High Density Endocardial Mapping of Shifts in the Site of Earliest Depolarization During Sinus Rhythm and Sinus Tachycardia

BETTS, T.R., et al. : High Density Endocardial Mapping of Shifts in the Site of Earliest Depolarization During Sinus Rhythm and Sinus Tachycardia. Previous mapping studies of sinus rhythm suggest faster rates arise from more cranial sites within the lateral right atrium. In the intact, beating heart, mapping has been limited to epicardial plaques or single endocardial catheters. The present study was designed to examine shifts in the site of the earliest endocardial depolarization during sinus rhythm and sinus tachycardia using high density activation mapping. Noncontact mapping of the right atrium during sinus rhythm was performed on ten anesthetized swine. Recordings were made during sinus rhythm, phenylephrine infusion, and isoproterenol infusion. The hearts were then excised and the histological sinus node identified. The mean minimum and maximum cycle lengths recorded were   355 ± 43   and   717 ± 108 ms   . A median of three (range two to five) sites of earliest endocardial depolarization were documented in each animal. With increasing heart rate the site of earliest endocardial depolarization remained stationary until a sudden shift in a cranial or caudal direction, often to sites beyond the histological sinoatrial node. The endocardial shift was unpredictable with considerable variation between animals; however, faster rates arose from more cranial sites   (r = 0.46, P = 0.023)   . There was no difference in the mean cycle length of sinus rhythm originating from specific positions on the terminal crest   (r = 0.44, P = 0.17)   . Cranial sites displayed a more diffuse pattern of early depolarization than caudal sites. In the porcine heart the relationship between heart rate and site of earliest endocardial depolarization shows considerable variation between individual animals. These findings may have implications for clinical mapping and ablation procedures. (PACE 2003; 26[Pt. I]:874–882)     

Density of sympathetic axons in sural nerve biopsies of neuropathy patients is related to painfulness

In this study, differences of unmyelinated nerve fiber density in sural nerve biopsy material from patients suffering from neuropathies of unknown origin with (n=14) or without pain (n=13) were analyzed. Immunocytochemistry was applied to differentiate afferent sensory and efferent sympathetic nerve fibers. All patients were evaluated for deficits of small fiber function with thermotesting, quantitative sudomotor-axon reflex-testing and testing of painfulness of mechanical stimuli before performing the biopsy. No difference was found between patients with and without pain concerning clinical deficits or results in any of the neurophysiological examinations. There were also no histopathological differences concerning the density of afferent C-fibers. However, absolute and relative density of efferent sympathetic nerve fibers was significantly higher in patients with painful neuropathy (P<0.001), although none of the patients demonstrated clinical sympathetic abnormalities. We conclude that an imbalance between afferent and sympathetic nerve fiber density in the periphery may contribute to neuropathic pain even in those patients without obvious clinical autonomic disturbances.     

The Effect and Safety of the Antithrombotic Therapies in Patients with Atrial Fibrillation and CHADS2 Score 1

Anticoagulation in CHADS₂ Score 1 . Background: The revised ACC/AHA/ESC 2006 guideline recommends either aspirin or warfarin for the prevention of ischemic stroke in patients with atrial fibrillation (AF) in CHADS₂ score 1. We hypothesized that warfarin is superior to aspirin therapy for the prevention of stroke without increasing bleeding complication in AF patients with CHADS₂ score 1. Methods and Results: Among 1,502 patients (mean 62.4 ± 13.8 years old, male 65.4%) who were treated for nonvalvular AF without previous stroke, the number of patients with CHADS₂ score 1 was 422 (62.9 ± 10.7 years old, male 290 [68.7%]) and their antithrombotic therapies were as follows: warfarin (n = 143), aspirin (n = 124), other antiplatelet (n = 45), and no antithrombosis (none: n = 110). We reviewed the incidences of ischemic stroke, mortality, and bleeding complications during the follow‐up period. Results were: (1) during 22.3 ± 17.8 months of follow‐up, the incidence of ischemic stroke was significantly lower in warfarin (6 patients, 4.2%, mean international normalized ratio [INR] 2.0 ± 0.5 IU) than in aspirin (16 patients, 12.9%, P = 0.008) than none (23 patients, 20.9%, P < 0.001) without differences in all‐cause mortality. (2) The incidence of major bleeding (decrease in hemoglobin ≥2 g/dL, requiring hospitalization or red blood cell transfusion ≥2 pints) was not different between warfarin (2.1%) and aspirin (0.8%, P = NS), but minor bleeding was more common in warfarin (10.5%) than in aspirin (2.4%, P = 0.007). Conclusion: In AF patients with CHADS₂ score 1, warfarin was better to prevent ischemic stroke than aspirin without increasing the incidence of major bleeding complications. However, the incidence of minor bleeding was higher in the warfarin group than the aspirin group. (J Cardiovasc Electrophysiol, Vol. 21, pp. 501‐507, May 2010)     

行胫骨高位截骨全膝关节置换手术患者的对照研究

目的探讨胫骨高位截骨术对随后进行的全膝关节置换术的影响。方法对23例行胫骨高位截骨术后行全膝关节置换术患者的术中情况以及术后膝关节功能与对照组进行了比较,两组患者在年龄、疾病和关节畸形方面具有可比性。结果胫骨高位截骨术后行全膝关节置换术患者的手术时间（118．5±32）与对照组（98．9±20．5）比较差异有统计学意义,伤口的并发症也较对照组多。但两组患者的围手术期的出血量和术后膝关节功能比较差异无统计学意义。结论胫骨高位截骨术后行全膝关节置换术患者的膝关节功能和活动范围与对照组相似,但其手术的技术要求较高,并发症也相对较多。     

Effect of auricular acupuncture on oxygen consumption of boxing athletes

Boxing is an official sport at the 2008 Beijing Olympic Games and the fast development of world-class high strength training and sport science has made a significant impact on scientific training. Boxing needs high cardio-respiratory function, speed, muscle strength, and anaerobic and intensive physical demands including weight control covering the grading of athlete＇s body weight and balancing physical ability and health. Sport training is important even for talented athletes. Weight cycling is a term used to describe rapid weight loss following self food limitation and/or dehydration. Both gradual （seasonal） reduction cycles are used and rapid （weekly） weight by athletes,     

Effect of auricular acupuncture on oxygen consumption of boxing athletes

Boxing is an official sport at the 2008 Beijing Olympic Games and the fast development of world-class high strength training and sport science has made a significant impact on scientific training. Boxing needs high cardio-respiratory function, speed, muscle strength, and anaerobic and intensive physical demands including weight control covering the grading of athlete's.     

Mutational analysis of hypoxia‐related genes HIF1α and CUL2 in common human cancers

Park SW, Chung NG, Hur SY, Kim HS, Yoo NJ, Lee SH. Mutational analysis of hypoxia‐related genes HIF1α and CUL2 in common human cancers. APMIS 2009; 117: 880–5. Hypoxia is a general feature of solid cancer tissues. Hypoxia upregulates hypoxia‐inducible factor 1α (HIF1α) that transactivates downstream genes and contributes to cancer pathogenesis. HIF1α is upregulated not only by hypoxia but also by genetic alterations in HIF1α‐related genes, including VHL. Cullin 2 (CUL2) interacts with the trimeric VHL‐elongin B‐elongin C complex and plays an essential role in the ubiquitinated degradation of HIF1α. The aim of this study was to explore whether HIF1α and CUL2 genes are somatically mutated, and contribute to HIF1α activation in common human cancers. For this, we have analyzed the coding region of oxygen‐dependent degradation domain of HIF1α in 47 colon, 47 gastric, 47 breast, 47 lung, and 47 hepatocellular carcinomas, and 47 acute leukemias by a single‐strand conformation polymorphism assay. In addition, we analyzed mononucleotide repeat sequences (A8) in CUL2 in 55 colorectal and 45 gastric carcinomas with microsatellite instability (MSI). We found one HIF1α mutation (p.Ala593Pro) in the hepatocellular carcinomas (1/47; 2.1%), but none in other cancers. We found two CUL2 frameshift mutations in colon cancers (p.Asn292MetfsX20), which were exclusively detected in high MSI cancers (4.9%; 2/41). Our data indicate that somatic mutation of HIF1α is rare in common cancers, and somatic mutation of CUL2 occurs in a fraction of colorectal cancers (colorectal cancers with high MSI). The data suggest that neither HIF1α nor CUL2 mutation may play a central role in HIF1α activation in gastric, colorectal, breast, lung and hepatocellular carcinomas, and acute leukemias.