Q172 / 180 · AIIMS 2014 · Zoology

Assertion : The enlarged $\mathrm{Q}$ and $\mathrm{R}$ waves indicate myocardial infarction. Reason: The QRS complex represents ventricular repolarisation.

  • A
    If both assertion and reason are true and reason is the correct explanation of assertion.
  • B
    If both assertion and reason are true but reason is not the correct explanation of assertion.
  • Correct answer
    C
    If assertion is true but reason is false.
  • D
    If both assertion and reason are false.

Solution

The enlarged $\mathrm{Q}$ and $\mathrm{R}$ waves indicate a myocardial infarction (heart attack). QRS complex begins as small downward deflection (Q) and continues as large upright $(\mathrm{R})$ and triangular wave ending as downward wave (S) at its base. It represents ventricular depolarisation (ventricular contraction).

Hence, the correct answer is option: 'C'.

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