Question

Match the Column-I with Column-II.

Column-I	Column-II
(a) P-wave	(i) Depolarization of ventricles
(b) QRS complex	(ii) Repolarization of ventricles
(c) T-wave	(iii) Coronary ischemia
(d) Reduction in the size of T-wave	(iv) Depolarization of atria
	(v) Repolarization of atria

Select the correct options:
A. a-iv, b-i , c-ii, d-iii
B. a-iv, b-i, c-ii, d-v
C. a-ii, b-i, c-v, d-iii
D. a-ii, b-iii, c-v, d-iv

Answer 1

Hint: The terms mentioned above are related to ‘Electrocardiography’. It is a process of forming an electrocardiogram (ECG). It is basically a graph of voltage versus time of the electrical activity of the heart using electrodes placed.

Complete answer: The P-wave is a summation wave that was produced by the depolarization front as it helps in transmission to the atria. Basically, the right atrium starts depolarizing slightly earlier than the left atrium since the depolarization wave starts originating in the sinoatrial node, in the high right atrium, and then moves to and through the left atrium. The QRS complex is the combination or addition of three of the graphical deflections which are visible on a typical electrocardiogram. It is generally the central and visually obvious part of the tracing, basically, it is the main spike visible on the ECG line. In electrocardiography, T-wave denotes the repolarization of the ventricles. The time duration from the beginning of the QRS complex to the apex of the T-wave is referred to as the absolute refractory period. The last half of the T-wave is referred to as the vulnerable period or relative refractory period. Reduction in the size of T-wave, that is, if the T-wave which denotes insufficient supply of oxygen, that is, coronary ischemia.
Hence, the correct answer is option (A), i.e., a-iv, b-i, c-ii, d-iii

Note: Flattened T-waves are a non-specific finding, but may also denote ischemia (dynamic or contagious leads) or electrolyte abnormality, hypokalemia. The T-wave is generally smaller than the QRS wave because it denotes ventricular repolarization. The T-wave is longer in duration or has more intervals than the QRS complex that denotes depolarization. The longer duration occurs because the conduction of the repolarization wave is slower than the wave of depolarization.