Diagnosis of paroxysmal supraventricular tachycardia (PSVT) may be difficult due to its episodic nature, which can be brief and self-limited, limiting the ability for clinicians to diagnose the specific rhythm disorder in a timely manner. We present a case of PSVT, which was unable to be diagnosed through typical evaluation with an event monitor despite several years of symptoms. The patient was ultimately diagnosed using the AliveCor Mobile ECG, a smartphone-based ECG device and application, which he purchased himself and captured a typical atrioventricular node re-entrant tachycardia. The patient was then able to email his cardiologist the tracing, which led to an electrophysiology study and successful slow pathway ablation procedure. Smartphone-based technology has the potential to push diagnostic evaluations outside of the healthcare system and empower patients.