ABSTRACT
INTRODUCTION: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging. METHODS AND RESULTS: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms. CONCLUSION: Some narrow QRS ectopy may originate from the vicinity of the conduction system, instead of the "true" conduction system, and have concealed connections from its origin to the conduction system.
Subject(s)
Action Potentials , Bundle of His , Catheter Ablation , Electrocardiography , Electrophysiologic Techniques, Cardiac , Heart Rate , Humans , Male , Adult , Bundle of His/physiopathology , Bundle of His/surgery , Treatment Outcome , Predictive Value of TestsABSTRACT
INTRODUCTION: The optimal slow pathway (SP) ablation site in cases with an inferiorly located His bundle (HIS) remains unclear. METHODS AND RESULTS: In 45 patients with atrioventricular nodal reentrant tachycardia, the relationship between the HIS location and successful SP ablation site was assessed in electroanatomical maps. We assessed the location of the SP ablation site relative to the bottom of the coronary sinus ostium in the superior-to-inferior (SPSI), anterior-to-posterior (SPAP), and right-to-left (SPRL) directions. The HIS location was assessed in the same manner. The HIS location in the superior-to-inferior direction (HISSI), SPSI, SPAP, and SPRL were 17.7 ± 6.4, 1.7 ± 6.4, 13.6 ± 12.3, and -1.0 ± 13.0 mm, respectively. The HISSI was positively correlated with SPSI (R2 = 0.62; P < .01) and SPAP (R2 = 0.22; P < .01), whereas it was not correlated with SPRL (R2 = 0.01; P = .65). The distance between the HIS and SP ablation site was 17.7 ± 6.4 mm and was not affected by the location of HIS. The ratio of the amplitudes of atrial and ventricular potential recorded at the SP ablation site did not differ between the high HIS group (HISSI ≥ 13 mm) and low HIS group (HISSI < 13 mm) (0.10 ± 0.06 vs. 0.10 ± 0.06; P = .38). CONCLUSION: In cases with an inferiorly located HIS, SP ablation should be performed at a lower and more posterior site than in typical cases.
Subject(s)
Tachycardia, Atrioventricular Nodal Reentry , Ventricular Septum , Humans , Bundle of His/surgery , Tachycardia, Atrioventricular Nodal Reentry/surgery , Heart Ventricles , Heart AtriaABSTRACT
BACKGROUND: The anatomic extent of the reentry circuit in idiopathic left posterior fascicular ventricular tachycardia (LPF-VT) is yet to be fully elucidated. We hypothesized that entrainment mapping could be used to delineate the reentry circuit of an LPF-VT, especially including the upper turnaround point. METHODS: Twenty-three consecutive LPF-VT patients (mean age, 29 ± 9 years, 18 males) were included. We performed overdrive pacing with entrainment attempts at the left bundle branch (LBB) and the left His bundle (HB) region. RESULTS: Overdrive pacing from the LBB region showed concealed fusion in all 23 patients (post-pacing interval [PPI], 322.1 ± 64.3 ms; tachycardia cycle length [TCL], 319.0 ± 61.6 ms; PPI-TCL, 3.1 ± 4.6 ms) with a long stimulus-to-QRS interval (287.9 ± 58.0 ms, approximately 90% of the TCL). Pacing from the same LBB region at a slightly faster pacing rate showed manifest fusion with antidromic conduction to the LBB and minimal in-and-out time to the LBB potential (PPI-TCL, 21.3 ± 13.7 ms). Overdrive pacing from the left HB region showed manifest fusion with a long PPI-TCL (53.9 ± 22.5 ms). CONCLUSIONS: Our pacing study results suggest that the upper turnaround point in a reentry circuit of the LPF-VT may extend to the proximal His-Purkinje conduction system near the LBB region but below the left HB region. The LPF may constitute the retrograde limb of the reentry circuit.
Subject(s)
Catheter Ablation , Tachycardia, Ventricular , Male , Humans , Young Adult , Adult , Cardiac Pacing, Artificial/methods , Heart Conduction System , Bundle of His/surgery , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/surgery , Heart Rate , ElectrocardiographySubject(s)
Accessory Atrioventricular Bundle , Catheter Ablation , Wolff-Parkinson-White Syndrome , Humans , Accessory Atrioventricular Bundle/diagnosis , Accessory Atrioventricular Bundle/surgery , Heart Conduction System/surgery , Bundle of His/surgery , Electrocardiography , Wolff-Parkinson-White Syndrome/surgeryABSTRACT
BACKGROUND AND AIMS: Ablation of anteroseptal accessory pathways (AS-AP) is challenging, with lower success and more complications compared to other APs. AS-APs can be successfully ablated from the right atrium (RA) or the aortic valve's noncoronary cusp (NCC). We report two patients who required a hybrid ablation approach to achieve successful abolition of both anterograde and retrograde AS-AP conduction. METHODS AND RESULTS: A 21-year-old female with supraventricular tachycardia (SVT) and pre-excitation on electrocardiogram (ECG) underwent electrophysiology study (EPS) confirming an AS-AP with anterograde and retrograde conduction. Ablation in the NCC achieved immediate and persistent anterograde conduction block. Electrophysiological maneuvers showed persistent retrograde AP conduction and orthodromic reciprocating tachycardia (ORT) remained easily inducible. Additional ablation in the NCC did not eliminate retrograde conduction. Further ablation in the RA opposite the NCC at the site of earliest retrograde atrial activation during ORT restored sinus and eliminated retrograde AP conduction. A 52-year-old male with SVT and ECG with pre-excitation underwent EPS that confirmed an AS-AP with anterograde and retrograde conduction. Ablation was performed in the NCC resulting in immediate elimination of pre-excitation. Retrograde conduction was still present and confirmed by repeating electrophysiological maneuvers. Ablation was performed in the RA opposite the successful ablation site in the NCC, eliminating retrograde AP conduction. CONCLUSION: Two cases of AS-AP with anterograde and retrograde conduction and successful elimination of pathway conduction required a hybrid ablation approach from the NCC and RA. This approach may be helpful in other cases to improve success rates without using excessive ablation near the normal conduction system.
Subject(s)
Catheter Ablation , Tachycardia, Paroxysmal , Tachycardia, Reciprocating , Tachycardia, Supraventricular , Ventricular Septum , Female , Humans , Male , Middle Aged , Young Adult , Bundle of His/surgery , Cardiac Conduction System Disease , Catheter Ablation/methods , Electrocardiography/methods , Heart Conduction System/surgery , Tachycardia, Supraventricular/diagnosis , Tachycardia, Supraventricular/surgeryABSTRACT
INTRODUCTION: The management of patients with conduction disease and supraventricular arrhythmias presents a multitude of clinical challenges.Intra-Hisian block, a condition characterized by delayed or blocked electrical conduction within the His bundle, can result in debilitating symptoms, such as syncope or presyncope. This case report aims to elucidate the diagnostic and therapeutic considerations that were taken in a patient who presented with recurrent syncopal episodes that corresponded to atrial flutter (AFL) and subsequently underwent cavotricuspid isthmus ablation. CASE PRESENTATION: A 65-year-old male with paroxysmal AFL and a pre-existing right bundle branch block and left anterior fascicular block (RBBB+LAFB) experienced recurrent syncopal episodes that were found to be correlated with AFL episodes. Following CTI ablation, an electrophysiology study (EPS) revealed a prolonged HV interval of 101ms, which indicated potential conduction abnormalities. With coronary sinus pacing, an intra-Hisian delay of 211ms was observed. During instances of atrioventricular block, intra-Hisian delay was evident on conducted beats, followed by intra-Hisian block on non-conducted beats. Ultimately, the patient's syncopal episodes prompted the placement of a dual-chamber pacemaker, which resulted in the resolution of symptoms. CONCLUSION: Intra-Hisian block is a condition that is often associated with delayed or blocked electrical conduction within the His bundle. When symptomatic, patients often present with syncope or presyncope. Etiologies of this condition include degenerative changes, myocardial infarction, autoimmune disorders, infections, medications, and more. This case emphasizes the importance of electrophysiology studies (EPS) in the diagnosis and management of patients with intra-Hisian block. Prompt intervention, such as the placement of a dual-chamber pacemaker, can alleviate symptoms and improve patient outcomes. Thus, clinical awareness and utilization of EPS can aid in accurate diagnosis and appropriate treatment selection for patients with conduction abnormalities and supraventricular arrhythmias.cuspid isthmus (CTI) ablation.
Subject(s)
Bundle-Branch Block , Electrocardiography , Male , Humans , Aged , Bundle-Branch Block/diagnosis , Bundle-Branch Block/therapy , Bundle-Branch Block/etiology , Bundle of His/surgery , Arrhythmias, Cardiac , Syncope/diagnosis , Syncope/etiology , Syncope/therapyABSTRACT
Radiofrequency catheter ablation (RFCA) to treat ventricular arrhythmias (VAs) originating below the His bundle (HB) region of the right ventricular (RV) septum could impair the atrioventricular node conduction. This study aimed to clarify the parameters of the 12-lead electrocardiography that predict successful RFCA of VAs originating from this region. This study included 20 consecutive patients (13 men; mean age, 68 ± 7 years) with monomorphic VAs in whom the earliest ventricular activation during the VA was below the HB region of the RV septum. According to the ablation results, the patients were divided into two groups: successful ablation (S-group; n = 10) and failed ablation groups (F-group; n = 10). The electrocardiographic parameters during the VAs and RFCA results were assessed. The R wave amplitudes in leads aVL (P = 0.001) and I (P = 0.010) in the S-group were both smaller than those in the F-group. In addition, the S-group had smaller negative deflection amplitudes in leads III (P = 0.002) and aVF (P = 0.003) than the F-group. According to the receiver operating characteristic curve analysis, the most useful electrocardiographic parameter for predicting successful ablation was the R wave amplitude in lead aVL (area under the curve, 0.895; P < 0.001); a cutoff value of < 1.3 mV predicted a successful RFCA with the highest accuracy (sensitivity, 90%; specificity, 80%; positive predictive value, 82%; negative predictive value, 89%). The R wave amplitude in lead aVL was the most useful parameter for predicting a successful RFCA to treat VAs originating below the HB region of the RV septum.
Subject(s)
Catheter Ablation , Tachycardia, Ventricular , Male , Humans , Middle Aged , Aged , Heart Ventricles , Bundle of His/surgery , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/surgery , Arrhythmias, Cardiac , Electrocardiography/methods , Catheter Ablation/methods , Treatment OutcomeABSTRACT
BACKGROUND: The electrophysiological characteristics of idiopathic ventricular arrhythmias (VAs) from the noncoronary sinus (NCS) have not been fully described. OBJECTIVES: This study sought to investigate electrophysiological characteristics and catheter ablation in patients with idiopathic NCS-VA. METHODS: This study comprised 11 patients undergoing radiofrequency (RF) catheter ablation for idiopathic NCS-VA. Angiography was performed to confirm the origin in the aortic sinus before RF ablation. RESULTS: Clinical arrhythmias presented left bundle block/inferior axis morphology in all patients. QRS morphology of R' and R/s' pattern was dominantly found in lead III. Mapping in the right ventricle demonstrated the earliest ventricular activation (EVA) site at the His Bundle region, whereas mapping in the NCS demonstrated that the EVA preceded the activation at the His Bundle region by 12.1 ± 7.9 milliseconds. All VAs were successfully ablated in <2.5 seconds within the NCS with 1 RF application. The successful ablation site was at the nadir of NCS in 10 patients, and near the junction of NCS and the right coronary sinus in the remaining one. A discrete potential can be observed at the EVA site within the NCS in 10 patients (91%); however, an excellent pace mapping at the EVA site was obtained in only 2 patients. Junctional beats did not occur during RF application in all 11 patients. There were no complications or clinical recurrence during a mean follow-up of 26.0 ± 9.8 months. CONCLUSIONS: NCS-VA presents a peculiar electrocardiogram. A discrete potential can be mapped within the NCS during VA and sinus rhythm, and can be used in guiding ablation.
Subject(s)
Catheter Ablation , Sinus of Valsalva , Tachycardia, Ventricular , Humans , Tachycardia, Ventricular/surgery , Sinus of Valsalva/diagnostic imaging , Sinus of Valsalva/surgery , Arrhythmias, Cardiac/surgery , Bundle of His/surgery , Heart Ventricles/surgeryABSTRACT
INTRODUCTION: Post ablation of the accessory pathway (AP), the patient is observed in the catheterization laboratory for a variable period for resumption of pathway conduction. Aim of the study was to determine whether the administration of intravenous adenosine at 10 min after ablation of AP would have the same diagnostic accuracy as waiting for 30 min in predicting the resumption of AP conduction. METHODS: This was a prospective interventional study conducted in two centers. Post ablation of the AP, intravenous adenosine was administered at 10 min to look for dormant pathway conduction. The response was recorded as positive (presence of pathway conduction), negative (absence), or indeterminate (not able to demonstrate AV and VA block and inability to ascertain AP conduction). RESULTS: The study included 110 procedures performed in 109 patients. Adenosine administration at 10 min showed positive result in 3 cases (2.7%), negative result in 99 cases (90%) and indeterminate result in 8 cases (7.3%). Reconnection of accessory pathway at 30 min postablation was seen in 8 cases (7.3%). Of these 8 cases, 10 min adenosine administration showed positive test in 3 patients and negative test in 5 patients. Adenosine test at 10 min has a sensitivity, specificity, positive predictive value, and negative predictive value of 37.5%, 100%, 100%, and 94.9% in identifying the recurrence of accessory pathway conduction at 30 min, respectively. CONCLUSION: Absence of pathway conduction on administration of adenosine 10 min postablation does not help predict the absence of resumption of conduction thereafter.
Subject(s)
Accessory Atrioventricular Bundle , Catheter Ablation , Humans , Adenosine , Prospective Studies , Bundle of His/surgery , Accessory Atrioventricular Bundle/surgery , Heart Rate , Catheter Ablation/methodsABSTRACT
AIMS: Fascicular ventricle tachycardia (FVT) arising from the proximal aspect of left His-Purkinje system (HPS) has not been specially addressed. Current study was to investigate its clinical, electrocardiographic, and electrophysiological characteristics. METHODS AND RESULTS: Eighteen patients who were identified as this rare FVT were consecutively enrolled, and their scalar electrocardiogram and electrophysiological data were collected and analysed. The ventricular tachycardia (VT) morphology was similar to sinus rhythm (SR) in eight patients, left bundle branch block type in one patient, right bundle branch block type in seven patients, and both narrow and wide QRS type in two patients. During VT, right-sided His potential preceded the QRS with His-ventricle (H-V) interval of 36.3 ± 12.4 ms, which was shorter than that during SR (-51.4 ± 8.6 ms) (P = 0.002). The earliest Purkinje potentials (PPs) were recorded within 7 ± 3 mm of left-side His and preceded the QRS by 49.1 ± 14.0 ms. Mapping along the left anterior fascicle and left posterior fascicle revealed an antegrade activation sequence in all with no P1 potentials recorded. In the two patients with two VT morphologies, the earliest PP was documented at the same site, and the activation sequence of HPS remained antegrade. Ablation at the earliest PP successfully eliminated the tachycardia, except one patient who developed complete atrial-ventricular block and two patients who abandoned ablations. After at least 12 months follow-up, 15 patients were free from any recurrences. CONCLUSIONS: Fascicular ventricle tachycardia arising from the proximal aspect of left HPS was featured by recording slightly shorter H-V interval and absence of P1 potentials. Termination of VT requires ablation at the left-sided His or its adjacent region.
Subject(s)
Catheter Ablation , Tachycardia, Ventricular , Humans , Purkinje Fibers/surgery , Catheter Ablation/methods , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/surgery , Bundle of His/surgery , Electrocardiography , Bundle-Branch Block/diagnosis , Bundle-Branch Block/surgeryABSTRACT
BACKGROUND: It was recently shown that template beats and fixation beats of the premature ventricular contractions (PVCs) were generated during lead deployment. These could be exploited to guide the left bundle branch (LBB) pacing (LBBP) procedure. However, lack of a revolving connector that can continuously record and pace during lead rotations has been a limitation when using the traditional implant technique. Here, we report ten cases in which a revolving connector was used and showed that the premature beats of selective left bundle branch (SLBB-PBs) were generated as the lead was reached and the electrical stimulus selectively captured the LBB. METHODS AND RESULTS: Ten patients who underwent the transseptal placement of the pacing lead using a revolving connector were included in the study. We aimed to examine whether the SLBB-PB was a marker of LBB capture during LBBP and the clinical significance of SLBB-PB. LBBP was performed and data of these cases were analyzed to show the characteristics of the electrocardiogram and the intracardiac electrogram of SLBB-PBs. CONCLUSIONS: This is the first case series on SLBB-PBs in LBBP. The presence of SLBB-PBs suggested that the LBB was reached and selectively captured and possibly increased the safety of lead implantation.
Subject(s)
Bundle of His , Bundle-Branch Block , Humans , Bundle of His/surgery , Bundle-Branch Block/therapy , Cardiac Pacing, Artificial/methods , Heart Conduction System/surgery , Electrocardiography/methods , Cardiac Complexes, PrematureABSTRACT
BACKGROUND: Left bundle branch area pacing (LBBAP) is an alternative to right ventricular (RV) and biventricular (BiV) pacing in patients scheduled for pace and ablate treatment strategy. However, current delivery sheaths are designed for left-sided implantation, making the right-sided LBBAP lead implantation challenging. CASE PRESENTATION: We report a case of a right-sided LBBAP approach via right subclavian vein in a heart failure patient with a persistent left superior vena cava scheduled for pace and ablate treatment of refractory atrial flutter. To enable adequate lead positioning and support for transseptal screwing, the delivery sheath was manually modified with a 90-degree curve at the right subclavian vein and superior vena cava junction to allow right-sided implantation. The distance between the reshaping point and the presumed septal region was estimated by placing the sheath on the body surface under fluoroscopy. With the reshaping of the delivery sheath, we were able to achieve LBBAP with relatively minimal torque. Radiofrequency ablation of the atrioventricular node was performed the next day and the pacing parameters remained stable in short-term follow-up. CONCLUSION: With the modification of currently available tools, LBBAP can be performed with the right-sided approach.
Subject(s)
Cardiac Resynchronization Therapy , Persistent Left Superior Vena Cava , Humans , Bundle-Branch Block/diagnosis , Bundle-Branch Block/surgery , Vena Cava, Superior/diagnostic imaging , Vena Cava, Superior/surgery , Cardiac Pacing, Artificial , Atrioventricular Node/surgery , Arrhythmias, Cardiac , Bundle of His/surgery , Electrocardiography , Treatment OutcomeABSTRACT
A 42-year-old man was admitted for recurrent atrioventricular reciprocating tachycardia. We performed a total activation mapping, which included a range from the ventricular to atrial waves during right ventricular pacing. The mapping revealed a delayed ventriculoatrial conduction on the left lateral wall. We performed ablation within the coronary sinus, and the ventriculoatrial conduction was lost. By widening the range, we could easily visualize the ventriculoatrial conduction through the accessory pathway. This mapping showed that the conduction in the area of the accessory pathway was delayed, and it was easy to estimate that the conduction pathway included the coronary sinus.
Subject(s)
Accessory Atrioventricular Bundle , Catheter Ablation , Accessory Atrioventricular Bundle/surgery , Adult , Bundle of His/surgery , Cardiac Pacing, Artificial , Electrocardiography , Heart Conduction System/surgery , Humans , Male , Tachycardia/surgeryABSTRACT
INTRODUCTION: Septal myectomy for obstructive hypertrophic cardiomyopathy (HCM) is associated with conduction block; however, the electrophysiological characteristics of conduction block have not been well characterized. The aim of study was to assess the feasibility and safety of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in patients with septal myectomy-associated conduction block. METHODS AND RESULTS: Patients with HCM and indications for pacing or cardiac resynchronization therapy after septal myectomy were included. Electrophysiological mapping was performed to identify the site of block. The success rates and pacing characteristics of HBP and LBBAP were also recorded. The echocardiographic data and complications were documented and tracked during follow-up. Ten patients with atrioventricular block (AVB) or left bundle branch block (LBBB) post-myectomy were included in the study. The site of block was infranodal in the nine patients with AVB. HBP failed due to the lack of distal His bundle capture (N = 7) or LBBB correction (N = 3). LBBAP was successful in nine patients and failed in one. QRS duration narrowed from 163.3 ± 16.6 ms after surgery to 123.6 ± 15.8 ms during LBBAP (p < .001). The mean depth of the leads was 13.3 ± 4.0 mm (range from 10 to 20 mm). At a mean follow-up of 5.3 ± 3.9 months, pacing parameters and left ventricular ejection fraction remained stable. CONCLUSIONS: Electrophysiological mapping revealed that the site of block was infra-Hisian and not correctable with HBP in patients with HCM post-myectomy. LBBAP appears to be a more feasible physiological strategy for these patients.
Subject(s)
Cardiac Resynchronization Therapy , Ventricular Function, Left , Bundle of His/surgery , Cardiac Pacing, Artificial/methods , Cardiac Resynchronization Therapy/methods , Electrocardiography/methods , Humans , Stroke Volume , Treatment OutcomeABSTRACT
INTRODUCTION: Accessory pathway potential often indicates a highly effective ablation target in Wolff-Parkinson-White syndrome. METHODS: A 27-year-old female presenting with palpitation underwent an electrophysiology study, who had mild pre-excitation in surface ECG. RESULTS: An accessory pathway with weak anterograde conduction was found. During isoproterenol infusion, the delta wave became prominent, an antidromic AV reentrant tachycardia was then induced. When the pathway was mapped, widely split double pathway potentials were observed at the 12 o'clock site of the tricuspid annulus during mild pre-excitation, demonstrating an example of intra-pathway conduction delay. Ablation at the site caused accelerated pathway rhythm and eliminated the pathway, rendering the tachycardia noninducible. CONCLUSION: Split pathway potentials can reflect slow conduction in patients with preexcitation.