Pre-diltiazem, Calcium Versus Placebo for Atrial Fibrillation With Rapid Ventricular Response

The goal of this randomized double blind controlled trial is to learn about the effects of calcium when it is given prior to diltiazem for patients with atrial fibrillation ( a type of irregular heart beat) who have rapid ventricular response ( a pulse over 100 beats per minute). Normally diltiazem 0.25mg/kg (max 20mg) is given to slow the heart rate. We will give Placebo versus Calcium Gluconate 2gm given prior to diltiazem.The main questions it aims to answer are:Does calcium decrease the incidence of low blood pressure (a side effect of diltiazem)?How does calcium effect the action of diltiazem? Does it interfere with the desired decrease in heart rate?Participants will receive either placebo or calcium immediately prior to the administration of diltiazem. Their blood pressure and pulse will be measured:prior to study drug administrationpost study drug and prior to diltiazem administration3 minutes post start of diltiazem5 minutes post start of diltiazem10 minutes post start of diltiazem20 minutes post start of diltiazem30 minutes post start of diltiazemResearchers will compare the placebo group to the calcium group to see if there is a difference in the blood pressure and pulse.

Inclusion Criteria: Diagnosis of atrial fibrillation with rapid ventricular response (ventricular rate over 100 bpm) due to an electrophysiologic etiology.-Exclusion Criteria:Unstable, requiring electric cardioversion -hypotensivealtered mental statusmyocardial infarctionpulmonary hypertensionPatients at risk of hypercalcemia - renal failureKnow cardiac valvular diseaseAllergic to calcium gluconate or diltiazemUnderlying cardiac disease - sick sinus syndrome2nd/3rd degree atrial ventricular blockcardiogenic shockrecent IV beta blocker administrationaccession bypass tract (WPW, short PR)