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What Makes a Drug Chronotropic?
Mary McMahon
Mary McMahon
A drug is considered chronotropic if it changes the heart rhythm in some way. Many drugs can alter the heart rhythm and may be administered specifically for this purpose, while in others, the change is a side effect and the patient has to be monitored to make sure the heart stays healthy. Drugs with a strong chronotropic effect are usually available by prescription only because they can be dangerous. Weaker drugs, like caffeine, known to increase the heart rate, are readily available.
Chronotropic drugs can work in a number of ways. One option is a dromotropic drug, one that works by influencing the electrical impulses used to control heart rhythm. Drugs to slow or speed impulses can be used to regulate the heartbeat in a patient and may also control the coordination of electrical impulses to make the heart more efficient. Inotropic drugs control the muscular contractions of the heart, influencing the strength of those contractions and the subsequent power of each heart beat.
Bathmotropic medications can increase excitability in the heart, making it more sensitive to signals, while lusitropic compounds influence relaxation, a phase in the heartbeat where the muscles release before preparing to tense up again. Calcium overload or increased uptake of calcium in the heart can make it harder for the heart to relax, interfering with the normal cycle of the heartbeat.
Chronotropic drugs can be used in emergency settings where a patient's heart is not beating normally and care providers want to stabilize it. The drug will be prescribed on the basis of the kind of abnormal rhythm, the cause, and any other symptoms being experienced. Doctors want to avoid pushing patients too far in the other direction and they are also concerned with the potential side effects of some chronotropic drugs. Often a patient with acute heart problems is having other medical issues and a cascading effect can be a cause for worry when people are providing treatment.
These drugs can also be used in the long term by people with heart problems who need help regulating the heartbeat. A pacemaker can be one option, but chronotropic drugs are less invasive and may be more suitable for the treatment of certain conditions. Beta blockers are an example of a class of chronotropic drugs designed for extended use in patients with cardiac problems. Usually, patients on such medications need regular follow-up appointments to monitor heart health, adjust drug dosages if needed, and to discuss any side effects and other symptoms the patient has developed.
Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.
Learn more...
Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.
Learn more...AS FEATURED ON:
AS FEATURED ON:
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![A chronotropic drug can change the heart's rhythm.]()
By: adimasA chronotropic drug can change the heart's rhythm. -
![Chronotropic drugs are typically only available through prescription because of the danger associated with their consumption.]()
By: Brian JacksonChronotropic drugs are typically only available through prescription because of the danger associated with their consumption. -
![Strong chronotropic drugs are available only with a prescription.]()
By: HconQStrong chronotropic drugs are available only with a prescription. -
![Chronotropic drugs may used if a patient's heart is not beating normally.]()
By: pathdocChronotropic drugs may used if a patient's heart is not beating normally.
Discussion Comments
I have a friend who is a vegetarian. She is super health conscious, and she doesn’t even consume caffeine or sugar that isn’t naturally found in fruit.
She was having problems with her heart, but she had an uncommon issue. Her blood pressure and pulse were too low, so her doctor had to put her on drugs to increase both.
He told her that a cup of caffeinated coffee a day would do her some good, so she tried that. It raised her heart rate some, but not enough to give her the energy she needed. So, he prescribed a stronger chronotropic drug.
She’s doing fine now. I know plenty of people with blood pressure issues, but she is the only one that actually needed hers kicked up a few notches.
@orangey03 - I have good news for you. You can consume as much caffeine as you want, because it only affects your blood pressure while it’s in your system.
My sister is a doctor, and she keeps me informed of research in the medical world. She told me that studies showed that once caffeine exits a person’s body, any increase in blood pressure it might have caused disappears, and the pressure returns to normal.
People who don’t currently have problems with high blood pressure don’t raise their risk by consuming caffeine. Even people who are on medication for it can ingest caffeine without any problems, in most cases.
I didn’t know that caffeine was considered a chronotropic drug. That makes it sound so serious! Just about everyone I know uses caffeine in some way.
I wonder if caffeine intake is linked to high blood pressure. I know that it speeds up your heartbeat, but can it lead to chronic heart problems?
I currently have normal blood pressure, but I do consume two cups of coffee, at least one soda, and a cup of tea just about every day. Am I at risk for developing high blood pressure? I’d hate to have to cut down on my caffeine intake, but if I find out it’s causing serious health problems, I’ll have no choice.
My doctor put me on beta blockers once he saw that my blood pressure was 150 over 100. I have a kidney condition that often causes high blood pressure, and though I had gone through many years with normal readings, it eventually rose.
He told me that without the chronotropic drugs, my pressure would remain high, and this could cause further damage to my kidneys. I hate having to rely on medication for the rest of my life, but it beats the alternative.
I started out just taking one drug, but my doctor kept having to increase the dosage, so he eventually added another drug to the mix. The second one leveled my pressure off, and I’ve had consistent readings for about five years now. I have a blood pressure monitor at home, so I keep a regular check on it, just to be safe.
My brother has had heart problems for many years, and has been on a variety of medications to keep it under control.
He has used more than one chronotropic drug during this time and always was monitored closely to make sure his heart rhythm was controlled and steady.
It finally got to the point where the drugs weren't controlling it as well as the doctor wanted. He finally got a pacemaker and has done quite well with that.
There are a lot of helpful medications out there that can that really make a big difference. If he had not had access to these chronotropic drugs for so many years, I don't know if he would still be with us today or not.
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