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Long- and Short-Time Analysis of Heartbeat Sequences: Correlation with Mortality Risk in Congestive Heart Failure Patients

Description: Article discussing long- and short-time analysis of heartbeat sequences and the correlation with mortality risk in congestive heart failure patients.
Date: 2003
Creator: Allegrini, Paolo; Balocchi, Rita; Chillemi, Santi; Grigolini, Paolo; Hamilton, P.; Maestri, Roberto et al.
Partner: UNT College of Arts and Sciences

The Adenosine Antagonist Aminophylline Attenuates Pacing-Induced Coronary Functional Hyperemia

Description: Left coronary blood flow (LCBF), left ventricular oxygen, extraction [(a-v)O₂ ], and myocardial oxygen consumption (MVO₂) were monitored in 10 dogs. HR was paced at 120 bpm and then increased to 180 bpm to elicit a hyperemic response (ΔLCBF). During the hyperemia, the vaso-dilatory response to exogenous adenosine (F_AD) was tested. Twenty min. after injection of aminophylline (100 mg/i.v.), HR was again increased. F_AD was again tested. The pacing-induced increase in MVO₂ (ΔMVO₂) was not affected by aminophylline (P>0.05). However, the slope ΔLCBF/ΔMVO₂ was decreased, and the slope (a-v)O₂ /ΔMVO₂ was increased. F_AD was also decreased and the magnitude of the reduction was correlated with the decrease in ΔLCBF/ΔMVO₂ (r=0.82). These results suggest that adenosine may play an role in coronary functional hyperemia induced by increases in heart rate.
Date: December 1984
Creator: Randall, John Robert
Partner: UNT Libraries

Depression and Heart Rate Variability in Patients with Coronary Artery Disease

Description: Depression is an independent risk factor for morbidity and mortality in patients with coronary artery disease (CAD). Altered autonomic nervous system (ANS) activity, a common feature of depression, is also a risk factor for cardiac events in patients with CAD. Heart rate variability (HRV) reflects ANS activity, and reduced HRV predicts morbidity in cardiac populations. The purpose of this study was to determine whether differences in HRV exist between depressed and nondepressed patients with CAD. Twenty-one depressed inpatients, with angiographically documented CAD were retrospectively matched to 21 nondepressed CAD patients by sex, age, and smoking status. Demographic, medical, psychological interview data, and 24-hour ECG recordings were obtained. Depressed subjects had significantly lower HRV, or trends toward lower HRV, than nondepressed subjects, even after controlling for severity of CAD. Subject groups did not differ on left ventricular ejection fraction, history of myocardial infarction, or any other relevant medical variable assessed. These results suggest that depression is associated with decreased HRV in patients with CAD, and may help to explain the increased rates of cardiac events observed in CAD patients with depression.
Date: December 1994
Creator: Saunders, Roger D. (Roger Dean)
Partner: UNT Libraries

Visualization of Fiber Structurein the Left and Right Ventricleof a Human Heart

Description: The human heart is composed of a helical network of musclefibers. Anisotropic least squares filtering followed by fiber trackingtechniques were applied to Diffusion Tensor Magnetic Resonance Imaging(DTMRI) data of the excised human heart. The fiber configuration wasvisualized by using thin tubes to increase 3-dimensional visualperception of the complex structure. All visualizations were performedusing the high-quality ray-tracing software POV-Ray. The fibers are shownwithin the left and right ventricles. Both ventricles exhibit similarfiber architecture and some bundles of fibers are shown linking right andleft ventricles on the posterior region of the heart.
Date: July 12, 2006
Creator: Rohmer, Damien; Sitek, Arkadiusz & Gullberg, Grant T.
Partner: UNT Libraries Government Documents Department

Effects of Age, Fitness Level, and Exercise Training upon Autonomic Control of Heart Rate

Description: In this study the effects of age (18-55 years), differing levels of fitness (VO 2max ranging from 35.5 to 68.8ml.kg-1.min-1) and endurance training (10 weeks) on heart rate control were investigated. Fitness level was initially determined by a VO2max stress test, succeeded by cold hand and cold face pressor test of autonomic activity. Following these baseline measurements, the subjects (32 nonsmoking male volunteers) were endurance-trained three to four times a week for a 10-week period. The baseline tests were readministered following the 10-week dynamic exercise training period. These data suggest that a natural consequence of aging is a diminishment of autonomic heart rate control; however, endurance training appears to interrupt the aging influence. Individuals of low fitness level appear to have heart rate control dominated by the sympathetic system, while individuals with high fitness levels have a vagally dominated heart rate control system.
Date: May 1980
Creator: Baun, William Boyd
Partner: UNT Libraries

Alpha-adrenergic modulation of coronary blood flow and cardiac function during exercise in dogs

Description: In the president study alpha-receptor modulation of coronary flow and cardiac function was examined in exercising dogs, chronically instrumented to measure: circumflex blood flow velocity (CFV), heart rate (HR), global left ventricular function (LVP and dp/dtmax) and regional left ventricular function (%SL and dL/dt(s)max).
Date: December 1985
Creator: Overn, Steven P. (Steven Paul)
Partner: UNT Libraries

Real event detection and the treatment of congestive heart failure: an efficient technique to help cardiologists to make crucial decisions

Description: Paper discussing the treatment of congestive heart failure. Abstract: Using a method of entropic analysis of time series we establish the correlation between heartbeat long-range memory and mortality risk in patients with congestive heart failure.
Date: September 2002
Creator: Allegrini, Paolo; Balocchi, Rita; Chillemi, Santi; Grigolini, Paolo; Hamilton, P.; Maestri, Roberto et al.
Partner: UNT College of Arts and Sciences

My Crown Is in My Heart, Not on My Head: Heart Burial in England, France, and the Holy Roman Empire From Medieval Times to the Present

Description: Heart burial is a funerary practice that has been performed since the early medieval period. However, relatively little scholarship has been published on it in English. Heart burial began as a pragmatic way to preserve a body, but it became a meaningful tradition in Western Europe during the medieval and early modern periods. In an anthropological context, the ritual served the needs of elites and the societies they governed. Elites used heart burial not only to preserve their bodies, but to express devotion, stabilize the social order and advocate legitimacy, and even gain heaven. Heart burial assisted in the elite Christian, his or her family, and society pass through the liminal period of death. Over the centuries, heart burial evolved to remain relevant. The practice is extant to the present day, though the motivations behind it are very different from those of the medieval and early modern periods.
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Date: May 2013
Creator: Duch, Anna M.
Partner: UNT Libraries

Control of Heart Rate by Progressive Relaxation Techniques and Cerebral Electrotherapy

Description: This study presents the findings of an investigation of the effects of two different treatments, progressive relaxation and cerebral electrotherapy, on heart rate. With progressive relaxation, the subject relaxes by following instructions. With cerebral electrotherapy, relaxation is due to an external source of stimulation. Decreases in heart rate for subjects receiving progressive relaxation were compared with decreases for subjects receiving cerebral electrotherapy. A placebo group was used to evaluate the effects of both treatments independently. While decreases in heart rate were observed for both treatments, only progressive relaxation produced decreases significantly greater than those of the placebo group. However, decreases in heart rate produced by progressive relaxation were not significantly greater than decreases produced by cerebral electrotherapy.
Date: December 1974
Creator: Chambers, Jim A.
Partner: UNT Libraries

Pharmacological, Temperature, and Electrogram Studies on the Posterior Lymph Heart of the Bullfrog

Description: In view of the discrepancies and conflicts produced by previous studies on amphibian lymph hearts, a study was initiated to reinvestigate the pharmacological, temperature, and electrical aspects of lymph heart physiology. Bullfrogs were chosen as the experimental animal, All lymph heart responses to experimentation were physiographically recorded as myograms and electrograms. The results are in agreement with previous studies on some aspects and in conflict on others. From the results obtained, lymph heart muscle appears to possess both skeletal and cardiac muscle properties as evidenced by drug responses and reactions to temperature. The precise components of the electrogram remain unclear. It is suggested that further investigation should be made to better determine the true nature of lymph hearts.
Date: May 1975
Creator: Oberndorfer, Carol E.
Partner: UNT Libraries

The Effects of Positive Emotion, Negative Emotion, Flourishing, and Languishing on Cardiovascular Risk

Description: Positive psychology has led a movement that concentrates on positive characteristics. The current study examined the relationship between positive emotions, negative emotions, flourishing, languishing, and cardiovascular functioning. The study uses guided imagery to help participants recall a negative emotional event and positive emotional event in a counterbalanced order. The reverse order allowed us to examine the differential contributions of stress buffering versus facilitated recovery effects to higher levels of heart rate variability (HRV). The study also examined the relationship between mental health categories and known cardiovascular disease risk. Univariate analysis of variance revealed that positive emotions can serve as a stress buffer and dampen cardiovascular responses to a negative event. Also, analysis revealed a trend for the prediction that positive emotions can facilitate cardiovascular recovery following a negative event. Exploratory analysis did not reveal differences between a facilitated recovery group and a buffering group for cardiovascular measures. Future studies should include tighter control to help compare the differential influences of stress facilitation and stress buffering on cardiovascular functioning. The results from the study indicate that it is still too early to tell whether mental health buffers those individuals from developing CVD, and to answer whether languishing increases the risk of CVD. Longitudinal studies of young individuals without a prior history of any risk of CVD and who are flourishing or languishing might help provide answers to these questions.
Date: August 2010
Creator: Purdum, Michael B.
Partner: UNT Libraries

The Effect of Steroid Dose Regimen on the Relationship Between Lower Extremity Muscle Function and Cardiac Function in Post Heart Transplant Patients

Description: Differences in cardiovascular/aerobic function in heart transplant patients might be attributed to the rate of corticosteroid withdrawal and/or to skeletal muscle function. This hypothesis was tested among nine male, cardiac transplant recipients. Prednisone dosage was monitored, and isokinetic strength testing was performed at 4 different time periods throughout the first year post-transplantation. Cardiovascular/aerobic measurements were obtained at the fourth time period. Pre-surgery characteristics were obtained from the patient's medical record. Significant Pearson-product moment correlations were only found between muscle function and aerobic function and between pre-surgery characteristics and cardiovascular/aerobic performance. The results of this study show no evidence that rapid reduction of prednisone dosage enhances aerobic function by benefiting skeletal muscle function.
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Date: May 2001
Creator: Galatas, Mary V.
Partner: UNT Libraries

Physiological Effects of Monetary Consequences

Description: Electrodermal responding (EDR) and heart rate (HR) were assessed for seven subjects participating in a reaction time task consequated with monetary bonuses (250, 100, and 10), monetary penalties (250,100, and 10), and a monetary neutral value (00). Unlike previous research employing group designs and a tonic measure (i.e., mean over long periods of time), this study utilized a single-subject design and a phasic measure (i.e., mean over 2-s intervals). Heart rate data was too variable for meaningful analysis. EDR data showed that the peak levels of EDR were higher for penalties than for the corresponding values of bonuses (e.g., -250 vs. +250) for most subjects. Similarly, peak levels of EDR were generally higher during sessions in which consequences were presented than in sessions during which consequences were absent.
Date: May 1998
Creator: Kessler, Jeffrey C. (Jeffrey Charles)
Partner: UNT Libraries

Chronic Ventricular Sympathectomy : Effects on Myocardial Metabolism

Description: Chronic ventricular sympathectomy elicits changes in the coronary circulation, myocardial oxygen consumption and size of infarction resulting fromcoronary occlusion. These changes indicate a change occurring in the basic metabolism of the heart in response to the removal of its sympathetic nervous input. This hypothesis was tested using two groups of dogs, a shamoperated control and a ventricular sympathectomized group. The sympathectomy procedure was an intrapericardial surgical technique which selectively removes ventricular sympathetic input. Four weeks after surgery, left ventricular tissue samples were obtained and rapidly frozen to -80°C. Selected metabolic variables were then compared between the two groups.
Date: August 1993
Creator: Adix Longlet, Nancy J.
Partner: UNT Libraries

The Implications of Cost-Effectiveness Analysis of Medical Technology: Background Paper 2: Case Studies of Medical Technologies: Case Study 9: The Artificial Heart: Cost, Risks, and Benefits

Description: A case study by the Office of Technology Assessment (OTA) that assesses the artificial heart program and "provides an opportunity to address policy questions concerning the distribution of research funds for treating heart disease, the equitable distribution of medical technology, and the potential costs to society before this life-saving technology is available for therapeutic use" (p. 3).
Date: May 1982
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department

Detection and Classification of Heart Sounds Using a Heart-Mobile Interface

Description: An early detection of heart disease can save lives, caution individuals and also help to determine the type of treatment to be given to the patients. The first test of diagnosing a heart disease is through auscultation - listening to the heart sounds. The interpretation of heart sounds is subjective and requires a professional skill to identify the abnormalities in these sounds. A medical practitioner uses a stethoscope to perform an initial screening by listening for irregular sounds from the patient's chest. Later, echocardiography and electrocardiography tests are taken for further diagnosis. However, these tests are expensive and require specialized technicians to operate. A simple and economical way is vital for monitoring in homecare or rural hospitals and urban clinics. This dissertation is focused on developing a patient-centered device for initial screening of the heart sounds that is both low cost and can be used by the users on themselves, and later share the readings with the healthcare providers. An innovative mobile health service platform is created for analyzing and classifying heart sounds. Certain properties of heart sounds have to be evaluated to identify the irregularities such as the number of heart beats and gallops, intensity, frequency, and duration. Since heart sounds are generated in low frequencies, human ears tend to miss certain sounds as the high frequency sounds mask the lower ones. Therefore, this dissertation provides a solution to process the heart sounds using several signal processing techniques, identifies the features in the heart sounds and finally classifies them. This dissertation enables remote patient monitoring through the integration of advanced wireless communications and a customized low-cost stethoscope. It also permits remote management of patients' cardiac status while maximizing patient mobility. The smartphone application facilities recording, processing, visualizing, listening, and classifying heart sounds. The application also generates an electronic medical ...
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Date: December 2016
Creator: Thiyagaraja, Shanti
Partner: UNT Libraries