Ablation Index Guided Left Atrial Posterior Wall Isolation.

Ablation index (AI)-guided linear ablation is reported to be feasible.We assessed the feasibility of AI-guided left atrial (LA) posterior wall isolations (PWIs) using different target AI values.Seventy-one persistent atrial fibrillation patients who underwent AI-guided PWIs following pulmonary vein isolation were included. LA linear lesions were created with strict contiguity (inter-lesion distance < 4 mm) and different predetermined AI target values (Group-1: 430, Group-2: 450). The data was analyzed retrospectively.The total radiofrequency application time of the roof and bottom-line ablation was a median of 2.8 (2.0, 3.8) and 3.6 (2.8, 4.3) minutes. The first-pass PWI success rate (26/35 [74.3%] versus 16/36 [44.4%], P = 0.011) and a first-pass roof line block (28/35 [80.0%] versus 21/36 [58.3%], P = 0.048) were significantly higher in Group-2 than Group-1, but that for the first-pass bottom line block was similar between Group-1 and Group-2 (29/36 [80.6%] versus 29/35 [82.9%], P = 0.80). Successful PWIs were achieved by additional applications in all. The significant parameter associated with a successful first-pass LA roof line block was a greater RF power, and that for the LA bottom were a higher radiofrequency power and shorter inter-lesion distance. Conduction gaps were mostly located at the middle of both lines. Among 22 roof line gaps, 12 were closed on the line whereas 10 (45.4%) required ablation inside the posterior wall for PWIs. On the contrary, all 11 gaps on bottom lines were closed on the line.Successful first-pass PWIs were obtained in 74% of patients using a target AI value of 450 and strict criteria for the lesion contiguity.

Impact of Catheter Ablation for Paroxysmal Atrial Fibrillation in Patients With Sick Sinus Syndrome　- Important Role of Non-Pulmonary Vein Foci.

BACKGROUND: The clinical efficacy of catheter ablation (CA) for paroxysmal atrial fibrillation (PAF) in patients with sick sinus syndrome (SSS) and the mechanism and predictors of recurrence are not yet completely elucidated. METHODS AND RESULTS: Of 963 consecutive patients who underwent PAF ablation during the study period, a total of 108 patients with SSS (SSS group) and 108 matched controls without SSS (non-SSS group) were followed up. During the follow-up period (mean, 32.8±17.5 months), the SSS group had significantly higher AF recurrence rate since the last procedure than the non-SSS group (26.9% vs. 12.0%; P=0.02). The SSS group had significantly higher prevalence of non-pulmonary vein (non-PV) foci than the non-SSS group (25.9% vs. 13.9%; P=0.027). On multivariate analysis congestive heart failure (HR, 13.7; 95% CI: 1.57-119; P=0.02) and non-PV foci (HR, 5.75; 95% CI: 1.69-19.6; P=0.005) were independent predictors of recurrence following CA in the SSS group. In the SSS group, 88 patients had bradycardia-tachycardia syndrome without prior permanent pacemaker implantation. Of these, 6 required pacemaker implantation because of AF and sinus pause recurrence. CONCLUSIONS: Patients with SSS are at higher risk of AF recurrence after CA. Non-PV foci are associated with AF recurrence following PAF with SSS.

Successful intervention for decompensated heart failure with complicated pathophysiologies with complex interdependence: a case report.

Background: There is limited evidence regarding the optimal strategy for treating patients with acute decompensated heart failure complicated by severe left ventricular dysfunction, functional mitral regurgitation (FMR), and atrial septal defect (ASD) that cannot be controlled despite optimal medical treatment. Case summary: A 72-year-old man with non-ischaemic cardiomyopathy presented with acute heart failure and recurrent atrial fibrillation. An electrocardiogram after electrical cardioversion revealed left bundle block with QRS duration of 152 ms. Transthoracic echocardiography revealed severe left ventricular dysfunction, severe FMR, and a left-to-right shunt through an iatrogenic ASD (IASD). Despite initial optimal medical therapy for heart failure, the patient's condition was not completely controlled. After a discussion among the heart team, we performed cardiac resynchronization therapy (CRT) as the next strategy. Two weeks after CRT device implantation, heart failure was controlled, with improvement in cardiac function and FMR. The left-to-right shunts through the IASD also improved. Discussion: When treating decompensated heart failure with complicated pathophysiologies, it is crucial to prioritize the predominant pathophysiological factor and engage in thorough discussions with the heart team regarding the most appropriate intervention.

Clinical Experience of Percutaneous Patent Foramen Ovale Closure Using the Amplatzer PFO Occluder in Japanese Patients to Prevent the Recurrence of Cryptogenic Stroke.

Objective Percutaneous patent foramen ovale (PFO) closure is a procedure widely used to prevent recurrence of cryptogenic stroke. Since December 2019, the Amplatzer PFO occluder device has been available in Japan through medical insurance. However, data on the clinical experience with this device are lacking, as it has been approved for use in only a limited number of institutions. This study assessed the clinical data of Japanese patients who underwent PFO closure using the Amplatzer PFO occluder. Methods Between February and October 2020, 14 patients at our institution underwent percutaneous PFO closure using the Amplatzer PFO occluder. The procedural characteristics, safety, and adverse events were retrospectively analyzed. Results The mean age of the patients was 52.4±13.3 years old, and 57.1% were women. Deep vein thrombosis was revealed in 2 patients, and the risk of paradoxical embolism score was 6.6±1.2 points. The PFO height and tunnel length were 2.3±1.4 mm and 11.5±4.1 mm. All patients had a PFO during the bubble study of grade >3 at the Valsalva maneuver on transthoracic echocardiography or transesophageal echocardiography. The average diameter of the PFO measured using a stiff guidewire and sizing balloon was 5.1±1.3 and 7.9±2.3 mm, respectively. Almost all cases (92.9%) were performed with a 25-mm device and without significant complications within approximately 1 hour. Conclusion Percutaneous closure using Amplatzer PFO occluder is a safe procedure for Japanese patients. However, further investigations with a larger sample and longer follow-up are needed to confirm this result.

Ostial atresia of the coronary sinus in patients with supraventricular arrhythmias.

Of 3577 patients with supraventricular arrhythmias, 3 demonstrated an atresia of the coronary sinus (CS) ostium. Two patients had the accessory pathways. One had atrial fibrillation. No unroofed CS or apparent persistent left superior vena cava was observed. Venous drainage through a small cardiac vein located on the lateral portion of the tricuspid annulus was observed in all patients. Those cases demonstrated that the incidence of ostial atresia of the CS was 0.084%. Accessory pathways were often accompanied by this anomaly. An abnormal venous orifice located on the lateral tricuspid annulus often functioned as the drainage of the CS flow.

Impact of transcatheter aortic valve replacement on hemodynamic status in patients with aortic stenosis and mitral stenosis: Doppler echocardiographic study.

BACKGROUND: Mitral stenosis (MS) is often concomitant with aortic stenosis (AS). However, little is known about the functional status following transcatheter aortic valve replacement (TAVR) alone in patients with severe AS and MS and the impact of TAVR for AS on MS hemodynamics. METHODS: We enrolled 11 patients (age 83.6±4.7 years, eight women) with severe AS and MS who underwent TAVR. We compared New York Heart Association (NYHA) functional class and mean transmitral pressure gradient (MPG), mitral valve area (MVA), and stroke volume (SV) measured by transthoracic Doppler echocardiography between baseline and after TAVR. We also examined the calcification of the mitral annulus and mitral leaflet opening. RESULTS: NYHA functional class improved after TAVR in all 11 patients. As SV increased after TAVR (52±12mL to 63±18mL, p=0.041), MPG decreased and MVA increased (6.9±3.8mmHg to 5.1±2.5mmHg, p=0.011 for MPG and 1.12±0.25cm2 to 1.49±0.43cm2, p=0.035 for MVA). However, MPG increased in one patient in whom calcification extended into the entire anterior mitral leaflet (AML) and AML mobility was severely reduced. CONCLUSIONS: NYHA functional class and hemodynamic status of MS improved after TAVR in patients with severe AS and MS. TAVR might provide therapeutic efficacy for selected symptomatic severe AS patients with MS.

Superiority of novel automated assessment of aortic annulus by intraoperative three-dimensional transesophageal echocardiography in patients with severe aortic stenosis: Comparison with conventional cross-sectional assessment.

BACKGROUND: Previous studies have demonstrated that three-dimensional (3D) transesophageal echocardiography (TEE) is an alternative to multi-detector computed tomography (MDCT) for aortic valve sizing in transcatheter aortic valve replacement (TAVR). However, conventional cross-sectional analysis of aortic annulus by 3D TEE has some limitations such as lengthy analytical time. A novel software for automated valve measurement has been developed for 3D TEE. We evaluated the accuracy and analytical time of aortic annular measurements using this novel automated software in the clinical setting. METHODS: We retrospectively studied 43 patients with symptomatic severe aortic stenosis (AS) who underwent TAVR. All patients underwent intraoperative TEE and MDCT. We measured aortic annular area by automated, semi-automated, and cross-sectional methods using 3D TEE datasets. These measurements were compared to the corresponding MDCT reference values. We also compared the analytical time of the three methods. RESULTS: Automated and semi-automated analyses required significantly shorter analytical time compared to cross-sectional analysis (automated: 30.1±5.79s, semi-automated: 74.1±15.0s, manual: 81.8±18.5s, p<0.05). Compared to MDCT measurement (393.7±81.0mm2), annular areas measured by automated and cross-sectional methods were significantly smaller (automated: 380.6±77.1mm2, cross-sectional: 374.7±76.8mm2, p<0.05), while that obtained by semi-automated method was not significantly different (387.7±75.8mm2). Annular areas determined by semi-automated and cross-sectional analyses had narrower limits of agreement (LOA) with MDCT measurements, compared to automated analysis (automated: -68.6 to 94.7mm2, semi-automated: -48.3 to 60.2mm2, cross-sectional: -40.0 to 77.9mm2). Measurements by all three methods using 3D TEE showed high correlation with MDCT measurement (automated: r=0.86, semi-automated: r=0.94, cross-sectional: r=0.93). CONCLUSIONS: For aortic annular measurements using 3D TEE in AS patients, semi-automated analysis using the novel automated software reduced analytical time while maintaining similar accuracy compared to the conventional cross-sectional analysis. This automated software may have acceptable feasibility in the clinical setting.

Electrogram characteristics of the coronary sinus in cases requiring epicardial ablation within the coronary sinus for creating a conduction block at the left lateral mitral isthmus.

BACKGROUND: Left lateral mitral isthmus (LLMI) linear ablation is a safe and effective technique for treating left mitral flutter. LLMI linear ablation with pulmonary vein isolation may reduce the recurrence of persistent atrial fibrillation. However, epicardial ablation within the coronary sinus (CS) is often required to create the LLMI block line. If the necessity for epicardial ablation is checked before ablation, complications may be reduced. METHODS: We recruited 135 patients who underwent their first LLMI ablation and divided them into two groups, one group not requiring epicardial ablation for creating a conduction block at the LLMI (Endo group) and another requiring it (Epi group). These two groups were compared in terms of the electrogram characteristics of the CS. RESULTS: Bidirectional block through the LLMI was achieved in 94.8% of patients. In 42% of these patients, not only the endocardium but also the epicardium was ablated. As for the electrogram, the Endo group had lower atrium voltage and atrioventricular voltage ratios (p = 0.009) than the Epi group before LLMI ablation. By contrast, there were no significant differences in the atrium voltage and the atrioventricular voltage ratio between these two groups after LLMI ablation. CONCLUSIONS: For creating a conduction block at the LLMI, the atrium voltage and the atrioventricular voltage ratio in the CS before ablation are important. The atrioventricular voltage ratio is a crucial criterion for determining whether epicardial ablation is necessary; furthermore, the atrioventricular voltage ratio in the CS must be reduced with or without epicardial ablation.

Transvenous extraction of advisory implantable cardioverter defibrillator leads with a relatively long implant duration.

BACKGROUND: Optimal management of advisory implantable cardioverter defibrillator (ICD) leads has not been established. Several studies were reported concerning the lead extraction of advisory ICD leads, but the implant duration of those studies was short. We estimated the efficacy of lead extractions of advisory ICD leads with a relatively longer duration in Japanese patients. METHODS: We retrospectively analyzed 28 patients who underwent a lead extraction at Kokura Memorial Hospital and Tokyo Medical and Dental University Hospital [Fidelis (Medtronic, Minneapolis, MN, USA): n=19, Riata (St. Jude Medical, Sylmar, CA, USA): n=8, Isoline (SORIN CRM SAS, Clamart, France): n=1]. The mean implant duration was 63.3±19.3 months. The indications were device related infections in 3, electrical lead failures in 18, electrical lead failures and venous obstructions in 3, and prophylactic reasons in 4 patients. Inappropriate shocks because of electrical lead failures were observed in 9 patients. RESULTS: Complete removals were achieved of all 28 advisory leads. In 23 out of 28 patients, new ICD leads were implanted during the same procedure. In one patient, open chest surgery was performed for a hemothorax that occurred during a new ICD lead implantation just after successfully removing the advisory ICD lead. There were no other major or minor complications. CONCLUSION: Transvenous extractions of advisory ICD leads with relatively long implant duration were performed with a high success rate and low complication and mortality rate in Japanese patients.

Identification of causative organism in cardiac implantable electronic device infections.

BACKGROUND: The causative organism in cardiovascular implantable electronic device (CIED) infection is usually diagnosed with the cultures from blood, removed leads, and/or infected pocket material. The cultured organism, however, is sometimes different among these samples. METHODS: Two hundred sixty patients with CIED infection, who underwent lead extraction between April 2005 and December 2014, were analyzed. More than two blood culture sets, all the extracted leads, and swab culture of the pocket were sent to the laboratory for culture. Among the patients all of whose microbiological examinations were available, we analyzed the causative organism defined as the species detected in at least two different sites. RESULTS: All the culture results were available in the 208 patients, showing 69 systemic infections (including 30 cases of infectious endocarditis) and 139 local infections. Blood culture, lead culture, and swab culture were positive in 57 (27%), 169 (81%), and 152 (73%), respectively. Staphylococcus aureus [37% including methicillin-resistant S. aureus (MRSA) (12%)] and coagulase-negative staphylococci (CoNS, 36%) were the most common causative organism, followed by non-staphylococci (23%), and poly-microbial infection (4%). The detection of S. aureus from pocket or removed leads rendered higher predictive value of a causative organism than that of CoNS. The detection of Gram-negative bacteria, fungi, and mycobacteria indicated that it was most likely a causative organism. Gram-positive bacteria excluding Staphylococcus, such as Corynebacterium spp., tended to coexist as a benign organism. CONCLUSIONS: The causative organism is mostly S. aureus and CoNS. Detection of S. aureus or Gram-negative bacteria means that it is more likely a causative organism.

Mortality and predictors of appropriate implantable cardioverter defibrillator therapy in Japanese patients with Multicenter Automatic Defibrillator Implantation Trial II criteria.

BACKGROUND: Data regarding long-term mortality and factors influencing appropriate therapies in Japanese patients with implantable cardioverter defibrillators (ICD), who satisfy the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) criteria for primary prevention, remain scarce. METHODS: A total of 118 consecutive patients who underwent ICD implantation without any prior ventricular arrhythmic event, from January 2000 to December 2012, were enrolled based on the MADIT II criteria: left ventricular ejection fraction (LVEF) of ≤30% with ischemic heart disease and at least 4 weeks after a myocardial infarction. We investigated the mortality and factors influencing appropriate ICD therapies in this population. RESULTS: The mean age was 69±10 years, and the mean LVEF was 25.1±4.5%. During the median follow up of 1406 days, the mortality rate was 20%, and the incidence of appropriate ICD therapy was 37% at 3 years. Multivariate analysis by using Cox regression model showed that left ventricular diastolic diameter ≥60 mm (hazard ratio [HR], 2.31; 95% confidence interval [CI], 1.07-5.38; P=0.033) and the presence of non-sustained ventricular tachycardia (NSVT) before implantation (HR, 2.26; 95% CI, 1.17-4.39; P=0.015) were independent predictors of appropriate ICD therapy. CONCLUSIONS: The mortality and incidence of appropriate ICD therapy were 20% and 37%, respectively, at 3 years in Japanese patients who met the MADIT II criteria during ICD implantation for primary prevention of sudden cardiac death. The presence of NSVT and dilated left ventricle independently predicted the incidence of appropriate ICD therapy after implantation.

Impact of catheter ablation of ventricular tachycardia in patients with prior myocardial infarctions.

BACKGROUND: Catheter ablation can reduce episodes of ventricular tachycardia (VT) after myocardial infarction (MI). However, the optimal endpoint of the ablation procedure remains unclear. METHODS: Fifty-one consecutive patients who received catheter ablation for VT after MI were included. The procedures targeted the isthmus of all the induced, sustained VTs. When the patients with induced VTs were hemodynamically stable, radiofrequency energy was delivered at the mid-diastolic potential recording site during VT. When the patients with VTs were hemodynamically unstable, the critical channel was identified at the delayed potential recording site, showing a good pace map, with a long stimulus-QRS interval. We delivered radiofrequency energy along the identified isthmus and across the exit of the circuit. RESULTS: At the end of the procedure, all VTs became non-inducible in 30 patients (59%) and some VTs were inducible in 21 patients (41%). During a mean of 40±29 months of follow-up, no VT or ventricular fibrillation recurred in 24 patients (80%) in the non-inducible group and in 12 patients (57%) in the inducible group, respectively (P=0.03). The identification of the channel during VT mapping tended to associate with no recurrence, although the difference was not statistically significant (P=0.2). Fourteen patients (27%) died during the follow-up period, mostly due to non-cardiac causes. CONCLUSIONS: The catheter ablation targeting the isthmus of prior-MIVT and non-inducibility at the end of the procedure can provide a satisfactory follow-up result.

Lead extractions in patients with cardiac implantable electronic device infections: Single center experience.

BACKGROUND: Lead extraction using laser sheaths is performed mainly for cardiac implantable electronic device (CIED) infections. However, there are few reports concerning the management of CIED infections in Japan. METHODS AND RESULTS: Lead extraction procedures were performed in 183 patients targeting 450 leads (atrial leads: 170, ventricular: 181, implantable cardioverter-defibrillators (ICDs): 79, and coronary sinus: 20). One hundred twenty patients (65.6%) presented with pocket infections without the presentation of an endovascular infection. Blood cultures were positive at least once in 63 patients (34.4%). Complete procedure success was achieved for 437 leads (97.1%) while partial removal occurred in nine, and failure in four leads. Major complications directly related to the procedure occurred in five patients (2.7%). Two of the four patients with a cardiac tamponade required a surgical repair. All patients received intravenous antibiotics, at least, one week after the procedure. Pocket or systemic infections were successfully controlled in 181 patients (98.9%). Coagulase-negative staphylococci (30.1%) and Staphylococcus aureus (37.1%) were the most common causes of CIED infections. CONCLUSION: The current status of CIED infections in Japan seems to be similar to that previously reported from foreign countries. The optimal treatment of CIED infections involves the complete explantation of all hardware, followed by antibiotic therapy.

Importance of nonpulmonary vein foci in catheter ablation for paroxysmal atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation is an established treatment strategy for paroxysmal atrial fibrillation (PAF). However, the recurrence rate of PAF is 8% to 37%, despite repeated procedures, and the catheter ablation strategy for PAF with non-PV foci is unclear. OBJECTIVE: The purpose of this study was to assess the PAF ablation strategy for non-PV foci. METHODS: The study included 304 consecutive patients undergoing PAF ablation (209 males, age 63.0 ± 10.4 years) divided into 3 groups: group 1 (245 patients) with no inducible non-PV foci; group 2 (34 patients) with atrial fibrillation (AF) originating from non-PV foci and all the foci successfully ablated; and group 3 (25 patients) with AF originating from non-PV triggers, but without all foci being ablated or with persistently inducible AF. RESULTS: Mean follow-up period was 26.9 ± 11.8 months, and AF recurrence rates since the last procedure were 9.8%, 8.8%, and 68.0% in groups 1, 2, and 3, respectively. There was no statistically significant difference in recurrence rate between groups 1 and 2 (P = .89); however, there were statistically significant differences between groups 3 and 1 (P <.0001) and groups 3 and 2 (P <.0001). The patients in group 2 had an AF-free outcome to equivalent to those who had PV foci in group 1 (P = .83). CONCLUSION: Success rates can be improved for PAF ablation if non-PV foci are detected and eliminated.

Long-term outcomes of catheter ablation of ventricular tachycardia in patients with structural heart disease.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long-term outcomes for different underlying diseases have not been well defined. METHODS: Eighty-eight consecutive patients who underwent catheter ablation of VT using a three-dimensional mapping system were analyzed. The primary endpoint was any VT or ventricular fibrillation (VF) recurrence. Secondary endpoints were a composite of death or any VT/VF recurrence. Underlying heart diseases were remote myocardial infarction (remote MI) in 51 patients and non-ischemic cardiomyopathy in 37 (arrhythmogenic right ventricular cardiomyopathy [ARVC] in 18 patients, and dilated cardiomyopathy [NIDCM] in 19). RESULTS: Acute success was achieved in 82 of 88 (93%) patients. During a follow-up period of 39.2±4.6 months, VT recurred in 26 of 87 (30%), and VT/VF recurrence or death occurred in 39 of 87 (45%) patients. ARVC had better outcomes than NIDCM for the primary (p<0.05) and secondary endpoints (p<0.05). Remote MI-VT revealed a midrange outcome. CONCLUSIONS: The long-term outcomes after catheter ablation of VT varied according to the underlying heart disease. ARVC-VT ablation was associated with better long-term prognosis than NIDCM. Remote MI-VT demonstrated a midrange outcome.

Ventricular tachycardia originating from a heart-shaped idiopathic left ventricular aneurysm diagnosed on a three-dimensional electroanatomical mapping system integrated with CT imaging.

Idiopathic left ventricular aneurysms and diverticula (LVA/Ds) are rare cardiac malformations that can be detected using certain imaging techniques. Although most patients with these malformations are clinically asymptomatic, some patients exhibit cardiac arrhythmias and other clinical manifestations. In electrophysiological studies, it is often difficult to establish the relationship between clinical manifestations of cardiac arrhythmias and those of LVA/Ds due to anatomical complexities. We herein report the case of a 67-year-old man who was successfully diagnosed with ventricular tachycardia originating from an idiopathic LVA that was clearly demonstrated on a three-dimensional electroanatomical mapping system integrated with CT imaging.