Search

Motion data are curves over time in a 1D, 2D, or 3D space. To analyze sets of curves, machine learning methods can be applied to cluster them and detect outliers. However, often metadata or prior knowledge of the analyst drives the analysis by defining cohorts. Our goal is to provide a flexible system for comparative visual analytics of cohorts in motion data. The analyst interactively defines cohorts by filtering on metadata properties. We, then, apply machine learning and statistical methods to extract the main features of each cohort. Summarizations of these features are visually encoded using, in particular, boxplots and their extensions to functional and curve boxplots, depending on the number of selected dimensions of the space. These summarizations allow for an intuitive comparative visual analysis of cohorts in a juxtaposed or superimposed representation. Our system provides full flexibility in defining cohorts, selecting time intervals and spatial dimensions, and adjusting the aggregation level of summarizations. Comparison of an individual sample against a cohort is also supported. We demonstrate the functionality, effectiveness, and flexibility of our system by applying it to a range of diverse motion data sets., Vision, Modeling and Visualization, Visualization and Visual Analytics, 151, 160, Ali Sheharyar, Alexander Ruh, Dimitar Valkov, Michael Markl, Othmane Bouhali, and Lars Linsen

Regional anomalies in the myocardial motion of the left ventricle (LV) are important biomarkers for several cardiac diseases. Myocardial motion can be captured using a velocity-encoded magnetic resonance imaging method called tissue phase mapping (TPM). The acquired data are pre-processed and represented as regional velocities in cylindrical coordinates at three short-axis slices of the left ventricle over one cardiac cycle. We use a spatio-temporal visualization based on a radial layout where the myocardial regions are laid out in an angular pattern similar to the American Heart Association (AHA) model and the temporal dimension increases with increasing radius. To detect anomalies, we compare patient data against the myocardial motion of a cohort of healthy volunteers. For the healthy volunteer cohort, we compute nested envelopes of central regions for the time series of each region and each of the three velocity directions based on the concept of functional boxplots. A quantitative depiction of deviations from the spatio-temporal pattern of healthy heart motion allows for quick detection of regions of interests, which can then be analyzed in more detail by looking at the actual time series. We evaluated our approach in a qualitative user study with imaging and medical experts. The participants appreciated the proposed encoding and considered it a substantial improvement over the current methods., Eurographics Workshop on Visual Computing for Biology and Medicine, Cardiovascular, 135, 144, Ali Sheharyar, Alexander Ruh, Maria Aristova, Michael Scott, Kelly Jarvis, Mohammed Elbaz, Ryan Dolan, Susanne Schnell, Kal Lin, James Carr, Michael Markl, Othmane Bouhali, and Lars Linsen

Intracardiac echocardiography (ICE) broadens the spectrum of available echocardiographic techniques and provides the operator direct visualization of cardiac structures in real time. ICE has clear advantages over fluoroscopy, transthoracic echocardiography, and transesophageal echocardiography as the imaging modality of choice in the cardiac catheterization and electrophysiological laboratories. With the development of steerable phased array catheters with low frequency and Doppler qualities, there is marked improvement in visualization of left-sided structures from the right heart. Appropriate utilization of ICE is likely to maximize safety and efficacy of complex interventional procedures and may improve patient outcomes. Future advances in ICE imaging will further improve the ease of device guidance and, in combination with new imaging modalities, could dramatically improve other applications of echocardiography which may result in improved patient outcomes. This review describes the technical evolution of ICE, the use of ICE in guiding percutaneous interventional procedures and possible future applications of ICE in the ever-growing field of interventional cardiology.

The causes of systemic venous hypertension (SVHT) include cardiac- and circulatory-related factors, whereas its consequences include the congestion of hepatic, splanchnic, and peripheral circulations, which contribute significantly to the clinical congestive heart failure syndrome. Based on a disequilibrium in hydrostatic and oncotic pressures, the increased filtration and formation of interstitial fluid at these sites with an accompanying increase in lymph flow mandates an increment in lymphatic drainage to protect against such congestion and the appearance of edema and ascites. However, lymph flow via the thoracic duct into systemic veins is opposed by elevations in central venous pressure. Various management strategies have the potential to prevent and/or correct SVHT. The case of a 54-year-old man with a dilated cardiomyopathy who presented with decompensated biventricular failure, expressed as anasarca and ascites, is used to illustrate the importance of SVHT.

Sudden cardiac death (SCD) due to ventricular tachyarrhythmias is a leading cause of death in the United States. Various etiologies, including ischemic and nonischemic cardiomyopathies, hypertrophic cardiomyopathy, valvular or congenital heart diseases and other less common disorders, may result in SCD. Beta blockers are the only class of medications that have been shown to be beneficial in the primary prevention of SCD. However, recently, aldosterone antagonism early after myocardial infarction has also been shown to significantly reduce the risk of SCD. Multiple trials have elaborated on the potential benefits of implantable cardioverter defibrillators (ICD) in appropriately selected patients. However, there is still some controversy regarding the optimum period for ICD implantation, and its cost-effectiveness. An evidence-based approach to primary and secondary prevention of SCD is presented. Management of out-of-hospital cardiac arrest is briefly discussed.

As data continue to show the benefits of radial artery access, the versatility and feasibility of this approach for complex coronary interventions is continually tested. We report successful angioplasty of a circumflex obtuse marginal coronary lesion crossed retrogradely via a saphenous vein graft arising from the descending aorta, accessed via the left radial artery.

In patients hospitalized with decompensated biventricular failure having hypoalbuminemia and lymphocytopenia without underlying hepatic or renal disease, we addressed the presence of a protein-losing enteropathy (PLE).We studied 78 patients having a dilated cardiomyopathy, who were hospitalized with congestive heart failure (CHF) and hypoalbuminemia of uncertain origin. In the first 19 patients, we investigated the presence of PLE using Tc-Dex scintigraphy together with serum albumin 2 to 4 weeks later when compensation had been restored. In the next 59 patients, presenting with reduced serum albumin and relative lymphocyte count at admission, these parameters were again monitored (2-4 weeks) later when symptoms and signs of CHF had resolved.PLE, documented by Tc-Dex(70) scintigraphy, was found in 10 of 19 patients and whose hypoalbuminemia (2.7 +/- 0.1 g/dL, mean +/- standard error of mean) were corrected (3.3 +/- 0.1 g/dL; P0.05) with the resolution of CHF, whereas in the 9 patients without a PLE, reduced baseline serum albumin (2.6 +/- 0.1 g/dL) failed to improve on follow-up (2.6 +/- 0.2 g/dL) in keeping with malnutrition. Relative lymphocyte count was reduced (14.6 +/- 1.5%) in patients with PLE but was normal (21.4 +/- 3.3%; P0.05) in those without PLE. Serum albumin and relative lymphocyte count were each reduced at admission (2.8 +/- 0.1 g/dL and 14.4 +/- 1.0%, respectively) in 59 patients and increased (P0.05) to normal values (3.5 +/- 0.1 g/dL and 24.9 +/- 1.0%) 2 to 4 weeks after they were compensated.Enteral losses of albumin and lymphocytes account for the reversible hypoalbuminemia and lymphocytopenia found in patients hospitalized with CHF having splanchnic congestion.

A reduction in relative lymphocyte count (%L) has been reported in whites with heart failure that inversely correlated with jugular venous pressure thereby implicating systemic venous hypertension with splanchnic congestion.: To study whether a reduced %L (20%) occurs in African-Americans (AA) with heart failure and to address pathophysiologic mechanisms having the potential to influence lymphocyte biology and survival, we monitored patients with or without systemic venous hypertension, hypoalbuminemia, hypovitaminosis D, and secondary hyperparathyroidism.In 131 AA (90 men; 53 +/- 12 years): 113 were hospitalized, 50 with decompensated biventricular failure (DecompHF), 24 with acute left heart failure, and 39 with heart disease, but no heart failure (HDNHF); and 18 were outpatients with compensated heart failure. At the time of admission or outpatient visit, we monitored: white blood cell count and %L; and serum albumin, 25(OH)D, and parathyroid hormone (PTH).White blood cell count did not differ among the groups, whereas %L was reduced only in those with DecompHF (15 +/- 1%; P0.05) versus 25 +/- 2% with left heart failure, 29 +/- 1% in HDNHF, and 28 +/- 3% in compensated heart failure. Serum albumin was reduced in DecompHF (2.8 +/- 0.1; P0.05), but not in any of the other groups. Reduced 25(OH)D (30 ng/mL), in keeping with hypovitaminosis D, was found in all AA, whereas elevated serum PTH (65 pg/mL) was found only in those with DecompHF (123 +/- 22 pg/mL).A relative lymphocytopenia, together with hypoalbuminemia and elevated PTH, were found only in hospitalized AA with DecompHF. These findings implicate splanchnic congestion and the enteric loss of lymphocytes and albumin with an associated secondary hyperparathyroidism.

Atrial fibrillation (AF) is the most common clinically encountered arrhythmia affecting 0.4% of the general population. Its prevalence increases with age, affecting more than 6% of people over 80 years of age. The annual risk of ischemic stroke in patients with lone AF is approximately 1.3%. This annual risk increases up to 10% -12% in patients with a prior stroke or transient ischemic attack. Randomized clinical trials (RCT) comparing adjusted-dose oral anticoagulation and placebo showed a risk reduction of 61% (95% CI 47% to 71%). The absolute risk reduction for stroke with oral anticoagulants is about 3% per year. Aspirin has been shown in meta-analyses to have on average a 20-25% relative risk reduction, and is inferior to oral anticoagulants. In high risk patients with AF warfarin is a class I ACC/AHA indication unless there is a contraindication for anticoagulation. Unfortunately, this therapy requires frequent monitoring with blood samples and the interaction with food and several medications makes its use difficult and sometimes unreliable. It requires strict patient compliance and its use is also linked to potentially serious bleeding complications. In clinical practice, less than 60% of patients who do not have contraindications to oral anticoagulation are actually receiving them. Additionally, of those that receive oral anticoagulation, less than 50% are consistently within therapeutic targets. As such, the “real world” efficacy of a strategy towards prescribing oral anticoagulants is likely significantly lower than that demonstrated in clinical trials. As such, the need to discover other methods of anticoagulation with oral bioavailability, predictable pharmacokinetics, and minimal interactions with diet and other pharmacological agents is imperative. In high risk patients with AF warfarin is a class I ACC/AHA indication unless there is a contraindication for anticoagulation. Unfortunately, this therapy requires frequent monitoring with blood samples and the interaction with food and several medications makes its use difficult and sometimes unreliable. It requires strict patient compliance and its use is also linked to potentially serious bleeding complications. In clinical practice, less than 60% of patients who do not have contraindications to oral anticoagulation are actually receiving them. Additionally, of those that receive oral anticoagulation, less than 50% are consistently within therapeutic targets. As such, the “real world” efficacy of a strategy towards prescribing oral anticoagulants is likely significantly lower than that demonstrated in clinical trials. As such, the need to discover other methods of anticoagulation with oral bioavailability, predictable pharmacokinetics, and minimal interactions with diet and other pharmacological agents is imperative. Low molecular weight heparin has a more predictable bioavailability and a longer half-life, but its subcutaneous mode of administration and long-term risks, in particular, osteoporosis makes the chronic use of this medication non-feasible. An-tiplatelet agents such as clopidogrel have proven efficacy and superiority compared to aspirin to prevent systemic vascular events in at-risk patient populations, but currently they do not play an important role in the prevention of AF related thromboembolic events. The ACTIVE study is a randomized trial comparing the combination of clopidogrel and aspirin therapy to oral anticoagulation with warfarin in patients with AF, and was unfortunately terminated prematurely by the data safety and monitoring board because of increased events in the antiplatelet arm. Direct thrombin inhibitors, such as ximelagatran, may be as effective as warfarin for stroke-risk reduction in patients with AF. No anticoagulation monitoring is needed and it has excellent bioavailability, with a twice-daily oral dose. Elevation of liver enzymes was an initial concern regarding the use of this new drug, which is not available for general use. Ongoing pharmacological research and future clinical trials may one day leave the “warfarin days” behind. Unfortunately, the new therapies that are being tested seem to be at least several years away from being available on a widespread basis. In this review, we discuss the underlying pathophysiology of AF and stroke. We also provide a comprehensive discussion regarding various available therapies to treat AF.