Outcomes of Aortomitral Continuity Reconstruction During Concomitant Aortic and Mitral Valve Replacement.

OBJECTIVES: To describe outcomes of reconstruction of the aortomitral continuity (AMC) during concomitant aortic and mitral valve replacement (ie, the "Commando" procedure). DESIGN: A retrospective study of consecutive cardiac surgeries from 2010 to 2022. SETTING: At a single institution. PARTICIPANTS: All patients undergoing double aortic and mitral valve replacement. INTERVENTIONS: Patients were dichotomized by the performance (or not) of AMC reconstruction. MEASUREMENTS AND MAIN RESULTS: A total of 331 patients underwent double-valve replacement, of whom 21 patients (6.3%) had a Commando procedure. The Commando group was more likely to have had a previous aortic valve replacement (AVR) or mitral valve replacement (MVR) (66.7% v 27.4%, p < 0.001), redo cardiac surgery (71.4% v 31.3%, p < 0.001), and emergent/salvage surgery (14.3% v 1.61%, p = 0.001), whereas surgery was more often performed for endocarditis in the Commando group (52.4% v 22.9%, p = 0.003). The Commando group had higher operative mortality (28.6% v 10.7%, p = 0.014), more prolonged ventilation (61.9% v 31.9%, p = 0.005), longer cardiopulmonary bypass time (312 ± 118 v 218 ± 85 minutes, p < 0.001), and longer ischemic time (252 ± 90 v 176 ± 66 minutes, p < 0.001). Despite increased short-term morbidity in the Commando group, Kaplan-Meier survival estimation showed no difference in long-term survival between each group (p = 0.386, log-rank). On multivariate Cox analysis, the Commando procedure was not associated with an increased hazard of death, compared to MVR + AVR (hazard ratio 1.29, 95% CI: 0.65-2.59, p = 0.496). CONCLUSIONS: Although short-term postoperative morbidity and mortality were found to be higher for patients undergoing the Commando procedure, AMC reconstruction may be equally durable in the long term.

Left-sided accessory pathways successfully ablated from the aortomitral continuity region: distinctive atrial activation patterns and anatomic concerns.

AIMS: Accessory pathways (APs) successfully ablated at the aortomitral continuity (AMC) were sporadically reported but relevant data are very limited. We aimed to describe the electrophysiological characteristics of AMC-AP and the related anatomy. METHODS AND RESULTS: This study involved eight (male/female = 3/5, mean age 42.6 ± 10.5 years) patients with left-sided AP successfully ablated in the AMC region. The retrograde atrial activation sequence was analysed and compared via recordings at the His-bundle (HB), coronary sinus (CS), and roving catheter during tachycardia, and the peak of QRS from the same cardiac circle used as time reference. Of the eight patients, two received prior ablations. During tachycardia, the activation time at the proximal CS (CSp), lateral CS (CSl), and HB region averaged 120 ± 26 ms, 124 ± 29 ms, and 117 ± 21 ms following the reference, respectively (P = 0.86). The latest atrial activation was recorded in the posterior CS which averaged 135 ± 25 ms following the reference. Placing the ablation catheter to AMC via retrograde approach was attempted in all cases but stable positioning achieved in none. Via transseptal approach, the ablation catheter could be easily placed at the AMC and recorded the earliest retrograde atrial activations with 60 ± 27 ms earlier than the relatively 'earliest' CS/HB recordings, and ablation at this site successfully eliminated AP conduction. No patients had recovered AP conduction after at least 12-month follow-up. CONCLUSION: AMC-AP is featured by recording comparable retrograde atrial activation times at CSp, CSl, and HB with the latest recordings at the posterior CS. Stable placement and successful ablation in the AMC via retrograde aortic approach was difficult but can be achieved via transseptal approach.

Clinical cardiac structural anatomy reconstructed within the cardiac contour using multidetector-row computed tomography: Left ventricular outflow tract.

The left ventricular outflow tract (LVOT) is a common site of idiopathic ventricular arrhythmia. Many electrocardiographic characteristics for predicting the origin of arrhythmia have been reported, and their prediction rates are clinically acceptable. Because these approaches are inductive, based on QRS-wave morphology during the arrhythmia and endocardial or epicardial pacing, three-dimensional anatomical accuracy in identifying the exact site of the catheter position is essential. However, fluoroscopic recognition and definition of the anatomy around the LVOT can vary among operators, and three-dimensional anatomical recognition within the cardiac contour is difficult because of the morphological complexity of the LVOT. Detailed knowledge about the three-dimensional fluoroscopic cardiac structural anatomy could help to reduce the need for contrast medium injection and radiation exposure, and to perform safe interventions. In this article, we present a series of structural images of the LVOT reconstructed in combination with the cardiac contour using multidetector-row computed tomography. We also discuss the clinical implications of these findings based on the accumulated insights of research pioneers.

Electrophysiologic characteristics of ventricular arrhythmias arising from the aortic mitral continuity-potential role of the conduction system.

INTRODUCTION: Catheter ablation of ventricular arrhythmia (VA) at the fibrous aortic mitral continuity (AMC) has been described, yet the nature of the arrhythmogenic substrate remains unknown. METHODS: Procedural records of 528 consecutive patients undergoing ablation of VA at Mayo Clinic, Rochester, MN, were reviewed. The electrocardiographic and electrophysiologic characteristics of patients with successful ablation at the AMC were analyzed to characterize the underlying arrhythmogenic substrate. RESULTS: Of the 21 patients (mean age 53.2 ± 13.4 years, 47.6% male) who underwent ablation of VA at the AMC with acute success, prepotentials (PPs) were found at the ablation sites preceding the ventricular electrogram (VEGM) during arrhythmias in 13 (61.9%) patients and during sinus rhythm in 7 (53.8%) patients. VAs with PPs were associated with a significantly higher burden of premature ventricular complexes (PVCs; 26.1 ± 10.9% vs. 14.9 ± 10.1%, P = 0.03), shorter VEGM to QRS intervals (9.0 ± 28.5 milliseconds vs. 33.1 ± 8.8 milliseconds, P = 0.03), lower pace map scores (8.7 ± 1.6 vs. 11.4 ± 0.8, P = 0.001), and a trend toward shorter V-H intervals during VA (32.1 ± 38.6 milliseconds vs. 76.3 ± 11.1 milliseconds, P = 0.06) as compared to those without PP. A strong and positive correlation was found between V-H interval and QRS duration during arrhythmia in those with PPs (B = 2.11, R(2) = 0.97, t = 13.7, P < 0.001) but not in those without PPs. CONCLUSION: Local EGM characteristics and relative activation time of the His bundle suggest the possibility of conduction tissue as the origin for VA arising from the fibrous AMC. Specific identification and targeting of PPs when ablating VAs at this location may improve procedural success.

Surgical Outcomes After Reconstruction of the Aortomitral Curtain.

Repair of concomitant aortic and mitral valvular disease with involvement of the aortomitral curtain requires a technically complex operation colloquially termed the commando procedure. Surgical outcomes of this procedure are not well described. The objective of this study was to examine outcomes of the commando procedure at our center. We identified all patients undergoing concomitant aortic and mitral valve replacements from 2004-2021. Of 363 patients, 41 underwent reconstruction of the aortomitral curtain. Survival analysis and multivariable modeling were used to examine outcomes and risk factors for mortality. The median age was 52 (IQR 44-71) years. Preoperatively, 4 of 41 (9.8%) patients had renal failure, and 10 of 41 (24.4%) had a stroke. The most common surgical indication was endocarditis in 25 of 41 (61.0%) patients. 25 of 41 (61.0%) patients underwent redo sternotomy, and 23 of 41 (56.1%) had previous prosthetic valves. Operative mortality was 14 of 41 (34.1%), and 8 of 41 (9.5%) patients received a permanent pacemaker. Survival at 1, 3, and 5 years was 55.4% (95% confidence interval (CI), 40.6-75.5%), 50.3% (35.0-72.3%), and 37.7% (19.3-73.9%) respectively. Cox proportional hazards regression identified previous sternotomy (HR 4.76, 95% CI 1.21-18.73), and female gender (HR 1.39, 95% CI 1.17-13.82) as risk factors for mortality. Patients undergoing reconstruction of the aortomitral curtain represent a high-risk population with complex surgical indications. Due to high perioperative morbidity and mortality, this procedure should be performed only when necessary. Despite a high up front morbidity burden, outcomes remain favorable for patients who survive the initial hospitalization.

[Anatomy of the left ventricle for endocardial ablation]. / Anatomie des linken Ventrikels als Grundlage für endokardiale Ablationen.

As with all cardiac interventions, performing left ventricular ablation requires profound knowledge of cardiac anatomy. The aim of this article is to provide an overview of left ventricular anatomy and to characterize complex and clinically relevant structures from an electrophysiologist-centered perspective. In addition to the different access routes, the trabecular network, the left ventricular outflow tract, and the left ventricular conduction system, complex anatomical structures such as the aortomitral continuity and the left ventricular summit are also explained. In addition, this article offers multiple clinical examples that combine ECG, anatomy, and electrophysiologic study.

Electrophysiological properties and involvement of anatomical factors for the prediction of intramural origin in patients with ventricular tachyarrhythmia arising from the left ventricular outflow tract.

PURPOSE: To elucidate the electrophysiological predictors of the intramural origins of left ventricular outflow tract-ventricular tachyarrhythmias (LVOT-VAs), and to clarify the involvement of anatomical factors. METHODS: Twenty-nine successfully ablated LVOT-VAs patients with origins in the aortomitral continuity (AMC) (n = 8), aortic sinus of valsalva (ASV) (n = 9), great cardiac vein (GCV) (n = 5), and intramural myocardium (n = 7) were enrolled. Intramural origins were defined as when effective ablation from AMC and epicardium (ASV and/or GCV) was needed. The local activation time difference (LATD) was calculated as follows: (earliest AMC activation) - (earliest epicardial activation), and was presented as an absolute value. Electrophysiological parameters and anatomical factors predisposing the intramural origins were investigated. RESULTS: LATD of intramural origins was significantly shorter than that of AMC and GCV (4.5 ± 2.6 vs. 12.1 ± 7.4 vs. 17.4 ± 4.7, P < 0.05), respectively. In multivariate logistic regression analysis, LATD was associated with intramural origins (odds ratio: 0.711, confidence interval: 0.514-0.985, P = 0.040). ROC analysis revealed LATD of 7 ms as cut-off value. In computed tomography analysis, some patients who had thick fat tissue below the GCV, and an unusual GCV running pattern might be misdiagnosed as intramural origins. CONCLUSION: LATD ≤ 7 ms was associated with intramural origins, but with some anatomical limitations.

Importance of Polarity Reversal in Leads I/aVL in the Diagnosis of an Accessory Pathway Originating from the Aortomitral Continuity.

Accessory pathways (APs) are commonly located around the tricuspid and mitral annulus; however, they can be rarely seen in unusual locations like the aortomitral continuity (AMC), the right atrium to the right ventricular outflow region, and the left atrial appendage to left ventricle connection. Although several electrocardiogram algorithms have been proposed to localize the AP, the sensitivity of these algorithms is not high and they may fail to localize the mentioned unusual localizations. In this report, we describe a case of a 37-year-old man presenting with an AP originating from the AMC, which was successfully ablated.

Should the Aortic Root Be the Preferred Route for Ablation of Focal Atrial Tachycardia Around the AV Node?: Support From Intracardiac Echocardiography.

OBJECTIVES: The purpose of this study was to determine the optimal approach to focal atrial tachycardia originating from around the atrioventricular node. BACKGROUND: Focal atrial tachycardia (FAT) demonstrating earliest activation around the atrioventricular (AV) node during right atrial (RA) mapping has been eliminated by ablation at the RA para-Hisian region, from the left atrium (LA) or the noncoronary aortic cusp (NCC). However the optimal approach has not been determined. METHODS: We conducted a retrospective analysis of a consecutive series of 148 patients undergoing catheter ablation for FAT between 2006 and 2014 in our institution. RESULTS: Earliest activation was recorded in the peri-AV nodal region during RA mapping in 34 patients (23%). Of these, 7 patients (20.5%) had successful ablation at the RA septum, using either radiofrequency (n = 4) or cryoenergy (n = 3). Seven FATs (20.5%) were ablated from the LA at the region of the aortomitral continuity, and 20 patients (59%) had successful ablation in the NCC, including 1 patient with a recurrence after a temporarily successful cryoablation from the RA. The proportion of the 3 approaches in this series showed a significant temporal evolution and overall frequency favoring ablation in the NCC (p = 0.011 for time trend and 0.013 for actual vs. expected frequencies). Intracardiac echocardiography proved superior catheter stability with the NCC approach. There were 2 cases of atrioventricular block and 1 recurrence after RA ablation versus no complications or recurrent FAT with NCC and LA approaches. CONCLUSIONS: Most peri-AV nodal FATs can be safely and effectively ablated from the NCC. The strategy of preferential NCC approach avoids RA para-Hisian ablation with the accompanying risk of AV block.

Demonstration of a hidden interaction between the aortomitral continuity and the conduction system in a case of idiopathic left ventricular outflow tract ventricular tachycardia.

We describe a case of idiopathic left ventricular outflow ventricular tachycardia. Monomorphic ventricular arrhythmia (VA) with a right bundle branch block morphology and an inferior axis was induced through exercise or isoproterenol infusion. During VA bigeminy, a spiked presystolic potential (PP) preceding the VA with a qrS pattern in the unipolar electrogram was recorded at the aortomitral continuity (AMC). Radiofrequency catheter ablation eliminated the VA despite the persistence of sinus-PP bigeminy. Furthermore, these PP rates were dependent on the preceding sinus rhythm rates. The present case suggests a hidden interaction between the AMC and the conduction system.