Impact of frailty in patients with non-valvular atrial fibrillation undergoing catheter ablation.

Background: The relationships between frailty and clinical outcomes in elderly Japanese patients with non-valvular atrial fibrillation (NVAF) after catheter ablation (CA) have not been established. We evaluated the frailty rate of patients undergoing CA for NVAF, examined whether CA for NVAF improves frailty, and analyzed the CA outcomes of patients with and without frailty. Methods: Elderly Japanese patients (≥65 years; mean age: 72.8 years) who participated in the real-world ablation therapy with anti-coagulants in management of atrial fibrillation registry and who responded to the frailty screening index survey were included (n = 213). Frailty and AF recurrence were assessed preoperatively and at 3 and 6 months after CA. Results: Twenty-six patients (12.8%) were frail, 109 (53.7%) were pre-frail, and 68 (33.5%) were robust. Cardiovascular (frailty: 0.5%/person-year; pre-frailty: 0.1%/person-year; robust: 0.1%/person-year) and cardiac (frailty: 0.5%/person-year; pre-frailty: 0.1%/person-year; robust: 0.1%/person-year) events, as well as major bleeding (frailty: 0.3%/person-year; pre-frailty: 0.1%/person-year; robust: 0.1%/person-year), were numerically more frequent in the frailty group. No deaths from cardiovascular or stroke/systemic thromboembolic events occurred. A large proportion of patients did not experience 3-month (frailty: 96.2%; pre-frailty: 96.3%; robust: 88.2%) or 6-month (frailty: 88.5%; pre-frailty: 91.7%; robust: 86.8%) AF recurrence after CA. Weight loss, walking speed, and fatigue improved in the frailty and pre-frailty groups after CA. Conclusion: Japanese patients aged ≥65 years with frailty or pre-frailty had improved frailty screening index components, such as weight loss, walking speed and fatigue, after CA. Therefore, elderly patients with frailty or pre-frailty may benefit from CA for NVAF.

Sex Differences in Cardiovascular Disease-Related Hospitalization and Mortality in Japan　- Analysis of Health Records From a Nationwide Claim-Based Database, the Japanese Registry of All Cardiac and Vascular Disease (JROAD).

BACKGROUND: The prevalence of cardiovascular disease (CVD) is rising in Japan with its aging population, but there is a lack of epidemiological data on sex differences in CVD, including acute coronary syndrome (ACS), acute heart failure (AHF), and acute aortic disease.Methods and Results: This retrospective study analyzed data from 1,349,017 patients (January 2012-December 2020) using the Japanese Registry Of All Cardiac and Vascular Diseases database. ACS patients were youngest on average (70.5±12.9 years) and had the lowest female proportion (28.9%). AHF patients had the oldest mean age (79.7±12.0 years) and the highest proportion of females (48.0%). Acute aortic disease had the highest in-hospital mortality (26.1%), followed by AHF (11.5%) and ACS (8.9%). Sex-based mortality differences were notable in acute aortic disease, with higher male mortality in Stanford Type A acute aortic dissection (AAD) with surgery (males: 14.2% vs. females: 10.4%, P<0.001) and similar rates in Type B AAD (males: 6.2% vs. females: 7.9%, P=0.52). Aging was a universal risk factor for in-hospital mortality. Female sex was a risk factor for ACS and acute aortic disease but not for AHF or Types A and B AAD. CONCLUSIONS: Sex-based disparities in the CVD-related hospitalization and mortality within the Japanese national population have been highlighted for the first time, indicating the importance of sex-specific strategies in the management and understanding of these conditions.

Exercise pulmonary hypertension in patients with systemic sclerosis based on updated guidelines.

Recent European guidelines have introduced the concept of exercise pulmonary hypertension (ex-PH). However, the clinical characteristics of ex-PH in systemic sclerosis (SSc) remains unknown. We aimed to investigate the characteristics of exercise pulmonary hypertension (ex-PH) in patients with systemic sclerosis (SSc), which are unknown. We retrospectively examined 77 patients with SSc who underwent symptom-limited exercise testing using a cycle ergometer with right heart catheterization at our hospital. Nineteen patients with postcapillary PH were excluded. Fifty-eight patients (median age, 63 years; 55 women) were divided into the overt-PH (n = 18, mean pulmonary arterial pressure [PAP] > 20 mmHg and pulmonary vascular resistance > 2 Wood units at rest), ex-PH (n = 19, mean PAP/cardiac output slope > 3), and non-PH (n = 21) groups. Exercise tolerance and echocardiography results were compared among the groups. Peak oxygen consumption was high in the non-PH group, intermediate in the ex-PH group, and low in the overt-PH group (14.5 vs. 13.0 vs. 12.5 mL/kg/min, p = 0.043), and the minute ventilation/peak carbon dioxide production slope was also intermediate in the ex-PH group (32.2 vs. 32.4 vs. 43.0, p = 0.003). The tricuspid annular plane systolic excursion/systolic PAP ratio decreased from non-PH to ex-PH to overt-PH (0.73 vs. 0.69 vs. 0.55 mm/mmHg, p = 0.018). In patients with SSc, exercise PH may represent an intermediate condition between not having PH and overt PH, according to the new guidelines.

Renin-angiotensin system inhibitors for patients with mild or moderate chronic kidney disease and heart failure with mildly reduced or preserved ejection fraction.

BACKGROUND: Renin-angiotensin system inhibitors (RASI) reduce adverse cardiovascular events in patients with heart failure (HF) with left ventricular ejection fraction (LVEF) ≤40% and mild or moderate chronic kidney disease (CKD). However, RASI administration rate and its association with long-term outcomes in patients with CKD complicated by HF with LVEF >40% remain unclear. METHODS: We analyzed 1923 consecutive patients with LVEF >40% registered within the multicenter database for hospitalized HF. We assessed RASI administration rate and its association with all-cause mortality among patients with mild or moderate CKD (estimated glomerular filtration rate [eGFR]: 30-60 mL/min/1.73 m2). Exploratory subgroups included patients grouped by age (<80, ≥80 years), sex, previous HF hospitalization, B-type natriuretic peptide (higher, lower than median), eGFR (30-44, 45-59 mL/min/1.73 m2), systolic blood pressure (<120, ≥120 mmHg), LVEF (41-49, ≥50%), and mineralocorticoid receptor antagonists (MRA) use. RESULTS: Among patients with LVEF >40%, 980 (51.0%) had mild or moderate CKD (age: 81 [74-86] years; male, 52.6%; hypertension, 69.7%; diabetes, 25.9%), and 370 (37.8%) did not receive RASI. RASI use was associated with hypertension, absence of atrial fibrillation, and MRA use. After multivariable adjustments, RASI use was independently associated with lower all-cause mortality over a 2-year median follow-up (hazard ratio: 0.58, 95% confidence interval: 0.43-0.79, P = 0.001), and the mortality rate difference was predominantly due to cardiac death, consistent in all subgroups. CONCLUSIONS: Approximately one-third of HF patients with mild or moderate CKD and LVEF >40% were discharged without RASI administration and demonstrated relatively guarded outcomes.

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.

Rapid progression of a coronary artery aneurysm caused by IgG4-related disease.

BACKGROUND: IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder that can affect almost any organ. IgG4-RD has also been reported in coronary arteries as periarteritis. IgG4-related coronary periarteritis may cause coronary artery aneurysms, and IgG4-related coronary artery aneurysms (IGCAs) are life-threatening. We describe a case of a patient with IGCA that highlights the usefulness and limitations of various IGCA evaluation modalities and provides insight into disease pathophysiology. CASE SUMMARY: A 60-year-old man with IgG4-RD diagnosed 2 years before and with IGCA at the proximal right coronary artery (RCA) on coronary angiography (CAG) 9 months prior to admission to the hospital presented with acute coronary syndrome. Emergent CAG revealed the rapid progression of IGCA at the RCA, an obstruction of the diagonal branch, and stenosis of the left anterior descending artery (LAD) and the high lateral branch (HL). The patient underwent percutaneous coronary intervention for the diagonal branch. The RCA aneurysm was resected and bypassed with a saphenous vein graft (SVG); coronary bypass grafting (left internal mammary artery to LAD and SVG to HL) was performed. Pathological findings showed inflammatory cell infiltration and disruption of the elastic plate. CONCLUSION: IGCAs require careful follow-up with computed tomography scans for early detection of aneurysmal enlargement.

Determinants of physical quality of life in patients with chronic thromboembolic pulmonary hypertension after treatment: Insights from invasive exercise stress test.

BACKGROUND: Impaired quality of life (QoL) is prevalent among patients with chronic thromboembolic pulmonary hypertension (CTEPH) despite improved survival due to medical advances. We clarified the physical QoL of patients with CTEPH with mildly elevated pulmonary hemodynamics and evaluated its determinants using a database of patients with CTEPH evaluated for hemodynamics during exercise. METHODS: The QoL was measured in 144 patients with CTEPH (age, 66 (58-73) years; men/women, 48/96) with mildly elevated mean pulmonary artery pressure (<30 mm Hg) at rest after treatment with balloon pulmonary angioplasty and/or pulmonary endarterectomy using the Short-Form 36 (SF-36) questionnaire. The enrolled patients were divided into 2 groups: physical component summary (PCS) scores in the SF-36 over 50 as PCS-good and those under 50 as PCS-poor. RESULTS: The median PCS in SF-36 score was 43.4 (IQR 32.4-49.5) points. The PCS-poor group (n = 110) was older and had lower exercise capacity and SaO2 during exercise. PCS scores were correlated with 6-minute walk distance (rs=0.40, p < 0.001), quadriceps strength (rs=0.34, p < 0.001), peak VO2 (rs=0.31, p < 0.001), SaO2 at rest (rs=0.35, p < 0.001) and peak exercise (rs=0.33, p < 0.001), home oxygen therapy usage (rs=-0.28, p = 0.001), and pulmonary vascular resistance at peak exercise (rs=-0.26, p = 0.002). CONCLUSIONS: The impairment of physical QoL was common in patients with CTEPH with improved hemodynamics; exercise capacity, hypoxemia, and hemodynamic status during exercise were related to the physical QoL.

Jugular Approach for the Transcatheter Pacemaker Implant　- Better Access for Smaller Hearts?

BACKGROUND: The Micra leadless pacemaker was developed to fit inside the right ventricle, thereby reducing overall complications by 48% compared with a historical control group. The current labeling restricts implants to the femoral approach. In this article we used 3-dimensional computer models of human hearts to demonstrate why implants can be difficult in small patients and how using the jugular approach reduces these difficulties.Methods and Results: Cardiac computed tomography scans were made of 45 pacemaker patients, 26 in the US and 19 from a single center in Japan. Dimensional measurements were taken in all 45 hearts, and these dimensions were compared between patient cohorts and between the Micra delivery tool dimension and patient heart dimensions. Hearts were smaller among patients in the Japanese than US cohort. In addition, the tool dimension exceeded heart dimensions in a larger percentage of hearts from Japanese patients. Three dimensions were identified that most likely limit navigating across the tricuspid valve to the right ventricle in smaller hearts and for which the jugular approach improved navigation. CONCLUSIONS: Although the femoral procedure today maintains an excellent safety profile and procedure experience for most global implants, this study provides the rationale as to why the jugular approach may improve the ease of the Micra implant in small hearts, namely by reducing the tortuosity of the navigation across the tricuspid valve.

A case report of limitation of transcatheter hepatic arterial embolization for hereditary hemorrhagic telangiectasia type 2 with pulmonary arterial hypertension.

INTRODUCTION AND IMPORTANCE: Arteriovenous malformations (AVMs) in the liver caused by hereditary hemorrhagic telangiectasia (HHT) influence pulmonary artery hypertension (PAH). Liver transplantation (LT) is the most common treatment for HHT-induced hepatic AVMs. However, LT is contraindicated for patients with severe PAH. There is controversy regarding the ideal therapeutic approach for HHT with PAH and hepatic AVMs. CASE PRESENTATION: We present the case of a 48-year-old female with PAH and HHT. After the initiation of PAH-targeted drugs, we considered that the PAH was mainly caused by high cardiac output secondary to multiple diffuse AVMs in the liver. LT was contraindicated due to high mean pulmonary arterial pressure (mPAP), and we opted to perform transcatheter embolization as an alternative treatment for the AVM. Multiple-stage embolization sessions did not effectively improve the shunt in the liver or the pulmonary hemodynamics. The patient died of an uncontrolled gastrointestinal hemorrhage. CLINICAL DISCUSSION: LT was considered in our case; it was contraindicated because of pulmonary hypertension that was in line with the model for end-stage liver disease exception criteria. Repeated embolization did not reduce the liver shunt or improve pulmonary hemodynamics, possibly due to the diffuse distribution of AVMs in the liver and the rapid development of new collateral vessels with each embolization. Recently, pulmonary vascular resistance (PVR) has been proposed as a more appropriate index for stratifying perioperative risk. CONCLUSION: Based on previous reports and our experience, rapid decision-making regarding LT may be needed based on mPAP and PVR after the initiation of PAH-targeted drugs.

Systematic observation-based diagnosis of atrioventricular nodal reentrant tachycardia with a bystander concealed nodoventricular pathway.

Background: This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP). Methods: We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP-SP) and two to the fast pathway (cNVP-FP), along with two cases of cNVP-related orthodromic reciprocating tachycardia (ORT). Results: The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His-refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio-His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His-refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP-ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast-slow AVNRT with a cNVP-SP and slow-fast AVNRT with a cNVP-FP or His reset preceding the atrial reset in slow-fast AVNRT with a cNVP-SP. Conclusion: AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His-refractory PVC is specifically diagnostic.

Understanding Patient Perspectives Toward Shared Decision-Making in Patients With Pulmonary Hypertension.

Clinical guidelines for pulmonary hypertension (PH) recommend shared decision-making and individualized treatment. However, patient perspectives on PH treatment goals, preference toward a decision-making style of treatment, and adoption of shared decision-making remain unclear. This cross-sectional questionnaire-based study assessed the patients' preferred and actual participation role in treatment decision-making, rated on 5 scales (ranging from passive [patients leave all decisions to physicians] to active [patients make the decision after physicians show patients several options]) and evaluated the concordance between preferred and actual participation roles. The important factors underlying patients' perspectives in treatment decision-making (i.e., prognosis; symptom, financial, family, and social burdens; patient values; and physician recommendation) were evaluated. Univariate logistic regression analysis was performed to determine the patients with a positive preference toward "physician recommendation" in treatment decision-making. Among 130 patients with PH (median age: 58 years; mean pulmonary arterial pressure: 23 mm Hg; 27.7% were males), 59.2% preferred that "physicians make the decision regarding treatment after showing patients therapeutic options (i.e., intermediate between passive and active roles)." The patient-preferred and actual participation roles in decision-making had moderate agreement (Cohen's kappa = 0.46). The most important factor in treatment decisions was "symptom burden reduction" (93.8%). Although 85.0% of patients chose "physician recommendation" as an important factor, 49.6% chose "alignment with my values." The determinants of patients who chose "physician recommendation" were less severe hemodynamics and better functional capacity. In conclusion, patients with PH preferred that the "physicians make the decision after showing patients therapeutic options" and prioritized physician recommendation over their values.

Electrophysiological and Histopathological Characteristics of Ventricular Tachycardia Associated With Primary Cardiac Tumors.

BACKGROUND: Ventricular tachycardia (VT) associated with primary cardiac tumors (PCTs) originating from the ventricles is rare, but lethal, in young patients. OBJECTIVES: This study aimed to clarify the mechanisms underlying primary cardiac tumor-related ventricular tachycardia (PCT-VT) and establish a therapeutic strategy for this form of VT. METHODS: Among 67 patients who underwent surgery for VT at our institute between 1981 and 2020, 4 patients aged 1 to 34 years, including 3 males, showed PCT-VT (fibroma, 2; lipoma, 1; and hamartoma, 1), which was investigated using a combination of intraoperative electroanatomical mapping and histopathological studies. RESULTS: All 4 patients developed electrical storms of sustained VTs refractory to multiple drugs and repetitive endocardial ablations. The VT mechanism was re-entry, and intraoperative electroanatomical mapping showed a centrifugal activation pattern originating from the border between the tumor and healthy myocardium, where fractionated potentials were detected during sinus rhythm. Histopathological studies of serial sections of specimens acquired from these areas revealed tumor infiltration into the surrounding myocardium with cell disorganization, exhibiting myocardial disarray. Several myocardia entrapped in the tumor edges contributed to the development and sustainment of re-entrant VT activation. In the 2 patients in whom complete resection was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing VT occurrence. CONCLUSIONS: The mechanism underlying PCT-VT involves re-entry localized at the tumor edges. Myocardial disarray associated with tumor infiltration is a substrate for this form of VT. Cryoablation along the border between the tumor and myocardium is a promising therapeutic option for unresectable PCT-VT.

Statement from the Asia Summit: Current state of arrhythmia care in Asia.

On May 27, 2022, the Asia Pacific Heart Rhythm Society and the Heart Rhythm Society convened a meeting of leaders from different professional societies of healthcare providers committed to arrhythmia care from the Asia Pacific region. The overriding goals of the meeting were to discuss clinical and health policy issues that face each country for providing care for patients with electrophysiologic issues, share experiences and best practices, and discuss potential future solutions. Participants were asked to address a series of questions in preparation for the meeting. The format of the meeting was a series of individual country reports presented by the leaders from each of the professional societies followed by open discussion. The recorded presentations from the Asia Summit can be accessed at https://www.heartrhythm365.org/URL/asiasummit-22. Three major themes arose from the discussion. First, the major clinical problems faced by different countries vary. Although atrial fibrillation is common throughout the region, the most important issues also include more general issues such as hypertension, rheumatic heart disease, tobacco abuse, and management of potentially life-threatening problems such as sudden cardiac arrest or profound bradycardia. Second, there is significant variability in the access to advanced arrhythmia care throughout the region due to differences in workforce availability, resources, drug availability, and national health policies. Third, collaboration in the area already occurs between individual countries, but no systematic regional method for working together is present.

Predictors of implantation failure in left bundle branch area pacing using a lumenless lead in patients with bradycardia.

Background: Left bundle branch area pacing (LBBAP) is a novel conduction system pacing technique. In this multicenter study, we aimed to evaluate the procedural success, safety, and preoperative predictors of procedural failure of LBBAP. Methods: LBBAP was attempted in 285 patients with pacemaker indications for bradyarrhythmia, which were mainly atrioventricular block (AVB) (68.1%) and sick sinus syndrome (26.7%). Procedural success and electrophysiological and echocardiographic parameters were evaluated. Results: LBBAP was successful in 247 (86.7%) patients. Left bundle branch (LBB) capture was confirmed in 54.7% of the population. The primary reasons for procedural failure were the inability of the pacemaker lead to penetrate deep into the septum (76.3%) and failure to achieve shortening of stimulus to left ventricular (LV) activation time in lead V6 (18.4%). Thickened interventricular septum (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.15-5.35), severe tricuspid regurgitation (OR, 8.84; 95% CI, 1.22-64.06), and intraventricular conduction delay (OR, 8.16; 95% CI, 2.32-28.75) were preoperative predictors of procedural failure. The capture threshold and ventricular amplitude remained stable, and no major complications occurred throughout the 2-year follow-up. In patients with ventricular pacing burden >40%, the LV ejection fraction remained high regardless of LBB capture. Conclusions: Successful LBBAP was affected by abnormal cardiac anatomy and intraventricular conduction. LBBAP is feasible and safe as a primary strategy for patients with AVB, depending on ventricular pacing.

Transition from Intravenous Epoprostenol to Treprostinil Due to Intolerable Side Effects in Patients With Pulmonary Arterial Hypertension.

Intravenous epoprostenol improves exercise capacity and survival in patients with pulmonary arterial hypertension (PAH); however, it has side effects. Reviewing the side effects associated with epoprostenol and treprostinil is essential for improving the long-term treatment strategies for PAH. This retrospective review included patients with PAH who transitioned from intravenous epoprostenol to intravenous treprostinil owing to intolerable side effects, including high cardiac output symptoms, ascites, and thrombocytopenia. Of the 85 patients who received epoprostenol at our hospital between 2013 and 2021, 16 (11 women), with a median age of 33 (range 26 to 40) years (including 12 with idiopathic PAH, 3 with hereditary PAH, and 1 with connective tissue disease pulmonary hypertension), had to switch from intravenous epoprostenol to treprostinil owing to the side effects. After transitioning, epoprostenol-associated intolerable side effects, such as high cardiac output symptoms, ascites, and thrombocytopenia, were ameliorated. In conclusion, for patients with PAH who have intolerable side effects from epoprostenol and have difficulty in continuing treatment, switching from epoprostenol to treprostinil may be an option. Switching treatment leads to better adherence and improved long-term prostacyclin therapy.

Pulmonary artery pressure-perfusion relation during exercise in patients with chronic thromboembolic pulmonary hypertension using pulmonary arteriography and right-heart catheterization.

Background: In pulmonary hypertension (PH), pulmonary artery pressure (PAP) does not increase to pulmonary perfusion (PP) < 50%. During exercise, PAP may be increased even at PP > 50% for the early detection of PP disorders. The relationship between PP estimated by pulmonary angiography (PAG) and PAP was evaluated in patients with chronic thromboembolic PH (CTEPH) treated by balloon pulmonary angioplasty with near-normal PH. Methods: Thirty-one patients (age 60 ± 11 years) with CTEPH underwent catheterization at rest and during exercise. Each segmental PP was determined by visualization of its segmental pulmonary artery and graded from 0 to 3 in the PAG. PP was estimated as the percentage PAG (%PAG) score-%summed total of all segmental PP/the full score-54. Results: The mean PAP (mPAP) increased from 28 ± 6 mmHg to 46 ± 10 mmHg during exercise. Transpulmonary pressure gradient, the value of mPAP with the pulmonary artery wedge pressure substituted at peak exercise, was negatively correlated with %PAG score (rs = -0.56, p < 0.001) and elevated at > 50% PP. Conclusions: The PAP-PP relationship at peak exercise was correlated, shifting from the relationship at rest, and the PAP started to rise with PP > 50%.

Diverse QRS morphology reflecting variations in lead placement for left bundle branch area pacing.

AIMS: Left bundle branch area pacing (LBBAP) is a potential alternative to His bundle pacing. This study aimed to investigate the impact of different septal locations of pacing leads on the diversity of QRS morphology during non-selective LBBAP. METHODS AND RESULTS: Non-selective LBBAP and left ventricular septal pacing (LVSP) were achieved in 50 and 21 patients with atrioventricular block, respectively. The electrophysiological properties of LBBAP and their relationship with the lead location were investigated. QRS morphology and axis showed broad variations during LBBAP. Echocardiography demonstrated a widespread distribution of LBBAP leads in the septum. During non-selective LBBAP, the qR-wave in lead V1 indicated that the primary location for pacing lead was the inferior septum (93%). The non-selective LBBAP lead was deployed deeper than the LVSP lead in the inferior septum. The Qr-wave in lead V1 with the inferior axis in aVF suggested pacing lead placement in the anterior septum. The penetration depth of the non-selective LBBAP lead in the anterior septum was significantly shallower than that in the inferior septum (72 ± 11 and 87 ± 8%, respectively). In lead V6, the deep S-wave indicated the time lag between the R-wave peak and the latest ventricular activation in the coronary sinus trunk, with pacemaker leads deployed closer to the left ventricular apex. CONCLUSION: Different QRS morphologies and axes were linked to the location of the non-selective LBBAP lead in the septum. Various lead deployments are feasible for LBBAP, allowing diversity in the conduction system capture in patients with atrioventricular block.