High-output heart failure

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High-output heart failure
Specialty Cardiology

High-output heart failure is a heart condition that occurs when the cardiac output is higher than normal due to increased peripheral demand. There is a circulatory overload which may lead to pulmonary edema secondary to an elevated diastolic pressure in the left ventricle. These individuals usually have a normal systolic function but symptoms are those of heart failure. With time, this overload causes systolic failure. Ultimately cardiac output can be reduced to very low levels. [1]

It may occur in situations with an increased blood volume, morbid obesity, from excess of water and salt (kidney pathology, excess of fluid or blood administration, treatment with retaining water steroids), chronic and severe anemia, large arteriovenous fistula or multiple small arteriovenous shunts as in HHT or Paget's disease of bone, some forms of severe liver or kidney disorders, hyperthyroidism, and wet beriberi, [2] and acutely in septic shock, especially caused by Gram-negative bacteria. [3] [4]

Related Research Articles

Blood pressure Pressure exerted by circulating blood upon the walls of blood vessels

Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" refers to the pressure in the large arteries. Blood pressure is usually expressed in terms of the systolic pressure over diastolic pressure in the cardiac cycle. It is measured in millimeters of mercury (mmHg) above the surrounding atmospheric pressure.

Edema Accumulation of fluid in body tissue

Edema, also known as fluid retention, dropsy, hydropsy or swelling, is the buildup of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area may feel heavy, and affected joints may be hard to move. Other symptoms depend on the underlying cause.

Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down. The drop in blood pressure may be sudden, within 3 minutes or gradual. It is defined as a fall in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg when a person assumes a standing position. It occurs predominantly by delayed constriction of the lower body blood vessels, which is normally required to maintain an adequate blood pressure when changing position to standing. As a result, blood pools in the blood vessels of the legs for a longer period and less is returned to the heart, thereby leading to a reduced cardiac output and inadequate blood flow to the brain.

Aortic stenosis

Aortic stenosis is the narrowing of the exit of the left ventricle of the heart, such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occur due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercising. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without narrowing is known as aortic sclerosis.

Heart failure Failure of the heart to provide sufficient blood flow

Heart failure (HF), also known as congestive heart failure (CHF), decompensatio cordis (DC), and congestive cardiac failure (CCF), is when the heart is unable to pump sufficiently to maintain blood flow to meet the body tissue's needs for metabolism. Signs and symptoms of heart failure commonly include shortness of breath, excessive tiredness, and leg swelling. The shortness of breath is usually worse with exercise or while lying down, and may wake the person at night. A limited ability to exercise is also a common feature. Chest pain, including angina, does not typically occur due to heart failure.

Diuresis is increased urination and the physiologic process that produces such an increase. It involves extra urine production in the kidneys as part of the body's homeostatic maintenance of fluid balance.

Pulmonary edema Fluid accumulation in the air spaces and parenchyma of the lungs tissue

Pulmonary edema is fluid accumulation in the tissue and air spaces of the lungs. It leads to impaired gas exchange and may cause respiratory failure. It is due to either failure of the left ventricle of the heart to remove blood adequately from the pulmonary circulation, or an injury to the lung tissue or blood vessels of the lung. Treatment is focused on three aspects: firstly improving respiratory function, secondly, treating the underlying cause, and thirdly avoiding further damage to the lung. Pulmonary edema, especially when sudden (acute), can lead to respiratory failure or cardiac arrest due to hypoxia. It is a cardinal feature of congestive heart failure. The term edema is from the Greek οἴδημα, from οἰδέω.

Pulse pressure is the difference between systolic and diastolic blood pressure.

Aortic insufficiency

Aortic insufficiency (AI), also known as aortic regurgitation (AR), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a consequence, the cardiac muscle is forced to work harder than normal.

Essential hypertension is the form of hypertension that by definition has no identifiable secondary cause. It is the most common type affecting 85% of those with high blood pressure. The remaining 15% is accounted for by various causes of secondary hypertension. Primary hypertension tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Prevalence of essential hypertension increases with age, and individuals with relatively high blood pressure at younger ages are at increased risk for the subsequent development of hypertension. Hypertension can increase the risk of cerebral, cardiac, and renal events.

Mitral insufficiency Form of valvular heart disease

Mitral regurgitation (MR), mitral insufficiency, or mitral incompetence is a form of valvular heart disease in which the mitral valve does not close properly when the heart pumps out blood. It is the abnormal leaking of blood backwards from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts, i.e. there is regurgitation of blood back into the left atrium. MR is the most common form of valvular heart disease.

Electrolyte imbalance

Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte.

Hypovolemic shock is a medical emergency and an advanced form of hypovolemia due to insufficient amounts of blood and/or fluid inside the human body to let the heart pump enough blood to the body. More specifically, hypovolemic shock occurs when there is decreased intravascular volume to the point of cardiovascular compromise. The hypovolemic shock could be due to severe dehydration through a variety of mechanisms or from blood loss.

Arteriovenous fistula

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. It may be congenital, surgically created for hemodialysis treatments, or acquired due to pathologic process, such as trauma or erosion of an arterial aneurysm.

Valvular heart disease Disease in the valves of the heart

Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart. These conditions occur largely as a consequence of aging, but may also be the result of congenital (inborn) abnormalities or specific disease or physiologic processes including rheumatic heart disease and pregnancy.

Hypertensive emergency Condition of markedly elevated blood pressure with diastolic pressure typically greater than 120 mm Hg

A hypertensive emergency is high blood pressure with potentially life-threatening symptoms and signs indicative of acute impairment of one or more organ systems. Hypertensive urgency is defined as having a systolic blood pressure over 180 mmHg or a diastolic blood pressure over 110 mmHg. Hypertensive emergency is defined as elevated blood pressure consistent with hypertensive urgency, plus evidence of impending irreversible hypertension-mediated organ damage (HMOD). Signs of organ damage will be discussed below.

Pulsus paradoxus, also paradoxic pulse or paradoxical pulse, is an abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration. The normal fall in pressure is less than 10 mmHg. When the drop is more than 10 mmHg, it is referred to as pulsus paradoxus. Pulsus paradoxus is not related to pulse rate or heart rate, and it is not a paradoxical rise in systolic pressure. The normal variation of blood pressure during breathing/respiration is a decline in blood pressure during inhalation and an increase during exhalation. Pulsus paradoxus is a sign that is indicative of several conditions, including cardiac tamponade, chronic sleep apnea, croup, and obstructive lung disease.

Volume overload

Volume overload refers to the state of one of the chambers of the heart in which too large a volume of blood exists within it for it to function efficiently. Ventricular volume overload is approximately equivalent to an excessively high preload. It is a cause of cardiac failure.

Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction - the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled - is normal, defined as greater than 50%; this may be measured by echocardiography or cardiac catheterization. Approximately half of people with heart failure have preserved ejection fraction, while the other half have a reduction in ejection fraction, called heart failure with reduced ejection fraction (HFrEF).

Pathophysiology of heart failure

The main pathophysiology of heart failure is a reduction in the efficiency of the heart muscle, through damage or overloading. As such, it can be caused by a wide number of conditions, including myocardial infarction, hypertension and amyloidosis. Over time these increases in workload will produce changes to the heart itself:

References

  1. O'Rouke, R.A., Fuster, V. (2001). Hurst's The Heart (10 (International edition) ed.). McGraw-Hill. p. 661. ISBN   978-0-07-116296-8.
  2. Susan Wolfsthal (ed). NMS Medicine Lippincott Williams & Wilkins, Nov 15, 2007 - page 2. ISBN   0781769752
  3. Anand IS, Florea VG. High Output Cardiac Failure. Curr Treat Options Cardiovasc Med. 2001 Apr;3(2):151-159. PMID   11242561
  4. Causes of High-Output Heart Failure Healthwise Staff of WebMD. Last updated: August 2010. Accessed 10/19/2012.
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