North American Journal of Medical Sciences最新文献

Background: Current guidelines do not support the routine use of computed tomography (CT) scan of the head in the diagnostic workup of syncope. There is a lack of research to support whether these guidelines apply to the Black population.

Aims: This study aims to evaluate the yield of neuroimaging in the evaluation of Syncope in a predominantly Black patient population and to test whether current guidelines based on studies conducted in other populations hold true in this group.

Material and methods: A retrospective review of records of 151 patients admitted to a University Hospital with Syncope from 2011 to 2014 was performed. Data collected include CT head, magnetic resonance imaging of the brain, magnetic resonance angiogram, electroencephalogram, and orthostatic vital signs. Demographic data, admitting service, and comorbid conditions were identified. Syncope was classified as cardiogenic, orthostatic, vasovagal, situational, or undetermined. Statistical analysis was performed to determine which diagnostic tools were useful in identifying the potential causes of syncope. Data analysis was conducted using the Statistical Analysis System software 9.3 (SAS Institute, Cary, NC) and Statistical Analysis and Graphics (NCSS 9.0.7, Kaysville, UT).

Results: One hundred and twenty eight (84.8%) of the patients were Black. The average age was 56.62 ± 18.78 standard deviation and 68.2% (103) were female. One hundred and fourteen patients (75.5%) had a CT brain. Five out of 114 patients had an acute abnormality on CT (4.4%). Only 1 of these 5 patients had an abnormality that was related to syncope. CT brain (P = 0.978) was not found to be predictive of underlying etiology of syncope despite high frequency of use.

Conclusions: CT head was not useful in determining the etiology of syncope in a predominantly Black population. Current guidelines and studies conducted in other populations have detected similar findings.

Background: Serum 25(OH) vitamin D levels are inversely associated with cardiovascular disease (CVD) mortality, mediated in part by independent positive relationships with high-density lipoprotein cholesterol (HDLC) and inverse relationships with low-density lipoprotein cholesterol (LDLC), triglyceride, and homocysteine.

Aims: In this study, we assessed relationships between fasting serum vitamin D and lipids, lipoprotein cholesterols, and homocysteine.

Materials and methods: We studied 1534 patients sequentially referred to our center from 2007 to 2016. Fasting serum total 25(OH) vitamin D, plasma cholesterol, triglyceride, HDLC, LDLC, and homocysteine were measured. Stepwise regression models were used with total cholesterol, triglyceride, HDLC, LDLC, and homocysteine as dependent variables and explanatory variables age, race, gender, body mass index (BMI), and serum vitamin D levels. Relationships between quintiles of serum vitamin D and triglycerides, HDLC, LDLC, and homocysteine were assessed after covariance adjusting for age, race, gender, and BMI.

Results: Fasting serum vitamin D was positively correlated with age, HDLC, and White race, and was inversely correlated with BMI, total and LDL cholesterol, triglyceride, and fasting serum homocysteine (P ≤ 0.0001 for all). Serum vitamin D was a significant independent inverse explanatory variable for total cholesterol, triglyceride, and LDL cholesterol, and accounted for the largest amount of variance in serum total cholesterol (partial R (2) =3.6%), triglyceride (partial R (2) =3.1%), and LDLC (partial R (2) =2.9%) (P < 0.0001 for all). Serum vitamin D was a significant positive explanatory variable for HDLC (partial R (2) = 1.4%, P < 0.0001), and a significant inverse explanatory variable for homocysteine (partial R (2) = 6.0-12.6%).

Conclusions: In hyperlipidemic patients, serum vitamin D was a significant independent inverse determinant of total cholesterol, LDLC, triglyceride, and homocysteine, and a significant independent positive determinant of HDLC. Thus, serum vitamin D might be protective against CVD.

Background: The use of renin-angiotensin system (RAS) inhibitors in patients with chronic kidney disease, and especially in diabetic kidney disease, has been shown to provide renoprotective effects and slow progression to end-stage renal disease. However, this protective effect in kidney transplant patient populations is unclear.

Aim: The objective of this systematic review and meta-analysis was to evaluate the effect of RAS inhibitors on kidney allograft survival.

Materials and methods: A literature search for randomized controlled trials (RCTs) was performed from inception through February 2016. Studies that reported relative risks or hazard ratios comparing the risks of renal graft loss in renal transplant recipients who received RAS inhibitors vs. controls were included. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using a random-effect, generic inverse variance method.

Results: Five studies (3 RCTs and 2 cohort studies) with 20024 kidney transplant patients were included in the meta-analysis. Pooled RR of allograft failure in recipients who received RAS inhibitors was 0.73 (95% CI: 0.45-1.21). When meta-analysis was limited only to RCTs, the pooled RR of allograft failure in patients using RAS inhibitors was 0.59 (95%: CI 0.20-1.69). The risk for mortality (RR: 1.13 [95% CI: 0.62-2.07]) in patients using RAS inhibitors compared to controls was not significantly reduced.

Conclusion: This meta-analysis demonstrated insignificant reduced risks of renal graft loss among renal transplant recipients who received RAS inhibitors. Future studies assessing the potential benefits of RAS inhibitors on allograft survival in specific kidney transplant patient populations are needed.

Background: Heart rate variability (HRV) analysis is a simple and noninvasive technique capable of assessing autonomic nervous system modulation on heart rate (HR) in healthy as well as disease conditions. The aim of the present study was to compare (validate) the HRV using a temporal series of electrocardiograms (ECG) obtained by simple analog amplifier with PC-based sound card (audacity) and Biopac MP36 module.

Materials and methods: Based on the inclusion criteria, 120 healthy participants, including 72 males and 48 females, participated in the present study. Following standard protocol, 5-min ECG was recorded after 10 min of supine rest by Portable simple analog amplifier PC-based sound card as well as by Biopac module with surface electrodes in Leads II position simultaneously. All the ECG data was visually screened and was found to be free of ectopic beats and noise. RR intervals from both ECG recordings were analyzed separately in Kubios software. Short-term HRV indexes in both time and frequency domain were used.

Results: The unpaired Student's t-test and Pearson correlation coefficient test were used for the analysis using the R statistical software. No statistically significant differences were observed when comparing the values analyzed by means of the two devices for HRV. Correlation analysis revealed perfect positive correlation (r = 0.99, P < 0.001) between the values in time and frequency domain obtained by the devices.

Conclusion: On the basis of the results of the present study, we suggest that the calculation of HRV values in the time and frequency domains by RR series obtained from the PC-based sound card is probably as reliable as those obtained by the gold standard Biopac MP36.

Context: Takotsubo translates to "octopus pot" in Japanese. Takotsubo cardiomyopathy (TTC) is characterized by a transient regional systolic dysfunction of the left ventricle. Catecholamine excess is the one most studied and favored theories explaining the pathophysiology of TTC.

Case report: We present the case of a 52-year-old Hispanic female admitted for venlafaxine-induced TTC with a review literature on all the cases of Serotonin-norepinephrine reuptake inhibitors (SNRI)-associated TTC published so far.

Conclusion: SNRI inhibit the reuptake of catecholamines into the presynaptic neuron, resulting in a net gain in the concentration of epinephrine and serotonin in the neuronal synapses and causing iatrogenic catecholamine excess, ultimately leading to TTC.

Background: Online social networking sites (SNSs) (e.g., Facebook, MySpace, Flickr, Twitter and YouTube) have emerged as rapidly growing mechanisms to exchange personal and professional information among university students. This research aims to determine the medical students' extent of usage of SNSs for educational purposes.

Materials and methods: Educational Resources Information Centre (ERIC), Cumulative Index of Nursing and Allied Health Literature (CINAHL), the Cochrane library, and Excerpta Medica Data Base (EMBASE) were searched to retrieve articles from 2004 to 2014, applying predefined search terms and inclusion criteria. The extracted 10 articles were outlined in a narrative synthesis of Quality, Utility, Extent, Strength, Target and Setting of the evidence (QUESTS).

Results: Majority (75%) of the respondents admitted using SNSs, whereas 20% used these sites for sharing academic and educational information. No single study explored the impact of the SNSs on the academic performance.

Conclusion: Understanding and knowledge of the significant use of SNSs by the medical students demand inclusion of such domains in medical curricula. This will train tomorrow's doctors in fostering their skills of digital technology for educational purposes.

Facial paralysis is one of the common problem leading to facial deformation. Bell's palsy (BP) is defined as a lower motor neuron palsy of acute onset and idiopathic origin. BP is regarded as a benign common neurological disorder of unknown cause. It has an acute onset and is almost always a mononeuritis. The facial nerve is a mixed cranial nerve with a predominant motor component, which supplies all muscles concerned with unilateral facial expression. Knowledge of its course is vital for anatomic localization and clinical correlation. BP accounts for approximately 72% of facial palsies. Almost a century later, the management and etiology of BP is still a subject of controversy. Here, we present a review of literature on this neurologically significant entity.

Context: Takotsubo cardiomyopathy (TCM) mimics acute coronary syndrome and is accompanied by reversible left ventricular apical ballooning in the absence of angiographically significant coronary artery stenosis. It is a transient condition that typically precedes physical or emotional triggers.

Case report: We describe the case of a 65-year-old woman who presented to our institution with symptomatic Clostridium difficile infection. 24 hours after admission, the patient complained of severe, retrosternal chest pain. Electrocardiogram showed diffuse elevation of ST-segment in the chest leads; however, coronary angiography demonstrated normal coronary arteries. Therein, an echocardiography was performed, which revealed apical ballooning and hypercontractile base with global left ventricular hypokinesis. These features were consistent with TCM. The patient was managed conservatively. Repeat echocardiogram 2 weeks later showed resolution of heart failure.

Conclusion: To our research, this is the first report of TCM caused by C. difficile infection. Clinicians involved in the care of patients with C. difficile infection must be aware of this complication and should consider TCM in those who develop atypical chest pain.

Acute esophageal necrosis (AEN) or "black esophagus" is a rare clinical entity with an unclear etiology. It is diagnosed at upper gastrointestinal endoscopy with the presence of strikingly black necrotic esophagus. The treatment is primarily medical, but the prognosis is generally poor due to advanced age and comorbid illnesses in patients who develop AEN. Herein, we discussed the implications of poor glycemic control in regards with AEN and undertook a literature review of this rare diagnosis.