Novel simultaneous mapping technique to treat multifocal atrial tachycardia.

Although a high-resolution three-dimensional mapping system has made it possible to treat complicated atrial tachyarrhythmia (AT), there remain cases that are difficult to diagnose and treat. However, when multiple different ATs alternately appear, mapping and diagnosis of those are more difficult. Parallel mapping module is well known as a good option to simultaneously map two or more different ATs when they alternately appear. When performing parallel mapping of two different ATs, one bipolar signal of the reference catheter is used as a timing reference and a cycle length filter is used for differentiating AT1, AT2, and others, including sinus rhythm, fusion beats, or catheter-induced premature atrial complex. Therefore, it has some limitations for differentiating multifocal ATs. We present a case wherein multifocal ATs were successfully eliminated by combining parallel mapping module and dual-chamber intra-cardiac pattern matching technique that we have previously reported. Learning objective: ▪Parallel mapping is a useful tool when two or more tachycardias alternately occur; however, it has some limitations.▪Dual-chamber intra-cardiac pattern matching technique, which combines right atrial and coronary sinus potentials, provides better discrimination than coronary sinus reference alone.▪By combining parallel mapping and dual-chamber intra-cardiac pattern matching, two or more atrial tachycardias could be automatically and simultaneously mapped.

The effect of ablation settings on lesion characteristics with DiamondTemp ablation system: An ex vivo experiment.

Introduction: Creating large lesion in ablations using the DiamondTemp (DTA) ablation system may reduce the frequency of arrhythmia recurrence and allow the treatment of ventricular arrhythmias. Therefore, this study aimed to investigate whether power, application time, contact force (CF), and contact angle affect lesion formation in the ventricles. Methods: Ablations were delivered to porcine myocardial preps to evaluate the lesion characteristics. Ablations were conducted with a maximum power of 50 W, target temperature of 58°C, CF of 10, 20, or 30 g, and contact angle between the catheter tip and tissue. The ablation durations were 15, 30, 60 s, 15 s × 2, or 30 s × 2. Results: Steam pops occurred only in cases with perpendicular contact. The lesion depth was larger in all settings in the perpendicular orientation than in the parallel orientation. The temperatures were lower in all settings in the perpendicular orientation than in the parallel orientation. The lesions became larger as CF increased with perpendicular contact and duration of ≥30 s. The longer application time resulted in larger surface area, depth, and volume of the lesion. Lesion depth was greater with single application of 30 and 60 s than with 15 s × 2 and 30 s × 2, respectively. Conclusion: It is important to perform a single prolonged application as much as possible to create deeper lesions. Parallel contact with the tissue should be maintained to take advantage of the temperature sensor's capabilities to avoid pop phenomenon.

Optimal treatment of biatrial tachycardia diagnosed by one-chamber mapping within an ultrahigh-resolution mapping system.

Biatrial tachycardia (BiAT) is a rare arrhythmia, and identification of the re-entry circuit is often complicated. By creating an activation map of the right atrium, left atrium, and coronary sinus as a single chamber, the LUMIPOINT module of the Rhythmia mapping system (Boston Scientific, Marlborough, MA, USA) can be used in real time to make an accurate diagnosis. Ablation of the Bachmann bundle is a feasible way to terminate BiAT, but might cause interatrial conduction delay and electrical isolation of the left atrial appendage. Chemical ablation into the vein of Marshall might be the more beneficial treatment, avoiding any potential interatrial conduction delay.

Detection of left coronary ostial obstruction during transcatheter aortic valve replacement by coronary flow velocity measurement in the left main trunk by intraoperative transesophageal echocardiography.

BACKGROUND: Coronary obstruction is a rare but catastrophic complication of transcatheter aortic valve replacement (TAVR) and occurs mostly at the left coronary artery (LCA) ostium. However, some patients do not show any clinical findings, and thus, its detection is sometimes difficult. The peak diastolic flow velocity in left main coronary artery (LM) was reportedly increased in significant stenosis lesions. We evaluated the effectiveness of measuring blood flow velocities in LM by transesophageal echocardiography (TEE) for the detection of LCA ostial obstruction during a TAVR procedure. METHODS: A total of 1105 consecutive patients who underwent TAVR in Sendai Kousei Hospital between September 2014 and December 2020 were enrolled. The LM blood flow velocity was measured at pre- and post-valve implantation. RESULTS: Among the 1105 patients, 9 had LCA ostial obstruction. The peak LM blood flow velocity at post-TAVR [0.90 (0.39-1.15) vs. 0.37 (0.28-0.50) m/s; p = 0.0046) was significantly higher in 9 patients who had LCA ostial obstruction, compared with the remaining 1096 patients who had not (controls), although no significant difference was observed before the TAVR procedures between the two groups. The post- to pre-TAVR LM flow velocity ratio [2.26 (1.31-3.42) vs. 1.06 (0.82-1.36); p = 0.0030] was also significantly higher in patients with LCA obstruction, compared to the controls. Furthermore, the post- to pre-TAVR LM blood flow velocity ratio was >2.0 in all six hemodynamically stable patients with LCA obstruction, whereas <2.0 in all three patients with LCA obstruction who showed hemodynamic collapse at post-TAVR procedure. CONCLUSION: Coronary blood flow velocity in LM significantly increased in hemodynamically stable LCA obstruction patients. The intraprocedural TEE measurement of the LM flow velocities would be potentially useful to detect asymptomatic and hemodynamically stable LCA ostial obstruction.

Delivery balloon volume positively correlates with the diameter and effective orifice area of implanted SAPIEN 3.

BACKGROUND: In transcatheter aortic valve replacement (TAVR) using SAPIEN 3 (S3) (Edwards Lifesciences, Irvine, CA, USA), some clinicians decrease or increase the delivery balloon volume (VOL) when deploying S3 or conducting post-dilatation. However, the effects of controlling VOL on transcatheter heart valve diameter (THVD) and valve function remain unclear. We assessed associations among VOL, THVD, and effective orifice area (EOA) of S3. METHODS: We enrolled patients undergoing TAVR using 23- and 26-mm S3 in Sendai Kousei Hospital between 2017 and 2019. VOL was controlled based on preprocedural computed tomography and intraprocedural transesophageal echocardiography (TEE). THVD were defined as the diameters of transcatheter heart valve at mid-level measured by TEE. RESULTS: In enrolled 332 patients (23-mm, n = 188; 26-mm, n = 144), one (0.3%) and two (0.6%) developed annulus rupture and moderate/severe paravalvular leak, respectively. VOL at deployment was positively correlated with THVD on deployment (23-mm, r = 0.44, p < 0.001; 26-mm, r = 0.57, p < 0.001) and EOA (23-mm, r = 0.23, p = 0.0019; 26-mm, r = 0.22, p = 0.0094). In multiple regression analyses, VOL and post-dilatation were significant determinants of THVD, although aortic annulus area, calcium volume, and pre-dilatation were not. The areas under the receiver operating characteristic curve that were used to evaluate the accuracy of the index obtained by dividing THVD by body surface area (indexed THVD) to predict patient-prosthesis mismatch (PPM) were 0.744 and 0.811 in the 23- and 26-mm cohorts, respectively. A cut-off indexed THVD of ≤11.5 and 12.1 mm/m2 well predicted PPM (23-mm, odds ratio, 5.20; 95% confidence interval, 1.33-20.3; 26-mm, odds ratio 14.1, 95% confidence interval 2.40-81.0). CONCLUSION: VOL was positively correlated with THVD and EOA. Smaller indexed THVD was associated with a higher incidence of PPM. Controlling VOL under on-site THVD evaluation may be useful in reducing the PPM incidence.

En face view of the transcatheter heart valve from deep right-anterior-oblique cranial position for coronary access after transcatheter aortic valve implantation: a case series.

BACKGROUND: Coronary access after transcatheter aortic valve implantation (TAVI) is challenging due to the changes in aortic geometry. The perpendicular (long-axis) view of the transcatheter heart valve (THV) is usually used as the primary fluoroscopic angle. However, it does not always provide sufficient information on the rotational axis needed for selective coronary ostia engagement. The en face (short-axis) view from the deep right-anterior-oblique cranial position gives us additional information about three-dimensional spatial relationship of the THV and coronary ostia. CASE SUMMARY: We present three cases of coronary access after TAVI. We were successful in the use of the 'en face' view along with the perpendicular view in these cases. DISCUSSION: The use of the en face view complements that of the perpendicular long-axis view since it allows the understanding of the three-dimensional spatial relationship of the THV and the coronary ostia during fluoroscopy and control of catheter manipulation in two directions (up/down for perpendicular and clockwise/counterclockwise for en face view). We believe that the en face view helps improve the technical success of coronary access after TAVI.

Selective Enumeration of Bifidobacterium bifidum , Enterococcus faecium , and Streptomycin-Resistant Lactobacillus acidophilus from a Mixed Probiotic Product.

Modified VF-Bouillon agar with 0.5 mg/ml lithium chloride, 20 µg/ml sodium lauryl sulfate, 5 mg/ml sodium propionate, and 10 µg/ml neomycin sulfate was used with a triple-layer diffusion technique to selectively enumerate Bifidobacterium bifidum . Modified Brigg's agar was used to enumerate Enterococcus faecium . Modified Brigg's agar with 1,200 µg/ml streptomycin sulfate was used in a double-layer diffusion technique to selectively enumerate a streptomycin-resistant strain of Lactobacillus acidophilus . Selective enumeration of the individual bacterial components was compared to the mixture with an average 99% recovery of each component.