Difference Between Inotropic vs. Chronotropic vs. Dromotropic

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Main Difference

The difference between inotropic, chronotropic and dromotropic is that inotropic is a cardiac drug that affects cardiac contraction, chronotropic is a cardiac drug that affects heart rate whereas dromotropic is a cardiac drug that affects conducting tissues of the heart.

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Inotropic vs. Chronotropic vs. Dromotropic

There are many types of cardiac drugs, inotropic, chronotropic and dromotropic are the types of cardiac medications. There are many cardiac problems, and each medicine is made for a specific kind of cardiac problem. The inotropic cardiac drug is used to treat cardiac contractions; the chronotropic cardiac drug is used to control heart rate whereas dromotropic is a cardiac drug works on conducting tissues of the heart. If we talk about Inotropic, there are two types of inotropic drugs. The positive inotropic drug increases the force of myocardial contraction whereas negative inotropic drug decreases the force of myocardial contraction. Likewise, there are types of chronotropic cardiac drugs that is a positive chronotropic cardiac drug that increases the heart rate whereas negative chronotropic drug slows the heart rate. If we talk about cardiac dromotropic medicines again, there are two types of cardiac dromotropic medicines, a positive dromotropic cardiac drug that increases the rate of conduction on the other hand negative dromotropic cardiac drug slow down the pace of conduction. The difference between these three drugs is by their function in our body.

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Comparision Chart

InotropicChronotropicDromotropic
Inotropic is a cardiac drug that affects cardiac contraction.Chronotropic is a cardiac drug that affects heart rate.Dromotropic is a cardiac drug that affects conducting tissues of the heart.
Types
Positive inotropic drug, negative inotropic drug.Positive chronotropic drug, negative chronotropic drugPositive dromotropic drug, negative dromotropic drug.
Function
Heart contractionControl heart rateConducting the tissues of the heart
Example
DigoxinDopaminePhenytoin

What is Inotropic?

There is a force that is always applied to the muscles on heart and Inotropic is a cardiac drug that controls that force of muscles on the hearta . Our heart undergoes contractions, and these contractions are also controlled by Inotropic. There are two types of inotropic cardiac drugs that are positive inotropic drug and negative inotropic drug. The functions of both positive inotropic and negative inotropic drug are different, positive inotropic drug increase the muscle contraction whereas negative inotropic drug decreases the muscle contraction. Myocardial contractility is a process that controls the contraction of heart muscles. If we talk about the benefits of the inotropic cardiac drug, one of the main advantage of this drug is to control the muscle contraction. The use of positive and negative inotropic drug depends on the condition of the patient.

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Positive inotropic cardiac drug and negative inotropic cardiac drug have different functions and use. The use of both depends on the condition of the patient.

Positive Inotropic Drug: Positive inotropic drug increase the rate of heart contractions, an increase of heart contraction mean pump more amount of blood to heart in a few heartbeats. A patient who faces a heart attack is treated with this drug. This drug is best for a patient with cardiomyopathy.

Negative Inotropic Drug: Negative Inotropic drug slows down the contraction of the heart. Patients with high blood pressure are treated with negative inotropic drug. Basically this drug deals with hypertension.

What is Chronotropic?

Word Chronotropic means “heart rate of human”. Chronotropic is a cardiac drug that affects the heart rate of a human. Two types of chronotropic cardiac medication are positive chronotropic drug and negative chronotropic drug. The positive chronotropic drug increases the heart rate whereas negative chronotropic drug decreases the heart rate.

What is Dromotropic?

Dromotropic is a cardiac drug that affects conducting tissues of the heart. Dromotropic improves the condition of heart impulse. Dromo word means long distance. There are two types of dromotropic cardiac drug that are positive dromotropic cardiac drug and negative dromotropic cardiac drug. The positive dromotropic cardiac drug increases the electric impulse conduction whereas negative dromotropic cardiac drug decreases the electrical impulse conduction. Example of positive dromotropic is phenytoin, an example of negative dromotropic is verapamil. These drugs are given according to the condition of the patient.

Key Differences

  1. Inotropic is a cardiac drug that affects cardiac contraction, Chronotropic is a cardiac drug that affects heart rate. Dromotropic is a cardiac drug that affects conducting tissues of the heart.
  2. Types of inotropic cardiac drug are: Positive inotropic drug, negative inotropic drug. Types of chronotropic drugs are: Positive chronotropic drug, negative chronotropic drug. Types of dromotropic cardiac drug are: Positive dromotropic drug, negative dromotropic drug.
  3. Inotropic are the medications which help in changing the force which is connected to the muscles. Chronotropic drugs are the ones which are utilized to deal with the heart rate of a patient. Dromotropic drugs are the ones which help in improvements in the state of electrical driving forces of the heart.
  4. Example of inotropic cardiac drug is Example of chromotropic cardiac drug is Dopamine whereas example of Dromotropic cardiac drug is Phenytoin.

Comparison Video