This hospital-based retrospective study is the first one from Riyadh and to our knowledge, the second in Saudi Arabia. We found acute AF to be more common in males and chronic AF more common in females. The most common symptoms included dyspnea, palpitations, and chest pain, while the main clinical findings were congestive heart failure, acute myocardial infarction, and acute respiratory problems, stroke, transient ischemic attacks, limb ischemia alone, or in combination as the main acute complications. DM, HTN, IHD, and valvular heart disease were the main underlying causes but lone AF was rare.
In a previous study from southern Saudi Arabia,[8
] the main causes included rheumatic valvular disease, IHD, HTN, and lung diseases in 26%, 24%, 24%, and 13%, respectively compared to 24%, 23%, 59%, and 32% in our study, indicating that more of our patients had HTN and lung disease. With DM present in 68% of our patients, this indicates that these diseases are either more prevalent in this part of Saudi Arabia or have increased over the last 12 years. Lone AF was only present in 1% of our patients compared to 13% in the previous Saudi study. This may be related to more thorough investigations including echocardiography and thyroid functions at our center.
In our study, AF was more common in females than males. This is in contrast to Western studies where AF is more common in males than in females.[9
] The main risk factors of DM, HTN, IHD in our study underscore the importance of these in the risk stratification for stroke in the CHADS2 scoring system.[12
DM which is reaching epidemic proportions in Saudi Arabia in affecting about 23% of population,[13
] is an important indirect risk factor for AF since it is associated with obesity and predisposes to HTN and IHD. DM also decreases the maintenance of sinus rhythm after successful electrical cardioversion in AF.[14
] Similarly, obesity is associated with an increased risk of AF due to left atrial dilatation.[15
Although hyperthyroidism was less common as a cause of AF in our study, it is an important reversible cause of AF and should be routinely checked as subclinical or overt hyperthyroidism increases the risk of AF as do thyroid function tests in the upper normal range.[16
] Dilated or hypertrophic cardiomyopathy was an uncommon cause of AF in our study, which confirmed findings of previously published reports. Alcoholism was not an important cause of AF in our study.
Echocardiographic evidence of left ventricular (LV) dilatation, depressed LV function, and LVH were present in 71%, 27%, and 26% of AF patients, respectively, in our study. LVH was detected by ECG in a smaller number of these patients compared to echocardiography (11% vs. 26 %), indicating the superiority of the latter in the diagnosis of LVH. The risk of AF is increased by these changes, while it is decreased and improved with medications.[19
Although this study is bigger than a previous Saudi study on AF (720 vs. 219 patients), we acknowledge the limitations of our study. Owing to its retrospective, cross-sectional nature, it was not always possible to classify AF into paroxysmal, persistent, and permanent because after 7 days it was not always clear whether AF terminated within 1 year or remained permanent. These two categories were therefore grouped as chronic. There is a need for bigger multicenter prospective studies to determine the changing trends in incidence, prevalence, risk factors, complications, and compliance to guidelines in the management of AF in different parts of Saudi Arabia. The categorization of AF into paroxysmal, persistent, and permanent can also be addressed in such a study.
In conclusion, we demonstrated the differences in presentation and the underlying causes between acute and chronic AF in our developing nation, which is witnessing a rise in the incidence of DM, HTN, and IHD, the most common predisposing factors for AF. Therefore, the control of these diseases, as well as the already existing high incidence of RHD, remains an important challenge to health authorities in Saudi Arabia. Community-based programs, such as intensive screening and health education will be required for primary prevention of these diseases.