AEMCA Practice Exam

What heart rhythm condition presents more P waves than QRS complexes?

1. Ventricular tachycardia.

2. Mobitz type 1.

3. Mobitz type 2.

4. Third-degree heart block.

The correct answer is: Mobitz type 2.

The heart rhythm condition characterized by more P waves than QRS complexes is third-degree heart block. In this condition, the electrical signals from the atria (which generate the P waves) are not effectively transmitted to the ventricles. As a result, the atria and ventricles are functioning independently. This results in the presence of numerous P waves as the atria contract at their own intrinsic rate, while the ventricles may contract at a much lower rate depending on the escape rhythm. The resulting appearance on an electrocardiogram shows more P waves than QRS complexes. In contrast, the other options refer to different types of heart block or arrhythmias that do not exhibit this specific P wave to QRS complex ratio. For instance, while Mobitz type 1 and type 2 may demonstrate some degree of dropped beats, their characteristics do not typically result in a significant number of P waves without corresponding QRS complexes over time. Ventricular tachycardia, on the other hand, features a rapid series of QRS complexes with few, if any, P waves due to the rapid firing of the ventricles. Therefore, third-degree heart block is the condition that distinctly presents more P waves than QRS complexes.