ECG abnormalities and stroke incidence

In this review, the authors discuss the role of ECG in prediction of stroke. ECG plays an important role in detection of several stroke risk factors/predictors including atrial fibrillation and left ventricular hypertrophy; both are components of the Framingham Stroke Risk Score. Multiple other ECG traits have also emerged as potential predictors of stroke, namely cardiac electrical/structural remodeling – Q wave, QRS/QT duration, bundle blocks, P wave duration/amplitude/dispersion, other waveform angles and slopes; higher automaticity – ectopic beats; and re-entry – atrial tachyarrhythmia; and higher vulnerability to arrhythmia – heart rate and its variability. Most of these predictors are not ready for prime time yet; however, further research focusing on their role in risk stratification and prevention of stroke may be useful. In this article, the authors discuss the prevalence, mechanisms and clinical applications of traditional and novel ECG markers in the prevention and treatment of stroke.     

Alterations in spontaneous contractions of rat proximal and distal colon after peritonitis

Background/Purpose

The aim of this study was to investigate the effect of peritonitis on spontaneous contractions of distal and proximal colon smooth muscle isolated from rats.

Methods

Peritonitis was induced by cecal ligation and puncture in 8 rats. Another group of 8 rats underwent a sham operation and acted as controls. Twenty-four hours after the operation, the rats were killed; and their distal and proximal colon smooth muscle was excised and placed in circular muscle direction in a 10-mL organ bath. Changes in the amplitude and frequency of contractions were analyzed before and after the addition of antagonists.

Results

Peritonitis induced the increase in the amplitude and frequency of spontaneous contractions. In both distal and proximal colon of the control group, the amplitude of spontaneous contractions was elevated by N^G-nitro-l-arginine and tetradotoxin; but the frequency of spontaneous contractions was significantly elevated only in the presence of N^G-nitro-l-arginine. In both distal and proximal colon of the peritonitis group, the enhanced amplitude and frequency were significantly decreased and returned to control values in the presence of celecoxib.

Conclusions

Peritonitis induces the increase in the amplitude and frequency of spontaneous contractions of distal and proximal colon, which can be attributed to a loss of inhibitor nitrergic and other neural control or rise of cyclooxygenase-2 levels.     

产前乳房按摩点穴对缩短产程和早泌乳的影响

目的探讨产前乳房按摩点穴对缩短产程和产后泌乳的影响。方法选择符合阴道试产的经产妇100例,按时间先后顺序分为观察组和对照组各50例。对照组采用常规护理方法,观察组由助产师进行产前乳房按摩点穴,每日2次,每次30 min。比较两组宫缩情况、产程时间、乳汁分泌始动时间。结果入院3 d内两组孕妇规律宫缩及分娩率、产妇泌乳始动分布比较,差异有统计学意义(均P0.01);观察组第二、三产程时间及总产程时间显著短于对照组(均P0.01)。结论产前乳房按摩点穴有利于诱发宫缩,缩短产程,促进产妇产后泌乳。     

Neuronal adrenergic and muscular cholinergic contractile hypersensitivity in canine jejunum after extrinsic denervation

Extrinsic denervation may be responsible for motor dysfunction after small bowel transplantation. The aim of this study was to examine the role of extrinsic innervation of canine jejunum on contractile activity. An in vitro dose response of cholinergic and adrenergic agonists was evaluated in canine jejunal strips of circular muscle at 0, 2, and 8 weeks in a control group and after jejunoileal extrinsic denervation (EX DEN). Neurons in circular muscle were quantitated by means of immunohistochemical techniques. Adrenergic and cholinergic responses did not differ at any time in the control group. However, at 2 and 8 weeks, extrinsic denervation caused an increased sensitivity to the procontractile effects of the cholinergic agonist bethanechol at the level of the smooth muscle cells, and increased sensitivity to the inhibitory effects of the adrenergic agent norepinephrine mediated at the level of the enteric nervous system. Immunohistochemical analysis showed a reduction in all neurons and a complete lack of adrenergic fibers in the EX DEN group after 2 and 8 weeks. Extrinsic denervation induces enteric neuronal cholinergic and adrenergic smooth muscle hypersensitivity in canine jejunal circular muscle. Presented in part at the annual meeting of the American Gastroenterological Association, Orlando, Florida, May 18, 1999 (poster presentation), and published as an abstract in Gastroenterology 116:A1075, 1999. Supported by United States Public Health Service grant DK39337 from the National Institutes of Health (M.G.S.); the Swiss National Science Foundation; the Swiss Society of Gastroenterology and Hepatology; the Swiss Foundation for Medical and Biological Science; the Novartis Foundation; Astra Zeneca Pharmaceuticals, Switzerland; and the Department of Visceral and Transplantation Surgery, University of Bern, Switzerland.     

Differing effects of N(G)-monomethyl L-arginine and 7-nitroindazole on detrusor activity

AIMS: Previous studies reported that nitric oxide (NO) synthase (NOS) inhibition decreases micturition volume threshold (MVT), the volume required to produce a centrally mediated micturition contraction, and that NO can be released from urothelium by means of certain stimuli. With elucidation of multiple isoforms of NOS, studies were performed to determine whether inhibition of specific isoforms of NOS altered MVT in different ways. METHODS: In naive, anesthetized cats, the urinary bladder was exposed by means of a midline abdominal incision and cannulated through a slit in the internal urethra approximately 4-5 cm distal to the neck of the bladder. The left renal artery and left radial vein were cannulated for the intra-arterial and intravenous administration of drugs, respectively. All nerves were left intact. A control MVT was determined by slowly infusing saline into the bladder at a rate of 0.018 mL/kg per minute. Varying doses of L-NMMA (N(G)-monomethyl-L-arginine) or 7-NI (7-nitro indazole) were administered and the MVT was again determined. RESULTS: Inhibition of endothelial NOS (eNOS), by L-NMMA, or neuronal NOS (nNOS), by 7-NI, produces varying effects on certain detrusor activities and that inhibition of different isoforms of NOS produces qualitatively different effects. L-NMMA significantly decreases MVT (up to 60% decrease), whereas 7-NI significantly increases MVT (over 300% increase). L-NMMA increases frequency and onset of small bladder contractions, whereas 7-NI produces opposite effects. CONCLUSIONS: The results suggest that detrusor relaxation and contractility may be modulated by NO levels and that NO released from the urothelium may be a mediator of detrusor relaxation during the storage phase of micturition.     

Extraction of Buried P Waves from Printed Electrocardiograms

Background: Morphologic identification of ectopic P‐waves from surface ECGs can be challenging, particularly when the P‐wave is buried in the QRST wave complex. Because ECGs are often available on paper and not digitally, we developed a method of subtracting the T‐wave from the buried P‐wave complex on paper ECGs. Methods: To validate our system, an atrial extrastimulus was introduced during and following the T‐wave. The ECGs were scanned and then transformed from an image format to a digital format. A computer algorithm digitally subtracted a QRST with no buried P‐wave from one with a buried P‐wave, thus resulting in an extracted P‐wave. The extracted P‐waves were compared to the nonburied P‐wave by determining correlation coefficients and by visual grading by two independent reviewers. Results: Visual grading comparing the buried P‐wave with the exposed paced P‐wave was 94%. The median correlation coefficient was 85%. Conclusions: An ectopic atrial P‐wave obscured by a coincident QRST wave complex can be accurately derived from printed ECG using this PC‐based system. Addition of this technique to the existing methods may aid in the localization and ablation of ectopic atrial foci.     

心可舒联合美西律治疗老年室性早搏56例的临床观察

目的：观察心可舒合用美西律治疗老年室性早搏的疗效。方法：选择2011年3~5月住院病例老年室性早搏87例,应用心可舒与美西律治疗56例,用心律平或乙胺碘呋酮治疗31例,两组疗程均为4周,对比两组患者临床疗效及临床副作用。结果：观察组显效33例,有效19例,无效4例,总有效率92.86%。对照组显效l9例,有效10例,2例因副反应停药中止观察,总有效率93.55%,经统计分析提示P〉0.05,观察组副作用较对照组明显减少44.82%,X2=15.98,P〈0.01。结论：对老年室性早搏的治疗,心可舒合用美西律不失为一种安全有效的选择,临床控制效果佳,副作用较少。