Anterior Interventricular Vein Research Articles

Manifestation of conduction block zones by substrate mapping evaluated under multidirectional pacing during ventricular tachycardia ablation

Abstract Introduction Catheter ablation (CA) has proven to be effective therapy for ventricular tachycardia (VT) in patients with structural heart disease. However, activation mapping during VT is often limited in case of non-inducible, non-sustained or hemodynamically tolerable. It has been reported that a substrate-based approach for identifying conduction block and slow-conducting sites during sinus rhythm and ventricular pacing is promising strategies for CA. However, detailed analysis on the effectiveness of substrate mapping with multidirectional pacing to identify critical isthmus in unmappable VT have been lacking. Purpose The purpose of the present study was to evaluate the effectiveness of substrate mapping with multidirectional pacing in VT ablation. Methods From April 2022 to July 2023, 7 consecutive patients (4 men, age 62±9years) who underwent CA of VTs at our institute were enrolled. Isochronal late activation mapping (ILAM) was performed during sinus rhythm, right ventricular (RV) and left ventricular (LV) pacing. Cardiovascular magnetic resonance were performed in 3 of 7 cases to assess the distribution of myocardial late gadolinium enhancement. For catheter ablation, 2Fr electrode catheter was inserted into the anterior interventricular vein (AIV) at the distal site of the coronary sinus. LV pacing was performed using an electrode catheter placed in the AIV. ILAM were constructed by annotating the last deflection of each electrogram. Results In the 7 patients, 5 had ischemic cardiomyopathy and 2 had non-ischemic cardiomyopathy (Figure 1). During sinus rhythm, a deceleration zone (DZ) was identified in only 1 of 7 cases, consistent with linear conduction block. RV pacing demonstrated DZ in 3 of 7 cases. LV pacing revealed DZ in 6 of 7 cases, all of which had conduction blocks. U-shaped conduction blocks, which was not detectable in activation mapping during sinus rhythm, was newly identified in 29% of RV pacing, 71% of LV pacing. Combined RV and LV pacing unmasked the U-shaped conduction block in 86% of the cases. Only in case 7, activation mapping of VT with a cycle length of 470ms could be performed, and VT isthmus activation was observed in the area surrounded by the U-shaped conduction block (Figure 2). In other cases, the clinical VTs were unmappable because of the hemodynamic instability with tachycardia cycle length of approximately 300 milliseconds. Eventually, VTs became non-inducible in 3 of 5 cases in which induction was performed after the CA. During the follow-up period of 7±5 months, 6 of 7 cases remained free from any VT episodes. One patient showed small amount of pericardial effusion after CA. However, there were no life-threatening complications in any patients. Conclusion Substrate mapping using several different wavefront vectors in unstable VTs unveiled conduction block zones that might be potential ablation target sites for VT.Figure 1Figure 2

Venous anatomy of the left ventricular summit region: Insights from high-speed rotational retrograde angiography.

Mapping and ablation through the coronary venous system (CVS) have shown potential for ventricular arrhythmias originating from the left ventricular summit (LVS). Multielectrode catheters and balloons are frequently used for mapping and venous ethanol ablation (VEA). However, there is limited data on the venous size and drainage condition in the LVS region. This study aimed to investigate the morphology, angiographic size, and drainage condition of LV summit veins via high-speed rotational angiography (RA). We measured and analyzed the size of the great cardiac vein (GCV), the anterior interventricular vein (AIV), veins near to the LVS, and other main tributaries of CVS in 102 patients undergoing electrophysiology study. Rotational retrograde angiography of LVS was successfully performed in 81 patients. The diameter of GCV at the level of the Vieussens valve and the distal end of GCV (junction of GCV-AIV) was larger in males than females (6.8 ± 1.1 vs. 5.6 ± 1.2 mm, p < .001; 5.2 ± 0.9 vs. 4.6 ± 0.8, p = .002, respectively) while no significant gender differences were observed in other tributaries. The LV summit veins presented downward drainage direction in half of the patients, indicating potential anatomic adjacency with His bundle. Left anterior oblique (LAO) 45° projection might provide the practical and optimal view of the LV summit veins. The coronary veins of the LVS region present various anatomical morphologies and ostium sizes. We provide a systematic description and angiographic size spectrum of CVS. RA could facilitate assessing the feature of CVS comprehensively.

P166 LEFT VENTRICULAR SUMMIT PVC–INDUCED CARDIOMYOPATHY: A CASE REPORT

Abstract A 76 y.o. patient referred to our attention for syncopal and presyncopal episodes. His ECG showed several premature ventricular contractions (PVC) with the morphology of a right bundle branch block (RBBB)– positive concordance in precordial leads and transtion in V3 lead– and an inferior axis. Echocardiographic finding was a moderate reduced ejection fraction. Furthermore coronarography did not identify critical stenosis, excluding an ischemic etiology. Cardiac MRI was performed, confirming the reduce ejection fraction and excluding LGE. Because of high burden of 25000 PVCs on 24 h ECG registration and progressive deterioration of ejection fraction, despite antiarrhythmic drugs, catheter ablation was considered. An high density multielectrode mapping catheter was used and an initial right ventricular mapping was perfomed, recording local electrograms but without identification of a clear earliest site of activation. Therefore a retrograde transaortic left ventricular mapping was performed. Earliest site of activation was not significant (about 15 milliseconds), as well as percentage of correlation during pace–mapping. Epicardial mapping through coronary sinus into the anterior interventricular vein (AIV) showed a significant earliest activation site (greater than 30 ms) and a negative unipolar signal (QS) was detected. Pacing in this region highlighted a significant percentage of correlation with native PVC (92%), then catheter ablation was attempted. A first short duration application of radiofrequency was erogated on the endocardial side in front of the projection of the catheter in the AIV, because of possible risks of procedure, obtaining a temporary PVC suppression. Subsequently, after execution of a coronary angiogram proving a distance of the ablator in AIV and IVA/Cx vessels greater than &amp;gt; 1 cm, an endovenous approach was attempted with application of radiofrequency into the AIV, obtaing complete PVC suppression. At a 6 months follow–up ejection fraction improved (FE 50%) and PVC were not detected. Discussion Epicardial approach throught coronary sinus is an effective strategy to map and ablate arrhythmias of left ventricular summit. In addiction this stretegy allows a less invasive epicardial approach than other procedures, requiring a cardiosurgery standby.

PO-04-201 A CASE OF PVC OCCURRING RIGHT BUNDLE BRANCH BLOCK AND PR INTERVAL PROLONGED DURING ETHANOL ABLATION VIA THE CORONARY VENOUS SYSTEM

Ethanol ablation via the coronary venous system (CVS) has been reported to be effective and safe as a novel therapy for ventricular arrhythmias, especially for the epicardial and intramural origin sites. Previous studies reported no heart block complications during retrograde coronary venous ethanol ablation, neither atrioventricular block (AVB) nor other types of conductive system block. N/A A 67-year-old female with symptomatic and drug-refractory premature ventricular contractions (PVCs) was admitted for ablation therapy. The PVC burden was 31.7%. The 12-lead ECG showed a PVC with LBBB, inferior axis with a precordial transition in lead V3, and QS pattern in lead I. The QRS duration of PVC was 143ms. The Q-wave ratio of lead aVL/aVR was 1.47. Endocardial mapping was performed using a 3.5mm open-irrigated-tip catheter (ThermoCool, Biosense Webster, CA, USA). The earliest activation time was -8ms and -10ms pre-QRS at the septal aspect of right ventricular outflow tract (RVOT) and the left coronary sinus (LCC), respectively (Fig 1A). Ablation with 35-40W, 45-50°C was attempted but no response. We considered it might be an intramural origin site. The CVS angiography was performed and the ablation catheter was positioned in LCC for reference (Fig 1B). The earliest activation time (-27ms) was mapped in a septal branch of the anterior interventricular vein (AIV) with a 3.3F quadripolar catheter and local pace mapping matched well. Selective angiography confirmed the quadripolar catheter was in the septal branch rather than AIV (Fig 1C-D). A balloon was used to deliver ethanal and prevent its backflow to AIV. 1ml 96% ethanol was infused slowly (Fig 1E-F). PVC was eliminated immediately as soon as the ethanol infusion. But we noticed the PR interval prolonged from 178 to 190ms. More ethanol was injected carefully to consolidate the effect but we stopped infusion after a total of 2.5ml ethanol because the ECG showed complete RBBB and PR interval prolonged further to 202ms. RBBB and I° AVB were persistent during the whole hospitalization for 3 days. However, at 1-month follow-up, the QRS morphology returned to normal and the PR interval shortened to 172ms (Fig 1G). 24-hour Holter showed no recurrence. Ethanol ablation via the CVS also might induce heart block complications due to the adjacent anatomical position with the conductive system, even though it might be reversible. Operators should be cognizant of the potential risk.

PO-05-007 CORONARY VENOUS ETHANOL ABLATION OF SUBEPICARDIAL SUBSTRATE IN PATIENTS WITH VENTRICULAR TACHYCARDIA AND LEFT VENTRICULAR ASSIST DEVICE.

Patients with a left ventricular assist device (LVAD) and ventricular tachycardia (VT) often have subepicardial substrate, which may not be amenable to epicardial ablation due to sternotomy-related adhesions and the LVAD itself. As an alternative approach, coronary venous ethanol ablation (VEA) can be used to ablate VT substrates without needing pericardial access. To assess the feasibility and acute safety of VEA in patients with LVAD and VT. We retrospectively studied patients with LVAD who underwent VT ablation using VEA between 8/2015 – 11/2022 at a tertiary referral medical center. Baseline patient and procedural characteristics were obtained. Of the 10 patients included, 7 presented with VT storm, 5 had prior VT ablation, 3 had multiple prior sternotomies, all were on amiodarone, 8 were on 2 or more antiarrhythmic drugs in the prior year, all had prior defibrillator implants, and 9 had shocks in the prior year. Across the cohort, 4 different vein territories were targeted for VEA, including the middle cardiac vein, posterolateral branch vein, anterolateral branch vein, and septal branch of the anterior interventricular vein. In 4 cases, 2 separate vein territories were targeted. An average of 17 ± 10 cc of ethanol was used per case. Concomitant radiofrequency ablation was used in all 10 patients. Procedure and fluoroscopy times were 290 ± 56 minutes, and 32 ± 15 minutes, respectively. Acute procedural success, defined as no inducible VT, was achieved in 9 cases. There was 1 complication, which was transiently increased threshold on the LV pacing lead and RV failure necessitating prolonged inotropic support. All the patients survived to hospital discharge. In an inherently high-risk LVAD population with VT, VEA can be used as an alternative approach to target subepicardial substrate that would otherwise be inaccessible via standard percutaneous access of the pericardial space. Acute procedural success was high in this limited cohort. Further study with larger numbers of cases and longer follow up is warranted.

PO-05-145 A CASE OF SUSPECTED CARDIAC SARCOIDOSIS MIMICKING ISCHEMIC CARDIOMYOPATHY

Cardiac sarcoidosis (CS) is challenging due to varied clinical presentation and limited accuracy of diagnostic criteria. We describe a case of suspected CS in a patient with ischemic cardiomyopathy (ICM) presenting in ventricular tachycardia (VT) storm. To describe the presentation of suspected CS in a patient with ICM and VT. N/A A 73 year old male with ICM and ejection fraction of 35% initially presented with myocardial infarct requiring 3-vessel coronary artery bypass surgery. Months later he developed sustained monomorphic VT which was detected on his pacemaker and underwent upgrade to a dual chamber implantable cardioverter defibrillator. He continued to have frequent VT ultimately presenting in VT storm. He was loaded on amiodarone and referred for radiofrequency catheter ablation. During index ablation, the left ventricular (LV) endocardial bipolar voltage was normal, which was inconsistent with the inferobasal and basal septal scar identified on pre procedural cardiac computed topography (CT) (Figure 1). The clinical VT was mapped to the anterior interventricular vein and targeted from the LV summit since proximity of AIV to the left anterior descending artery precluded ablation from the AIV. His arrhythmic presentation and LV dysfunction was disproportionate to degree of coronary disease. In addition, discordance between clinical VT origin site, bipolar endocardial voltage, and scar on cardiac CT prompted suspicion of an alternate underlying diagnosis, such as an arrhythmogenic inflammatory cardiomyopathy. A positron emission tomography/computed tomography (PET/CT) later obtained showed evidence of patchy 18F-fluorodeoxyglucose uptake along the inferolateral LV, suggestive of CS. He was started on immunosuppressants but developed recurrent VT despite anti arrhythmic therapy and required 2 subsequent ablations. He has since remained quiescent from a VT standpoint on amiodarone with plans for alcohol septal ablation or stereotactic body radiation therapy if VT recurs. Symptoms have improved with steroids and immunosuppressants with no inflammation detected on most recent PET/CT High suspicion of CS should remain in patients presenting with significant arrhythmic burden. Normal endocardial voltage during VT ablation can be suggestive of an acute inflammatory process and should prompt consideration of CS, especially in cases with discordant areas of scar and wall thinning on imaging.

Intramyocardial Mapping of Ventricular Arrhythmias via Septal Venous Perforators: Defining the Superior Intraseptal Space.

Left ventricular outflow tract arrhythmias that fail endocardial mapping and ablation have traditionally been labeled as originating from the epicardial left ventricular summit. Although these sometimes can be targeted from the epicardial surface of the left ventricular ostium, such approach poses significant technical challenges. A significant proportion of such arrhythmias, however, exhibit intramyocardial origin, demonstrated by mapping intraseptal branches of the anterior interventricular vein, and henceforth defined as the basal superior intraseptal space.

Wellens Syndrome on the basis of critical occlusion of the medial segment of the anterior ventricultural branch of the left coronary artery (clinical type)

The aim of the work is to determine the peculiarities of the clinical course of Wellens syndrome due to the presence of critical occlusion of the medial segment of the anterior interventricular coronary artery bifurcation.Material and Methods. Clinical manifestations of the disease, including dynamics of ECG changes; coronary angiography data; results of echocardiographic and laboratory tests.Results. This article presents the peculiarities of the clinical course of Wellens syndrome in patient L., 70, who met the currently recognized diagnostic criteria of the syndrome, but the critical occlusion of the anterior interventricular branch of the left coronary artery was localized in its medial segment. Along with this, there was hemodynamically irrelevant stenosis of the proximal coronary artery section (60%). Electrocardiographic changes were consistent with pattern B (deeply inverted T waves in V2-V6). Сonditional normalization of the T waves, indicating the absence of repeated coronary artery occlusion after spontaneous reperfusion. Stenting of the anterior interventricular coronary artery vein of the left coronary artery prevented the possible occurrence of “stuttering” pattern and the occurrence of myocardial infarction.Conclusions. Acute coronary syndrome with complete coronary artery occlusion is often accompanied by spontaneous reperfusion, which contributes to the relief of chest pain and the appearance of characteristic T waves on ECG and is the basis of the so-called Wellens syndrome. The most frequent localization of coronary artery occlusion is the proximal segment of the anterior interventricular branch of the left coronary artery, but we witnessed the occlusion in the medial segment of these coronary arteries. Immediate coronary angiography with stenting of the occluded artery will prevent the occurrence of myocardial infarction in the patient.

The veins of the left ventricular summit in patients undergoing cardiac resynchronization therapy

Abstract Introduction While the coronary sinus and its left ventricular branches have been extensively described, the veins of the left ventricle summit (LVS) have been much less studied. The emergence of new ablation techniques for ventricular tachycardias, which make use of the LVS veins, has generated a renewed interest in the anatomy of these venous conduits. Purpose The aim of the study was to describe in detail the anatomy of the LVS veins using rotational venous angiography. Material and methods All patients (N=106, age 68±12 years, 72 men) underwent coronary venous angiography during the cardiac resynchronization implant procedures. Results The LVS veins identified were the great cardiac vein (GCV), the anterior interventricular vein (AIV) and the mitro-aortic LVS vein (MALVSV). The MALSV emerged from the GCV between 12 and 2 o'clock on the mitral ring, coursed inside the left atrioventricular groove, towards the aorto-mitral continuity (AMC), where it turned towards the ventricular septum and coursed parallel to the AIV, tapered down and ended at midventricular level. Most of the course of this vein was in the region of the LVS. The diameter of the venous conduit at the GCV-AIV junction was 4.9±1.0 mm. The MALVSV was present in 76 patients (72%; Figure 1). The MALVSV diameter was 2.4±0.6mm at the ostium (Figure 2) and 1.8±2.0 mm at the AMC. The takeoff angle was 134±27°. The total length of the vein was 34±16 mm, of which 23±14mm were inside the AV groove and 11±9mm, were along the ventricular septum. The length of the MALSV segment embedded in the left AV groove as well as the total length of MALSV correlated significantly with the left atrial diameter (r=0.44; P=0.040 and r=0.45; p=0.016 respectively) as well as with the right ventricular systolic pressure (r=0.50; p=0.028 and r=0.57; P=0.030 respectively). Conclusions This study brings new insights into the angiographic anatomy of the LVS veins. Detailed knowledge of these venous tributaries could help with the development of new strategies for ablation of LVS tachycardias. Funding Acknowledgement Type of funding sources: None.

Study of coronary sinus anatomy during levophase of coronary angiography.

BACKGROUNDCoronary sinus (CS) imaging has recently gained importance due to increasing need for mapping and ablation of electrophysiological arrhythmias and left ventricular (LV) pacing during cardiac resynchronization therapy (CRT). Retrograde venogram is the current standard for imaging CS and its tributaries. AIMTo evaluate CS anatomy during levophase of routine coronary angiography to aid LV lead implantation during CRT.METHODSIn this prospective observational study, 164 patients undergoing routine coronary angiography for various indications (Chronic stable angina-44.5%, acute coronary syndrome- 39.5%, Dilated cardiomyopathy-11%, atypical chest pain-5%) were included. Venous phase (levophase) of left coronary injection was recorded in left anterior oblique - cranial and right anterior oblique -cranial views. Visibility of coronary veins, width and shape of CS ostium, angulations of proximal CS with body of CS were noted. Presence, size, take-off angle and tortuosity of posterolateral vein (PLV), anterior interventricular veins (AIV) and middle cardiac vein (MCV) were also noted.RESULTSDuring levophase, visibility grade (Muhlenbruch grade) for coronary veins was 3 in 74% and 2 in 26% of cases. Visibility of CS did not correlate with body mass index. The diameter of CS ostium was < 10 mm, 10-15 mm and > 15 mm in 48%, 42% and 10% of patients respectively. Proximal CS was tubular in 136 (83%) patients and funnel-shaped in 28 (17%) patients. Sharp take-off angulation between ostium and body of CS was seen in 16 (10%) patients. Two or more PLV were present in 8 patients while PLV was absent in 52 (32%) patients. Angle of take-off of PLV with body of CS was favourable (0°-45°) in 65 (40%) patients. The angle was 45°-90° in 36 patients and difficult take-off angle (> 90°) was seen in 8 patients. Length of PLV reached distal third of myocardium in 84 cases and middle third in 11 cases. There was no tortuosity in 79 cases, a single bend in 29 cases and more than 2 bends in 4 cases. Thirty nine (24%) patients had other veins supplying posterior/Lateral wall of LV. There was a single vein supplying lateral/posterior wall in 31 (19%) patients. Diameter of MCV and AIV was significantly larger in patients with absent PLV as compared to patients with a PLV. CONCLUSIONLevophase study of left coronary injection is effective in visualization of the CS in almost all patients undergoing coronary angiography and may be an effective alternative to retrograde venogram in patients with LV dysfunction or LBBB.

Usefulness of the over-the-wire microelectrodes catheter in treatment of ventricular arrhythmia arising from the left ventricular summit.

This study was aimed to investigate the efficacy of the over-the-wire (OTW) microelectrodes catheter in coronary venous system (CVS) mapping and treatment of outflow tract ventricular arrhythmia (OTVA) arising from the vicinity of the left ventricular summit (LVS). Consecutive 62 patients with idiopathic OTVA in whom the OTW microelectrodes catheter was routinely used for CVS mapping were analyzed. CVS mapping was performed for both main trunk (from great cardiac vein to anterior interventricular vein) and branches including the annular branch or septal branch. The earliest activation site (EAS) was within the CVS in 21 patients. Among them, the EAS was within the main trunk of the CVS in seven (33%) and within the branch of the CVS in 14 (67%) patients. Radiofrequency catheter ablation was started at an anatomically adjacent site to the EAS, which eliminated OTVA in 16 (76%) patients (the endocardial LVOT in 10 and the aortic sinus of Valsalva in six patients). For the remaining five patients with unsuccessful catheter ablation at an anatomically adjacent site, targeted OTVA was eliminated by catheter ablation at the EAS within the CVS in two patients and by chemical ablation with ethanol injection in one patient, resulting in the overall success rate of 90% (19/21). The OTW microelectrodes-guided ablation of OTVA from the vicinity of the LVS was effective. In maximizing the efficacy of ablation, CVS branch mapping is important since the earliest activation was commonly recorded not in the main trunk but within the branch of the CVS.

PO-666-08 CONFINED INTRASEPTAL REENTRY IN LAMIN CARDIOMYOPATHY DEMONSTRATED BY INTRAMURAL SEPTAL PERFORATOR VEIN RECORDINGS

Despite advanced techniques including high resolution mapping, defining intramural circuit components remains challenging. The septal perforator veins (SPV) that originate from the anterior interventricular vein (AIV) provides access into the basal superior intraseptal region of the LV and may inform the most optimal vantage point for ablation.

PO-700-07 INTRAMURAL WIRE ABLATION WITHIN COMMUNICATING VENOUS BRANCH BETWEEN GREAT AND SMALL CARDIAC VEIN: A NOVEL TECHNIQUE

Premature Ventricular Complexes (PVCs) originating in the region of Left Ventricular summit and intraseptal region are challenging for ablation due to accessibility. Often adjacent areas to earliest activation as mapped through Great cardiac vein (GCV) and Anterior interventricular vein (AIV) are ablated through right ventricular outflow tract (RVOT), left ventricular outflow tract (LVOT) or from coronary cusps.

PO-672-06 SIMULTANEOUS HIS BUNDLE, LATERAL LV AND LATERAL RV PACING IN A PATIENT WITH REPAIRED TETRALOGY OF FALLOT

Patients with repaired Tetralogy of Fallot (ToF), who have RBBB and predominant right ventricular (RV) dysfunction may benefit from RV electromechanical resynchronization. We describe the case of a patient with repaired ToF, biventricular (BiV) dysfunction and ineffective cardiac resynchronization therapy (CRT) in whom His bundle pacing (HBP) fused with RV wall pacing achieved RV CRT and acute hemodynamic improvement. N/A 58 YOF with repaired ToF and BiV dysfunction presented with decompensated heart failure (HF). BiV implantable cardioverter-defibrillator (ICD) with RA, RV and coronary sinus (CS) leads (Biotronik, Berlin, Germany) was placed at an outside facility one year ago. Underlying EKG showed sinus rhythm with 1stdegree AVB (PR 240 ms), RBBB (QRSd 200ms) and left posterior fascicular block. With presenting CRT, QRS was wider (QRSd 240). Chest Xray revealed RV ICD lead in the right ventricular outflow tract (RVOT) and the CS lead in the anterior interventricular vein with the tip electrode also near RVOT. Given concern for suboptimal CRT, defibrillation vector and limited alternative options, we pursued individualized CRT optimization. Activation mapping showed latest RV activation in the basal lateral tricuspid annulus. Pacing from this site simultaneously with the His Bundle narrowed the QRS significantly and improved RVEF and dyssynchrony on intracardiac echocardiography. Fick cardiac output and index improved to 4.4 and 2.4 respectively from 3.7 and 2.0 at baseline. Thus, we removed the old CS lead and replaced the ICD lead with a new DF-1 defibrillator lead (Medtronic, Minneapolis, MN) in the RV apical septum. Then, we placed a SelectSecureTM His lead (3830 model, Medtronic, Minneapolis, MN). Non-selective His capture threshold was 1.0 V at 0.4 ms. Then, we placed a SelectSecureTM lead (3830 model, Medtronic, Minneapolis, MN) in the RV basal lateral wall and this was Y-adapted to a new LV lead (4196Y model, Medtronic, Minneapolis, MN) which was placed on a lateral branch of the CS. HBP fused with LV and RV lateral wall pacing resulted in a QRS of 120ms. At one year follow up, she has not had HF admissions. Simultaneous HBP and RV basal lateral wall pacing may be a feasible strategy for RV CRT in patients with ToF, RBBB and predominant RV dysfunction.

Catheter ablation of left ventricle summit PVC using anterior interventricular vein approach.

ResumenSe desarrolla el caso de una paciente de 24 años con corazón estructuralmente sano y antecedente de ablación por radiofrecuencia (ARF) de extrasístole ventricular (EV) del tracto de salida del ventrículo izquierdo (VI). Evoluciona a los dos años postablación nuevamente con EV muy frecuentes (> 47,000 en Holter de 24 h) refractarias a múltiples esquema antiarrítmicos y muy sintomática por palpitaciones. Electrocardiograma con EV con morfología izquierda con origen en el summit del VI con ARF epicárdica exitosa a través de la vena interventricular anterior y sin recurrencia arrítmica en la evolución de seis meses.

Idiopathic Ventricular Arrhythmias Originating from Different Portions of the Coronary Venous System: Prevalence, Electrocardiographic Characteristics, Catheter Ablation, and Complications.

(1) Background: To determine the prevalence, electrocardiographic characteristics, mapping, and ablation of IVAs arising from the CVS. (2) Methods: Detailed activation and pace mapping of the CVS IVAs was performed before attempted radiofrequency ablation (RFCA). (3) Results: The IVAs originating from the vicinity of the CVS represented approximately 5.27% (164/3113) of all IVAs; 94.51% (155/164) cases were accessed at the earliest identified site and 83.54% (137/164) IVAs were successfully ablated. The main coronary vein group had a relatively short procedure time, short fluoroscopy time, fewer radiofrequency lesions prior to success, and less Swartz sheath support. IVAs originating from the CVS had distinct ECG characteristics: Rs, RS or rS (with s or S) wave in lead V1 indicate the Vas arising from the proximal portion of the anterior interventricular vein (AIV) and summit-CV; Rs (with s or S) wave in leads V5–V6 indicate the Vas arising from the adjacent regions of the distal great cardiac vein 1 (DGCV1); positive wave (R, Rs or r) In lead I indicate the VAs ori”inat’ng from Summit-CV and posterior wall subgroup (including middle cardiac vein [MCV], posterior lateral vein [PLV], coronary sinus [CS]). Compared with the IVAs originating from the endocardial mitral annulus, a PdW > 45 ms, an IDT > 74 ms, and an MDI > 0.50 indicate a CVS origin of the IVAs. The common peri-procedure complications were CV dissection (6.45%, 10/155), CV rupture (1.29%, 2/155), coronary artery spasm (1.29%, 2/155), coronary artery stenosis (0.65%, 1/155), pericardial effusion (0.65%, 1/155) and tamponade (1.29%, 2/155). Stenosis of coronary arteries was not observed at the adjacent ablation site in the CVS during follow-up. (4) Conclusions: vAs arising from the CVS are not a rare phenomenon. Several ECG and procedure characteristics could help regionalize, map, and ablate the origin of IVAs from different portions of the CVS. RFCA within the CVS was relatively effective and safe.

Catheter Ablation of Ventricular Arrhythmias Originating From the Region of DGCV-AIV via a Swartz Sheath Support Approach.

Aims: This study aimed to investigate an appropriate catheter manipulation approach for ventricular arrhythmias (VAs) originating from the left ventricular epicardium adjacent to the transitional area from the great cardiac vein to the anterior interventricular vein (DGCV-AIV).Methods: A total of 123 patients with DGCV-AIV VAs were retrospectively analyzed. All these patients underwent routine mapping and ablation by conventional approach [Non-Swartz sheath support (NS) approach] firstly. In the situation of the distal portion of the coronary venous system (CVS) not being accessed or a good target site not being obtained, the Swartz sheath support (SS) approach was attempted alternatively. If this still failed, the hydrophilic coated guidewire and left coronary angiographic catheter-guided deep engagement of Swartz sheath in GCV to support ablation catheter was performed.Results: A total of 103 VAs (103/123, 83.74%) were successfully eliminated in DGCV-AIV. By NS approach, the tip of the catheter reached DGCV in 39.84% VAs (49/123), reached target sites in 35.87% VAs (44/123), and achieved successful ablation in 30.89% VAs (38/123), which was significantly lower than by SS approach (88.61% (70/79), 84.81 % (67/79), and 75.95% (60/79), P < 0.05). There were no significant differences in complication occurrence between the NS approach and the SS approach (4/123, 3.25% vs. 7/79, 8.86%, p > 0.05). The angle between DGCV and AIV <83° indicated an inaccessible AIV by catheter tip with a predictive value of 94.5%. Width/height of coronary venous system>0.69 more favored a SS approach with a predictive value of 87%.Conclusion: For radiofrequency catheter ablation (RFCA) of VAs arising from DGCV-AIV, the SS approach facilitates the catheter tip to achieve target sites and contributes to a successful ablation.

Morphometric Characterization of Human Coronary Veins and Subvenous Epicardial Adipose Tissue-Implications for Cardiac Resynchronization Therapy Leads.

Subvenous epicardial fat tissue (SEAT), which acts as an electrical insulation, and the venous diameter (VD) both constitute histomorphological challenges for optimal application and lead design in cardiac synchronization therapy (CRT). In this study, we characterized the morphology of human coronary veins to improve the technical design of future CRT systems and to optimize the application of CRT leads. We retrospectively analyzed data from cardiac computed tomography (CT) of 53 patients and did studies of 14 human hearts using the postmortem freeze section technique and micro CT. Morphometric parameters (tributary distances, offspring angles, luminal VD, and SEAT thickness) were assessed. The left posterior ventricular vein (VVSP) had a mean proximal VD of 4.0 ± 1.4 mm, the left marginal vein (VMS) of 3.2 ± 1.5 mm and the anterior interventricular vein (VIA) of 3.9 ± 1.3 mm. More distally (5 cm), VDs decreased to 2.4 ± 0.6 mm, 2.3 ± 0.7 mm, and 2.4 ± 0.6 mm, respectively. In their proximal portions (15 mm), veins possessed mean SEAT thicknesses of 3.2 ± 2.4 (VVSP), 3.4 ± 2.4 mm (VMS), and 4.2 ± 2.8 mm (VIA), respectively. More distally (20–70 mm), mean SEAT thicknesses decreased to alternating low levels of 1.3 ± 1.1 mm (VVSP), 1.7 ± 1.1 mm (VMS), and 4.3 ± 2.6 mm (VIA), respectively. In contrast to the VD, SEAT thicknesses alternated along the further distal vein course and did not display a continuous decrease. Besides the CRT responsiveness of different areas of the LV myocardium, SEAT is a relevant electrophysiological factor in CRT, potentially interfering with sensing and pacing. A sufficient VD is crucial for successful CRT lead placement. Measurements revealed a trend toward greater SEAT thickness for the VIA compared to VVSP and VMS, suggesting a superior signal-to-noise-ratio in VVSP and VMS.

Evaluation of the anatomical variations of the coronary venous system in patients with coronary artery calcification using 256-slice computed tomography.

The factors that determine the anatomical variations of the coronary venous system (CVS) are poorly understood. The objective of this study was to evaluate the anatomical variations of the CVS in patients with coronary artery calcification. 196 patients underwent non-contrast CT and coronary CT angiography using 256-slice CT. All subjects were divided into four groups based on their coronary artery calcium score (CACS): 50 patients with CACS = 0 Agatston unit (AU), 52 patients with CACS = 1–100 AU, 44 patients with CACS = 101–400 AU, and 50 patients with CACS > 400 AU. The presence of the following cardiac veins was evaluated: the coronary sinus (CS), great cardiac vein (GCV), posterior interventricular vein (PIV), posterior vein of the left ventricle (PVLV), left marginal vein (LMV), anterior interventricular vein (AIV), and small cardiac vein (SCV). Vessel diameters were also measured. We found that the CS, GCV, PIV, and AIV were visualized in all patients, whereas the PVLV and LMV were identified in a certain proportion of patients: 98% and 96% in the CACS = 0 AU group, 100% and 78.8% in the CACS = 1–100 AU group, 93.2% and 77.3% in the CACS = 101–400 AU group, and 98% and 78% in the CACS > 400 AU group, respectively. The LMV was less often identified in the last three groups than in the first group (p < 0.05). The frequency of having either one PVLV or LMV was higher in the last three groups than in the first group (p < 0.05). No significant differences in vessel diameters were observed between the groups. It was concluded that patients with coronary artery calcification were less likely to have the LMV, which might hamper the left ventricular lead implantation in cardiac resynchronization therapy.

Vascular supply of the anterior interventricular epicardial nerves and ventricular Purkinje fibers in the porcine hearts.

The aim of this study was to perform a pilot histological and quantitative analysis of the blood vessels accompanying the epicardial nerves (vasa nervorum) in the porcine hearts. Twenty healthy porcine hearts were used in this study. The blood vessels were analyzed by light microscopy using four different staining techniques in transverse sections taken from the upper, middle, and lower segments of the anterior part of the interventricular region and the adjacent parts of the right and left ventricles containing epicardial nerves and the endocardial peripheral parts of the Purkinje fibers. In total, 317 epicardial nerves were detected. The vasa nervorum were present in 75.7% of these nerves. The vasa nervorum resembled arterioles and postcapillary and collecting venules. One hundred and forty nine epicardial nerves were perivascular, located in the adventitia of the anterior interventricular artery and vein. The remaining 168 nerves ran freely through the epicardial interstitium. The presence of the vasa nervorum was not related to topographical location or nerve diameter. Additionally, from a total of 33 analyzed ventricular complexes of Purkinje fibers small blood vessels located in their proximity were identified in only two cases. It can be concluded that the majority of the anterior epicardial nerves of porcine heart possess well-developed vasa nervorum. In contrast, similar blood vessels are rarely present in the vicinity of the Purkinje fibers. The data obtained contribute to a better understanding of the nutrition of the cardiac nerves.