What effect does Hyperkalemia have on Cardiac Output? Why?
Is an elevated level of blood potassium and can cause cardiac arrhythmia. Cardiac arrhythmia (also dysrhythmia) is a term for any of a large and heterogenous group of conditions in which there is abnormal electrical activity in the heart. The heart beat may be too fast or too slow, and may be regular or irregular and thus affect cardiac output.
How are heart rates and cardiac outputs related and how do they differ?
Cardiac output = stroke volume x heart rate.So cardiac output and heart rate is directly proportional.But nor is this all. Stroke volume depends on cardiac contractility, preload and afterload. Preload is roughly the blood volume in the ventricle to be pumped in next systole and afterload is roughly the forces against the pump. Thus afterload is inversely proportional to cardiac output, whereas contractility and preload (not always, note that these descriptions are not for health specialists, but for public) are directly proportional to cardiac output.If heart rate increases especially in patients with impaired contractility and arrhythmias, preload decreases because there is not enough time for blood to flow from atria to ventricles during diastole. If so, heart rate becomes inversely proportinal to cardiac output, contrary to proposition at the beginning.Finally, heart rate influences cardiac output not in a usual manner. It is related to patient cardiac status.
Which has the greater effect on cardiac output, stroke volume or heart rate?
It's complex and depends on a number of variables, at higher heart rates there is less time for diastolic filling of the ventricle so as heart rate increases stroke volume will decrease, also if the patient is not in sinus rhythm or has diastolic heart failure the stroke volume is decreased further at higher heart rates because of loss of atrial ‘kick’ or decreased ventricular filling from a stiff ventricle respectively. At lower heart rates SV will increase because of increased ventricular filling to a certain point.In a reasonably normal heart in sinus rhythm cardiac output is maximised at a heart rate of about 70–100 beats per minute this allows for optimal diastolic ventricular filling.
Why does cardiac output decrease with a slow heart rate?
Simple; cardiac output is the amount of blood pumped per minute. That amount consists of the volume of blood in the heart expelled with each contraction times the number of contractions per minute. In the case of a slower heart beat, there is also more time between contractions for the heart to fill, however the increased filling time effect is much less than the reduction in total blood pumped due to reduced heart rate.
What effect does donating blood have on heart rate?
When your blood pressure decreases your heart rate usually increases.
What is the effect of exercise on tidal volume and cardiac output? Would they increase or decrease?
Ironic. I just finished the cardiorespiratory chapter from my ACE manual. I'm pleasantly surprised to see somebody use those terms. Tidal volume increases drastically with aerobic exercise. Strength building is fueled mostly by the faster working systems of cellular energy, but there will be some benefit from that, too. Back to cardio. Oxygen intake is the standard measure of cardiovascular improvement. It is measured in milliliters of oxygen inhaled per kilogram of body weight per minute: ml/kg/min. There is at least a 50% improvement between 10 and 90 percentiles in all age groups for men and at least 60% in all age groups for women. The difference increases with age. Here is the best part. During exercise, most of the body's increased oxygen demand is met with a tidal volume increase. Only when the anaerobic threshold is approached does respiration rate start increasing more to meet demand. In case you are still wondering, this is a very good thing. As for cardiac output, it only changes slightly at rest because there is no need for improvement unless there is something wrong. If a heart condition is present, see a doctor before starting *any* exercise program, and only exercise under supervision of a trained professional with current CPR and defibrillation credentials. Cardiac output in the most important factor in cardio endurance. Exercise cardiac output can increase by 50% or more with conditioning. Some elite athletes (ie: Michael Phelps) have twice the cardiac output of an unconditioned person. As the heart becomes better at what it does, heart rate at all levels does not need to be as high because the stroke volume improves. This also leads to improvement in blood pressure and can correct hypertension in some people. So both tidal volume and cardiac output increase, and in both cases that is a positive. Cardiorespiratory fitness is a strong predictor of morbidity and mortality. So if and when you see improvements, smile at the thought of a few more healthy birthdays in you life.
How does Lisinopril affect heart rate?
Lisinopril is what is called an ACE (angiotensin-converting enzyme) inhibitor, a type of antihypertensive (blood pressure lowering) medication. It works by relaxing blood vessels and causing the excretion of sodium (salt) and water via the kidneys.The therapeutic effect of this drug is to decrease cardiac workload and increase cardiac output by decreasing the pressure the heart has to pump against when it ejects blood into the vascular system. If blood pressure is lowered too much, there can be a reflex tachycardia (fast heart rate).Most patients with cardiovascular disease take more than one drug, and the drugs interact, so if there is a change in heart rate, it’s important to understand that it may not be solely the Lisinopril that is the cause. Patients should contact their prescribing physician or mid-level provider if concerned about their heart rate.© 2018 Lucinda M. Ludwig
What are the differences between stroke volume and cardiac output?
Cardiac output is the amount of blood pumped out of the heart (ventricles) to the body per minute, and stroke volume is the amount of blood pumped out of your heart with each heartbeat. Stroke volume = 60-70 ml/heartbeat and cardiac output = 3-5 liters per minute. Cardiac output is determined by multiplying stroke volume by heart rate.