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Year : 2023  |  Volume : 24  |  Issue : 1  |  Page : 17-23  

The relation between atrial fibrillation cardioversion success rate with Vitamin D Level in patients underwent elective cardioversion in King Abdulaziz Cardiac Center, King Abdulaziz Medical City for National Guards, Riyadh Saudi Arabia

1 King Abdulaziz Cardiac Center, KAMC National Guard, Riyadh, Saudi Arabia
2 Invasive Cardiovascular Technology, King Abdulaziz Cardiac Center, KSAU-HS, KAMC National Guard, Riyadh, Saudi Arabia
3 Department of Nursing, King Abdulaziz Cardiac Center, KAMC National Guard, Riyadh, Saudi Arabia
4 Department of Invasive Cardiovascular Technology, Invasive Cardiovascular Technology, KSAU-HS, Riyadh, Saudi Arabia

Date of Submission02-Sep-2022
Date of Acceptance30-Jan-2023
Date of Web Publication23-Feb-2023

Correspondence Address:
Mr. Nawaf Mohammed Alharbi
Invasive Cardiovascular Technology, KSAU-HS, Riyadh
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/heartviews.heartviews_80_22

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Objectives: To investigate the relation between serum Vitamin D (Vit-D) levels and the success rate of cardioversion for atrial fibrillation (AF). To examine the association between Vit-D level and successful cardioversion. This study also describes the general characteristics of patients with successful cardioversion.
Materials and Methods: In this retrospective study, patients with AF who were treated using electrical cardioversion at King Abdulaziz Cardiovascular Center (KACC) between 2010 and 2021 were included. The information on demographic and clinical characteristics as well as outcome variables was collected.
Results: Of 100 patients who were admitted to KACC during the study period, 63% were females and 9% were diagnosed with Vit-D deficiency. Furthermore, 66% of patients had successful cardioversion. Moreover, no significant difference in Vit-D deficiency was observed between patients who had successful cardioversion and those with unsuccessful outcomes (P = 0.485).
Conclusions: There is no association between serum Vit-D levels and the success rate of cardioversion in patients with AF. However, further studies are needed for more conclusive evidence.

Keywords: Atrial fibrillation, cardioversion, Vitamin D deficiency

How to cite this article:
Hussain A, Al Anazi F, Alanazi A, Alshahrani A, Alharbi NM, Aleshaiwy TA, Alomran YA, Alshehri RM, Alasmarei NA. The relation between atrial fibrillation cardioversion success rate with Vitamin D Level in patients underwent elective cardioversion in King Abdulaziz Cardiac Center, King Abdulaziz Medical City for National Guards, Riyadh Saudi Arabia. Heart Views 2023;24:17-23

How to cite this URL:
Hussain A, Al Anazi F, Alanazi A, Alshahrani A, Alharbi NM, Aleshaiwy TA, Alomran YA, Alshehri RM, Alasmarei NA. The relation between atrial fibrillation cardioversion success rate with Vitamin D Level in patients underwent elective cardioversion in King Abdulaziz Cardiac Center, King Abdulaziz Medical City for National Guards, Riyadh Saudi Arabia. Heart Views [serial online] 2023 [cited 2023 May 30];24:17-23. Available from: https://www.heartviews.org/text.asp?2023/24/1/17/370265

   Introduction Top

Normal cardiac conduction is based on a network of specialized cell types (pacemakers) that produce an organized and synchronized rhythm to coordinate the contraction of the cardiac chambers. The normal conduction initiates at the sinoatrial node that provides impulses to the atrium leading to its contraction in a synchronous pattern defined by the P-wave on electrocardiogram (ECG). The impulse then arrives at the atrioventricular node which conducts the impulse slower. After, the impulse travels fast along the bundle of His, bundle branches, and Purkinje fibers, leading to ventricular contraction represented by the QRS complex on ECG.[1] Any abnormality in this normal sequence results in cardiac arrhythmia.

Atrial fibrillation (AF), the most common type of cardiac arrhythmia, is associated with high mortality and morbidity.[2] It is one of the most prevalent cardiovascular diseases affecting more than 30 million individuals worldwide. The prevalence of AF in Europe, New Zealand, and the USA is 2.3%, 2%, and 1.7%, respectively.[3],[4],[5] Moreover, 2043 consecutive cases of AF have been reported from 23 hospitals in six countries of the Middle East Gulf during the period between October 2009 and June 2010. The mean age of the patients was reportedly 57 years and 52% of them were males.[6] Several studies on AF have been conducted in the Kingdom of Saudi Arabia.

A previous study conducted in 2015 in Riyadh reported 152 cases of AF, with a mean age of patients to be 66 years.[7] Another study performed between 2010 and 2017 in Jeddah reported 167 cases with a mean patient age of 63.3 years.[8] Several cardiovascular diseases and risk factors are associated with the development of AF, such as hypertension, diabetes, myocardial infarction, obesity, and heart failure.[9] Vitamin D (Vit-D) is important for maintaining skeletal system health and calcium homeostasis. Vit-D deficiency increases the risk of developing cardiovascular diseases, such as hypertension, heart failure, AF, and coronary artery disease, by activating the renin-angiotensin-aldosterone system, which affects the cardiovascular system. Furthermore, Vit-D deficiency is linked with diabetes and obesity, both of which are strong risk factors for cardiovascular diseases.[10],[11],[12],[13]

Vit-D deficiency is more common in the Middle East. A previous study on Vit-D deficiency in Saudi Arabia analyzed 20,787 patients, and among them, 62% were females.[14] Although the main causes of AF are not obvious, several diseases and risk factors are linked to the development and progression of AF. These include hypertension and heart attack, left ventricular dysfunction, congenital heart disease, hypertrophic cardiomyopathy, stroke, valve disease, obesity, and alcohol intake.[15] Moreover, a variety of acute and chronic illnesses including periodontitis, preeclampsia, autoimmune diseases, respiratory diseases, lethal tumors, neurological disorders, type 2 diabetes, and cardiovascular diseases have been associated with Vit-D deficiency.[16] The renin-angiotensin-aldosterone pathway that regulates the cardiovascular system is activated due to Vit-D deficiency, suggesting a relationship between Vit-D deficiency and AF.[17] Several patients with no cardiovascular diseases initially experience AF as short bursts of fibrillation that runs from minutes to hours before reverting to the normal sinus rhythm spontaneously. This pattern is known as paroxysmal AF.[18] These bursts are triggered by electrical impulses originating from the pulmonary veins. After some time, AF becomes more frequent and more long-lasting, and eventually, the condition becomes continuous and self-sustaining, which is known as persistent AF.[19] Vit-D negatively regulates the renin-angiotensin-aldosterone system and controls calcium homeostasis. Vit-D binds to the Vit-D receptors present on the cell membrane of cardiac myocytes. Moreover, Vit-D has antioxidant properties and can decrease atrial levels of reactive oxygen species (ROS) that can lead to inflammation and proarrhythmic substrate development.[20] AF is associated with an increased risk of stroke, high morbidity, and mortality. Restoring and maintaining the normal sinus rhythm can improve the quality of life in symptomatic patients.[21]

Direct current (DC) cardioversion, a well-known rate control method, is used to restore sinus rhythm. In emergency conditions, DC cardioversion has several benefits as its effects are immediate and the subsequent possible adverse effects of drugs can be prevented. Besides other factors, the duration of AF, age of the patient, and left atrial (LA) size influence the success rate of the DC cardioversion procedure. In addition, pharmacological intervention such as oral BB is a good single agent for the control of AF.[22] Amiodarone can also be used for the treatment of AF; however, it has several side effects which makes it one of the most problematic anti-arrhythmic agents. Vit-D deficiency in patients should be treated with either ergocalciferol (Vit-D2) or cholecalciferol (Vit-D3).[23]

Yaman et al. showed a strong correlation between Vit-D deficiency and the success of cardioversion in patients with AF. Moreover, the authors also showed that Vit-D deficiency indicates a high risk of AF recurrence following cardioversion, and Vit-D supplementation during the follow-up period could help preserve the sinus rhythm.[12] In general, cardioversion is the first-choice procedure for normalizing the heart rhythm. This procedure is used when the heart beats very fast and the patient is symptomatic in cases of AF and atrial flutter. Studies have shown that a relationship exists between serum Vit-D levels and the development of AF.[24]

However, studies comparing the relationship between serum Vit-D levels and the success rate of cardioversion for AF and sinus rhythm maintenance in Saudi Arabia are rare. Therefore, this study aimed to correlate the success rate of cardioversion for AF and sinus rhythm maintenance with Vit-D deficiency in patients admitted to the King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia.

   Materials and Methods Top

]This retrospective cohort study was conducted at King Abdulaziz Cardiovascular Center (KACC) located at KAMC in Riyadh, Saudi Arabia. KACC has one of the most comprehensive heart disease management programs in Saudi Arabia and the Gulf. This internationally recognized center provides a full range of high-quality cardiovascular services for adults and children.

The study was performed at Cardiac Catheterization Laboratories. The study population included adult male and female patients (age > 14 years) who were diagnosed with AF or atrial flutter arrhythmia, defined by documented 12 leads ECG and underwent elective cardioversion procedure. Only those patients who underwent a blood test for Vit-D levels within 6 months of cardioversion were included. Unstable and intensive care unit patients were excluded. In addition, patients who were admitted to emergency department (ER) for emergency cardioversion were also excluded. Patients' ECG and Vit-D levels were monitored within the specified period (6 months to 1 year) at KACC. Recurrence was defined as the presence of AF by 12 leads ECG during the follow-up period from 6 months to 1-year post successful cardioversion. Failed cardioversion was defined by the persistence of AF at the time of hospital discharge post-DC cardioversion procedure. The study duration was from January 2010 to December 2021. A sample size of 100 was calculated using openpi. com. The sampling technique used was nonprobability convenience.

In our study, the exposure was cardioversion and the outcome was the association between AF and serum Vit-D levels. The following information was collected from the medical files of the hospital information system (best care) using the data collection sheets: demographic information, ECG at follow-up, ejection fraction, AF duration, AF onset, and Vit-D levels. The data were entered using Microsoft Excel and then exported to SPSS (ver 23-IBM SPSS Statistics for Windows, version 21 [IBM Corp., Armonk, N. Y., USA]) for analysis. Numerical data (e.g. age, Vit-D levels) were reported as mean ± standard deviation, whereas categorical data (gender, nationality, comorbidities, and diagnosis) were reported as frequencies and percentages. The relationship between the demographical characteristics (gender, comorbidities, and diagnosis) and the presence of arrhythmia was evaluated using the Chi-square test. A P value < 0.05 was considered statistically significant. Independent t-test bivariate variables were used to assess the relationships among numerical variables such as age and Vit-D levels.

   Results Top

Of 100 patients who underwent cardioversion, 63% were female and 9% were diagnosed with Vit-D deficiency. Furthermore, 66% had successful outcomes following cardioversion [Table 1] and [Figure 1]. Vit-D deficiency was defined as serum Vit-D levels ≤25 nmol/L. While comparing the mean prevalence of Vit-D deficiency between the patient groups with successful and unsuccessful cardioversion, no significant differences were observed (P = 0.485) [Figure 2]. The success rate of cardioversion in hypertensive patients was 62%, in diabetic patients was 54.5%, and in dyslipidemic patients was 47% [Table 2], [Table 3] and [Figure 3]. Normal sinus rhythm on ECG was observed in 67% of patients, whereas AF was observed in 29% of patients during the follow-up [Table 1] and [Figure 4]. The mean of successful cardioversion in Vit-D level was 56.31 (±27.23) (P = 0.280). The mean age of patients who had successful cardioversion was 63 (±12) years [P = 0.757; [Table 3] and [Table 4].
Figure 1: Shows the number of successful and unsuccessful cardioversion

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Figure 2: The relation of successful and unsuccessful cardioversion with Vit-D level. Vit-D: Vitamin D

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Figure 3: It shows the number of patients presented with and without Vit-D deficiency. Vit-D: Vitamin D

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Figure 4: This figure illustrates the clinical types of atrial fibrillation at presentation

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Table 1: Demographic, clinical characteristics of each cardioverted patient presented in percentage

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Table 2: Demonstration of successful and unsuccessful cardioversion illustrated in percentages and P value

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Table 3: Mean±standard deviation and P value for successful and unsuccessful cardioversion patients

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Table 4: Mean±standard deviation of general characteristics of all patients

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   Discussion Top

In our study, no association was observed between serum Vit-D levels and outcomes of cardioversion in patients with AF. A previous study showed an association between Vit-D levels and the development of AF after successful and unsuccessful cardioversion.[12] In our study, only nine patients were diagnosed with Vit-D deficiency; therefore, it cannot be concluded that Vit-D deficiency is a risk factor for AF recurrence following cardioversion. Cardioversion is one of the main treatment modalities in symptomatic patients with AF. In our study, cardioversion was successful in 66% of the patients. It is well-known that LA size can predict AF recurrence; patients with LA size >4 cm are at the risk for AF recurrence.[10] However, in our study, the mean LA diameter was 4.5 cm which suggests there is no significant risk for AF recurrence in patients with a large LA. There are several limitations of our study. First, the patients were taking different types of anti-arrhythmic drugs. Second, the sampling technique employed in our study was more like a non-probability technique since we have a limited number of patients having clear Vit-D deficiency. Third, since this was a retrospective analysis, we were unable to collect the blood samples for evaluating Vit-D level and perform echocardiography for LA size evaluation during 6–12 months of the follow-up. Finally, the small sample size is another limitation of the study.

   Conclusions Top

Our study suggests that is no relationship between serum Vit-D levels and the success rate of cardioversion in patients with AF. Further high-quality studies are needed to confirm our observation.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2], [Table 3], [Table 4]


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