<prompt> Delayed afterdepolarization implies?Increased intracellular CaExcessive catecholaminesDigitalis toxicityAll of the above  <response>: Ans. is d i.e., All of the aboveDelayed afterdepolarizations occur in late phase 3 or early phase 4 when the action potential is nearly of fully repolarized.The mechanism is poorly understood; however, this type of arrhythmia is found to be associated with high intracellular Ca concentrations as occurs with digitalis toxicity or excessive catecholamine stimulation.The triggered impulse can lead to a series of rapid depolarizations i.e. a tachyarrhythmia. 