmias. Physiological pacing activates the normal cardiac conduction, thereby providing synchronized contraction of ventricles. Though His bundle pacing (HBP) acts as an ideal physiological pacing modality, it is technically challenging and associated with troubleshooting issues during follow-up. Left bundle branch pacing (LBBP) has been suggested as an effective alternative to overcome the limitations of HBP as it provides low and stable pacing threshold, lead stability, and correction of distal conduction system disease. This paper will focus on the implantation technique, troubleshooting, clinical implications, and a review of published literature of LBBP.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias: executive summary.

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Response to atrial overdrive pacing during narrow QRS tachycardia. What is the mechanism?

A 35-year old lady with no pre-excitation on surface electrocardiogram underwent EP study for recurrent palpitation and documented adenosine responsive narrow QRS tachycardia. Regular narrow QRS tachycardia was induced with critical AH delay on programmed atrial stimulation. An atrial overdrive pacing (AOD) was performed during the tachycardia (Fig: 1 & 2). What is the response to AOD and what is the mechanism of tachycardia?

Interesting response to ventricular overdrive pacing during regular narrow QRS tachycardia. What is the mechanism?

33 year old gentleman has undergone an electrophysiology study for recurrent paroxysmal palpitation. During one of the episodes of palpitation a regular narrow QRS tachycardia was documented which has terminated with intravenous adenosine. Baseline electrocardiogram did not show any pre-excitation. Atrial-His (AH) and His-Ventricular (HV) intervals were normal at baseline. There was no evidence of dual atrioventricular (AV) nodal physiology. Earliest atrial electrogram during ventricular pacing was recorded at coronary sinus (CS) 9,10 dipoles placed at CS OS region. Narrow QRS tachycardia with cycle length (TCL) of 400 ms and earliest retrograde atrial activation at CS 9,10 dipoles was induced with programmed ventricular stimulation. Ventricular overdrive (VOD) pacing was performed at 30 ms shorter than TCL during the tachycardia (Fig: 1). What is the mechanism of tachycardia?

Response of narrow QRS tachycardia in a patient with surgical closure of atrial septal defect to atrial overdrive pacing: What is the mechanism?

A 57-year old woman who had pericardial patch closure of ostium secundum atrial septal defect (ASD) at the age of 23 years presented with shortness of breath. Her echocardiogram showed no residual ASD, good biventricular function and normal pulmonary artery pressures.

Interesting case of dual tachycardia in a patient with surgical closure of atrial septal defect.

A 34-year-old gentleman, who had undergone pericardial patch closure of ostium secundum atrial septal defect (ASD) at 8 years of age, was evaluated for shortness of breath. Electrocardiogram revealed typical atrial flutter with varying atrioventricular conduction. Echocardiogram showed no residual ASD or pulmonary hypertension and good biventricular function. He was taken for an electrophysiological study with the intention of radiofrequency ablation of the typical flutter.