Effectiveness of a percutaneous left ventricular assist device in preventing acute hemodynamic decompensation during catheter ablation of ventricular tachycardia in advanced heart failure patients: A retrospective single-center analysis.

INTRODUCTION: Acute hemodynamic decompensation during catheter ablation of ventricular tachycardia is associated with increased mortality. We assessed the effectiveness of mechanical circulatory support using a micro-axial percutaneous assist device in preventing acute hemodynamic decompensation. METHODS AND RESULTS: Twenty-six consecutive patients with structural heart disease undergoing 28 ventricular tachycardia ablations between May 2013 and October 2017 were included. All patients presenting with left ventricular ejection fraction <25%, symptomatic heart failure and arrhythmia associated hemodynamic decompensation underwent catheter ablation with mechanical circulatory support (Impella 2.5; Impella CP, Abiomed, Danvers, MA). Electro-anatomic mapping was performed using Ensite NavX (Abbott, Chicago, IL) or Rhythmia (Boston Scientific, Marlborough, MA) mapping systems. Mapping/ablation strategy included a substrate and activation mapping/ablation. Of the 26 patients, 80% had ischemic cardiomyopathy, the mean age was 68 ± 9 years; mean left ventricular ejection fraction 19.6% ± 3%, mean PAAINESD score was 21 ± 3. Mean tachycardia cycle length was 348 ± 76 ms (range 280-500 ms). The assist device was used pre-emptively in 25 patients and as rescue therapy in one patient. All ventricular tachycardias occurring during substrate ablation were activation mapped and ablated. The ablation procedure was accomplished in 25 of 26 patients, acute decompensation occurred only in one patient receiving circulatory support as bail-out therapy. CONCLUSION: In patients with advanced heart failure and a high probability of acute hemodynamic decompensation during catheter ablation, mechanical circulatory support prevented acute decompensation in 25 of 26 patients. Thus, mechanical circulatory support facilitates catheter ablation of unstable ventricular tachycardia in a critically ill patient population.

Left atrial appendage closure with the Amplatzer™ Cardiac Plug: Rationale for a higher degree of device oversizing at implantation.

BACKGROUND: In left atrial appendage (LAA) closure, the correct sizing of the implantable devices is crucial. Data on the time-dependent changes in the shape and positioning of LAA occlusion devices are missing. We analyzed the results of 33 consecutive patients after implantation of an Amplatzer™ Cardiac Plug (ACP) LAA closure device to get more information on the optimal device sizing during implantation. METHODS AND RESULTS: Thirty-three consecutive patients were enrolled in this observational study. ACP implantation was guided by fluoroscopy and three dimensional transesophageal echocardiography (3-D TEE). Device sizing was based on the largest measured diameter of the intended landing zone adding 2-4 mm of device oversizing. Fluoroscopies were performed at 1 day after, and after 3 months, control 3-D TEE was performed 3 months after implantation. The stability of device positioning and shape was matched with the results of 3-D TEE. Patients' mean age was 70.2 ± 8 years; mean CHA2DS2VASc score was 3.8 ± 1.1. According to the manufacture's classification, the post-implant degree of compression of the device-lobe was classified in three categories 1) undercompression "square-like shape" (1 patient); 2) optimal compression "tire-like shape" (20 patients), 3) overcompression "strawberry-like shape" (12 patients). Changes in the degree of device compression by more than one classification class occurred in 18/33 of our patients. A complete loss of device compression ("square-like shape") was observed in 9 patients. Despite the changes in device compression, a complete closure of the LAA was achieved in 32/33 patients. CONCLUSIONS: There is a temporal change in shape and positioning of the ACP within 3 months after implantation. A late decompression of the ACP lobe was observed in 61% of our patients, leading to a complete loss in device compression in 27%. This observation may be the rationale for a higher degree of ACP oversizing during implantation.