BACKGROUND

As smartwatches with atrial fibrillation detection features gain popularity, it is important to assess the accuracy of these devices to guide decision-making.

OBJECTIVES

Our study aimed to assess the sensitivity and specificity of the irregular rhythm notification and the electrocardiogram (ECG)–based detection features of a commonly used smart wearable device (Apple Watch) in detecting atrial fibrillation.

METHODS

This was a prospective, pragmatic study conducted in Perpetual Succour Hospital–Cebu Heart Institute from August 2023 to January 2024. To assess the irregular rhythm notification feature, participants were asked to wear an Apple Watch alongside a 24-hour Holter monitor to verify notifications. For the ECG-based detection feature, participants had to tap the crown of the Apple Watch for 30 seconds to get a single-lead ECG similar to a lead I ECG tracing. They were instructed to get manual ECGs hourly, or more often while awake. Irregular rhythm notifications and ECG readings were then compared with that of the 24-hour Holter monitor. Sensitivity and specificity were then computed.

RESULTS

A total of 140 participants consented to join after full study disclosure. The irregular rhythm notification feature of the Apple Watch exhibited a low sensitivity of 21.4% but achieved a high specificity of 100% in detecting atrial fibrillation. Meanwhile, the ECG-based detection feature, analyzed from 1295 manually taken ECGs with interpretable sinus rhythm or atrial fibrillation, demonstrated a high level of agreement with the Holter monitor, with a sensitivity of 100% and a specificity of 99.1%.

CONCLUSION

The low sensitivity of the irregular rhythm notification feature of the Apple Watch in detecting atrial fibrillation cautions against relying on it as a primary screening tool. However, the high concordance of manually taken Apple Watch ECGs positions the device as a robust tool for detecting atrial fibrillation through manual ECG detection.

Human ; Atrial Fibrillation

Introduction: Erectile dysfunction (ED) has numerous links to cardiovascular disease. Numerous studies show the severity of ED is strongly associated with atherosclerosis and endothelial dysfunction implicated in the pathogenesis of coronary artery disease (CAD). These common vascular pathways have led to evidence that ED onset may be used as a marker of the severity of CAD as well as a preclinical marker of early onset-CAD. The researchers aim to determine the association of ED and CAD in terms of prevalence, clinical presentation and severity and extent of vessel involvement by SYNTAX score among CAD patients undergoing coronary angiography. Methods: This is a prospective, cross sectional, analytical study design set at Perpetual Succour Hospital – Cebu Heart Institute, a private, tertiary hospital with cardiac specialty units located in Cebu City. This study includes all Filipino patients admitted at Perpetual Succour Hospital suspected to have coronary artery disease based on symptoms of angina, dyspnea or other anginal equivalent with indications to undergo coronary angiography during the period of October 1, 2014 to September 30, 2015 were included. Results: A total of 160 patients were included in the study. The mean age is 57.23 years with most of the patients admitted for stable ischemic heart disease (SIHD) of 54.7%, non-ST elevation acute coronary syndromes (NSTEACS) 33.5% and ST-elevation myocardial infarction (STEMI) 11.8% with multiple cardiovascular risk factors like hypertension, diabetes mellitus, smoking and dyslipidemia. Eighty-two percent complained of ED symptoms with a mean International Index of Erectile Function (IIEF) score of 15.15. Most ED patients identified had mild to moderate ED (31.7%), mild ED (21.7%), moderate ED (17.4%) and severe ED (11.8%). There were only 17.4% of patients who had undergone coronary angiography for CAD complaints that had no ED symptoms on admission. Per clinical presentation, there was a significant association between patients presenting with severe ED, moderate ED and mild to moderate ED with those presenting with SIHD and ACS-NSTEMI on admission, moderate ED and mild to moderate ED. ED was significantly associated with obstructive CAD (p=0.001) and correlated directly with the number of vessels involved (p<0.01) and inversely related to SYNTAX scores (p<0.001). ED symptoms were noted to precede CAD diagnosis by 4.9 to 5.9 years. Conclusion In conclusion, there is a high prevalence of ED among CAD patients and its existence is significantly associated with obstructive CAD varying directly with extent and number of vessel involvement. There is a significant inverse relationship with severity of ED and SYNTAX scores. The existence of ED was present in all subsets of CAD patients, regardless of presentation of admission and preceded CAD symptoms and diagnosis by four to five years.
Erectile Dysfunction ; Coronary Artery Disease