Left ventricular size determines tissue Doppler-derived longitudinal strain and strain rate

AIMS: Tissue Doppler-derived indices of strain (epsilon) and strain rate (SR) have been developed to assess regional cardiac function. However, the effect of left ventricular (LV) size on epsilon and SR has not been studied in depth. The aim of this study was to assess to what extent heart size influence epsilon or SR. METHODS AND RESULTS: In 21 anaesthetized pigs ranging from 12.5 to 70.0 kg, tissue Doppler-derived epsilon and SR, and haemodynamic parameters, were assessed during controlled heart rates and different loading conditions. dP/dt did not correlate to pig weight, suggesting constant contractility during growth. Longitudinal epsilon and SR were significantly higher in smaller compared with larger hearts. The hyperbolic correlation between pigs weight and epsilon and SR was r(2)=0.621 and 0.372, respectively, both P<0.0001. Afterload elevation induced a reduction in longitudinal epsilon (from -24.2+/-3.2 to -12.1+/-5.5%, P=0.001) and SR (from -2.3+/-0.8 to -1.3+/-2.4 s(-1), P=0.034), whereas increasing preload increased epsilon (from -26.4+/-10.3 to -38.1+/-14.3%, P=0.006) and SR (from -2.3+/-0.9 to -4.22+/-1.8 s(-1), P=0.002). CONCLUSION: Longitudinal epsilon and SR decrease with increasing LV dimensions in spite of an unaltered contractility. These results show and confirm that heart size influences epsilon and SR, which are highly load-dependent parameters.     

Injection-induced sciatic nerve injury in Nigerian children

OBJECTIVES: A retrospective study of all children with a diagnosis of sciatic nerve injury managed at the University College Hospital, Ibadan, Nigeria over a 12 year period was carried out in order to determine predisposing factors to the nerve injury and highlighting practical preventive measures. DESIGN: The necessary data was collected from the case files of children seen at the hospital with a diagnosis of sciatic nerve injury, from 1988 to 1999. RESULTS: There were 27 children aged five months to 12 years with a diagnosis of sciatic nerve injury. Twenty (74%) of the children were aged five years or less. While seven patients (26%) presented within two weeks of development of foot drop consequent on intramuscular (i.m.) injection given on the buttock, 20 patients (74%) presented much later. Fever was the most common complaint for which the injection had been given. The identity of the drugs given was not known in 10 patients. In the remaining 17 patients drugs administered were specified and included Chloroquine, Novalgin, Paraldehyde, Procaine penicillin, and Sulfadoxine-Pyrimethamine. Most of the patients had received the injections in privately owned medical facilities where staff with minimal training are often allowed to administer i.m. injections. CONCLUSION: It is suggested that the i.m. route for injection be strongly discouraged when a drug can be given by other routes. Only trained staff should be allowed to administer i.m. injections. Giving i.m. injections at sites other than the buttock maybe advantageous in children particularly those aged five years and below.     

Knowledge and attitudes about hepatitis C virus (HCV) infection and its treatment in HCV mono‐infected and HCV/HIV co‐infected adults

Hepatitis C virus (HCV) treatment is rapidly changing but little is known about patients' attitudes and knowledge about HCV. This study used a cross‐sectional survey to examine the relationship between HCV knowledge and attitudes towards HCV in patients with HCV mono‐infection and HIV/HCV co‐infection. Subsequently, an education intervention was developed with an abridged version of the cross‐sectional survey administered before and after the education session to assess changes in knowledge and attitudes. 292 people participated in the cross‐sectional survey, and 87 people participated in the education intervention. In the cross‐sectional survey, the mean knowledge score regarding HCV was low (<50% of the total possible score). Mono‐infected and co‐infected individuals shared similar knowledge deficits and attitudes towards HCV despite having distinct demographic differences. Attitudes endorsed by patients included the following: 57% feared the consequences of HCV on their life, 37% felt HCV was not fatal, 27% did not believe they needed HCV medication, 21% felt ashamed of having HCV and 16% felt HCV treatment was not important. Attitudes that reflected indifference and shame towards HCV were associated with lower knowledge scores (HCV knowledge score of 15.1 vs. 17.5, P < 0.01 for indifference and 15.3 vs. 17.2 for shame, P = 0.02). The education intervention improved knowledge scores but did not modify the assessed attitudes. Intervention studies are needed to effectively change attitudes towards HCV infection and treatment.