Approximately 5.8 million Americans suffer from the lasting effects of heart failure, estimates the American Heart Association. Resulting from damage caused by congenital disorders or cardiovascular diseases, heart failure is a decrease in the heart's ability to pump oxygen-rich blood throughout the system. The failing pump causes structural changes within the heart and damages several other organ systems. Treatment programs slow the progression of disease but are unable to completely reverse the damage.
Structural Changes
Damage to the heart muscle that limits its ability to pump causes structural changes to occur. In the text "Heart Failure," Dr. Arnold Katz explains that these changes are an attempt to compensate for the loss of function and is termed compensatory heart failure. In this condition, the chambers of the heart will become enlarged and the walls will thicken. These changes allow contractions to remain relatively forceful and blood flow to be maintained. However, the heart cannot compensate forever and eventually these mechanisms fail to make up for the tissue damage. As the compensatory mechanisms begin to fail the enlarged heart and thickened walls become stiff and lose their functionality. This causes the outward signs of heart failure become more prominent.
Observable Effects
The lack of forceful pumping ability allows fluid to back up in the system. Fluid overload in the lungs causes shortness of breath on exertion and even at rest in more advanced stages of heart failure. Swelling, also known as edema, in the feet and lower legs is also a common effect of fluid overload in the system as a result of heart failure. Fatigue is a persistent effect because the body is not being supplied with an adequate amount of oxygen-rich blood. Skeletal muscles rely on oxygen for energy production, and, in advanced stages, heart failure patients have difficulty moving short distances or rising from a seated position without becoming exceedingly fatigued.
Kidney Damage
Heart failure and kidney failure often coexist and are commonly referred to as cardio-renal syndrome. The American Heart Association explains that heart failure negatively affects the kidneys by altering renal blood flow. Sodium and water retention results from the decreased in kidney blood flow and strains the function of the kidneys. Cardio-renal syndromes have been classified into five categories based on the primary cause of organ damage and the time frame that the damage occurred within. Heart failure is the cause of kidney failure in two of the five classes of cardio-renal syndrome, according to a 2010 report in the "European Heart Journal."
Liver Damage
Similar to the damage incurred by the kidney, the liver is also susceptible to damage resulting from heart failure. A 2009 report in the "European Journal of Heart Failure" indicates that heart failure is responsible for a variety of liver abnormalities, generally termed cardio-hepatic syndromes. The decreased pumping ability of the heart leads to poor blood flow to the liver. Lack of oxygen-rich blood causes portions of the liver to die off and become nonfunctional. Likewise, systemic fluid buildup from poor circulation leads to congestion in the liver and decreases its functionality.
Reducing the Effects
Current therapies for heart failure include medications that reduce salt and water retention and reduce the excess fluid load on the lungs, kidneys and liver. Pacemakers and defibrillators prevent the heart from beating too slowly or erratically, which would further decrease blood flow. These therapies slow the progression of heart failure but do not prevent its progression from occurring. Current research is aimed at reversing the effects of heart damage such that heart failure can be prevented and the multiple organ systems damaged by worsening heart failure can be spared.
References
- "Circulation"; Heart Disease and Stroke Statistics 2010 Update; Donald Lloyd-Jones, M.D.; 2010
- "Heart Failure: Pathophysiology, Molecular Biology, and Clinical Management"; Arnold M. Katz, M.D.; 2009
- American Heart Association: An Overview of the Kidney in Cardiovascular Disease
- "European Heart Journal"; Cardio-Renal Syndromes; Claudio Ronco, M.D.; 2010
- "European Journal of Heart Failure"; Liver Function Abnormalities and Outcome in Patients with Chronic Heart Failure; Larry A Allen, M.D.; 2009
