tbuckley/cabot-search huggingface dataset:
Abstract 8697: Left Atrial Appendage Function Assessed by Speckle Tracking Echocardiography as a Predictor of Thrombus in Patients with Permanent Atrial Fibrillation
Authors: Tomoko Fujii, Masanori Kawasaki, Ryuhei Tanaka, Koji Ono, Takatomo Watanabe, Maki Nagaya, Noriyuki Onishi, Fumitaka Tokoro, Reiko Matsuoka, Shintaro Abe, Yoshiaki Goto, Takashi Yoshizane, Takashi Kato, Syunichiro Warita, Tai Kojima, Makoto Iwama, Takeshi Hirose, Shintaro Tanihata, Toshiyuki Noda, Mami Iida, Sachiro Watanabe, Shinya Minatoguchi
Journal: Circulation (2011)

Background: Left atrial appendage (LAA) thrombus is a high risk factor of thromboembolism in patients with atrial fibrillation (AF). Spontaneous echo contrast (SEC) and LAA emptying velocity are echocardiographic predictors of LAA thrombus and CHADS2 score is used as a risk stratification of thrombus. However, LAA contractile function may be an important determinant of thrombus. Thus, we assessed the hypothesis that LAA emptying function (EF) would be more useful to predict LAA thrombus in AF. Methods: Using speckle tracking echocardiography (STE) (ACUSON sequoia 512, Siemens), time-LAA or LA volume curve can be automatically provided. LAAEF and LAEF were measured by STE and compared with manual tracing method using transesophageal (TEE) and transthoracic echocardiography in consecutive 142 patients with AF and treated with warfarin. They were grouped according to the presence of thrombus; AF with thrombus (n=38, age 69±10, 30 men) and AF without thrombus (n=104, age 65±12, 80 men). LAAEF and LAEF were defined as (maximum - minimum volume) / maximum volume x 100% during a cardiac cycle. SEC score, LAA peak and mean velocity, left ventricular ejection fraction and LA dimension were also measured. Average values of 3 cardiac cycles were analyzed. Results: LAAEF and LAEF by STE correlated with manual tracing method (r=0.98, r=0.95, respectively, p&lt;0.001). Patients with AF and thrombus were older and had more prior strokes, longer AF duration and reduced LAAEF (Table). Using 20% of LAAEF as a cutoff value, sensitivity was 92% and specificity was 88% for thrombus. In multivariate analysis, LAAEF and age were independent predictors of LAA thrombus. Conclusion: LAA thrombi appeared to exist in elderly patients with AF and more reduced LAAEF compared to AF with preserved LAAEF despite no difference in PT-INR, suggesting that LAA thrombus formation depends on LAA contractility. LAAEF by STE using TEE may be a useful predictor of LAA thrombus in patients with AF and warfarin therapy.
Abstract 15412: PSGL-1 Expressing CD4 T Cells Contribute Plaque Instability in ACS
Authors: Kayoko Sato, Keiko Gomita, Atsuko Futase, Fumiaki Mori, Motoji Sawabe, Nobuhisa Hagiwara
Journal: Circulation (2011)

Background: Adhesion molecules have essential roles for the development of atherosclerosis. We examined whether PSGL-1 expressing CD4 T cells in acute coronary syndrome (ACS) contribute to plaque i...
Abstract 275: The Effect of Cardiopulmonary Resuscitation Using a 30:2 Compression-Ventilation Ratio, Inclusive of 1-Shock Protocol, by Emergency Medical Services Responders
Authors: Ken Nagao, Eizo Tachibana, Kei Nishikawa, Tsukasa Yagi, Naohiro Yonemoto, Morimasa Takayama, Hiroshi Nonogi, Shinichi Shirai, Takeshi Kimura
Journal: Circulation (2012)

BACKGROUND Cardiopulmonary Resuscitation (CPR) using a 30:2 compression-ventilation ratio was designed to increase the number of compressions, reduce the likelihood of hyperventilation, minimize interruptions in chest compressions for ventilation, and simplify instruction for teaching and skills retention. It is unclear whether a 30:2 ratio, inclusive of a 1-shock followed immediately by 2 minutes of CPR using a 30:2 ratio (1-shock protocol) improves survival in patients with out-of-hospital cardiac arrest. METHODS From the All-Japan Utstein Registry, a prospective, nationwide, population-based registry of out-of-hospital cardiac arrest, 287,176 adult patients with out-of-hospital cardiac arrest were included; 199,701 received EMS-responder CPR using a 30:2 ratio and/or 1-shock protocol based on the 2005 CPR guidelines, and 87,475 received EMS-responder CPR using a 15:2 ratio and/or a 3-shock sequence followed by 1 minute of CPR using a 15:2 ratio (3-shock protocol) based on the 2000 CPR guidelines. The primary endpoint was 30-day favorable neurological outcome after cardiac arrest. RESULTS Among all study patients and the subgroups of patients who were classified in layperson CPR status, the 30:2 group had significantly higher frequency of favorable neurological outcome than the 15:2 group. The adjusted odds ratio for favorable neurological outcome after the 30:2 group (reference; the 15:2 group) was 1.97 (95% CI, 1.82 to 2.14) in the whole cohort, and 2.20 (95% CI, 1.94 to 2.50) in the subgroups of patients receiving layperson CPR and 1.81 (95% CI, 1.63 to 2.02) in patients not receiving layperson CPR. In the subanalysis, 4 subsets based on the quartiles of collapse to return of spontaneous circulation (ROSC) interval, the 30:2 ratio had no neurological benefits in quartile 1 (≤13 minutes) not receiving layperson CPR (adjusted odds ratio, 1.22; 95% CI, 0.94 to 1.60) or in quartile 4 (≥29 minutes) receiving layperson CPR (adjusted odds ratio, 1.84; 95% CI, 0.93 to 3.63). CONCLUSIONS EMS-responder CPR using a 30:2 ratio and/or 1-shock protocol improved neurologically intact survival in adults with out-of-hospital cardiac arrest. However, a 30:2 ratio was not the optimal ratio for patients having achieved ROSC after bystander-witnessed arrest.
Abstract 16012: Transcatheter Aortic Valve Frame Covering the Coronary Ostia - Prevalence and Implications for Subsequent Percutaneous Coronary Interventions
Authors: Spyridon Katsanos, Philippe Debonnaire, Frank van der Kley, Meindert Palmen, Arend de Weger, Arthur Scholte, Martin Schalij, Jeroen Bax, Nina Ajmone Marsan, Victoria Delgado
Journal: Circulation (2012)

Introduction. In patients undergoing transcatheter valve implantation (TAVI) with Edwards SAPIEN valve, the prosthesis frame is ideally deployed below the coronary ostia. However, the frame reaches...
Clinical Characteristics and Treatment Outcome Of CNS Involvement (Bing-Neel Syndrome) In Waldenstrom’s Macroglobulinemia
Authors: Tushar Kulkarni, Steven Peter Treon, Robert Manning, Lian Xu, Mikael Rinne, Eudocia Quant Lee, Irene M. Ghobrial, Andrew Norden, Michael J. Kluk, Lakshmi Nayak
Journal: Blood (2013)
Abstract 2347: Atrial Fibrillation Due to Mitral Valve Disease, but Not Lone Atrial Fibrillation is Associated With Increased Left Atrial Fibrosis
Authors: Guillaume S Geuzebroek, Shirley C Van Amersfoorth, Mark G Hoogendijk, Norbert M Van Hemel, Peter C De Bruin, Wim-Jan Van Boven, Jacques M De Bakker, Ruben Coronel
Journal: Circulation (2009)

Introduction: Surgical procedures for AF are less effective in patients with mitral valve disease (MVD) than in patients with lone AF. Left atrial structural changes due to MVD are likely to be responsible. Because atrial fibrosis constitutes a substrate for AF, we hypothesized that left atrial fibrosis is more pronounced in patients with AF and mitral valve disease (AF+MVD) compared to patients without AF or with lone AF. Methods: Left and right atrial appendages (LAA and RAA) amputated during Maze III surgery for lone AF or AF+MVD (5 patients in each group) were embedded in paraffin. Atria from 10 post-mortem patients without a cardiac history served as a control. A total of 160 random images (4 μm sections, Picro Sirius Red staining, 10-fold magnification) were obtained and digitalised. The percentage of fibrous tissue was calculated by quantitative morphometry. Perivascular and subepicardial fibrous tissue were excluded from analysis. Results: The control group showed that the amount of fibrous tissue...
THE PATHOLOGIC PHYSIOLOGY OF PELLAGRA
Authors: Roy H. Turner, Virginia Blanchard
Journal: Journal of Clinical Investigation (1931)

Many clinical observers have considered acidosis to be a common and important feature of pellagra, an impression due chiefly to the acid reaction of the urine.An elaborate theory, based largely on an active imagination, explained the pathogenesis of the disease as an acidosis due to taking acid silicates in the drinking water.The first clear indication that a disturbance in acid-base equilibrium occurred in pellagra was furnished by Sullivan and Stanton (1), who showed that for some pellagrins an abnormally high proportion of the urinary nitrogen was bound as ammonia.Ballif and Gherscovici, in Roumania, are the only workers who have used modern methods in the study of acid-base equilibrium in pellagra.Their reports are characterized by a distressing scarcity of clinical and chemical detail.They report (2) determinations of CO2 combining power for 80 pellagrins by stating that for 59 per cent it was less than 65 volumes per cent, for 27 per cent less than 50 volumes per cent, for 6 per cent less than 40 volumes per cent, and for 8 per cent greater than 65 volumes per cent.They also found that the administration by mouth of 10 grams of sodium bicarbonate had little effect on the urinary pH and the CO2 combining power of the plasma.In a later study (3) they determined plasma pH by a colorimetric method, and for 20 patients with grave acute pellagra they found an average pH of 7.27, and for the same patients an average CO2 combining power of 49 volumes per cent.For 10 patients with chronic pellagra the aver- age values given were normal.Ballif, Rennescu and Reznic (4)
Abstract 1925: Prognostic Value of Cardiac MRI in Patients Referred to Evaluate Known or Possible Coronary Artery Disease
Authors: Jie J Cao, W P Bandettini, Johnny Pang, Andrew E Arai
Journal: Circulation (2006)

Introduction: The assessment of left ventricular (LV) function and myocardial viability is part of a comprehensive evaluation for coronary artery disease (CAD) by cardiac MRI. The specific aim of t...
禽流感引起的传播危险：对人类的危险性很小，但我们需要做好准备
Authors: WendySBarclay, MariaZambon, 王爱霞
Journal: BMJ (2004)

一场暴发流行的禽流感席卷了东南亚的家禽行业，严重的摧毁了该地区的社会经济，但是怎样与人的健康相关联呢?至少在越南有7人感染了从家禽中发现的流感病毒亚型H5N1，其中6人死亡。在泰国3个男孩接触了病毒，2个死亡。这些病例很少，但研究者们至今从病例中发现，病毒并非通过人传播人，而是通
胸闷-呼吸困难-水肿-皮肤色素沉着及过度角化
Authors: 宋俊贤, 陈红, 陈江天
Journal: BMJ (2010)

患者,男,60岁,因活动后胸闷、气短、呼吸困难和双下肢水肿11年来院就诊. 11年前患者因银屑病开始服用雄黄等中药治疗,在服用中药1个月后突然出现活动后胸闷、气短、呼吸困难和双下肢水肿,无胸痛,无晕厥、黑曚,无头痛、头晕,无意识丧失和精神异常,无腹痛、腹胀、恶心、呕吐等,在当地医院给予强心、利尿和扩血管等治疗后好转。
Abstract 8738: Long-term Outcomes of Catheter Ablation or Surgical Ablation to Eliminate Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy
Authors: Moustafa Banna, Patrick Tchou, Walid Saliba, Bruce D Lindsay, A. M Gillinov, Nicholas G Smedira, Eugene H Blackstone, Harry M Lever, Oussama M Wazni
Journal: Circulation (2010)
Substantial study is imminent
Authors: S. Thacker, R. Jones
Journal: BMJ (1996)

EDITOR,—Alice McGrath and Graham Jackson's survey of neuroleptic prescribing in nursing homes is a timely addition to the scant British literature on this important subject.1 They report a high prevalence of “inappropriate” neuroleptic prescribing according to American guidelines. However, judging appropriateness by guidelines fails to recognise …
Abstract 16199: Sleep Disordered Breathing is an Independent Risk Factor for Left Atrial Enlargement in Patients With Congestive Heart Failure
Authors: Wanda Maeuser, Thomas Demming, Sarah Sandrock, Hendrik Bonnemeier
Journal: Circulation (2011)

Left atrial enlargement (LAE) is a predictor for adverse outcome in patients with congestive heart failure (CHF). Sleep apnea syndrome (SAS) is highly prevalent in CHF and is also associated with p...
Abstract 16746: The Utility of a National Online Weight Reduction Intervention: Experience with “Beat the Holiday Bulge”
Authors: Caitlin Johnson, Fatima Rodriguez, Yun Wang, JoAnne Foody
Journal: Circulation (2011)

Background: Novel approaches to the obesity epidemic are required. While the use of online intervention to reduce weight and improve cardiovascular (CV) health, little research has assessed the efficacy of online weight management programs in reducing CV risk factors. Methods: A free online weight management program, Beat the Holiday Bulge (BHB), was offered to employees at workplaces nationwide during the holiday season from Nov 1 st to Jan 31 st , 2011, to prevent weight gain during the holidays. Rolling enrollment was open from Nov 1 st to Jan 1 st , and participants completed a comprehensive health risk assessment (HRA) upon enrollment and participated in a 4-week weight-maintenance program including 4 one-week workshops on exercise, diet, and risk factors for CV disease. Those completing HRA and all four workshops were eligible for prizes. Results: From Nov 1 st to Jan 31 st , 1,640 participants enrolled in BHB. Most participants were female (83% female vs. 17% male) between ages 46 and 55, followed by those 46-55 (28.9%), 36-45 (23.7%), 56-65 (19.6%), 26-35 (17.3%), 25 and under (5.4%) and 66 and over (3.2%). Among participants, 1,480 completed an HRA. Of those completing an HRA, 31.2% were obese (BMI &gt;30), 21.9% had high cholesterol, 20.7% had hypertension, and 65% do not exercise regularly (&lt; 3 days/week). Of 1640 total participants enrolled, 1600 completed week 1 tasks, 286 completed weeks 1 and 2, 126 completed weeks 1-3 and 67 completed all 4 weeks. From Nov 1 st - Jan 31 st , there were a total of 14,369 log-ins (Average 8.8 times per person), and participants lost of a total of 1,132.8 lbs (average 0.69 lbs per person). Conclusion: A seasonal online weight-maintenance intervention was successful in not only preventing weight gain but promoting weight loss during the holidays. Women were more likely to participant than men, and most had at least one CV disease risk factor. While nearly all participants completed the first week of tasks and less then 1% completed all four, weight-loss was associated with participation, regardless of completion of tasks. With high rates of CV risk factors in the workforce and growing interest in online wellness programs, our results support online interventions as effective strategies for weight loss and improvement of CV health.
A 3-bp Deletion VK600-1E in the BRAF Gene Detected in a Young Woman with Papillary Thyroid Carcinoma
Authors: S. Dvorakova, V. Sykorova, E. Vaclavikova, P. Sykorova, P. Vlcek, D. Kodetova, P. Lastuvka, J. Betka, M. Mokrejs, J. Vcelak, B. Bendlova
Journal: Endocrine Pathology (2015)
Abstract 15780: Sinoatrial Node Mapping and the Mechanisms of Sinus Rate Acceleration
Authors: Tetsuji Shinohara, Boyoung Joung, Mitsunori Maruyama, Su-Kiat Chua, Seongwook Han, Mark J Shen, Peng-Sheng Chen, Shien-Fong Lin
Journal: Circulation (2010)

Background: Studies using isolated sinoatrial node (SAN) cells indicate that rhythmic spontaneous sarcoplasmic reticulum Ca release (Ca clock) plays an important role in SAN automaticity. However, ...
Abstract 15014: Initial Clinical Indications for Revascularization Determine the Cardiovascular Outcomes In Patients with Unprotected Left Main Coronary Artery Stenosis
Authors: Suk-Won Choi, Duk-Woo Park, Yong-Giun Kim, Gyung-Min Park, Ki Won Hwang, Chang Hee Kwon, Jeong Yoon Jang, Hae-Geun Song Song, Jung-Min Ahn, Won-Jang Kim, Jong-Young Lee, Soo-Jin Kang, Seung-Whan Lee, Young-Hak Kim, Cheol Whan Lee, Seong-Wook Park, Seung-Jung Park
Journal: Circulation (2011)

Introduction: The simple risk stratification that identify high-risk subsets of patients with unprotected left main coronary artery (ULMCA) stenosis undergoing revascularization has not been well e...
Abstract 16072: Calcium-Dependent PKC Activation Inhibits Slow Repolarizing Cardiac Current by Decreasing Ion Channel Membrane Expression
Authors: Jin O-Uchi, Coeli M Lopes
Journal: Circulation (2011)

Background:  Sudden cardiac death due to fatal arrhythmias is a major cause of mortality in patients with congestive heart failure. Decrease in the slow delayed rectifier K +  current (IKs) is linked to increased propensity to ventricular arrhythmias observed in human failing hearts and animal models of heart failure, but the mechanisms are largely unknown. Ca 2+ -dependent PKC isoforms (cPKC) are strongly activated in human heart failure.   Methods:  Human IKs channels were expressed in HEK293T cells and infected into isolated adult rat ventricular myocytes. IKs current was measured by patch clamp. Subcellular localization of GFP-tagged KCNQ1 subunits was observed by confocal microscopy.   Results:  IKs currents were inhibited by α 1 -adrenergic receptor stimulation (α 1 -AR), application of a cPKC activator peptide, or overexpression of PKCα catalytic subunit, due to a dramatic decrease in plasma membrane localization (Figure A&B). Internalization was abolished by expression of dominant-negative dynamin. Application of a non-isoform-specific PKC inhibitors or cPKC inhibitory peptide abolished channel internalization (Figure B). Expression of the auxiliary KCNE1 subunit was necessary for the effect and mutation of a putative cPKC phosphorylation site in KCNE1 abolished inhibition. In adult ventricular myocytes, 2-hr α 1 -AR-cPKC stimulation strongly decreased IKs membrane expression at transverse tubule.   Conclusion:  Persistent cPKC activation strongly inhibits IKs currents by decreasing channel plasma membrane expression via direct phosphorylation of the KCNE1 auxiliary subunit. Our results suggest that PKCα-dependent phosphorylation of the IKs channel contributes to QT prolongation and arrhythmogenesis in heart failure and implicate cPKC inhibitors as potential novel antiarrhythmic drugs.
Abstract 988: Tissue Inhibitor Of Metalloproteinase-3 Regulates Myocardial Fibrosis By Regulating The TGF{beta}-TNF Interaction
Authors: Zamaneh Kassiri, Mehrdad Hariri, Shalini Anthwal, Gavin Y Oudit, Fayez Dawood, Peter P Liu, Rama Khokha
Journal: Circulation (2007)

Fibrosis is the outcome of excess deposition of extracellular matrix components and underlies diastolic and systolic heart failure. Metalloproteinases (MMPs and ADAMs) and their inhibitors (TIMPs) ...
T Cells Engineered with a Chimeric Antigen Receptor (CAR) Targeting CD19 (CTL019) Have Long Term Persistence and Induce Durable Remissions in Children with Relapsed, Refractory ALL
Authors: Stephan A. Grupp, Shannon L Maude, Pamela Shaw, Richard Aplenc, David M. Barrett, Colleen Callahan, Anne Chew, Simon F. Lacey, Bruce L. Levine, J. Joseph Melenhorst, Laura Motley, Susan R. Rheingold, Angela Shen, David T. Teachey, Patricia A. Wood, David L Porter, Carl H. June
Journal: Blood (2014)
Abstract 3403: Progression of Isolated Tricuspid Regurgitation Late After Left-Sided Valve Surgery
Authors: Chisato Izumi, Shuichi Takahashi, Sumiyo Hashiwada, Kazuyo Kuwano, Hayato Matsutani, Seiko Nakajima, Masataka Nishiga, Kazuya Yamao, Jiro Sakamoto, Koji Hanazawa, Kazuyasu Yoshitani, Makoto Miyake, Kazuaki Kaitani, Toshiaki Izumi, Yoshihisa Nakagawa, Kazuo Yamanaka
Journal: Circulation (2009)

Objectives:   Severe tricuspid regurgitation (TR) sometimes develops late after left-sided valve surgery without significant left heart failure, pulmonary hypertension or rheumatic tricuspid valve. The degree of TR influences functional status and prognosis in patients after surgery. The purpose of this study is to clarify the clinical characteristics and mechanism of severe isolated TR late after left-sided valve surgery.    Methods:   Among 520 consecutive patients who underwent left-sided valve surgery between 1990 and 2003, we studied 372 patients (mitral only; 179, aortic only; 133, both; 60patients), who showed no or mild TR early after operation and were followed up with echocardiography for at least 5 years. Concominant tricuspid annuloplasty was performed in 54 patients and 199 patients were afflicted with atrial fibrillation. Mean follow-up period was 9.4 years. The degree of TR, tricuspid annular diameter, right atrial area and tenting area were measured at follow-up echocardiographic examinations and chronological changes of these factors were evaluated.    Results:   Among the 372 patients, severe isolated TR was detected in 23 patients (6%). Atrial fibrillation and mitral valve surgery were significant clinical risk factors for progression of severe isolated TR. 9.2% of the patients after mitral valve surgery, in particular, 18% of the patients after mitral valve replacement showed severe isolated TR. In the 23 patients with severe isolated TR, the tricuspid annular diameter and the right atrial area were already enlarged early after left-sided valve surgery and both of these increased prior to TR progression. Tenting area wasn’t related to the progression of severe isolated TR. Severe TR devloped at a mean of 8.6 years (2–18 years) after surgery.    Conclusions:   Severe isolated TR developing late after mitral valve surgery wasn’t uncommon, thus it is important to recognize this disease entity. Annular dilatation was the main cause of isolated TR and serial echocardiographic data is important to detect late progression of isolated TR and to assess its mechanisms.
Abstract 1685: Thieno[2,3-c]isoquinolin-5-one (TIQ-A), a Potent Poly(ADP-ribose) Polymerase Inhibitor, Promotes Atherosclerotic Plaque Regression in High Fat Diet-fed ApoE-deficient Mice: Effects on Inflammatory Markers and Lipid Content
Authors: Chetan P Hans, Mourad Zerfaoui, Amarjit Naura, Dana Troxclair, Jack P Strong, Hamid Boulares
Journal: Circulation (2008)

Background: We recently showed that poly(ADP-ribose) polymerase (PARP) is activated within atherosclerotic plaques in an animal model of atherosclerosis and that PARP inhibition pharmacologically o...
Abstract 2288: Does Perioperative Diastolic Dysfunction Affect Postoperative Outcome ?
Authors: Robina Matyal, Feroze Mahmood, Balachundar Subramaniam, Peter Panzica, Swaminathan Karthik, Frank Pomposelli, Philip Hess
Journal: Circulation (2007)

Objective: To assess the presence of perioperative diastolic dysfunction (DD) in patients undergoing vascular surgery with transesophageal echo (TEE) and its association with postoperative morbidity and mortality. Methods: We conducted TEE examinations on 282 patients undergoing high-risk vascular surgery under general anesthesia (GA). All TEE examinations were conducted after induction of GA and endotracheal intubation. We used transmitral flow propagation velocity (Vp); a validated echocardiographic index of left ventricular filling and DD, for assessment of perioperative DD. A Vp value of &lt; 0.45m/sec is considered diagnostic of DD. We used Fisher’s Exact Test and Pearson’s Chi-Square to compare the incidence of postoperative complications i.e. congestive heart failure (CHF), myocardial infarction (MI), arrhythmias, prolonged intubation and death in patients with and without DD. Statistical significance was set at a p-value of ≤ 0.05. Results: There were 176 males and 102 females. The mean age in males was 68.6 and 72 years in females. We were able to assess Vp in all these patients. A total of 184 (66%) patients had Vp &lt; 0.45 m/sec. Of these patients with DD, 60 patients (32.6%) had at least one adverse outcome. Ejection fraction (EF) was comparable between the patients with and without adverse outcomes. A Vp value of &lt;0.45m/sec was associated with a statistically significant increase in the incidence of postoperative CHF and arrhythmias and a trend towards higher incidence of postoperative prolonged intubation but not that of MI or death (Table 1 ). Conclusion: Vp is an easily obtained index of left ventricular filling. Almost 2/3 rd (66%) of the patients presenting for vascular surgery were diagnosed to have DD by an abnormal Vp. Presence of perioperative DD is associated with a higher incidence of postoperative complications (CHF, Arrhythmias, Prolonged Intubation). Table 1 Vp: Transmitral Flow Propagation Velocity