LBBB and heart failure-Relationships among QRS amplitude, duration, height, LV mass, and sex.

Background: Height, left ventricular (LV) size, and sex were proposed as additional criteria for patient selection for cardiac resynchronization therapy (CRT) but their connections with the QRS complex in left bundle branch block (LBBB) are little investigated. We evaluated these.

Methods: Among patients with "true" LBBB, QRS duration (QRSd) and amplitude, and LV hypertrophy indices, were correlated with patient's height and LV mass, and compared between sexes.

Postapproval Study of a Subcutaneous Implantable Cardioverter-Defibrillator System.

Background: The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to avoid complications related to transvenous implantable cardioverter-defibrillator (TV-ICD) leads. Device safety and efficacy were demonstrated previously with atypical clinical patients or limited follow-up.

Objectives: The S-ICD PAS (Subcutaneous Implantable Cardioverter-Defibrillator System Post Approval Study) is a real-world, multicenter, registry of U.

Correlating Optical Microspectroscopy with 4×4 Transfer Matrix Modeling for Characterizing Birefringent Van der Waals Materials.

Van der Waals materials exhibit intriguing properties for future electronic and optoelectronic devices. As those unique features strongly depend on the materials' thickness, it has to be accessed precisely for tailoring the performance of a specific device. In this study, a nondestructive and technologically easily implementable approach for accurate thickness determination of birefringent layered materials is introduced by combining optical reflectance measurements with a modular model comprising a 4×4 transfer matrix method and the optical components relevant to light microspectroscopy.

High predictive value of paced QRS frequency in verification of left bundle branch pacing.

Background: Left bundle branch area pacing (LBBAP) is a newer technique to deliver more synchronous left ventricular activation. Several criteria have been proposed, but not fully validated, to confirm LBBAP during implantation of the pacing lead. Spectral analysis has been used to characterize the frequency components of the clinical QRS utilizing the Fourier transform algorithm.