Propranolol and Adrenaline-Induced Arrhythmia

Effect of Propranolol on Adrenaline-Induced Arrhythmia

• Adrenaline (epinephrine): A α and β agonist, activating β receptors in the heart causes cardiac excitation. High doses or rapid administration can induce cardiac arrhythmia.
• Propranolol: A β-receptor antagonist that counteracts the effects of adrenaline on the heart, reducing cardiac excitation.
• Atropine: An M receptor antagonist that reduces the heart's response to vagus nerve inhibition. This promotes cardiac excitation, counteracting the inhibitory effect of the vagus nerve.
• ECG: Electrocardiogram measures the electrical activity of the heart.
• Normal ECG: Displays distinct waveforms (P, QRS, T) indicating normal electrical conduction and heart function.
• Sinus arrhythmia: Abnormal heart rate characterized by variations in heart rate, a common effect of adrenaline or other factors. Can present as tachycardia (shortened R-R intervals) or bradycardia (prolonged R-R intervals).
• Drug Administration Protocol: Includes steps for administering adrenaline, propranolol, and atropine, and recording ECG readings at specific time intervals post-administration. Adrenaline is administered rapidly while propranolol is given slowly.
• Cautions: Rapid administration of adrenaline and slow administration of propranolol are critical for preventing unwanted side effects.
• Results Table: Shows effects of first, second, and third doses of adrenaline, propranolol, and atropine on heart rate and rhythm abnormalities. First adrenaline dose tends to give obvious arrhythmia, second dose leads to normal readings. The subsequent propranolol and atropine administrations also show different affects, leading to further normal readings.