Accuracy and clinical feasibility of 3D‑myocardial thickness map measured by cardiac computed tomogram

Background@#Although myocardial thickness is an important variable for therapeutic catheter ablation of cardiac arrhythmias, quantification of wall thickness has been overlooked. We developed a software (AMBER) that measures 3D-myocardial thickness using a cardiac computed tomogram (CT) image, verified its accuracy, and tested its clinical feasibility. @*Methods@#We generated 3D-thickness maps by calculating wall thickness (WT) from the CT images of 120 patients’ hearts and a 3D-phantom model (PhM). The initial vector field of the Laplace equation was oriented to calculate WT with the field lines derived from the 3D mesh. We demonstrate the robustness of the Laplace WT algorithm by comparing with the real thickness of 3D-PhM, echocardiographically measured left ventricular (LV) WT, and regional left atrial (LA) WT reported from previous studies. We conducted a pilot case of catheter ablation for atrial fibrillation (AF) utilizing real-time LAWT map-guided radiofrequency (RF) energy titration. @*Results@#AMBER 3D-WT had excellent correlations with the real thickness of the PhM (R = 0.968, p < 0.001) and echocardiographically measured LVWT in 10 patients (R = 0.656, p = 0.007). AMBER 3D-LAWT (n = 120) showed a relatively good match with 12 previously reported regional LAWT. We successfully conducted pilot AF ablation utilizing AMBER 3D-LAWT map-guided real-time RF energy titration. @*Conclusion@#We developed and verified an AMBER 3D-cardiac thickness map measured by cardiac CT images for LAWT and LVWT, and tested its feasibility for RF energy titration during clinical catheter ablation.

Efficacy and Safety of Outpatient Clinic-based Elective External Electrical Cardioversion in Patients with Atrial Fibrillation

Background and Objectives@#Little is known about the outcomes of outpatient clinic-based elective external cardioversion (OPC-ECV) for persistent atrial fibrillation (PeAF). We investigated the acute, short-term, and long-term elective external cardioversion (ECV) outcomes. @*Methods@#We included 1,718 patients who underwent OPC-ECV (74% male, 61.1±11.0 years old, 90.9% long-standing PeAF, 9.1% after atrial fibrillation [AF] ablation) after excluding patients with atrial tachycardia or inappropriate antiarrhythmic drug medication, and in-patient ECV. Biphasic shocks were delivered sequentially until successful cardioversion was achieved (70-100-150-200-250 J). If ECV failed at 150 J, we administered intravenous amiodarone 150 mg and delivered 200 J. @*Results@#ECV failed in 11.4%, and the complication rate was 0.47%. Within 3 months, AF recurred in 55.5% (44.7% as sustaining AF, 10.8% as paroxysmal AF), and the AF duration was independently associated (odds ratio [OR], 1.01 [1.00–1.02]; p=0.006), but amiodarone was independently protective (OR, 0.46 [0.27–0.76]; p=0.002, Log rank p<0.001) against an early recurrence. Regarding the long-term recurrence, pre-ECV heart failure was protective against an AF recurrence (hazard ratio, 0.63 [0.41–0.96], p=0.033) over 32 (9–66) months of follow-up. ECV energy (p<0.001) and early recurrence rate within 3 months (p=0.007, Log rank p=0.006) were significantly lower in post-ablation patients than in those with long-standing persistent AF. @*Conclusions@#The success rate of OPC-ECV was 88.6%, and the complication rate was low. However, AF recurred in 55.5% within 3 months. Amiodarone was protective against short-term AF recurrences, and long-term AF recurrences were less in patients with baseline heart failure.

Combined Subpectoral Implantation of Implantable Cardioverter-Defibrillator and Augmentation Mammoplasty in a Young Female Patient

Subcutaneous implantation of a cardiac implantable electronic device is the standard method. Occasionally, subpectoral cardiac implantable electronic device (CIED) implantation via axillary incisions is performed in young female patients for cosmetic purposes. Because subpectoral CIED implantation and augmentation mammoplasty involve the same layer, it is feasible to perform both procedures simultaneously. We report a case of combined subpectoral implantation of an implantable cardioverter-defibrillator and augmentation mammoplasty via the axillary approach in a young female patient with dilated cardiomyopathy and small breasts.

Reversible Pulmonary Hypertension due to Sick Sinus Syndrome / 대한내과학회지

A 60-year-old man visited the hospital after experiencing dyspnea after exertion for 2 weeks. An electrocardiogram showed sinus arrest with junctional escape rhythm at 40 beats/min. Transthoracic echocardiography showed that the right ventricular systolic pressure (RVSP) was approximately 71 mmHg and that the left ventricular ejection fraction was preserved. The ratio of peak early diastolic transmitral inflow velocity to early diastolic peak mitral annular velocity (E/E') was 29. Cardiac catheterization revealed a systolic pulmonary artery pressure (SPAP) of 63 mmHg, a mean pulmonary artery pressure of 27 mmHg, and a pulmonary capillary wedge pressure of 22 mmHg with a rhythm of 40 beats/min. The patient was diagnosed with pulmonary hypertension (group 2) due to sick sinus syndrome. SPAP decreased to 48 mmHg during atrial pacing at 60 beats/min. After permanent pacemaker insertion, RVSP decreased from 71 mmHg to 44 mmHg. In this case, passive group 2 pulmonary hypertension occurred due to sick sinus syndrome.

Transvascular Implantation of an Implantable Cardioverter-Defibrillator in a Patient Who has Undergone One-and-a-Half Ventricle Repair

Implantable cardioverter-defibrillator (ICD) therapy is acknowledged as a valid treatment method for the effective prevention of sudden cardiac death, which is a major cause of mortality in adult congenital heart disease patients. But ICD implantation by the conventional transvascular approach is not always possible in patients who have undergone palliative surgery due to congenital and structural heart disease. Here, we report a case in which an ICD was transvascularly implanted in an arrhythmogenic right ventricular cardiomyopathy patient who had undergone a one-and-a-half ventricle repair.