Final answer:
The differences between atrial flutter, sinus tachycardia, and ventricular tachycardia can be discerned by examining the ECG for characteristic patterns; atrial flutter has sawtooth flutter waves, sinus tachycardia shows a regular but fast rhythm from the SA node, and ventricular tachycardia presents with wide QRS complexes and an irregular P wave relationship.
Step-by-step explanation:
The differences between atrial flutter, sinus tachycardia, and ventricular tachycardia on an ECG are distinct and can be identified by examining the P waves, QRS complexes, and the rhythm of the heart beats.
Atrial flutter is characterized by sawtooth-like flutter waves (called F waves), occurring at a regular rapid rate that usually lead to a ventricular rate that is an exact fraction of the flutter rate, commonly 2:1. This means for every two flutter waves, there is one QRS complex.
Sinus tachycardia is a fast heartbeat originating from the sinoatrial node, with a heart rate greater than 100 beats per minute, but the rhythm remains regular. The P wave precedes every QRS complex, and the P wave is normal in shape and size.
Ventricular tachycardia features wide and bizarre QRS complexes due to abnormal electrical signals originating from the ventricles. The rate is usually rapid, and the P waves, if visible, do not typically have a regular relationship with the QRS complexes.