Propranolol and Adrenaline-Induced Arrhythmia

Adrenaline, a hormone and neurotransmitter, acts as an agonist for both alpha (α) and beta (β) receptors. Its activation of β receptors in the heart leads to increased heart rate and contractility.

When administered in high doses or injected too quickly, adrenaline can cause an imbalance in the autonomic nervous system, leading to irregular heart rhythms (arrhythmias).

Propranolol is a drug that blocks the action of beta (β) receptors in the heart. This reduces heart rate and contractility.

Atropine is a drug that blocks the action of muscarinic (M) receptors, particularly in the heart. By inhibiting the effects of the vagus nerve, atropine increases heart rate and contractility.

The ECG (Electrocardiogram) is a graphical representation of the electrical activity of the heart. Changes in the ECG can indicate abnormal heart rhythms or other cardiac issues.

In this experiment, adrenaline, propranolol, and atropine were administered to observe their effects on heart rate and rhythm. The ECG recordings were taken at various time points after each drug administration.

The results of the experiment show that adrenaline initially caused increased heart rate and arrhythmia. Propranolol helped regulate the heart rhythm, while atropine further increased the heart rate.

While adrenaline, propranolol, and atropine each have distinct effects on heart rate and rhythm, the experiment also explores whether repeated administrations of adrenaline result in different physiological responses.