Abnormal left ventricular relaxation and symptoms of heart failure

Objectives

The purpose of our study was to assess the echocardiographic and angiographic parameters in patients with symptomatic heart failure (HF) and mild diastolic dysfunction (grade I).

Background

It remains uncertain why some patients with mild diastolic dysfunction exhibit HF symptoms and others are asymptomatic.

Methods

The study enrolled 80 hospitalized patients with impaired left ventricular (LV) relaxation. Patients were divided into two groups; one group had chronic functional class II to III dyspnea and the other group had no symptoms of HF. After admission, echocardiography and coronary angiography were performed for all patients and LV systolic and diastolic parameters were compared between the two groups.

Results

More patients in the asymptomatic group were hypertensive (p-value: 0.012). However, coronary artery disease was more prevalent in symptomatic patients (p-value: 0.022). The LV ejection fraction (EF) was significantly lower in symptomatic patients [median 54.33 %, 95 % confidence interval (53.76–54.87 %) in asymptomatic patients and median 49.43, 95 % confidence interval (47.23–50.91 %) in symptomatic patients, p-value <0.001]. Furthermore, the systolic LV internal dimension was significantly larger in this group (p-value: 0.037). The results of logistic regression identified that only the absolute level of the LVEF was the negative determinant of the occurrence of HF in patients with impaired LV relaxation.

Conclusion

Our study showed that LV systolic performance has an important role in occurrence of HF symptoms in patients with grade I diastolic dysfunction.

     

Priming with an adenovirus 35-circumsporozoite protein (CS) vaccine followed by RTS,S/AS01B boosting significantly improves immunogenicity to Plasmodium falciparum CS compared to that with either malaria vaccine alone

The RTS,S/AS02A protein-based vaccine consistently demonstrates significant protection against infection with Plasmodium falciparum malaria and also against clinical malaria and severe disease in children in areas of endemicity. Here we demonstrate with rhesus macaques that priming with a replication-defective human adenovirus serotype 35 (Ad35) vector encoding circumsporozoite protein (CS) (Ad35.CS), followed by boosting with RTS,S in an improved MPL- and QS21-based adjuvant formulation, AS01B, maintains antibody responses and dramatically increases levels of T cells producing gamma interferon and other Th1 cytokines in response to CS peptides. The increased T-cell responses induced by the combination of Ad35.CS and RTS,S/AS01B are sustained for at least 6 months postvaccination and may translate to improved and more durable protection against P. falciparum infection in humans.     

Analysis of electrocautery smoke released from the tissues frequently cut in orthopedic surgeries

BACKGROUND Electrosurgical smoke could be different by the device of cutting or the type of tissue that is being cut.AIM To analyze the electrocautery smoke released from the tissues that are frequently cut in orthopedic surgeries.METHODS The released smoke from electrocautery of five different tissue types(meniscus,ligament,adipose,muscle,and synovium) of five patients who underwent total knee arthroplasty were collected and analyzed for volatile organic compounds(VOCs) and 27 candidate polycyclic aromatic hydrocarbons(n = 25).Surgical smoke was produced with an electrocautery device for 4 min.RESULTS None of the 27 evaluated polycyclic aromatic hydrocarbons compounds were detectable in electrocautery smoke collected from the surgical cutting of the different tissues.The number and identity of detected VOCs were similar between the patients but not between tissue types.The number of detected VOCs was the highest in synovial tissue(n = 21) and the lowest in the meniscus and adipose tissue(n = 12).The number of toxic and/or carcinogenic VOCs were the most in the muscle and meniscus tissues(Toluene,Ethylbenzene,and Styrene).No toxic and/or carcinogenic VOCs were identified in the ligament and adipose tissue.CONCLUSION Meniscus and muscle tissue are associated with the highest number of toxic and/or carcinogenic VOCs.Therefore,we recommend that surgeons avoiding the electrocautery of these tissues.     

Coronary computed tomography–angiography quantitative plaque analysis improves detection of early cardiac allograft vasculopathy: A pilot study

Cardiac allograft vasculopathy (CAV) is an increasingly important complication after cardiac transplant. We assessed the additive diagnostic benefit of quantitative plaque analysis in patients undergoing coronary computed tomography–angiography (CCTA). Consecutive patients undergoing CCTA for CAV surveillance were identified. Scans were visually interpreted for coronary stenosis. Semiautomated software was used to quantify noncalcified plaque (NCP), as well as its components. Optimal diagnostic cut‐offs for CAV, with coronary angiography as gold standard, were defined using receiver operating characteristic curves. In total, 36 scans were identified in 17 patients. CAV was present in 17 (46.0%) reference coronary angiograms, at a median of 1.9 years before CCTA. Median NCP (147 vs 58, P < .001), low‐density NCP (median 4.5 vs 0.9, P = .003), fibrous plaque (median 76.1 vs 31.1, P = .003), and fibrofatty plaque (median 63.6 vs 27.6, P < .001) volumes were higher in patients with CAV, whereas calcified plaque was not (median 0.0 vs 0.0, P = .510). Visual assessment of CCTA alone was 70.6% sensitive and 100% specific for CAV. The addition of total NCP volume increased sensitivity to 82.4% while maintaining 100% specificity. NCP volume is significantly higher in patients with CAV. The addition of quantitative analysis to visual interpretation improves the sensitivity for detecting CAV without reducing specificity.     

Robust H∞ output feedback design for networked control systems with partially known delay probabilities

This article develops a predictive robust H_∞ static output feedback control approach for networked control systems where random network-induced delays in both forward and feedback communication channels are modeled as two mutually uncorrelated Markov chains. By making use of the system augmentation method, the closed-loop system is formulated as a singular Markovian jump system with two modes, wherein the transition probability matrices of the underlying Markov chains are considered to be partially accessible. Necessary and sufficient conditions for the stochastic admissibility and robust H_∞ performance of the closed-loop system are given under the assumption of partially known transition probability matrices. A linear matrix inequality condition is proposed to determine the two-mode-dependent static output feedback controller gains to compensate for the random network-induced delays efficiently and provide the desired control performance. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.