Quantified planar collagen distribution in healthy and degenerative mitral valve: biomechanical and clinical implications.

Degenerative mitral valve disease is a common valvular disease with two arguably distinct phenotypes: fibroelastic deficiency and Barlow's disease. These phenotypes significantly alter the microstructures of the leaflets, particularly the collagen fibers, which are the main mechanical load carriers. The predominant method of investigation is histological sections.

In silico analysis provides insights for patient-specific annuloplasty in Barlow's disease.

Objective: To predict the required mitral annular area reduction in patients with Barlow's disease to obtain a predefined leaflet area index by a novel in silico modeling method.

Methods: Three-dimensional echocardiography was used to create patient-specific mitral valve models of 8 patients diagnosed with Barlow's disease and bileaflet prolapse preoperatively. Six patients were also studied postoperatively in a finite element framework, to quantify the optimal coaptation area index.

Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model.

The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted equidistantly around the mitral annulus. High-fidelity catheters measured left ventricular pressures and the slope of the end-systolic pressure-volume relationship (E ) determined LV contractility.

Mechanical behavior and collagen structure of degenerative mitral valve leaflets and a finite element model of primary mitral regurgitation.

Degenerative mitral valve disease is the main cause of primary mitral regurgitation with two phenotypes: fibroelastic deficiency (FED) often with localized myxomatous degeneration and diffuse myxomatous degeneration or Barlow's disease. Myxomatous degeneration disrupts the microstructure of the mitral valve leaflets, particularly the collagen fibers, which affects the mechanical behavior of the leaflets. The present study uses biaxial mechanical tests and second harmonic generation microscopy to examine the mechanical behavior of Barlow and FED tissue.

Sympathetic and vagal interaction in the control of cardiac pacemaker rhythm in the guinea-pig heart: Importance of expressing heart rhythm using an appropriate metric.

There are many reports that, through pre- and post-junctional mechanisms, sympathetic and parasympathetic (vagal) nerves can interact in the control of heart rate. The predominant interaction is accentuated antagonism (AA), where the bradycardia produced by vagal stimulation (VNS) is amplified when heart rate has been increased by sympathetic stimulation (SNS) or beta-adrenergic agonists. The acetylcholine-activated potassium current (I), is the primary driver of vagal bradycardia.

Finite element analysis of mitral valve annuloplasty in Barlow's disease.

Barlow's Disease affects the entire mitral valve apparatus causing mitral regurgitation. Standard annuloplasty procedures lead to an average of 55% annular area reduction of the end diastolic pre-operative annular area in Barlow's diseased valves. Following annular reduction, mitral valvuloplasty may be needed, usually with special focus on the posterior leaflet.

Short-term outcome after open-heart surgery for severe chronic rheumatic heart disease in a low-income country, with comparison with an historical control group: an observational study.

Objectives: Rheumatic heart disease (RHD) is a major burden in low-income and middle-income countries (LMICs). Cardiac surgery is the only curative treatment. Little is known about patients with severe chronic RHD operated in LMICs, and challenges regarding postoperative follow-up are an important issue.

A novel case of impaired C-reactive protein response following open-heart surgery: A case report and review of the literature.

Background: C-reactive protein (CRP) is expected to increase in response to a range of inflammatory stimuli such as infections or extensive tissue trauma.

Case Report: We present a novel case of severely impaired CRP response following NSTEMI, influenza A infection and open-heart surgery in which serum CRP concentrations remained < 1 mg/L during an observational period of 28 days.

Conclusion: To our knowledge, no previous publications exists describing patients with a lack of CRP response following cardiothoracic surgery.