The objective of this study is to examine the efficacy and safety of IV calcium pretreatment at varying doses prior to weight-adjusted IV Diltiazem on the incidence of Diltiazem-related hypotension in adult patients presenting to the Emergency Department due to Atrial Fibrillation with Rapid Ventricular Response. Specifically, we tested the hypothesis that patients with Atrial Fibrillation who receive IV calcium pretreatment prior to IV Diltiazem suffer less hypotension than those receiving Diltiazem monotherapy.

Patients were randomly divided into one of three groups. We assessed the Systolic Blood Pressure and Heart Rate of participants before treatment and 5, 10, and 15 min after treatment among the patient groups. Successful rhythm control was defined as achieving an HR of <100 bpm, a reduction in HR by >20% compared to baseline, or the restoration of normal sinus rhythm (NSR). If adequate rhythm control was not achieved within 15 min of the initial treatment, we administered 0.35 mg/kg of IV diltiazem slowly over 2 minutes as a rescue treatment. The need for rescue treatment or any intervention for hypotension, as well as any adverse effects, were recorded in a prepared data form. Also, patient demographics (age and sex), new onset versus chronic AFib/AFL, relevant medical history, vital signs on admission (SBP and HR), complaints and symptoms on admission, and laboratory parameters were documented in a prepared data form.

Inclusion Criteria:

• Patients aged ≥ 18 years
• Patients with documented AFib/AFL (confirmed by ECG)
• Patients with a Heart Rate of ≥ 120 bpm, and a Systolic Blood Pressure of ≥ 90 mmHg

Exclusion Criteria:

• Patients under 18 years of age
• pregnant individuals
• Patients with hemodynamic instability requiring electrocardioversion
• Patients with a documented history of sick sinus syndrome, third-degree AV block, Wolff-Parkinson-White syndrome
• Patients with hypotension (SBP <90 mmHg)
• Patients with known or suspected hypercalcemia
• Patients with a confirmed allergy to diltiazem
• Patients with concurrent use of another Heart Rate control agent (such as beta-blockers, amiodarone, or digoxin) on the same admission

Stored in non-publicly available Available on request

Each participant was assigned an identification number indicating their treatment group. An emergency nurse prepared the treatment solutions just before administration based on the assigned identification number and stored them in labeled containers with no indication of their content. A clinician with eight years of experience, who was blinded to the study's null hypothesis and did not participate in the evaluation of results, administered the treatments and recorded patient data onto a pre-prepared case data form. Another physician, who was not present during the treatment, assessed the findings post-treatment.