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Afterload
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∙ 11y ago
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How does dehydration affect preload?
Severe dehydration will decrease preload because there won't be as much volume coming into the heart.
Do the kidneys affect angiotensin II?
Certain kidney disorders increase the production of angiotensin II, another cause of hypertension
Do beta blockers thin blood?
No. Beta blockers slow the heart rate and only affect the heart and how fast it pumps.
What are 3 important factors affecting stroke volume?
Venous return controls EDV (end diastolic volume) and thus stroke volume and cardiac output. Venous return is dependent on: - blood volume and venous pressure - vasoconstriction caused by the sympathetic nervous system - skeletal muscle pumps - pressure drop during inhalation
How does severe dehydration affect preload?
It lowers the energy of a certain person causing him/her to move slowly.
What is the difference between metoprolol and ramipril?
Metoprolol is a drug that is in the class of beta blockers, that are intended to control high blood pressure, and (in my case) heart rate. Meloxicam is an NSAID intended to reduce pain, and should not be combined with aspirin.
How does preload affect the stroke volume?
Preload refers to the degree of stretch of cardiac muscle cells before contraction. These muscles exhibit a length-tension relationship. When the cardiac muscle cells are at rest, they are shorter than their optimal length. The most important factor affecting the stretching of cardiac muscles is the venous return, that is, the amount of blood returning back to the heart. Slow heartbeat and exercise can increase the venous return. This will lead to the stretching of the ventricles and it will hence increase the contraction force.As reflected by the Frank-Starling Law, the stroke volume increases with the end diastolic volume. The greater filling volume will lead to the heart to stretch more and this will increase its force of contraction.
How do beta blockers and ACE inhibitors affect tattooing?
Beta blockers and ACE inhibitors have an affect on people's experiences during tattooing. For instance, people on beta blockers and ACE inhibitors report not being able to sit for tattoos as long as they would like. Additionally, it decreases people's threshold for pain, making the tattoo experience less pleasurable.
How do other drugs interact with calcium channel blockers?
Taking calcium channel blockers with certain other drugs may affect the way the drugs work or may increase the chance of side effects.
Does decreased peripheral resistance increase cardiac output?
Decreased peripheral resistance can increase cardiac output, yes, but it is not necessarily a 1 to 1 relationship. Cardiac output is a complex mechanism - cardiac output depends on stroke volume and heart rate. Heart rate is easy to understand, but stroke volume is a little trickier. Stroke volume depends on three things: contractility of the cardiac muscle, preload - or the filling of the heart, and afterload. Contractility is partially determined by preload, how healthy the cardiac muscle is, and the effects of circulating bioamines, such as epinephrine, norepinephrine, dopamine, as well a any medications being taken that may affect contractility, such as beta blockers. Increased contractility causes a harder "squeeze," increasing the stroke volume on a beat by beat basis. Infarction of a portion of the wall decreases the amount of cardiac muscle present, decreasing the ability to contract, but also decreasing the ability to fill the ventricle, since scar tissue does not stretch like healthy muscle. Excessive hypertrophy (such as that caused by prolonged hypertension or hypertrophic cardiomyopathy), while helpful to a point in increasing contractility, will eventually impede filling of the ventricle by preventing the "stretch" before contraction and decrease the cardiac output. Preload is basically how filled the ventricle is before it contracts. Decreased filling, obviously, decreases the stroke volume, thereby decreasing the cardiac output. The cardiac myocyte works best when slightly overstretched. This optimally apposes the actin and myosin myofilaments and produces the best power for contraction, which is the purpose of the atrial contraction - it provides just that little bit of extra fill before the AV valves close and optimizes the preload on the heart. Too much preload, however, is bad, as the myofibrils can be overstretched and then are less effective. This is all nicely explained by the Starling curve. Afterload is basically what you asked about. It is partially determined by peripheral vascular resistance, but other factors interact as well. You have to remember that the vascular system is not a rigid tube, it is a living thing. As such, other obstacles can, and do, occur. For instance, aortic sclerosis is the most common cause of heart murmur in adults. The narrowing of the aortic valve and its impedence to blood flow increases the afterload on the heart, thereby decreasing the stroke volume. Septal hypertrophy, as seen in hypertrophic cardiomyopathy, can cause an intermittent occlusion or partial occlusion of the aortic outflow tract, increasing afterload, especially during high flow states and high heart rates.
When Losar 25 used?
Losar refers to Losartan, a blood pressure medicine of the category called Angiotensin Receptor Blockers, or ARB's.ARB's work by blocking a substance called Angiotensin from binding with receptors that usually initiate a signal telling blood vessels to constrict. Angiotensin is a messenger your body puts out to regulate your overall blood pressure. By interfering with the messenger, your arteries stay more relaxed, thus having a larger diameter.If you have the same amount of blood going through a greater volume of vessel, then the pressure is, necessarily, less. That is how Losar works. Many doctors consider it a more benign method of affecting high blood pressure than other drugs that directly affect the heart rate, or instruct the kidneys to reduce blood volume by increasing urine production.
When Losar-25 used?
Losar refers to Losartan, a blood pressure medicine of the category called Angiotensin Receptor Blockers, or ARB's.ARB's work by blocking a substance called Angiotensin from binding with receptors that usually initiate a signal telling blood vessels to constrict. Angiotensin is a messenger your body puts out to regulate your overall blood pressure. By interfering with the messenger, your arteries stay more relaxed, thus having a larger diameter.If you have the same amount of blood going through a greater volume of vessel, then the pressure is, necessarily, less. That is how Losar works. Many doctors consider it a more benign method of affecting high blood pressure than other drugs that directly affect the heart rate, or instruct the kidneys to reduce blood volume by increasing urine production.
