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Doctor insights on: How Could Vasoconstriction Affect Cardiac Output

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How could vasoconstriction affect cardiac output?

How could vasoconstriction affect cardiac output?

It lowers it: Vasoconstriction increases the resistance to flow. This is called an afterload. It is like a pump having to pump water up a steep hill; it won't pump as well as on flat land. ...Read more

Vasoconstriction (Definition)

Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in staunching hemorrhage ...Read more


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Does an adrenaline surge (from anxiety or exercise) when taking a non-selective B-blocker cause coronary vasoconstriction? Selective B1-blckr better?

Does an adrenaline surge (from anxiety or exercise) when taking a non-selective B-blocker cause coronary vasoconstriction? Selective B1-blckr better?

Beta blockers: B blockers are used to treat angina caused by coronary disease, and they are effective. They reduce heart rate and the workload of the heart, including response to exercise. With very high norepinephrine conditions, eg. pheochromocytoma, blocking beta can cause unopposed alpha and raise BP. But that is a very rare condition. ...Read more

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Will midodrine cause any vasoconstriction of coronary arteries aswell?

Will midodrine cause any vasoconstriction of coronary arteries aswell?

No evidence seen: Mididrine is an alpha1-agonist and exerts its actions via activation of the alpha-adrenergic receptors of the arteriolar and venous vasculature, producing an increase in vascular tone and elevation of blood pressure.

There is some recent evidence in animal coronaries there are Alpha and beta receptors in large coronaries and beta in small coronaries, but no data avialabe for midodrine. ...Read more

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If Nictotine causes coronary & cerebral vasoconstriction why doesn't it cause angina or light headedness in people running with a HR of 180BPM?

If Nictotine causes coronary & cerebral vasoconstriction why doesn't it cause angina or light headedness in people running with a HR of 180BPM?

Internal controls: Dominate responses, not chemistry administered from outside; despite marketing to the contrary. Medicine is low-Tech: the Hi-Tech (as embodied Soul↔Mind↔Brain↔Body creatures sending >1, 000, 000 orders/sec brain→body with similar feedback) is within. Artery & arteriole control is from brain plus local control. Study: http://goo. Gl/zZT5ou & https://goo. Gl/xqf4e4 for better understanding. ...Read more

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Does a cigarette cause coronary artery vasoconstriction? If yes, wouldn't this cause a angina if you started exercising?

Does a cigarette cause coronary artery vasoconstriction? If yes, wouldn't this cause a angina if you started exercising?

Vasoconstriction: Cigarettes are associated with coronary artery vasoconstriction. This constriction could cause angina if combined with exercise in some people, but it would not do so in everyone. Much of the response would be based on the underlying health of the heart and coronary arteries. ...Read more

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Does nicotine cause a big vasoconstriction effect on coronary arteries? If any how long does it last? Surely body would override to myocardium needs?

Does nicotine cause a big vasoconstriction effect on coronary arteries? If any how long does it last? Surely body would override to myocardium needs?

Not necessarily so: Here's an article witch will answer most of your questions:
http://content. Onlinejacc. Org/article. Aspx? Articleid=1121737
Just like the body can't override the effects of cyanide gas ...Read more

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When could cardiac output decrease?

When could cardiac output decrease?

Low blood pressure: Cardiac output is related to the heart rate, and volume of blood the heart can pump with each heart beat. A low cardiac output occurs when the pump function of the heart is compromised by an event such as a heart attack or when the blood volume is reduced by and event such as dehydration, or bleeding. ...Read more

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I'm curious what could happen when cardiac output is low and what if it's high?

I'm curious what could happen when cardiac output is low and what if it's high?

Low cardiac output: Cardiac output depends on heart rate and stoke volume. Therefore, the cardiac output increases when heart rate goes up in normal heart. However, when the heart is failing the stroke volume is lower as well as the cardiac out which is called heart failure. Sometimes, heart failure could occur when cardiac output is high due to other medical problems such as a severe anemia, hyperthyroidism, etc ...Read more

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Can you tell me how could an increased cardiac output help exercise?

Can you tell me how could an increased cardiac output help exercise?

Increase O2 delivery: During exercise, the muscles burn more oxygen for fuel. Increasing cardiac output increases the amount of oxygen carried by the blood to the tissues. ...Read more

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How could hypertension affect cardiac output?

How could hypertension affect cardiac output?

Two ways: It can cause the heart muscle to get thick and stiff so that it does not relax and fill up with blood properly. It could also cause the heart muscle to become weak so that it does not squeeze or contract as forcefully. These are called diastolic dysfunction (too thick) or systolic dysfunction (weak and flabby). ...Read more

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Why doesn't tachycardia always affect cardiac output?

Why doesn't tachycardia always affect cardiac output?

Cardiac output: Is stroke volume times heart rate. If stroke volume goes down more than heart rate goes up, cardiac output won't increase. Stroke volume depends on preload (filling of the heart), afterload (resistance to flow), and contractility (how much the heart pumps for how much it is filled. For instance, if the heart rate goes up but the the heart doesn't have time to fill, output won't increase. ...Read more

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How could hyperthyroidism affect cardiac output?

How could hyperthyroidism affect cardiac output?

Hyperthyroidism: Hyperthyroidism is a excess metabolic state. If other systems are normal it will usually cause increased heart rate and cardiac output. In the face of a weak heart, it could be associated with decrease in cardiac output. Chronic hyperthyroidism can be associated with a cardiomyopathy causing decreased heart function. ...Read more

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What could increase cardiac output?

What could increase cardiac output?

Cardiac output: Basically an increase in demand for oxygen by the body. This may be physiological (exercise) or pathological (sepsis - infection - fever) or increased metabolism (hyper active thyroid gland - hyperthyroidism) or abnormal conducts (shunting of blood). ...Read more

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How could venoconstriction affect cardiac output?

How could venoconstriction affect cardiac output?

Venoconstriction?: Cardiac output is inversely proportional to total peripheral resistance (which is related to mean arterial pressure.) venoconstriction refers to the venous system and can't be measured. If venous return increases, preload increases, and by starling's law of the heart, cardiac output increases. However, severe venoconstriction could eventually diminish venous return and reduce co. Yes? ...Read more

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Can you define cardiac output?

Can you define cardiac output?

Cardiac output: Stroke volume times heart rate equals cardiac output. Stroke volume relates to myocardial contractility, vascular resistance, vascular volume, anemia and metabolic state. There are subcomponents to all of these. ...Read more

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How do you? Measure cardiac output?

How do you? Measure cardiac output?

Several: Can use 2d echo, mra of heart, and right heart cath. Cardiac output is the measure of how many liters per minute the blood is being circulated in the body. ...Read more

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What exactly does cardiac output mean?

CO is the: Amount of oxygenated blood the heart pump from the left ventricle to the whole body in one minute. Stroke volume x heart rate. ...Read more

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What factors can affect cardiac output?

What factors can affect cardiac output?

Cardiac output: In strict physiologic terms, cardiac output is determined by something called stroke volume and heart rate. Heart rate is self-explanatory. Stroke volume is the amount of blood that the heart pumps out with each beat. This in turn is dependent on blood pressure, total blood volume, and how strong the heart contracts. ...Read more

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Describe the features of a cardiac output problem.?

Poor heart pumping: This is when the heart is unable to pump out enough blood. This can be caused by many things, including scarring of the heart after a heart attack, valve problems, infections, and other causes. ...Read more

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What factors in the body affect the cardiac output?

What factors in the body affect the cardiac output?

Many factors: Congenital heart disease, vitamin b1 defiency, anemia, thyroid problem, renal disease, liver disease, brain disease, vascular disease, blood disease, atherosclerosis, valve disease - these are the biggest influencers of cardiac output. ...Read more

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What are? Influences that can alter cardiac output?

What are? Influences that can alter cardiac output?

In general four: Cardiac output is influence by the amount of blood the heart recieves, the resistance against which the blood is ejected, the strength of contraction and the heart rate. For ex. CO increases with heart rate, increase in blood volume, increase in cardiac contraction and less resistance to ejection because of lower peripheral resistance. Clinical conditions that affects any 4 will alter cardiac output ...Read more

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What happens when you have low or high cardiac output?

What happens when you have low or high cardiac output?

Fatigue: Low cardiac output will lead to fatigue and shortness of breath. High cardiac output failure caused by severe anemia or paget's disease have similar manifestation. ...Read more

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Why would the cardiac output be the same for an athlete and a non-athlete?

Why would the cardiac output be the same for an athlete and a non-athlete?

CO=need: Your cardiac output will match your need. The difference between an athlete and a non-athlete is that the athlete can increase their co and reduce their need at peak exertion through conditioning and the rest of us can't. Think of a race car and an oldsmobile (both 8 cyl) traveling at 25 mph. They both use the same amount of gas but the former can go 200 mph, while the latter is sputtering at 100. ...Read more

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How can I maintain cardiac output?

How can I maintain cardiac output?

Exercise: The only way is exercising so your heart can be more efficient. When you exercise your cardiac reserve and stroke volume increase. ...Read more

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How does rest affect cardiac output?

Lowers it: It temporarily lowers heart rate and cardiac output. ...Read more

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How do you calculate? Cardiac output?

How do you calculate? Cardiac output?

Several: Can use 2d echo, mra of heart, and right heart cath. Cardiac output is the measure of how many liters per minute the blood is being circulated in the body. ...Read more

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Will acetylcholine raise cardiac output?

Will acetylcholine raise cardiac output?

No: Acetylcholine neurotransmission has an inhibitory effect on the heart, which lowers heart rate thereby decreasing cardiac output. ...Read more

Dr. Cynthia Archer
918 Doctors shared insights

Cardiac Output (Definition)

Cardiac output is a measurement of the amount of blood a person's heart can pump out during a set amount of time. The measurements help doctors figure out how strong or weak ...Read more


Dr. Daniel Saurborn
5 Doctors shared insights

Cardiac (Definition)

Cardiac translates literally to "heart, " and any place the term is seen, such ...Read more