How is the EKG of a patient with a very high heart rate classified?

The classification of an EKG with a very high heart rate hinges on key characteristics such as the origin of the tachycardia and the morphology of the QRS complex. When a patient exhibits a high heart rate, it is essential to determine whether the tachycardia originates from above the ventricles (supraventricular) or from the ventricles themselves.

In the case of supraventricular tachycardia (SVT), the heart rate is typically rapid, often exceeding 100 beats per minute, with a narrow QRS complex. This indicates that the impulse is originating from atrial structures or the AV node. Conversely, ventricular tachycardia (VT) usually presents with a wide QRS complex, meaning the impulse arises from the ventricles and generally indicates a more serious cardiac condition.

The ability to differentiate between SVT and VT based on the width of the QRS complex is vital. If the QRS complex is narrow, it’s likely SVT; if it's wide, it suggests VT. Thus, classifying the EKG of a patient with a very high heart rate involves assessing the QRS width to make an accurate determination, making the provided answer appropriate.