The QT interval represents the total electrical activity of the ventricles, spanning from the onset of depolarization, marked by the Q wave within the QRS complex, to the end of repolarization, signaled by the T wave [1]. Accurate determination of the corrected QT interval (QTc) requires adjustments for variables such as age, gender, and heart rate [2]. Multiple formulas, including those proposed by Bazett, Fridericia, Framingham, Hodges, and Rautaharju, are utilized to calculate the QTc. A prolonged QTc interval is a marker of repolarization disturbances that may precipitate life-threatening ventricular arrhythmias, most notably Torsades de Pointes (TdP). While TdP carries a high risk of sudden cardiac death, the risk remains minimal when the QTc is below 500 milliseconds, and the performance characteristics for detecting a QTc ≥ 500 ms remained acceptable, with a sensitivity of 88.5 %, specificity of 44.5 %, and a negative predictive value (NPV) of 99.8 % [3]. Failure to accurately diagnose or correct a prolonged QT interval can lead to significant consequences, including misdiagnosis, inappropriate treatment decisions, and inadequate safety monitoring, all of which undermine the quality of healthcare delivery [4].

Over the past decade, advancements in digital health have facilitated the global development of tools aimed at enhancing the diagnosis, treatment, and monitoring of cardiovascular conditions [5]. Among these innovations, Mobile Health Applications (mHAs), stand out for their accessibility and potential utility. However, concerns persist regarding the lack of standardized procedures for data analysis and limited regulatory oversight for mHAs. These limitations interfere with their integration into electronic health records and their acceptance in clinical settings [6].

This systematic review aims to evaluate the quality and functionality of MHAs designed to measure and calculate the QT interval. Given that their use remains largely empirical, this review highlights the critical need to demonstrate their validity before these tools can be confidently incorporated into clinical practice.