ECG changer in digitalis toxicity are A/E ?
Ans. is 'b' i.e., Diminished T wave amplitude All the given ECG changes can be produced by digitalis. o But, examinar has asked specifically about the ECG changes in digitalis toxicity (not at therapeutic concentration) Diminished T wave amplitude occurs at therapeutic concentration, in toxicity T wave becomes inveed. o There are some characteristic ECG changes by digitalis use, some of which occur at therapeutic concentration and some occurs at toxic leve. 1. At therapeutic level o Prolongation of PR interval Scooping of ST segment --> Also known as digitalis wave or dig sag there is down sloping ST depression (initially) Shoening of QT interval o Decreased T wave amplitude/or T wave inversion 2. At toxic level: Above changes are amplified o Prolongation of PR interval -p conduction block may occur o T wave inversion ST depression o QT interval shoens fuher o Increased automaticity --> Arrhythmias
T wave inversion
Diminished T wave amplitude
Conduction block
ST depression in proximal pa