Cardiocirculatory System Research Articles

Mechanical ventilation strategies alter cardiovascular biomarkers in an infant rat model.

Mechanical ventilation (MV) is routinely used in pediatric general anesthesia and critical care, but may adversely affect the cardiocirculatory system. Biomarkers are increasingly measured to assess cardiovascular status and improve clinical treatment decision‐making. As the impact of mechanical ventilation strategies on cardiovascular biomarkers in ventilated infants is largely unknown, we conducted this retrospective study in a healthy in vivo infant rat ventilation model using 14‐days old Wistar rats. We hypothesized that 2 h of mechanical ventilation with high and low positive end‐expiratory pressure (PEEP), hyperoxemia, hypoxemia, hypercapnia, and hypocapnia would significantly impact B‐type natriuretic peptide (BNP), vascular endothelial growth factor (VEGF), and endothelin‐1 (ET‐1). We found BNP to be driven by both high (9 cmH2O) and low (1 cmH2O) PEEP compared to ventilated control animals (P < 0.05). VEGF concentrations were associated with high PEEP, hyperoxemia, hypoxemia, and hypocapnia (P < 0.05), whereas ET‐1 levels were changed only in response to hypoxemia (P < 0.05). In conclusion, the mode of mechanical ventilation alters plasma biomarker concentrations. Moreover, BNP and VEGF might serve as surrogate parameters for ventilation induced cardiovascular compromise and lung tissue damage. Furthermore, our data support the hypothesis, that sudden onset of hyperoxemia may trigger a quick VEGF release as a possible cellular survival reflex.

Biological Roles of the Eclectic Chromogranin-A-derived Peptide Catestatin.

Research on Chromogranin A (CGA) and its derived fragments convincingly demonstrated the multifunctional activity of the 21 amino acid peptide named Catestatin (CST: human CGA352-372, bovine CGA344-364, rat CGA367-387). This review aims to provide a synopsis of the current information concerning the biological role of CST in health and disease. Structured search of bibliographic databases for peer-reviewed research literature. CST is mainly known as an inhibitor of the nicotinic-dependent Catecholamine (CA) release, and an anti-hypertensive peptide, but its role includes a modulation of antioxidant and immune defense, epidermal function, and adipose tissue homeostasis. CST influences the cardiocirculatory system acting both indirectly, via the autonomic nervous system, and directly by influencing the basal cardiac function, and the stretch-dependent myocardial performance. It also counteracts the effects of adrenergic stimulation on the heart and protects the myocardium from ischemia/reperfusion (I/R) injury, acting in pre- and postconditioning protection. The knowledge on CST is constantly expanding, thanks to a growing number of human studies that document its involvement in physiological modulation and in many severe diseases, also revealing its applicative potential as a clinical biomarker.

Mortality Trends among Cocaine Users Treated between 1989 and 2013 in Northern Italy: Results of a Longitudinal Study

ABSTRACTA total of 852 participants attending 11 centers for addiction treatment in north Italy following problems due to cocaine abuse between 1989 and 2013 were recruited. Two typologies were created: cocaine users (never heroin) (CU) and heroin and cocaine users (HCU). During the 38-year follow-up period, 4.8% of the whole cohort died. Over the whole period, tumors were the main causes of death; starting in 2010, suicide deaths became the first cause of death. Among CUs, most deaths were due to road accidents and suicide; among HCUs, most of the deaths were from opiate overdose and from cardio-circulatory system diseases. The excess mortality observed for all causes in either sex was 6.24; higher in females (15.03) as compared in males (6.23), higher in HCUs (9.06) as compared in CUs (5.21). The directly age-sex standardized mortality rates were 5.31 per 100, higher for females, declining after 2009 for all patients and after 2004 for HCUs. Multivariate analysis confirms the decreasing trend in the risk of death and shows a higher mortality risk for participants in the under-25 age group. Among cocaine users, special attention should be paid to the prevention of suicide deaths.

M for Models

In this short notice I illustrate the role of mathematical models and their impact on our daily life. In particular I provide a couple of instances of applications: one to the enhancement of sports performances, the others to the improvement of our knowledge of the human cardio-circulatory system.

Scholars and scientists in the history of the lymphatic system.

The discovery of the lymphatic system has a long and fascinating history. The interest in anatomy and physiology of this system paralleled that of the blood cardiocirculatory system and has been maybe obscured by the latter. Paradoxically, if the closed blood system appeared open in Galen's anatomy and physiology, and took a very long time to be correctly described in terms of pulmonary and general circulation by ibn Al-Nafis/Michael Servetus/Realdo Colombo and William Harvey, respectively, the open lymphatic system was incorrectly described as a closed circuit connected with arteries and veins. In ancient times only macroscopic components of the lymphatic system have been described, although misinterpreted, including lymph nodes and lacteals, the latter being easily identified because of their milk-like content. For about 15 centuries the dogmatic acceptance of Galen's notions did not allow a significant progress in medicine. After Vesalius' revolution in anatomical studies, new knowledge was accumulated, and the 17th century was the golden age for the investigation of the lymphatic system with several discoveries: gut lacteals (Gaspare Aselli), cloacal bursa (Hieronimus Fabricius of Acquapendente), reservoir of the chyle (Jean Pecquet), extra-intestinal lymphatic vessels (Thomas Bartholin and Olaus Rudbeck dispute), hepatic lymph circulation (Francis Glisson). In the Enlightenment century Frederik Ruysch described the function of lymphatic valves, and Paolo Mascagni provided a magnificent iconography of the lymphatic network in humans. In recent times, Leonetto Comparini realized three-dimensional reconstructions of the liver lymphatic vessels, and Kari Alitalo discovered the lymphatic growth factor/receptor system. Far from a complete understanding of its anatomy and function, the lymphatic system still needs to be profoundly examined.

The cardiovascular system: Mathematical modelling, numerical algorithms and clinical applications

Mathematical and numerical modelling of the cardiovascular system is a research topic that has attracted remarkable interest from the mathematical community because of its intrinsic mathematical difficulty and the increasing impact of cardiovascular diseases worldwide. In this review article we will address the two principal components of the cardiovascular system: arterial circulation and heart function. We will systematically describe all aspects of the problem, ranging from data imaging acquisition, stating the basic physical principles, analysing the associated mathematical models that comprise PDE and ODE systems, proposing sound and efficient numerical methods for their approximation, and simulating both benchmark problems and clinically inspired problems. Mathematical modelling itself imposes tremendous challenges, due to the amazing complexity of the cardiocirculatory system, the multiscale nature of the physiological processes involved, and the need to devise computational methods that are stable, reliable and efficient. Critical issues involve filtering the data, identifying the parameters of mathematical models, devising optimal treatments and accounting for uncertainties. For this reason, we will devote the last part of the paper to control and inverse problems, including parameter estimation, uncertainty quantification and the development of reduced-order models that are of paramount importance when solving problems with high complexity, which would otherwise be out of reach.

Predictors of survival in VA-ECMO: Whom should we cannulate?

The application of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is becoming an increasingly frequent procedure in emergency medicine.1 Correct appraisal of clinical conditions and patient selection are critical not only in terms of expected outcome, but also in terms of adequate temporary support configuration, optimization of resources, and organization of daily hospital activities, since inappropriate implant may remarkably impact all these aspects. According to recent analysis of ECMO use in the USA,1 VA-ECMO was most commonly applied in post-cardiac surgery candidates, however with a constant decline for the period from 2007 to 2011. Indeed, from 57% of the total ECMO cases, post-cardiotomy VA-ECMO went to 38%, but with a significant rise in cases of cardio-pulmonary failure (from 3.9 to 11.1%).1 This situation is certainly further changing during the last 5 years as VA-ECMO in cardiogenic shock and cardiac arrest is becoming more popular. Cardiac arrest: Patient selection in this setting is rather variable. However, potential cardiac etiology (acute myocardial infarction – AMI) represents almost 50% of the causes, and witnessed cardiac arrest, immediate cardio-pulmonary resuscitation (CPR) by bystanders, adequate CPR (possibly with mechanical cardiac massage devices), and not prolonged time from cardiac arrest to ECMO application ( &lt; 60 min) represent positive predictors in the setting of extracorporeal cardio-pulmonary resuscitation (ECPR).2 Recent publications have shown that ECPR might achieve respectful outcome also in elderly patients.3,4,5 Therefore, age should not disqualify potential candidates. Absence of severe acidosis and still acceptable end-tidal CO2 may represent additional elements for patient selection in this setting. Post-cardiotomy: ECMO results in this setting appear rather unsatisfactory with in-hospital survival below 30%.5 Prompt initiation of ECMO and avoiding unnecessary prolonged cardio-pulmonary bypass and metabolic as well as coagulation derangement are among the most relevant key factors. The absence of severe cardiac or co-morbidities prior to surgery and the expected temporary impairment of the cardio-respiratory systems represent additional indications for post-cardiotomy ECMO. Cardiogenic shock: This setting represents the most expanding field of ECMO application. Indications may derive from refractoriness of cardio-circulatory impairment to conventional therapies (drug and IABP). Moreover, in this setting, advanced age and severe co-morbidities may represent relative contraindications. Furthermore, in this field, the potential for cardiac recovery or the possibility to bridge the patient to other treatments, if recovery is considered unlikely, represents indication for ECMO use. Respiratory distress: VA-ECMO is generally indicated if right ventricular dysfunction is present or develops, and if VV-ECMO does not provide sufficient peripheral oxygenation. In the last case, hybrid configuration (VVA or VAV) might be more suitable and advisable. Uncommon indications: Sepsis, trauma (most often treated with VV-ECMO), fulminant myocarditis, Tako-Tsubo, or complicated interventional procedures (TAVI, PCI, balloon valvuloplasty) represent areas in which ECMO is increasingly applied.6,7 Despite wider use in these settings, more clinical evidences are still needed to conclusively define patient selection criteria and ultimate benefits. Finally, a developing indication might be prophylactic VA-ECMO in critically ill patients undergoing either cardiac surgery or interventional cardiological procedures. In these patients, in whom post-procedural severely complicated course is expected, timely and pre-crash support may help to provide a smooth peri-procedural period. Short-time controlled support of cardio-circulatory system and peripheral organ perfusion, with avoidance of metabolic and hemodynamic derangement, may also affect emergency VA-ECMO implant should patient deterioration occur, and allow a better complicated patient management with better final outcome.

Cardiovascular adjustments to heat stress during prolonged exercise.

Prolonged effort in hot environments is increasing popular in extreme sports. The number of long distance athletes taking part in races in extremely warm condition, as in deserts, is larger than in the past and also the race distances are increased thus. The demanding for the heart function are higher than those challenged in the past only by few athletes and in easier conditions. This puts news challenges on the professional involved in these activities and there is a need to better understand how the cardiocirculatory system responses in these extreme environmental conditions. This review paper is focused on the mechanism of cardiovascular drift function during prolonged exercise in heat conditions. Many aspects are treated in the literature. The emerging topics treated in this paper are the sympathetic and vagal nervous activity, heart rate functioning during exercise, dehydration and hyperthermia, the relationships between heart rate and stroke volume oxygen uptake and blood flow dynamic, circulatory responses, left ventricular functions in athletes after strenuous prolonged exercise, and heart rate variability. The literature on the topic appear to be vast and address many important factors of interest for the performance development occurred in hot condition and necessary to be known for the preservation of the health of the athletes.

BASIC HEALTH INDICATORS OF RUSSIAN NAVAL OFFICERS IN 2003-2015

A selective statistical analysis of medical reports on servicemen health status and military service activities on the form 3/MED of military units was performed. Health status of 60% of naval officers who did military service from 2003 to 2015 was analyzed. The analysis of officers’ health problems for 13 years showed that the average annual sick rate was 940±43‰, primary disease incidence — 347±12‰, dispensary observation 154±11‰, inpatient hospitalization — 237±13‰, days away from service — 5018±170‰, dismissal from service for health reasons — 17,48±1,3‰, death rate per 100 000 officers — 127±6 persons. It was found that the level of sick rate and primary disease incidence in naval officers was significantly lower than that of the Russian Armed Forces officers, but the level of dispensary observation, inpatient hospitalization and dismissal was higher. The structure of the formed complex index of naval officers’ health problems was determined in 79% by 6 classes of diseases according to International Classification of Diseases, 10 Edition (ICD-10CM): IX (cardiocirculatory system), IXI (traumas, intoxications, and some other consequences of external causes) X (respiratory system), XI (digestive diseases), XIII (skin and subcutaneous tissue diseases) and IV (endocrine, nutritional and metabolic disorders). Prevention of injuries and diseases of the listed classes will improve the health of Russian naval officers.

Looking for the Word "Angiogenesis" in the History of Health Sciences: From Ancient Times to the First Decades of the Twentieth Century.

This review deals with the origin of the term "angiogenesis", with an attention to John Hunter who is credited with this neologism. A part of the literature refers to a Hunter's work dating 1787, and the other part claims the first use of the term "angiogenesis" in the Hunter's masterpiece published in 1794. Since we were unable to find the term "angiogenesis" in Hunter's works, this review attempts to bring a new contribution to the historical research of this important concept, moving from ancient times to the first decades of the twentieth century, when "angiogenesis" begun to appear on titles of scientific articles. The development of the knowledge on the cardiocirculatory system and the principal steps of this fascinating subject were examined, with particular regard to microvascular bed and vessel sprouting, and to the intriguing observations on blood vessel neoformation that have been also made in the premicroscopic era. In Hunter's works, the concept of angiogenesis indeed emerges, but not the term "angiogenesis". The scientific language occurring during Hunter's time was still old-fashioned, and the term "angiogenesis" was not one of those he used, rather a much later neologism that sounds too modern to appear in that context. Would the first appearance of the term "angiogenesis" occur in late nineteenth century in studies dealing with embryogenesis and organ vascularization? The present study aims to explore the scientific literature and to open a debate to better define this matter.

Tumor Necrosis Factor Related Apoptosis Inducing Ligand (Trail) in endothelial response to biomechanical and biochemical stresses in arteries.

Shear stress is determined by three physical components described in a famous triad: blood flow, blood viscosity and vessel geometry. Through the direct action on endothelium, shear stress is able to radically interfere with endothelial properties and the physiology of the vascular wall. Endothelial cells (ECs) have also to sustain biochemical stresses represented by chemokines, growth factors, cytokines, complement, hormones, nitric oxide (NO), oxygen and reactive oxygen species (ROS). Many growth factors, cytokines, chemokines, hormones, and chemical substances, like NO, act and regulate endothelium functions and homeostasis. Among these cytokines Tumor Necrosis Factor Related Apoptosis Inducing Ligand (TRAIL) has been assigned a regulatory role in ECs physiology and physiopathology. Thus, the aim of this review is to provide a general overview of the endothelial response pathways after different types of biomechanical and biochemical stress in in vitro models and to analyze the crucial role of TRAIL under pathological conditions of the cardiocirculatory system like atherosclerosis, coronary artery disease, and diabetes.

Female sex protects from organ failure and sepsis after major trauma haemorrhage

IntroductionBiological sex is considered a risk factor for adverse outcome after major trauma. We hypothesized that female sex is protective against organ failure, sepsis and mortality in patients with traumatic haemorrhage. Patients and methodsWe selected patients from TraumaRegister DGU® (TR-DGU) with primary admission for blunt trauma with an injury severity score ≥16 and an ICU stay ≥3 days that presented with relevant bleeding in the years 2007–2012. Relevant bleeding was defined as Abbreviated Injury Scale (AIS) ≥3 with an estimated blood loss exceeding 20%, any femoral shaft fracture, any pelvic clamp as surrogate for unstable pelvic fracture or the presence of at least one criteria of haemorrhagic shock: shock index of 0.8–1.4; base excess of −2.0 to −10.0mmol/L; body temperature ≤34°C; transfusion of ≥4 units of packed red blood cells; application of recombinant activated factor VII; any embolization during trauma room phase and pre-hospital resuscitation volume ≥3000ml or any catecholamine use during pre-hospital care in the absence of cardiopulmonary resuscitation. A total of 7560 males and 2774 females were selected and analyzed for sex differences. ResultsHigher rates of multiple organ failure (24.4 vs. 21.3%, Odds ratio [OR] 1.19 (95% confidence interval [95%CI] 1.07–1.33), p=0.001*) and sepsis (16.5 vs. 11.3%, OR 1.55 (95%CI 1.35–1.77), p<0.001*) were observed in males. Organ function of lung, cardio-circulatory system, liver and kidney were better in females, however, there was no difference in mortality. Stratification by age group revealed that in particular age-group 16–44 years was related to improved organ function which may indicate effects of sex hormones in females at reproductive age. Increased rates of sepsis in males were observed throughout virtually all age groups starting at 16 years of age, except in age group 54–64 years. This may suggest suppressive effect of testosterone on immune function. ConclusionsOur study supports the hypothesis that female sex is associated with improved organ function following traumatic injury and haemorrhagic shock, in particular in age groups that are at reproductive age. However, further studies are warranted before sex steroids can be deployed as therapeutic intervention in critically ill trauma patients.

Pre-existing cardiovascular conditions and high altitude travel

The number of persons visiting high altitude regions for various purposes (recreation, business etc.), and the age of people who do so, increases. Therefore there are more and more patients who need specific and individual advice to prevent emergency situations at altitude and to deal with emergencies if the safety strategy should fail. Since literature concerning cardiocirculatory diseases at altitude is scarce and studies with a controlled setting and high evidence level are missing, UIAA MedCom has checked all available literature for specific information to enable physicians who are active in travel or high altitude medicine to advise the patients at the highest possible level of evidence. It must be pointed out that there are several other medical fields where such information is mandatory, e.g. in occupational medicine, when employees depart to high altitude destinations for business purposes. The recommendations are based on a detailed literature research (databases, handbooks and the respective references). For easier use the paper has been structured as follows: general information, cardiocirculatory system and ECG at altitude, several cardiocirculatory diseases and their specific recommendations. The commission concludes, that a general "don't go!" is no state-of-the-art advice for the patients. With the information presented here a safe trip to altitude should be possible for many patients.

Identification of Physical Parameters in a Robotized IPC Device Interacting with Human

Intermittent Pneumatic Compression devices are widely used for various therapies concerning the cardio-circulatory or lymphatic system, and also for performance recovery in sports activity. The development and setup of such devices are mainly based on empirical procedures, while few researches adopt an engineering approach based on mathematical modeling and identification. In this approach, the most critical point is the definition of parameters concerning the human-machine interaction. This paper proposes an original and simple method to identify such parameters, which allows to describe in effective way the main dynamic characteristics, fundamental for a correct design and control of the device.

Systems Biology Approach to the Dissection of the Complexity of Regulatory Networks in the S. scrofa Cardiocirculatory System

Genome-wide experiments are routinely used to increase the understanding of the biological processes involved in the development and maintenance of a variety of pathologies. Although the technical feasibility of this type of experiment has improved in recent years, data analysis remains challenging. In this context, gene set analysis has emerged as a fundamental tool for the interpretation of the results. Here, we review strategies used in the gene set approach, and using datasets for the pig cardiocirculatory system as a case study, we demonstrate how the use of a combination of these strategies can enhance the interpretation of results. Gene set analyses are able to distinguish vessels from the heart and arteries from veins in a manner that is consistent with the different cellular composition of smooth muscle cells. By integrating microRNA elements in the regulatory circuits identified, we find that vessel specificity is maintained through specific miRNAs, such as miR-133a and miR-143, which show anti-correlated expression with their mRNA targets.

Alterations of Short Term Heart Rate Variability in Periinduction Period of General Anaesthesia with Two Intravenous Anaesthetics

Alterations of the parameters of heart rate variability, phenomenon associated with autonomic nervous system balance, have been shown as a possibly very important factor for monitoring of cardiocirculatory system in the perioperative period. Periinduction period of general anaesthesia is very important with significant changes of haemodynamics what could be reflected in the changes of the parameter of heart rate variability. A hundred patients of ASA I and ASA II status who were scheduled for elective abdominal surgical procedures of moderate stress response, were randomly assigned to group I and group II, who were administered propofol or thiopentone as induction anaesthetic, respectively. Monitoring during periinduction period included of monitoring of mean blood pressure (noninvasively), heart rate, pulseoxymetry and recording of electrocardiogram by holter ECG recorder for further analysis of heart rate variability, in four time segments in periinduction period: Tp, T1, T2, T3. Data were presented as mean values of absolute values of the power of the total spectrum of heart rate variability, mean values of the spectrum of low frequency band (LF), mean values of the high frequency range, and the ratio LF/HF. Analysis of the values of hemodynamic parameters has shown decrease of mean arterial blood pressure after induction of anaesthesia with intravenous anesthetics thiopental or propofol, with simultaneous changes of heart rate in the four time segments in periinduction period, without statistically significant changes between the groups. Analysis of the values of parameters of heart rate variability measured in the frequency domain has shown changes of mean values of the absolute values of total power spectrum, mean values of the power of low frequency spectrum and mean values of the power of high power spectrum with reduction of the values of total power spectrum, the power of low frequency spectrum and the power of high frequency spectrum, most pronounced just after induction of anaesthesia with slight increase of the values of total power spectrum and individual components of the spectrum of heart rate variability in the later postinduction period, without statistically significant differences between the groups. The results have shown that in the groups of patients who underwent induction of general anaesthesia with propofol or thiopentone, there have been reductions of the total spectral power and the power of the spectrum of low frequency components and high frequency components with variations in the relationship between the components in the different periods of periinduction time.

Epistasis Analysis for Estrogen Metabolic and Signaling Pathway Genes on Young Ischemic Stroke Patients

BackgroundEndogenous estrogens play an important role in the overall cardiocirculatory system. However, there are no studies exploring the hormone metabolism and signaling pathway genes together on ischemic stroke, including sulfotransferase family 1E (SULT1E1), catechol-O-methyl-transferase (COMT), and estrogen receptor α (ESR1).MethodsA case-control study was conducted on 305 young ischemic stroke subjects aged ≦ 50 years and 309 age-matched healthy controls. SULT1E1 -64G/A, COMT Val158Met, ESR1 c.454−397 T/C and c.454−351 A/G genes were genotyped and compared between cases and controls to identify single nucleotide polymorphisms associated with ischemic stroke susceptibility. Gene-gene interaction effects were analyzed using entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional multiple regression models.ResultsCOMT Val158Met polymorphism showed a significant association with susceptibility of young ischemic stroke among females. There was a two-way interaction between SULT1E1 -64G/A and COMT Val158Met in both MDR and CART analysis. The logistic regression model also showed there was a significant interaction effect between SULT1E1 -64G/A and COMT Val158Met on ischemic stroke of the young (P for interaction = 0.0171). We further found that lower estradiol level could increase the risk of young ischemic stroke for those who carry either SULT1E1 or COMT risk genotypes, showing a significant interaction effect (P for interaction = 0.0174).ConclusionsOur findings support that a significant epistasis effect exists among estrogen metabolic and signaling pathway genes and gene-environment interactions on young ischemic stroke subjects.

84 How can we Improve Tissue Perfusion After Cardiac Surgery

Tissue perfusion is the ultimate goal of a functional cardio-circulatory system and its integrity should remain the essential endeavor of all caregivers in charge of hemodynamically compromised patients. The postoperative...

Influence of blood pressure profile on frailty phenotype in community-dwelling elders in Brazil – FIBRA study

Frailty is a clinical condition associated with pathological aging and biological vulnerability. In the spectrum of events related to frailty, aging of the cardiocirculatory system and abnormalities in arterial blood pressure (BP) partly explain the changes in tissue perfusion and, potentially, the decrease in physiological reserves. This study investigated the relationship between BP levels, systemic arterial hypertension (SAH) and the frailty phenotype by analyzing frailty criteria in a cross-sectional model into the FIBRA network, a populational sample of community-dwelling elders in Southeastern Brazil. Study participants with ≥65 years were selected by probabilistic sampling of residents in the urban area of the municipality of Campinas (n=900). Considering frailty as a whole and the difference between genders, there was a greater proportion of frail or pre-frail individuals among women than men. Analysis of individual frailty criteria showed that weight loss and fatigue were more common among women (18.3% vs. 12.5%, p=0.034 and 22.5% vs. 11.9%, p<0.001, respectively). Comparison of individuals with or without SAH failed to reveal any differences related to frailty criteria. Nevertheless, averages of diastolic blood pressure (DBP) and mean arterial blood pressure values were lower among elderly individuals with reduced grip strength, physical activity and the frailty classification as a whole (OR 0.986, IC 0.975–0.997) (for every 1mmHg reduction in MBP values, the likelihood of being frail increased 1.4%). Our findings corroborate the relationship between BP values and frailty in the elderly and contribute to an understanding of the pathophysiological mechanisms of the syndrome.

A Consecutive Study of Some Electrocard ogramVariables of during Applying Aerobic Stress to (11-12) Years Old Children

Exploring the effect and immediate response of standard aerobic stress in the circulatory system dynamic variables, and recognizing their values at rest, during and directly after aerobic stress in healthy children (11-12) are obviously necessary to reach a scientific basis. The exercises and training modules will be built on such a basis in concord with the children's abilities through discovering and comparing the research variables. Moreover, the results of these studies are part of the basis that is necessary for any sports field work. This agrees with the experts and other concerned views that high sports levels require for physical, skill, and physiological preparation. This study aims to: recognize the values of some physiological variables before, during aerobic stress in (11-12) years old children. Also to discover the different values of the physiological variables between the different measure stages in (11-12) years old children.. To validate the research hypotheses, the researcher used the descriptive method for being suitable to the research methodology. The samples was randomly selected and included (30) male pupils from Bilal Al-Habashi and Al-Muthanna primary schools in Mosul. The researchers used Bruce test for aerobic stress and body measurements to collect data. Some variables were taken as vital indicators for the adequate functioning of the cardio-circulatory system. The variables covered some variables were related to the electrocardiogram (ECG) such as: Heart Rate (HR), Left Ventricular Hypertrophy (LVH),RightVentricularHypertrophy (RVH), QRS Interval,S-T Interval,Q-T Interval, P-R Interval, P-R Segment, T-wave and Heart Axis. To validate the study aims, the researchers applied Bruce test for aerobic stress in all the subjects between (24/3/2008 to 2/4/2008). The researchers used the following statistical tools: (Arithmetic Mean, Standard Deviation, Coefficient of Variation "C.V", Paired- Sample t-test and Relative Change Equation). It is concluded that there is clear increase of HR over the different measure stages of the aerobic stress. And there is more evident decrease of the Diastolic duration than the Systolic duration in successive stress stages, expressed by the variables of the ECG measurements. And there is more increase in the right ventricle' voltage than the that of the left ventricle, especially in the intermediate stage of the consecutive test, although there are no obvious differences in the heart voltage values throughout the variables (LHV, RVH and T-Wave). Finally, although there are no obvious differences in Heart Axis, there is a simple rightward deviation of the heart axis to the intermediate stage of the consecutive test, and up to normalcy at the final stages of the consecutive test.