Which condition can result in a heart rate instability?

Atrial flutter is a condition that can lead to heart rate instability due to its nature of causing rapid and erratic electrical signals in the heart. This arrhythmia typically results in an increased heart rate as the atria contract rapidly and do not allow for a coordinated rhythm. The instability arises from this irregularity in heartbeats, which can lead to symptoms such as palpitations, fatigue, and in severe cases, contribute to complications like stroke or heart failure if not managed properly.

In contrast, the other listed conditions—peripheral artery disease, hypertension, and cardiomyopathy—although they may impact cardiovascular health and overall heart function, do not inherently cause the same level of immediate heart rate instability as atrial flutter does. These conditions may contribute to chronic heart issues or exacerbate existing heart problems over time, but they typically present with a more stable heart rate rather than the erratic rhythms characteristic of atrial flutter.