Prevalence and frequency of arrhythmias and electrocardiographic abnormalities in Pakistan: An outpatient ECG-based study

Background Little is known about the prevalence of arrhythmias in Pakistan. We assessed the frequency of arrhythmias and electrocardiographic (ECG) abnormalities among the Pakistani population, attending the outpatient department, categorized by age, gender, and geographic region. Objective This study aimed to evaluate variations in arrhythmia prevalence and ECG abnormalities across a large sample of a South Asian population. Methods This retrospective study analyzed 8746 ECGs from Aga Khan University Hospital in 2022. The ECGs were digitally saved, initially interpreted by an ECG-trained cardiac technician, reviewed by a junior cardiologist using the Minnesota Code, and validated by a senior cardiologist. An electrophysiologist resolved discrepancies to ensure accurate final results. Results A total of 8746 ECGs were analyzed (56.86% from men). The prevalences of common arrhythmia were sinus bradycardia 8.53%, sinus tachycardia 5.08%, atrial fibrillation (AF) (1.17%), atrial flutter (AFL) (0.18%), first-degree atrioventricular (AV) block (1.31%), and other AV blocks (0.14%). Women had more sinus tachycardia (6.44%, P <.05), AF (1.59%, P <.001), and poor R-wave progression (6.41%, P <.005), whereas men had more sinus bradycardia (10.68%, P <.05), left-anteiror fasicular block (8.32%, P <.005), left ventricular hypertrophy (LVH) (2.59%, P <.005), pathologic Q waves (3.86%, P <.005), and early repolarization pattern (5.87%, P <.05). Patients from Khyber Pakhtunkhwa region had higher rates of LVH (7.69%, P <.005) and AF (3.85%, P <.05). In contrast, patients from Gilgit-Baltistan had the highest rates of sinus bradycardia (28.57%, P <.005). Right bundle branch block (10.61%, P <.005) and long QT (3.79%, P <.005) were more prevalent in the youngest population, whereas patients aged >65 years had more AF (3.31%, P <.005), AFL (0.59%, P <.005), sinus bradycardia (10.71%, P <.001), first-degree AV block (4.62%, P <.005), left anterior fascicular block (13.08%, P <.005), left bundle branch block (2.43%, P <.005), poor R-wave progression (8.82%, P <.005), and pathologic Q waves (5.98%, P <.005). Conclusion This study details important information about arrhythmia prevalence in a large sample of a South Asian population. AF is more common in women, the elderly, and people from Khyber Pakhtunkhwa.