Final answer:
An ECG in the case of reentrant supraventricular tachycardia (SVT) will typically show a tachycardic rhythm, reflecting a higher than normal heart rate, characterized by increased frequency of QRS complexes.
Step-by-step explanation:
The ECG in the usual form of reentrant supraventricular tachycardia (SVT) would likely be characterized as c) Tachycardic. Supraventricular tachycardia refers to a range of arrhythmias that result in a faster than normal heart rate originating above the ventricles. It can be identified on an ECG by a high frequency of QRS complexes, which are associated with ventricular depolarization, one of the key phases of the cardiac cycle.
Common ECG abnormalities in various heart conditions include patterns such as atrial fibrillation, where the electrical pattern is irregular before the QRS complex and the frequency between QRS complexes is increased, indicating an increased heart rate. In contrast, a third-degree block shows no correlation between the P waves, which represent atrial depolarization, and the QRS complexes, indicating a severe disruption in the heart's normal electrical activity.
Given that a characteristic of SVT is an abnormally fast heartbeat that arises from the atria or upper chambers of the heart, the correct answer would be tachycardic. Arrhythmias can result from issues in the heart's conduction system and can present in various forms, which are diagnosed using an ECG.