Final Answer:
The most likely diagnosis based on the given ECG is Ventricular Tachycardia with Pacemaker Rhythm. Thus the correct option is C.
Step-by-step explanation:
The ECG demonstrates a wide QRS complex rhythm with a rate exceeding 100 beats per minute, suggestive of ventricular tachycardia (VT). The absence of distinct P waves and irregular rhythm rules out sinus rhythm or atrial fibrillation. Additionally, the consistent pacing spikes followed by wide QRS complexes indicate a pacemaker rhythm. The fusion of paced and intrinsic QRS complexes is characteristic of VT with a pacemaker capturing some beats while others follow the VT's intrinsic rhythm.
Ventricular tachycardia is diagnosed when the heart rate exceeds 100 beats per minute, the QRS complexes are wide (>0.12 seconds), and there is a lack of discernible P waves. In this ECG, the rapid, wide QRS complexes without identifiable P waves suggest VT. The presence of pacing spikes indicates a pacemaker, and the fusion of intrinsic and paced beats is a hallmark of VT with pacemaker rhythm.
This diagnosis is critical for appropriate management and intervention to prevent potential adverse cardiac events associated with sustained VT. Therefore, recognizing these ECG findings is essential for prompt and accurate diagnosis in clinical practice.Thus the correct option is C.