Family Nurse Practitioner Exam

A 45-year-old male has an irregular rhythm with a pulse rate of 110 BPM. What is the most likely diagnosis?

1. Atrial fibrillation

2. Ventricular fibrillation

3. Cardiac arrhythmia

4. First-degree right bundle branch block

The correct answer is: Atrial fibrillation

In this scenario, the patient's irregular rhythm and elevated pulse rate of 110 BPM strongly suggest atrial fibrillation. Atrial fibrillation is characterized by an irregularly irregular heart rhythm and can often lead to a rapid ventricular response, which explains the increased pulse rate. This condition occurs due to disorganized electrical activity in the atria, resulting in a lack of coordinated contraction and an irregular pulse. While ventricular fibrillation is a critical and life-threatening arrhythmia, it typically presents with a rapid, chaotic rhythm and no palpable pulse, which is not indicated here. Cardiac arrhythmia is a broad term that encompasses any irregular heartbeat, but it does not specify the nature of the arrhythmia as clearly as atrial fibrillation does in this case. Lastly, a first-degree right bundle branch block would manifest as a delayed conduction with a specific ECG pattern, rather than an irregular pulse, making it an unlikely diagnosis in this context. Thus, considering the symptoms and common presentations, atrial fibrillation is the most fitting diagnosis for this patient.