Myocardial energy depletion and dynamic systolic dysfunction in hypertrophic cardiomyopathy

Evidence indicates that anatomical and physiological phenotypes of hypertrophic cardiomyopathy (HCM) stem from genetically mediated, inefficient cardiomyocyte energy utilization, and subsequent cellular energy depletion. However, HCM often presents clinically with normal left ventricular (LV) systolic function or hyperkinesia. If energy inefficiency is a feature of HCM, why is it not manifest as resting LV systolic dysfunction? In this Perspectives article, we focus on an idiosyncratic form of reversible systolic dysfunction provoked by LV obstruction that we have previously termed the 'lobster claw abnormality' — a mid-systolic drop in LV Doppler ejection velocities. In obstructive HCM, this drop explains the mid-systolic closure of the aortic valve, the bifid aortic pressure trace, and why patients cannot increase stroke volume with exercise. This phenomenon is characteristic of a broader phenomenon in HCM that we have termed dynamic systolic dysfunction. It underlies the development of apical aneurysms, and rare occurrence of cardiogenic shock after obstruction. We posit that dynamic systolic dysfunction is a manifestation of inefficient cardiomyocyte energy utilization. Systolic dysfunction is clinically inapparent at rest; however, it becomes overt through the mechanism of afterload mismatch when LV outflow obstruction is imposed. Energetic insufficiency is also present in nonobstructive HCM. This paradigm might suggest novel therapies. Other pathways that might be central to HCM, such as myofilament Ca2+ hypersensitivity, and enhanced late Na+ current, are discussed

Do orthopaedic journals provide high-quality evidence for clinical practice?

BACKGROUND: In the hierarchy of research designs, randomized controlled trials and meta-analyses are considered to be evidence of the highest grade, and scientific journals are the main source of scientific information. METHODS: Using the National Library of Medicine Medline database, all randomized controlled trials and meta-analyses from 1966 to 1999 were retrieved from the journals indexed in the core list of the Science Citation Index in 1999, dedicated primarily to orthopaedics. The abstracts of the articles were reviewed independently by each author and classified by the year, journal name and subject. RESULTS: The total number of articles was 36,293, of which only 671 were randomized controlled trials (1.85%) and 12 were meta-analyses (0.03%). Although there was a progressively increasing trend for randomized controlled trials, more than half of them (81.9%) were published in four journals. Of the randomized controlled trials, 66% was about arthroplasty, and hip and knee arthroplasties covered 90.7%. CONCLUSION: Although the number of randomized controlled trials and meta-analyses is tending to increase, the conclusion of this study is that the high-quality evidence provided by the major orthopaedic journals is quite low, and more randomized controlled trials and meta-analyses are needed for evidence-based orthopaedic practice

Spontaneous regeneration of the large femoral defect in patient with diffuse osteomyelitis after intramedullary nailing.

Infection of the long bones after intramedullary nailing is a troublesome condition and management of the infection remains challenging to orthopedic surgeons. Associated infection can be more problematic and more diffuse in intramedullary bone fixation, since it may spread along the nail. Surgical treatment choices are also difficult especially in cases with large bone defects after debridement. In this article, we present a 75-year-old woman that had been treated only with in-situ external fixation, antibiotic therapy and observation. Despite diffuse femoral osteomyelitis, a 10 cm femoral defect healed with unexpected bone regeneration which couldn't be explained reasonably

Spontaneous regeneration of the large femoral defect in patient with diffuse osteomyelitis after intramedullary nailing

Infection of the long bones after intramedullary nailing is a troublesome condition and management of the infection remains challenging to orthopedic surgeons Associated infection can be more problematic and more diffuse in intramedullary bone fixation since it may spread along the nail Surgical treatment choices are also difficult especially in cases with large bone defects after debridement In this article, we present a 75-year-old woman that had been treated only with in-situ external fixation, antibiotic therapy and observation Despite diffuse femoral osteomyelitis, a 10 cm femoral defect healed with unexpected bone regeneration which couldn't be explained reasonabl