Blood Flow in the Heart

It is a diuretic. An extract of the flowers and leaves improves cardiac output and the contractility of the heart muscle. Flavonoids in hawthorn have been shown to increase blood flow in the heart by dilating blood vessels in coronary arteries. Hawthorn has lowered cholesterol in animal studies, probably due to its oligomeric procyanidins (OPC), a type of bioflavonoid similar to that found in the extracts of grape seed and grape skin. 

P. J. An anatomically based model of transient coronary blood flow in the heart. SIAM Journal of Applied Mathematics 2001, 62 990-1018. 

C.S. Peskin, Numerical Analysis of Blood Flow in the Heart, J. Comput. Phys., 25 (1977). 

Peskin CS (1977) Numerical analysis of blood flow in the heart. Journal of Computational... 

The immersed boundary method was first introduced by Peskin [5] to simulate the blood flow in the heart. Since then a few variants have emerged and the method has been used to compute many flows with complex and/or moving geometries (Mittal and laccarino [4]). The distinguishing feature of this method is that the computations are done on either a Cartesian grid or a curvilinear grid which do not necessarily conform to the flow boundary. 

Peskin, C.S., McQueen, D.M. A three-dimensional computational method for blood flow in the heart (I) immersed elastic fibers in a viscous incompressible fluid. J. Comput. Phys. 81, 372-405 (1989)... 

A patient may be given radioactive tracers such as technetium-99m, iodine-131, gallium-67, and thallium-201 that emit gamma radiation, which is detected and used to develop an image of the kidneys or thyroid or to follow the blood flow in the heart muscle. Radiologists must be knowledgeable about radiation exposure to limit the amount of radiation to which patients are exposed. 

In this thallium-201 scan of a normal heart, y rays released in the radioactive decay of ° T1 are detected and used to provide an image of blood flow in the heart muscle. Normal ° T1 uptake by healthy heart muscle appears as a pink and red donutshaped feature in this image. Comparing scans with those made during exercise can reveal blood supply issues. 

In addition to its internal blood flow operation, the heart has its own system of blood vessels to keep the muscle wall of the heart, the myocardium, supphed with oxygenated blood (Fig. 3a). The coronary arteries, which branch from the aorta to the right and left sides of the heart, are vital to maintaining that supply. The heart is an extraordinary electromechanical muscle that can be trained to increase blood flow to the body sixfold. It can range from 5 to 30 L /min during exertion. 

Venous stasis is slowed blood flow in the deep veins of the legs resulting from damage to venous valves, vessel obstruction, prolonged periods of immobility, or increased blood viscosity. Conditions associated with venous stasis include major medical illness (e.g., heart failure, myocardial infarction), major surgery, paralysis (e.g., stroke, spinal cord injury), polycythemia vera, obesity, or varicose veins. 

Nitroglycerine reduces the load on the heart by dilating peripheral veins, reducing the myocardial need for oxygen, and facilitating redistribution of coronary blood flow in the region of the myocardium with reduced blood flow. 

Finally, at the Texas Heart Institute, we are developing a concept device that will consist of a catheter deployed micropump in the descending aorta and fixated with metallic struts to the aortic wall. It is designed to accelerate blood flow in the descending aorta to unload the heart. Its power will be supplied through a transarterial power cable to an outside power source. Though still in the conceptual phase only, it may be truly implantable in the cath lab without surgery. 

Abciximab is indicated in patients with heart disease caused by poor blood flow in the arteries of the heart (ischemic cardiac complications). It is also used in patients with unstable angina not responding to conventional treatment and for precutaneous coronary intervention. It can reduce the incidence of abrupt closure and restenosis... 

An antihypertensive substance is one which does not affect blood volume, blood viscosity, or the function of the heart it lowers blood pressure to normal levels in hypertensive states by generalized arteriolar dilatation, including those of the kidneys. Vasodilators (such as histamine), which lower arterial pressure at the expense of renal blood flow, are not antihypertensive. Furthermore, an ideal substance should affect the blood pressure in normal states to little or no extent. It can be predicted, however, that when true antihypertensive substances are found, they will not increase or maintain renal blood flow in the face of lowered arterial pressure when renal arterioles have lost the ability to dilate because of pathological changes (see Figure 3). 

Placebos are effective for a variety of conditions. Patients with angina pectoris (insufficient blood flow to the heart) responded to placebo surgery in which surgeons made only an incision in the chest. And in a study of the drug propranolol that is used after heart attacks to prevent further damage, investigators noticed that patients who took placebo pills regularly had a lower death rate than patients who took placebos sporadically. Therefore, the placebo effect is not unique to psychiatric illness. 

The usual cause of pain arising from the heart is a deficiency ofblood flow to cardiac muscle, which is usually caused by atheroma in coronary vessels, which restricts blood flow. Diminished blood flow to the heart muscle causes ischaemia and pain. A patient may have no problems at rest and show a... 

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