Congestive Heart Failure

Congestive Heart Failure Alexis J. A. CoCo 12-07-03 A & P II MW 6:00 – 9:00 p.m.

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Congestive Heart Failure, or CHF, is a condition in which the heart can not pump enough blood to the body’s other organs. (2) This can be caused by the following: scar tissue from a previous heart attack that interferes with the heart’s normal work, high blood pressure, heart valve disease, cardiomyopathy, a heart defect present at birth, coronary artery disease, endocarditis and/or myocarditis. (2)

Another definition of congestive heart failure is when the heart is unable to

adequately pump blood throughout the body and/or unable to prevent blood from “backing up” into the lungs. (1) This condition may cause symptoms such as dyspnea, fatigue, weakness, edema of the legs and sometimes abdomen. (1) At one point in time congestive heart failure was an almost untreatable disorder. Luckily today there are lots of important and effective measures that can be utilized to improve symptoms and the survival of the patients with CHF. (5) When you hear the term heart failure it would seem as if the heart just quits working all together. This is not the case, it does not stop working completely, it just does not work enough to deliver all of the oxygen – rich blood the body needs. (3) As the heart’s ability to pump weakens , it can not distribute enough blood to meet the needs of the body. (3) With an increased stress on the heart muscle, its ability to contract is reduced and cardiac output declines. (3) Blood flow into the ventricles pretty much remains the same. Without the ability to eject normal amounts of blood, the ventricles begin to accumulate blood. (3) As the amount of blood in the ventricles increases, the heart makes both short and long term adaptations. (3) Blood accumulation in the ventricles causes ventricular muscle fibers to increase in length at the end of the diastole. (3) As end-diastolic

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fiber length increases, the muscles respond by dilating and increasing force of contraction. (3) If heart failure continues long enough, ventricular hypertrophy occurs. (3) The myocardium enlarges, increasing the heart’s ability to push blood into circulation. (3) Ventricular hypertrophy can adequately compensate for heart failure for a little while, but eventually the heart weakens and acute failure ensues. (3) The underlying heart conditions that commonly cause congestive heart failure, such as coronary artery disease or high blood pressure, typically develop slowly over many years. (3) The most severe manifestation of CHF, pulmonary edema, develops when the imbalance causes an increase in lung fluid secondary to leakage from pulmonary capillaries into the interstitium and alveoli of the lung. (3) There are many ways to classify CHF there is right or left sided heart failure, forward or backward heart failure and acute or chronic heart failure. (3) Right sided heart failure is when the ability of the right ventricle to contract is impaired or ineffective. (3) Left sided failure occurs most often and results from profound backflow of the blood into the left ventricle. (3) Forward heart failure is caused by increased peripheral resistance. Backward heart failure results when the left ventricle fails to empty completely. (3) Acute heart failure is when the signs and symptoms are new and compensatory mechanisms such as natural diuresis have not engaged yet. Chronic heart failure describes a condition where signs and symptoms have been present for an extended period and compensatory mechanisms have taken effect. (3)

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In this case study it said that congestive heart failure is characterized by the inability of the heart to meet the demands of the body. (4) Nearly five million Americans are living with CHF and approximately one-half of the people with heart failure will die with in 5 years of diagnosis. (4) During the early stages of CHF a series of drugs is prescribed to increase the contractility of the heart. (4) As the heart deteriorates, native compensatory mechanisms attempt to adjust the declining efficiency of the heart. (4) Eventually , drugs become less effective as the heart continues to deteriorate and enlarge. (4) Additionally, drugs used in later stages of heart failure come with serious side effects. (4) Treatment for late-stage heart failure include surgical procedures and invasive medical devices. (4) Currently the most effective alternative for severe CHF is a new heart; there are no fully effective treatments for this widespread disease. (4) Orqis™ Medical is pursuing a therapeutic treatment for CHF patients with impaired cardiac function. (4) Orqis has developed a method to mechanically supplement circulation, thus potentially reversing the negative feedback loop associated with CHF. (4) The Orqis approach is unique in that, unlike heart assist devices, it does not attempt to take over the function of the failing ventricles instead, the system uses extra-corporeal blood circuit to assist the heart. (4) Although the full mechanism of action is currently under investigation, it is believed that by mechanically unloading the distressed heart, the system leads to a subsequent reversal of the negative compensatory mechanisms and to geometric recovery of the heart itself. (4) The Cancion CRS will begin clinical trials in Europe during the third quarter of 2002. (4)

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Orqis Medical’s Cancion™ CRS requires disposable cannulae for vascular access, a blood pump, and a pump control and monitoring console. (4) Minnetronix was chosen to develop the console because of their extensive experience with the artificial heart and other blood pumps. (4) Minnetronix’s ability to rapidly prototype the device for Orqis allowed them to meet rapidly approaching milestones in Orqis’ project schedule. (4) Minnetronix continues to manufacture and support the console for Orqis’ specifications. (4) This included developing the console’s mechanical structure, uninterruptible power supply, user interface, pump monitor control, integrated flow sensor, and the associated safety systems. (4) Significant effort went into an operator-centered design to ensure the device would be well received by those using it. (4) Ultimately, Minnetronix completely documented the assembly methods to streamline future production. (4) Specifically, Minnetronix: Designed the user interface with motor control, flow display, battery and pressure display, Integrated multiple pump technologies, Implemented power management (A/C power with one hour battery backup), Integrated flow and pressure sensors display, Implemented the user interface in multiple languages, performed risk analysis including Hazard and Failure Modes and Effective Analysis, and complied technical data files including environmental and regulatory testing. (4) It has specially designed features such as: blood pump control expertise, portable enclosure design, ultrasonic flow sensing integration, rechargeable NiMh battery integration, Multiple language user interface design and a design for product safety. (4)

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In conclusion, congestive heart failure is a disease that effects millions of Americans. There are many ways available to treat congestive heart failure like: Lifestyle modifications (a person’s diet , drinking and exercise), medications (digoxin, diuretics, ACE (angiotensin-converting enzyme) inhibitors, ARBs (Angiotensin receptor blockers, Hydralazine and isosorbide dinitrate, beta blockers and inotropic agents) and medical devices and surgery ( intra-aortic balloon pump (IABP), left ventricular assist device (LVAD) and of course a heart transplant surgery) None of these treatments can really guarantee a person will live on for ten years but the heart transplant surgery has a 90% outcome of the patients being a live one year later, the five year survival rate is also very encouraging. (1) What Orqis is trying to do could become an effective way to treat congestive heart failure. It will help the heart to circulate and potentially reverse the negative feedback that come a along with congestive heart failure. Unlike most artificial devices this will not take over the function of the failing ventricles but become a great aide to geometric recovery of the heart itself. (4) Recovery of the heart is key because with out it our body can not survive and therefore we would die. I know that I would much rather have a device to help my heart start to recover than to have to get it replaced with someone else’s heart. The best way in my opinion to treat congestive heart failure is with early detection and you do that by regularly going to your doctor. As stated in this paper late treatment can have serious side effects and with early detection you can begin to change your habits to help take the burden off of your heart.

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Works Cited

1.

www.cardiologycahnnel.com/chf/

2.

www.americanheart.org/presenter.jhtml?identifer=4585

3.

www.acc.org/media/patient/chd/chf.htm

4.

www.minnetronix.com/case_studies/orqis.shtml>

5.

www.heartpoint.com/congheartfailure.html

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