Publications by authors named "Spyridon Akrivakis"

Background: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed.

Objectives: The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling.

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Background: Atrial fibrillation (AF) ablation is facilitated by anatomical visualization of the left atrium (LA) and the pulmonary veins (PVs). The purpose of this study was to compare accuracy, radiation exposure, and costs between three-dimensional atriography (3D-ATG) and cardiac computed tomography (CCT).

Methods: Seventy patients with an indication for AF ablation were included.

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Background: Rotational angiography with three-dimensional reconstruction (3DRA) is a new imaging tool recently introduced to guide mapping and ablation of the left atrium.

Objective: The purpose of this study was to determine the utility of 3DRA for imaging the ventricles and guiding ventricular tachycardia (VT) ablation.

Methods: Using the Philips Allura Xper FD10 system, 3DRA was performed in eight patients referred for right ventricular outflow tract (RVOT) VT ablation.

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Background: Theoretically, the use of electroanatomical mapping systems may reduce radiation exposure, while three-dimensional rotational atriography (3DATG) may increase exposure. Anatomical representation and image registration using 3DATG are likely to be superior, but the net clinical benefit of either system is unknown.

Objective: The purpose of this prospective randomized two-center study was to compare the procedural and clinical outcome of patients with atrial fibrillation (AF) treated by catheter ablation using either three-dimensional (3D) electroanatomical mapping (Carto) or 3DATG.

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Purpose: We prospectively determined whether preimplant myocardial perfusion imaging (MPI) predicts outcome with biventricular pacing (BiVP).

Methods: Single-photon emission computed tomography (SPECT) MPI, left ventricular (LV) volumes, ejection fraction (EF), 6-min hall walk (6MW) were assessed at baseline and at 4 months in 19 patients with ischemic cardiomyopathy undergoing BiVP. Clinical and hemodynamic responses were correlated with MPI.

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We sought to assess the role of regional diastolic function by Doppler echocardiography in predicting myocardial viability. Sixteen dogs underwent left anterior descending coronary artery (n = 8) or circumflex (n = 8) occlusion. All animals were imaged at baseline and 1-8 wk postinfarction (post-MI).

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Angiogenesis is a critical process in healing of myocardial infarcts, leading to the formation of highly vascular granulation tissue. However, effective cardiac repair depends on mechanisms that inhibit the angiogenic process after a mature scar is formed, preventing inappropriate expansion of the fibrotic process. Using a canine model of reperfused myocardial infarction, we demonstrated that maturation of the infarct leads to the formation of neovessels, with a thick muscular coat, that demonstrate distinct morphological characteristics.

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Myocardial infarction is associated with the rapid induction of mononuclear cell chemoattractants that promote monocyte infiltration into the injured area. Monocyte-to-macrophage differentiation and macrophage proliferation allow a long survival of monocytic cells, critical for effective healing of the infarct. In a canine infarction-reperfusion model, newly recruited myeloid leukocytes were markedly augmented during early reperfusion (5-72 h).

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