Question

Match the following with regard to ECG.

Wave/interval of ECG	Clinical interference
(A) Prolonged Q-T interval	(I) Fast beating of the heart
(B) Tail T-wave	(II) Block of conduction through bundle of His
(C) Shortened P-R interval	(III) Hypothyroidism
(D) Variation in QRS interval	(IV) Enlarged atria
	(V) Hyperkalemia

• A. A-V, B-IV, C-II, D-I
• B. A-II, B-IV, C-V, D-I
• C. A-III, B-V, C-II, D-I
• D. A-III, B-V, C-I, D-II

Answer 1

The correct option is D A-III, B-V, C-I, D-II

• Hypothyroidism may be the cause of atrioventricular blocks and of acquired long QT syndrome (LQTS).
• Tall and narrow (peaked) T wave in the electrocardiogram indicates the hyperkalemia, which can cause life-threatening arrhythmia. The shortened P-R interval causes the pre-excitation (the presence of an accessory pathway between the atria and ventricles) or AV nodal (junctional) rhythm.
• It is associated with Wolff Parkinson's White syndrome. Increasing age along with other common conditions such as ischemia or myocardial infarction can lead to damage to the AV node or the more conduction tissues such as the bundle of His.
• Damage to these structures can lead to a delay or even complete failure of conduction to the ventricles. This is called AV block.
• Variation in the QRS interval causes the blockage of conduction through a bundle of His. The QRS complex is normal because conduction through the bundle of His and its branches proceeds normally.
  So, the correct option is D.