The class iv calcium blocker that exclusively administered to treat acute supraventricular tachyxardia is Diltiazem. Calcium channel blockers obstruct the movement of calcium into conductive and contractile myocardial cells by inhibiting the influx of calcium through its channels, causing a slower conduction through the SA and AV. Diltiazem is administered intravenously to treat acute supraventricular tachycardia.