<prompt> Digoxin is contraindicated inHypertrophic cardiomyopathySupraventricular tachycardiaCongestive heart failureAtrial flutter  <response>: A. i.e. Hypertrophic cardiomyopathy 1485 - H17thHypertrophic CMP - Digitalis, diuretics, nitrates, dihydropyridine calcium blockers, vasodilators and b- adrenergic agonists are best avoided, particularly in patients with know LV out flow tract pressure gradients - 1485 - H17thDose reduction in Digitalis in following conditions Hypokalemia Advanced age Hypomagnesemia Hypoxia Renal failure Hypothyroidism Hypercalcemia Myocarditis Electrical - cardioversion Lidocaine is the drug of choice in digoxin induced arrhythmias Diuretics Hemodialysis are NOT used for treatment of digitalis toxicity Major electrophysiological effect of digitalis1. Hyperpolarization2. Shortening of atrial action potential3. Increase in AV node refractoriness 