cardiac output(redirected from Cardiac output, low)
Also found in: Dictionary, Thesaurus, Encyclopedia.
the yield or total of anything produced by any functional system of the body. When measuring output for a patient record, the volume of urine, drainage from tubes, vomitus, and any other measurable liquid should be recorded.
cardiac output the effective volume of blood expelled by either ventricle of the heart per unit of time (generally per minute); it usually refers to left ventricle output. It is equal to the stroke volume multiplied by the heart rate. Normal values are 4 to 8 liters per minute.
decreased cardiac output a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which inadequate blood is pumped by the heart to meet the metabolic demands of the body. The most obvious causative factors are pathologic changes in the heart's muscle or electrical conduction system, congenital heart defects, electrolyte imbalances (as of calcium or potassium), blood dyscrasias, and chronic pulmonary disease. Factors that could lead to changes in a patient's functional capacities because of decreased cardiac output might include physical exercise of a type or intensity that the patient cannot tolerate because of diminished oxygen supply, ingestion of large meals that place an added workload on the heart, obesity, retention of fluid (edema), hypovolemia or hypervolemia, emotional stress, and smoking.
Patient Care. Nursing interventions are planned only after a thorough nursing assessment has been conducted to collect the relevant subjective and objective data. For example, it may be that the patient will need instruction and guidance in limiting sodium intake, reducing caloric intake to lose excess fat and maintain normal body weight, decreasing fat consumption to reduce blood lipid levels, or otherwise striving for dietary management of the problem.
energy output the energy a body is able to manifest in work or activity.
stroke output stroke volume.
urinary output the amount of urine secreted by the kidneys. See also fluid balance.
the amount of blood ejected by the heart in a unit of time (that is, the minute volume), usually expressed in liters per minute.
Synonym(s): minute output
The volume of blood pumped from the right or left ventricle in one minute.
cardiac output (CO)
the volume of blood expelled by the ventricles of the heart with each beat (the stroke volume) multiplied by the heart rate. Cardiac output is commonly measured by the thermodilution technique. A normal, resting adult has a cardiac output of 4 to 8 L per minute.
cardiac outputCardiology A measure of blood flow through the heart to the systemic circulation, expressed as volume of blood/unit time or L/min, calculated as left ventricular forward stroke X heart rate; CO is calculated by Fick method–O2 consumption divided by the AV O2 difference,
or by thermodilution, with Swan-Ganz catheterization. See Bradycardia, Tachycardia.
car·di·ac out·put(CO) (kahr'dē-ak owt'put)
The product of heart rate and stroke volume, measured in liters per minute; the amount of blood that is pumped by the heart in 1 minute.
cardiac outputThe volume of blood pumped by the heart in one minute. It is equal to the stroke volume—the output per beat—multiplied by the number of beats per minute.
cardiac outputthe total volume of blood pumped out by the heart per unit time.
n the volume of blood forced out by the ventricles of the heart per beat multiplied by the heart rate. The cardiac output of a normal adult is 4 to 8 L per minute.
car·di·ac out·put(kahr'dē-ak owt'put)
Amount of blood ejected by the heart in a unit of time in liters per minute (L/min).
1. pertaining to the heart. See also heart.
2. pertaining to the gastric cardia.
the impedance to ventricular emptying presented by aortic pressure.
an uncommon clinical procedure. May be performed via thoracotomy or with a biopsy catheter introduced intravenously.
the insertion of a catheter into a vein or artery and guiding it into the interior of the heart for purposes of measuring cardiac output, determining the oxygen content of blood in the heart chambers, and evaluating the structural components of the heart.
in cardiac disease the compensation for the inefficiency of the heart's pump action by enlisting the various reserves of the heart such as hypertrophy, enlargement, increase in rate, so as to maintain circulatory equilibrium and prevent the appearance of signs of congestive heart failure.
an emergency measure to empty the ventricles of the heart in an effort to circulate the blood, and also to stimulate the heart so that it will resume its pumping action. Involves the application of pressure through the thoracic wall. More commonly used in animals than other forms of cardiac massage.
cardiac conducting cells
specialized cardiac fibers modified to conduct impulses from the A-V node via the septum to the ventricles. Called also Purkinje fibers.
cardiac conducting system
the cardiac tissue responsible for electrical conduction, made up of the sinoatrial node, the atrioventricular node, and the atrioventricular bundle and cardiac conducting fibers.
cardiac depressor nerve
a branch of the vagus nerve composed of afferent nerve fibers which arise around the base of the heart; called also aortic nerve.
the heart volume is increased but the effective mass of cardiac muscle is not. A dilated heart has lost some of its reserve.
the area of the chest wall over which a dull sound, indicating the position of the heart, can be elicited by percussion.
see heart failure.
see ventricular fibrillation.
see cardiac cirrhosis.
cardiac flow load
the work required of the heart can be increased by a need for an increased flow rate of blood, e.g. when there is an anastomosis, congenital arteriovenous defect, portosystemic shunt.
cardiac function curves
statistical curves used in modeling the cardiovascular functions, relating e.g. venous return to cardiac output.
in the cardiac region of the gastric wall; branched, tubular, coiled, mucus-secreting.
the glycosides of Digitalis purpurea (digitoxin, gitalin and gitoxin) and digoxin (from D. lanata). Strophanthin and ouabain are glycosides found in Strophanthus spp. Other cardiac glycosides are present in the skin of toads (Bufo maritimus, B. vulgaris), but are of toxicological rather than therapeutic interest.
cardiac horse sickness
see african horse sickness.
enlargement of the heart coincident with an increase in muscle mass; an indication of response to an increase in load which may or may not be associated with disease. It is an expression of cardiac compensation but some of the cardiac reserve has been lost.
see cardiac impulse. Called also apex beat.
cardiac output divided by the animal's body surface area in m2. The normal range for dogs is 1.8-3.5 l/m2.
left-sided cardiac enlargement
may involve either the left ventricle or atrium, or both, and can be demonstrated on radiographs and electrocardiography. Seen most commonly in mitral valvular disease in dogs.
manual massage of the heart or stimulation with an electrical current through an open thoracic wall. The term is sometimes used interchangeably with cardiac compression.
the most cranial of the gastric mucosae; secretes only mucus, except in pigs, in which the area covered by this mucosa is much larger than in the other species and bicarbonate is also secreted.
see heart murmur.
the volume of blood pumped per unit of time. May be calculated by oxygen consumption measurement or determined by dilution of indocyanine green or cold saline, using catheters with thermistors placed intravenously (thermodilution method). It can be estimated clinically by measuring heart rate, pulse quality or pressure, and assessment of tissue perfusion, e.g. capillary refill time.
employing cardiac pacemakers to control heart rate.
ventricular end-diastolic volume.
cardiac pressure load
the stress of working against an elevated blood pressure in the arterial circuit; one of the two major groups of causes of heart disease; the other is flow load.
cardiac racing syndrome
a disease of companion birds manifested by a sudden increase in heart rate, up to 1000/min, in the period immediately after being restrained. Death occurs within a few seconds.
the reserve mechanisms in the heart to compensate for defects which could make the heart's pumping action ineffective. The reserve mechanisms include hypertrophy, enlargement, increase in heart rate and an increase in stroke volume, a result of the increase in muscle mass and the enlargement of the ventricles.
right-sided cardiac enlargement
may involve either the right ventricle or atrium. Occurs in heartworm disease in dogs.
penetration of the myocardium by a reticular foreign body in cows, or rupture of a patch of chronic fibrotic myocarditis in horses, causes cardiac tamponade and sudden death.
may increase as a result of hypertrophy, dilatation or a combination of the two. A common belief with some scientific support is that performance of horses in sprint races is closely related to heart size.
cardiac stroke volume
the amount of blood ejected with each systole.
cardiac valve fenestration
the valve surface is incomplete, creating a lattice effect; mostly congenital defects in foals.
cardiac valve hematocysts
congenital, blood-filled cysts on the atrioventricular valves considered to be of no pathogenic significance.
cardiac valve laceration
tearing of the valve tissue or attachment to myocardium may occur spontaneously or as a sequel to endocarditis; adds a significant additional flow load to the heart.
cardiac valve rupture
see cardiac valve laceration (above).
heart valves formed by evaginations of the cardiac and vascular endothelium supported by connective tissue; includes atrioventricular and semilunar valves on both sides of the heart.
cardiac valvular disease
see valvular disease.
cardiac vascular shunts
includes patent foramen ovale, ventricular septal defect, tetralogy of Fallot, patent ductus arteriosus.
includes effective work—that needed for the onward propulsion of blood through the correct channels against arterial pressure, total work—includes all of the work performed by the heart including some involved in moving blood in the wrong direction.