<prompt> ECG changer in digitalis toxicity are AE ?T wave inversionDiminished T wave amplitudeConduction blockST depression in proximal pa  <response>: 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 amplitudeor 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 