What term describes manifestations of electrical activity in the heart that cause problems when the rhythm breaks down?

• A. Arrhythmias
• B. Myocardial infarction
• C. Hypertension
• D. Aneurysm

Answer: (A)

The focus here is on abnormalities in the heart’s electrical activity that disrupt the rhythm. When the normal electrical timing breaks down, the heart may beat too fast, too slow, or with an irregular pattern—that set of problems is called arrhythmias. Arrhythmias arise from issues in the conduction system (like the SA node, AV node, or Purkinje fibers) or from ectopic electrical foci, and they can range from harmless skipped beats to lifethreatening rhythms that impair cardiac output. On a 12‑lead ECG, they show up as abnormal rhythm patterns, altered rates, or irregular intervals.

The other terms describe structural or vascular problems rather than electrical rhythm disturbances: myocardial infarction is damage from ischemia to heart muscle, hypertension is high blood pressure, and an aneurysm is a bulge in a vessel or heart chamber. Because those describe anatomy or pathology outside the electrical rhythm, they don’t fit as well as arrhythmias.