A review on atrioventricular junction ablation and pacing for heart rate control of atrial fibrillation

Radiofrequency ablation alters the microstructural organization of healthy and enzymatically digested porcine mitral valves

BACKGROUND

Myxomatous mitral valve degeneration is a common cause of mitral regurgitation and is often associated with mitral valve prolapse. With no known targets to pharmacologically treat mitral valve prolapse, surgery is often the only treatment option. Recently, radiofrequency ablation has been proposed as a percutaneous alternative to surgical resection for the reduction of mitral valve leaflet area.

OBJECTIVE

Using an in vitro model of porcine mitral valve anterior leaflet enlargement following enzymatic digestion, we sought to investigate mechanisms by which radiofrequency ablation alters the geometry, microstructural organization, and mechanical properties of healthy and digested leaflets.

METHODS

Paired measurements before and after ablation revealed the impact of radiofrequency ablation on leaflet properties. Multiphoton imaging was used to characterize changes in the structure and organization of the valvular extracellular matrix; planar biaxial mechanical testing and constitutive modeling were used to estimate mechanical properties of healthy and digested leaflets.

RESULTS

Enzymatic digestion increased leaflet area and thickness to a similar extent as clinical mitral valve disease. Radiofrequency ablation altered extracellular matrix alignment and reduced the area of digested leaflets to that of control. Additionally, enzymatic digestion resulted in fiber alignment and reorientation toward the radial direction, causing increased forces during ablation and a structural stiffening which was improved by radiofrequency ablation.

CONCLUSION

Radiofrequency ablation induces radial extracellular matrix alignment and effectively reduces the area of enlarged mitral valve leaflets. Hence, this technique may be a therapeutic approach for myxomatous mitral valve disease and is thus an avenue for future study.

Acute and long-term outcomes of left-sided atrioventricular node ablation in patients with atrial fibrillation

PURPOSE

To present our experience regarding acute and long-term outcomes of left-sided atrioventricular node (AVN) ablation in patients with atrial fibrillation (AF).

METHODS

A total of 47 patients with AF in whom left-sided AVN ablation via retroaortic approach as a first-line approach were enrolled in this retrospective study. Indications for AVN ablation were high ventricular rate refractory to medical therapy, inappropriate implantable cardioverter defibrillator (ICD) shocks, or loss of cardiac resynchronization therapy (CRT) pacing. Both acute and long-term outcomes were assessed for all participants.

RESULTS

Left-sided AVN ablation was successfully performed in 46/47 (98%) patients without any procedural complication. In the remaining 1 patient (2%), right-sided AVN ablation was performed. No mortality was observed within 30 days of the procedure. Upgrade to CRT was performed in 9 (19%) of the patients. During the median 22.5 months of follow-up, all-cause mortality was 25%. Device interrogations on the last clinical visit revealed complete AV block and intrinsic ventricular rate of < 40 bpm in all patients.

CONCLUSION

Left-sided AVN ablation is a safe and effective procedure without recurrence during long-term follow-up.

Outcomes and Resource Utilization Associated With Readmissions After Atrial Fibrillation Hospitalizations

Background

Atrial fibrillation is the most common arrhythmia worldwide. Data regarding 30‐day readmission rates after discharge for atrial fibrillation remain poorly reported.

Methods and Results

The Nationwide Readmission Database (2010–2014) was queried using the International Classification of Diseases, Ninth Revision (ICD‐9) codes to identify study population. Incidence, etiologies of 30‐day readmission and predictors of 30‐day readmissions, and cost of care were analyzed. Among 1 723 378 patients who survived to discharge, 249 343 (14.4%) patients were readmitted within 30 days. Compared with the readmitted group, the nonreadmitted group had higher utilization of electrical cardioversion and catheter ablation. Atrial fibrillation was the most common cause of readmission (24.1%). Median time to 30‐day readmission was 13 days. Advancing age, female sex, and longer stay during index hospitalization predicted higher 30‐day readmissions, whereas private insurance, electrical cardioversion, catheter ablation, higher income, and elective admissions correlated with lower 30‐day readmission. Comorbidities such as heart failure, neurological disorder, chronic obstructive pulmonary disease, diabetes mellitus, chronic kidney disease, chronic liver failure, coagulopathy, anemia, peripheral vascular disease, and electrolyte disturbance, correlated with increased 30‐day readmissions and cost burden. Trend analysis showed a progressive decline in 30‐day readmission rates from 14.7% in 2010 to 14.3% in 2014 (P trend, <0.001).

Conclusions

Approximately 1 in 7 patients were readmitted within 30 days of discharge, with symptomatic atrial fibrillation being the most common cause. We identified a predictive model for increased risk of readmissions and treatment expense. Electrical cardioversion during index admission was associated with a significant reduction in 30‐day readmissions and service charges. The 30‐day readmissions correlated with a substantial rise in the cost of care.

Revisiting Atrioventricular Nodal Ablation and Cardiac Pacing of Atrial Fibrillation in a Patient with Dextrocardia

Patient: Female, 77

Final Diagnosis: Tachycardia induced cardiomyopathy

Symptoms: Shortness of breath

Medication: —

Clinical Procedure: —

Specialty: Cardiology