The Right Ventricle in Health and Disease: Insights into Physiology, Pathophysiology and Diagnostic Management

Until recently, the right ventricle (RV) received little attention in adult patients with congenital heart disease and even less attention in the setting of acquired heart failure. However, in the last two decades, our perspective towards the right side of the heart has begun to change. Advances in imaging modalities have permitted the accurate study of RV physiology and made it apparent that RV function is an important determinant of prognosis in heart failure irrespective of the underlying etiology. This article summarizes the existing data on the unique anatomical and physiological features of the RV. The hemodynamic conditions and cellular and biochemical pathways that lead to right heart failure are presented. Moreover, the imaging modalities that aid in the assessment of RV structure and function are described and the importance of the diagnostic and prognostic information they provide is discussed.     

Changes in masticatory mandibular movements in growing individuals: a six-year follow-up

The pattern of mandibular movement during chewing is influenced by several central and peripheral factors. The aim of the present study was to determine whether changes in masticatory function, characterized by mandibular velocity and displacement, occurred during individuals' normal growth. Forty-seven children, 9-15 years of age, were followed over a 6-year period. All had an Angle Class I occlusion with no obvious orthodontic problems. Oral motor function with respect to mandibular displacement, duration, and velocity was monitored 3-dimensionally with an opto-electronic method. The chewing cycle was divided into an opening, closing, and occlusal phase. Total body height was measured. During the follow-up period, all masticatory variables except the 3-dimensional opening distance showed significant changes. The total chewing cycle duration, the opening and occlusal time of the chewing cycle, and the 3-dimensional closing distance increased during the growth period, while the closing time of the chewing cycle, the 2-dimensional lateral and vertical distances and both the opening and closing velocity decreased. The children who grew proportionally most in height during the 6-year period, i.e. the youngest children in the group studied, showed a significantly larger decrease in the opening velocity. From this study it becomes evident that the variables of the chewing cycle undergo a continuous process of change during growth. This is possibly a reflection of anatomical changes, maturation of the central nervous system, and altered functional demands.     

Changes in oro-facial function and hand-grip strength during a 2-year observation period after stroke

Objectives

Recovery from stroke-related oro-facial impairment has rarely been investigated. In this longitudinal study chewing efficiency, maximum lip and bite force as well as masseter muscle thickness were evaluated and compared with hand-grip force.

Materials and methods

Thirty-one hospitalized stroke patients and 24 controls were recruited for this cohort study with 2-year follow-up. Chewing efficiency was evaluated with a color mixing ability test, lip forces with a traction dynamometer, bite force with a digital gauge, masseter muscle thickness using ultrasound measurements and grip strength with a hand dynamometer.

Results

During the 2-year observation period, patients were evaluated four times. A total of 21 patients dropped out of the study. Stroke patients showed significantly impaired chewing efficiency and lower lip forces than controls with no significant improvement over time. Bite forces were not different between ipsi- and contralesional sides, in contrast to contralesional hand-grip strength which was significantly impaired and did not improve during the observation period. On the first examination with a median of 40 days after stroke, masseter thickness was reduced contralesional, but did not continue to show significant side-differences during follow-up.

Conclusions

Stroke affects the upper limb and the masseter muscles differently on a functional and morphological level. Further research is needed to evaluate the predictive value of oro-facial parameters on functional outcome after stroke.

Clinical relevance

Impaired chewing efficiency and reduced lip force are quantifiable symptoms in stroke patients which seem not to improve in absence of oro-facial rehabilitation procedures.     

Consensus Statement from the Consensus Conference on Bilateral Total Knee Arthroplasty Group

Background

Controversy exists regarding many aspects of decision making pertaining to same-day versus staged bilateral TKA (BTKAs), including patient selection, perioperative management decisions, and other important choices.

Questions/purposes

In the absence of suitable randomized trials, we sought to determine areas of consensus among national experts on the following questions: (1) What are the comparative risks of same-day BTKAs compared with unilateral TKA (UTKA) and staged BTKAs? (2) Who should be considered an appropriate candidate for same-day BTKAs? (3) What constitutes appropriate workup and perioperative management for BTKAs? (4) What is the optimal time between procedures if same-day BTKAs are not deemed appropriate? (5) Are there orthopaedic or rehabilitation considerations for BTKAs that might outweigh medical contraindications?

Methods

In the setting of a consensus conference of national experts in orthopaedic surgery, anesthesiology, perioperative medicine, and epidemiology, the major questions surrounding same-day BTKAs were addressed by using an extensive literature review and the modified Delphi process. The process concluded with a meeting of participants and formulation of consensus statements.

Results

Eighty-one percent of participants agreed that BTKAs are more invasive and complex procedures associated with increased risk for perioperative adverse events compared with UTKA in an unselected group of patients. The consensus group agreed that physicians and hospitals should consider using more restrictive patient selection criteria and exclude those with a modified cardiac risk index greater than 3 to mitigate the potentially increased risk. The majority of the group agreed that perioperative assessment and management should reflect the higher level of acuity of same-day BTKAs. Eighty-one percent of participants agreed that if a patient is not deemed a candidate for same-day BTKAs, a second TKA should be scheduled no sooner than 3 months after the first. The entire group agreed that when there is a conflict between the orthopaedic need and the medical adequacy of same-day BTKAs, the medical concern for the patient’s safety should prevail over the orthopaedic need.

Conclusions

Experts perceived that same-day BTKAs increase medical risk, and thus a systematic approach to the management of patients should be taken to minimize complications.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-013-2976-9) contains supplementary material, which is available to authorized users.     

Successful high‐risk percutaneous coronary intervention with the use of minimal extracorporeal circulation system

Minimal extracorporeal circulation (MECC) represents a contemporary system which integrates several advances in cardiopulmonary bypass technology in a single circuit. We challenged the efficacy of the MECC system to support the circulation in elective high‐risk percutaneous coronary intervention (PCI). A 78‐year‐old patient with complex coronary disease who would have been otherwise rejected for interventional therapy underwent PCI with rotablation on MECC support. The MECC system provided hemodynamic support at a flow of 1.8 L min^?1 m^?2 while perfusion pressure was kept at a minimum of 70 mm Hg. This allowed for successful angioplasty of the left main stem and a chronically occluded right coronary artery, which otherwise produced significant hemodynamic compromise. This case illustrates that mechanical circulatory support with the MECC system could provide a stable environment and a “safety net” for carrying out complex percutaneous coronary intervention in high‐risk patients. © 2012 Wiley Periodicals, Inc.