Several different patterns of wave break have been described by mapping of the tissue surface during fibrillation. However, it is not clear whether these surface patterns are caused by multiple distinct mechanisms or by a single mechanism. To determine the mechanism by which wave breaks are generated during ventricular fibrillation, we conducted optical mapping studies and single cell transmembrane potential recording in six isolated swine right ventricles (RV). Among 763 episodes of wave break (0.75 times x s(-1) x cm(-2)), optical maps showed three patterns: 80% due to a wave front encountering the refractory wave back of another wave, 11.5% due to wave fronts passing perpendicular to each other, and 8.5% due to a new (target) wave arising just beyond the refractory tail of a previous wave. Computer simulations of scroll waves in three-dimensional tissue showed that these surface patterns could be attributed to two fundamental mechanisms: head-tail interactions and filament break. We conclude that during sustained ventricular fibrillation in swine RV, surface patterns of wave break are produced by two fundamental mechanisms: head-tail interaction between waves and filament break.
Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the CF transmembrane conductance regulator gene(CFTR) resulting in impaired ion transport. Nearly all people with CF will develop chronic rhino-sinusitis (CRS) and present with the characteristic viscous mucus, impaired mucociliary clearance and chronic inflammation/infection of the sinonasal cavity. While some individuals with CF can appear relatively asymptomatic in terms of their sinus disease, commonly reported symptoms include anosmia, headache, facial pain, nasal obstruction, chronic congestion and nasal discharge. Nasal endoscopy typically reveals mucosal edema, purulent discharge and nasal polyposis. Computed tomography (CT) imaging classically demonstrates the distinguishing findings of sinus hypoplasia or aplasia with generalized opacification, medial bulging of the lateral sinonasal sidewall and a demineralized uncinate process. Current treatment for CF sinusitis includes the use of hypertonic saline, topical and systemic steroids, antibiotics and endoscopic surgery. Research investigating novel therapies designed at targeting the primary defect of CF is showing promise for reversal of CF sinus disease, in addition to potential for disease prevention.
Obstructive sleep apnea (OSA) is a sleep disorder caused by partial or complete collapse of the pharyngeal airway. Genioglossal advancement (GGA) is a well-tolerated surgical procedure intended to address hypopharyngeal collapse, yet there are few studies that monitor changes in airflow dynamics at this site. Computation fluid dynamics (CFD) utilizes airflow simulation to predict changes in airflow after anatomic manipulation.
We propose a novel technique for peritonsillar abscess (PTA) drainage in which the patient is lying in the Trendelenburg position. We provide evidence that this novel technique is relatively safe and effective in PTA drainage.