Which arrhythmia is characterized by changes in ventricular filling and preload as a result of breathing?

Which arrhythmia is characterized by changes in ventricular filling and preload as a result of breathing?

• A. Ventricular fibrillation
• B. Sinus arrhythmia/dysrhythmia
• C. Atrial flutter
• D. Premature ventricular contractions

Answer: (B)

The correct answer is sinus arrhythmia/dysrhythmia, which is characterized by variations in heart rate that correlate with the breathing cycle. This reflects changes in intrathoracic pressure during inspiration and expiration. When a person inhales, the increased negative intrathoracic pressure promotes venous return to the heart, leading to an increased preload. This results in a slightly increased heart rate during inspiration. Conversely, during expiration, the heart rate may decrease as venous return diminishes due to the positive pressure in the thorax. This natural and physiological response to breathing is what distinguishes sinus arrhythmia from other types of arrhythmias, making it a normal and often benign finding in individuals, especially in younger patients.

The correct answer is sinus arrhythmia/dysrhythmia, which is characterized by variations in heart rate that correlate with the breathing cycle. This reflects changes in intrathoracic pressure during inspiration and expiration. When a person inhales, the increased negative intrathoracic pressure promotes venous return to the heart, leading to an increased preload. This results in a slightly increased heart rate during inspiration. Conversely, during expiration, the heart rate may decrease as venous return diminishes due to the positive pressure in the thorax. This natural and physiological response to breathing is what distinguishes sinus arrhythmia from other types of arrhythmias, making it a normal and often benign finding in individuals, especially in younger patients.