Heart and Vascular System

It is important to perform an immediate check of the blood oxygen saturation using a pulse oximeter (note that cyanide poisoning can interfere with the readings due to the formation of cyanohaemoglobin). 

There may be bradycardia or tachycardia (both can occur following nerve agent exposure together with hyper- or hypotension). 

The overall perfusion state should be assessed quickly (pulse 120/min and capillary return 2 s) to determine the possible shock state and the need for infusional support. This is important where there is also associated physical injury. 

The regularity of the pulse, supplemented by ECG evidence should be assessed. 

Life-threatening dysrhythmia can be produced by a number of toxic agents. 

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Most of our fat intake will consist of fatty acids with an even number of carbon atoms, but not all dietary fatty acids nor all those synthesized in the liver are saturated. A variable, but probably not inconsiderable, proportion of dietary fatty acids are unsaturated, partly perhaps because a high intake of unsaturated fat is recommended to help reduce the risk for diseases of the heart and vascular system. Unsaturated and odd-numbered fatty acids pose particular chemical problems to the 3-oxidation pathway and additional enzymes are required for their metabolism. 

Physiologists had postulated for a long time about the existence of a sodium excreting hormone to prevent Na overload and consequent deleterious effects of high blood pressure on the heart and vascular system. At least two such natriuretic factors have been described atrial or A-type and brain or B-type natriuretic factors. Structurally, the natriuretic factors are peptides with a cysteine-cysteine disulfide bridge creating a characteristic loop , this is illustrated by Figure 8.8. 

Ramos KS, Melchert RB, Chacon E, et al. Toxic responses of the heart and vascular systems. In Klaassen CD, ed. Cassarett and DouII s Toxicology, The Basic Science of Toxicology. 6th ed. New York McGraw Hill, 2001. 

Ramos, K.S., Chacon, E., and Acosta, D., Toxic responses of the heart and vascular systems, in Casarett and Doull s Toxicology The Basic Science of Poisons, 5th ed., Klaassen, C.D., Ed., McGraw-Hill, New York, 1996, chap. 17, pp. Ail-521. 

Diseases of the heart and vascular system encompass a variety of conditions, the most relevant of them being strictly interrelated, as show in Fig. 1. 

Thyroid Hormone Action within the Heart and Vascular System from Cellular to Hemodynamic Effects... 

TH clearly affects the homeostasis of the cardiovascular system the principal basic mechanisms involved in TH control of the heart and vascular system are briefly discussed below. 

Red clover contains isoflavones, compounds that are structurally similar to the human hormone estradiol and capable of binding to estrogen receptors (Umland et al. 2000). Some studies have indicated that red clover isoflavones have a greater affinity for the estrogen receptor P (found primarily in bone, brain, heart, and vascular system) than estrogen receptor a (found primarily in uterus, breast, ovaries, and adrenal glands) (Beck et al. 2005 Dornstauder et al. 2001). 

Cardiovascular Pharmacology. Cardiovascular pharmacology examines the effects of drugs on the heart and vascular system, as well as on other body... 

Spleen and Stomach, transform dampness and promote digestion, particularly the metabolism of fats. If hyperlipidemia has developed and has resulted in detectable damage to the heart, brain and vascular system, herbs to strongly remove dampness and phlegm, clear heat, stimulate Qi movement and blood circulation, nourish the Yin and pacify the Liver should be added to the formula. In all conditions, herbs that tonify the Spleen and Kidney should be prescribed. 

Human, Organ Directed Blood, Immune system Liver, Kidney, Nervous System Heart and vascular Reproductive and endocrine Eye and Skin... 

Carbon dioxide is a rapid, potent stimulus to ventilation. Inhalation of 10% CO can produce minute volumes of 75 L/min in normal individuals. Carbon dioxide acts at multiple sites to stimulate ventilation. Elevated Pco causes bronchodilation, whereas hypocarbia causes constriction of airway smooth muscle these responses may play a role in matching pulmonary ventilation and perfusion. Circulatory effects of CO result from the combination of direct local effects and centrally mediated effects on the autonomic nervous system. The direct effects are diminished contractility of the heart and vascular smooth muscle (vasodilation). The indirect effects result from the capacity of CO to activate the sympathetic nervous system these indirect effects generally oppose the local effects ofCO. Thus, the balance of opposing local and sympathetic effects determines the total circulatory response to CO. The net effect of CO inhalation is an increase in cardiac output, heart rate, and blood pressure. In blood vessels, however, the direct vasodilating actions of carbon dioxide appear more important, and total peripheral resistance decreases when the Pco is increased CO also is a potent coronary vasodilator. Cardiac arrhythmias associated with increased Pco are due to the release of catecholamines. 

Counterpressure (Fig. 4.19) is performed by simultaneously applying a forward pressure on the sheath and traction to the lead. Pressure describes the pushing force applied to the sheath that is directed toward the heart, and its objective is to overcome binding sites between lead and vascular system. Traction refers to the pulling force applied to the lead in the opposite direction, and its objective is to allow the sheath to follow the lead around the bends in the vascular system. The goal of counterpressure is to counterbalance the advancement force (pressure) with the retraction force (traction). An imbalance between these two forces can produce failures or complications. 

Haditional use In Tibetan and Mongolian medicine the roots are used to treat diseases of the heart, aorta, and vascular system, diphtheria, and rheumatism, and are used as an antipyretic and restorative as well (Khaidav 1965). The ground seeds are used to treat poor digestion and loss of appetite (Khalmatov 1964). 

Research Hospitals. At the Covenant Heart and Vascular Institute, a member of the Covenant Health System in West Texas, research and clinical trials are conducted to develop therapeutics, procedures, and medical devices for the treatment of heart disease. It is an accredited Cycle III Chest Pain Center with Percutaneous Coronary Intervention, one of only fourteen in the state. This certificate is for excellence in providing acute cardiac medicine. 

Carbon monoxide, emitted by motor vehicles, is toxic because it diminishes the blood s ability to carry oxygen, in high concentrations, carbon monoxide is lethal, in lower concentrations, it causes the heart and respiratory system to work harder. The adverse health effects related to carbon monoxide exposure include impairment of visual perception, decreased work capacity, decreased manual dexterity, and lower learning ability. Those who suffer from cardiovascular disease, especially those with angina or peripheral vascular disease, are most sensitive. 

Several chemical compounds can have an adverse effect on the heart and the vascular system. The effect may first appear as a transient change in the cardiac function. However, prolonged exposure increases the risk of permanent effects. Occasionally, functional effects such as cardiac arrhythmias may even lead to death. Furthermore, in many cases the effects of chemicals... 

Histamine is a substance present in various tissues of die body, such as die heart, lungs, gastric mucosa, and skin (Pig. 36-1). The highest concentration of histamine is found in die basophil (a type of white blood cell) and mast cells diat are found near capillaries. Histamine is produced in response to injury. It acts on areas such as die vascular system and smooth muscle, producing dilatation of arterioles and an increased permeability of capillaries and venules. Dilatation of die arterioles results in localized redness. An increase in die permeability of... 

Systemic and coronary arteries are influenced by movement of calcium across cell membranes of vascular smooth muscle. The contractions of cardiac and vascular smooth muscle depend on movement of extracellular calcium ions into these walls through specific ion channels. Calcium channel blockers, such as amlodipine (Norvasc), diltiazem (Cardizem), nicardipine (Cardene), nifedipine (Procardia), and verapamil (Calan), inhibit die movement of calcium ions across cell membranes. This results in less calcium available for the transmission of nerve impulses (Fig. 41-1). This drug action of the calcium channel blockers (also known as slow channel blockers) has several effects on die heart, including an effect on die smooth muscle of arteries and arterioles. These drug dilate coronary arteries and arterioles, which in turn deliver more oxygen to cardiac muscle. Dilation of peripheral arteries reduces die workload of die heart. The end effect of these drug is the same as that of die nitrates. 

Cardiovascular disease (CVD) is characterized by the involvement of the heart and allied vascular system. High cholesterol, associated lipid abnormahties and high blood pressure are recognized as the major risk factors of CVD. There have been several animal experiments and clinical studies using rice bran and rice bran oil, which have demonstrated a hypocholesterolemic effect (Raghuram et al., 1989 Rukmini and Raghuram, 1991 Sugano and Tsuji, 1997). The mechanisms involved are briefly summarized. 

An example of this type of reflex is the baroreceptor reflex (see Figure 1.2). Baroreceptors located in some of the major systemic arteries are sensory receptors that monitor blood pressure. If blood pressure decreases, the number of sensory impulses sent from the baroreceptors to the cardiovascular control center in the brainstem also decreases. As a result of this change in baroreceptor stimulation and sensory input to the brainstem, ANS discharge to the heart and blood vessels is adjusted to increase heart rate and vascular resistance so that blood pressure increases to its normal value. 

The goal of sympathomimetic therapy is to augment both coronary and cerebral perfusion pressures during the low-flow state associated with CPR. These agents increase systemic arteriolar vasoconstriction, thereby improving coronary and cerebral perfusion pressure. They also maintain vascular tone, decrease arteriolar collapse, and shunt blood to the heart and brain. 

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