Why are uncontrolled cardiac arrhythmias with haemodynamic compromise an absolute contraindication?

• A. Exercise may be stopped for minor discomfort.
• B. Arrhythmias are harmless during exercise.
• C. Remedies can calm the heart rate.
• D. Exercise may exacerbate arrhythmias, leading to hypotension, syncope, or sudden cardiac arrest.

Answer: (D)

The key idea is that exercising with an unstable heart rhythm can tip a fragile situation into serious collapse. When an arrhythmia is uncontrolled and the body’s perfusion is already compromised, adding physical exertion ramps up sympathetic drive, increasing heart rate and oxygen demand while the unstable rhythm may further deteriorate. This combination can drop blood pressure (hypotension), cause fainting (syncope), or trigger life-threatening outcomes like cardiac arrest. That risk is why such a condition is listed as an absolute contraindication to exercise. The other options imply safety or controllability that isn’t present here, so they don’t fit the danger posed by exertion in this context.