Relation between 25-Hydroxy Vitamin D Deficiency and Success of Cardioversion for Lone Atrial Fibrillation (AF)
Authors: Labib Hossam Raafat , Fakhry Emad Effat , Ibrahim Mazen Tawfik 
Published: August 2023

Abstract

Aim and objectives
The aim of this study was to assess the relationship between vitamin D deficiency and extent of success of cardioversion in patients with lone atrial fibrillation (AF).

Patients and Methods
This observational cross-sectional study included 50 patients (18-60 years old) who presented to the cardiology department of Ain Shams university hospitals with lone atrial fibrillation with structurally normal heart for cardioversion after fulfilling the inclusion criteria, considering that failure of cardioversion was defined as failure of restoration to normal sinus rhythm after applying the cardioversion protocol that is being used in our cardiology department in Ain Shams University hospitals. Serum vitamin D level on admission was sampled for all patients before cardioversion, and cardioversion was assessed after then whether success or failure. Cardioversion success was restoration of normal sinus rhythm and that the patient was discharged in sinus rhythm. Cardioversion protocol that was being used was applied as Loading dose of Intravenous (IV) Amiodarone of 300 mg diluted in 250 ml 5% dextrose over 30-60 minutes, then follow up dose of 900 mg IV over 24 hours diluted in 500-1000 ml of normal saline, then if failed, application of biphasic synchronized direct current electrical cardioversion at 200 joules at anteriorlateral electrode positions.

Results
The success rate of cardioversion was 80% (40 out of 50) in all the patients presented, and the failure rate was 20% (10 out of 50). In the success group, majority of patients 23 (57.5%) had sufficient Vitamin D levels (≥30 ng/ml), 15 patients (37.5%) had insufficient vitamin D levels (21-29 ng/ml) and 2 patients (5%) had deficient vitamin D levels (≤20 ng/ml). Meanwhile, in the failure group, the majority of patients 8 (80%) had deficient vitamin D levels (≤20 ng/ml), 1 patient (10%) had insufficient vitamin D level (21-29 ng/ml), and 1 patient (10%) had sufficient vitamin D level (≥30 ng/ml).This difference was statistically significant with a P value of &lt; 0.01. Vitamin D level measured (25-OH vitamin D) had values of mean ± SD of 29.41 ± 4.89 ng/ml in the success group vs 19.22 ± 4.68 ng/ml in the failure group, which was statistically significant with a P value of &lt;0.01. A-P (antero-posterior) LAD (left atrial diameter) measured in parasternal long axis view during routine pre-cardioversion work-up study by echocardiography that has been done, had values of mean ± SD of 37.60 ± 3.20 mm in the success group vs 37.80 ± 2.86 mm in the failure group, which was statistically non- significant with a P value of 0.858. There was not a statistically significant difference between the 2 groups regarding age, sex, BMI, smoking, duration of AF(duration of onset of symptoms), number of previous trials of cardioversion, previous antiarrythmic drugs that have been administered and heart rate at time of cardioversion.

Conclusion
Failure rate of cardioversion was found to be higher in patients with vitamin D deficiency in comparison to patients with sufficient and insufficient vitamin D levels.

Abbreviations
AF: Atrial Fibrillation; A-P: Antero-posterior; BMI: Body mass index; LAD: Left atrial diameter; SD: Standard deviation