Experience and insights from a prolonged electrocardiographic monitorization with a wearable system after an embolic stroke of unknown source.

BACKGROUND: Embolic cerebrovascular events that remain of unknown etiology after a thorough diagnostic evaluation, are known as Embolic Strokes of Undetermined Source (ESUS). Subclinical atrial fibrillation (AF) represents a significant underlying cause of ESUS. Our aims were to examine the overall diagnostic yield of a prolonged cardiac monitoring wearable system (PCMw) after an ESUS to detect AF and factors associated with it, including the time frame from the ESUS event to PCMw initiation. Additionally, to evaluate the frequency of unexpected arrhythmic events (UAE) and their prognostic implications. METHODS: We retrospectively analyzed 200 ECG recordings (3-leads, 30 days duration) by means of a PCMw in patients with an ESUS to detect AF lasting longer than 30 s, between 2017 and 2021. UAE were defined as arrhythmia events that were not correlated to the main reason of prolonged cardiac monitoring. RESULTS: AF was detected in 21 patients (10.5%). Patients with AF had more left atrial enlargement (OR = 4.22 [1.59-6.85]; p = .01) and atrial arrythmias in the initial 24-h Holter during hospitalization (OR = 5.73 [2.03-16.49]; p = .001). The detection of AF was significatively higher if the PCMw was worn within the first 30 days after the ESUS compared to beyond 30 days (17% vs. 10.3%; p = .002). Fifty three patients (26.5%) had UAE during PCMw. In six of them these findings led to targeted treatment. CONCLUSION: PCMw represents a feasible non-invasive device that could reliably detect subclinical AF episodes after an ESUS. Diagnostic yield was significatively higher when used within the first 30 days after the event, especially in selected patients. UAE were common, but did not impact prognosis.

Trapped p waves causing loss of physiological left bundle branch pacing.

We present the case of a 75-year-old woman with severe aortic stenosis and moderate left ventricular dysfunction, who underwent elective transcatheter aortic valve replacement. After the procedure, the patient developed a left bundle branch block and a long PR interval. For this reason, a dual chamber pacemaker with pacing in the left bundle branch area was implanted. On device interrogation, we confirmed the presence of functional atrial undersensing causing loss of ventricular electric resynchronization. This case highlights the importance of recognizing this problem and, by means of device reprogramming and pharmacological intervention, suggests a stepwise approach to solve it.

Ventricular Fibrillation during Optical Coherence Tomography.

Optical Coherence Tomography (OCT) imaging is a valuable tool for complex coronary interventions. While complications are rare, the occurrence of ventricular arrhythmias during its use is one of the most feared. Unfortunately, the mechanism by which these arrhythmias arise remains unclear. We describe the case of a patient under continuous electrocardiographic (ECG) monitoring who experienced ventricular fibrillation during an OCT procedure. A detailed analysis of the ECG event sequence was performed, from the administration of the contrast medium to the onset of ventricular fibrillation. Utilizing the collected data, we examined potential precipitating factors based on the observed alterations in the electrocardiogram. A comprehensive understanding of the mechanisms underlying these arrhythmias is crucial for the development of preventive measures that avoid such incidents in the future.