24 h Holter Monitoring and 14-Day Intermittent Patient-Activated Heart Rhythm Recording to Detect Arrhythmias in Symptomatic Patients After Severe COVID-19—A Prospective Observation

<b>Background/Objectives:</b> COVID-19 is associated with various arrhythmias that continue into a post-COVID period and become a concern for patients and healthcare a long time after the infection. This study aimed to assess the incidence of arrhythmias and their relationship to presented symptoms in patients with no history of rhythm disturbances who underwent severe COVID-19 within the past 6 months. <b>Methods:</b> A total of 54 severe COVID-19 survivors with no history of known arrhythmia were enrolled in the study 3-6 months after discharge. All subjects underwent echocardiography, 24 h Holter monitoring, and received a handheld ECG event recorder for 14 days of ambulatory single-lead ECG recording, which was evaluated for supraventricular and ventricular arrhythmias and patient-reported events. After 12 months of follow-up (FU), Holter monitoring and ECG recordings were repeated. <b>Results:</b> The incidence of palpitations was high at baseline and halved after 12 months (65% vs. 36%, <i>p</i> = 0.018), as was the symptom-induced utilization of the event monitor (36% vs. 12%, p0.012). Palpitations were more common in patients with CAD, diabetes, and hypertension, but were not related to any rhythm disturbances except sinus tachycardia (OR of 5.8 for each 10 bpm increase in HR; CI: 1.3-26.5, <i>p</i> = 0.02). Holter monitoring revealed a higher burden of PVCs 3-6 months after COVID vs. FU (PVCs > 200/d in 36% vs. 17%, <i>p</i> < 0.05), and PVCs were more commonly recorded events in symptomatic patients. Symptomatic subjects more frequently reported sinus tachycardia (48% vs. 13%, <i>p</i> < 0.05) and PVC (21% vs. 0%, <i>p</i> < 0.05). Neither arrhythmias nor palpitations were related to the severity of the infection. <b>Conclusions:</b> Palpitations are common after severe COVID-19, but the symptoms are related to sinus tachycardia rather than actual arrhythmia and are more pronounced in patients with cardiovascular conditions. Ventricular ectopy was the predominant finding early after severe COVID-19 and might have been responsible for symptoms in a fraction of symptomatic subjects. Both symptoms and sinus tachycardia resolved over time.