Background: Cardiovascular magnetic resonance (CMR) has emerged as the most accurate, non-invasive method to support the diagnosis of clinically suspected myocarditis and as a risk-stratification tool in patients with cardiomyopathies. We aim to assess the diagnostic and prognostic role of CMR at diagnosis in patients with myocarditis. Methods: We enrolled consecutive single-center patients with 2013 ESC consensus-based endomyocardial biopsy (EMB)-proven or clinically suspected myocarditis undergoing CMR at diagnosis. The pre-specified outcome was defined as NYHA class > I and echocardiographic left ventricular ejection fraction (LVEF) < 50% at follow-up. Results: We included 207 patients (74% male, median age 36 years; 25% EMB-proven). CMR showed the highest sensitivity in myocarditis with infarct-like presentation. Patients with EMB-proven myocarditis were more likely to have diffuse LGE and right ventricular LGE (p < 0.001), which was also more common among patients with arrhythmic presentation (p = 0.001). The outcome was met in 17 patients at any follow-up time point, more commonly in those with larger biventricular volumes (p < 0.001), CMR-based diagnosis of dilated cardiomyopathy (p < 0.001), and ischemic LGE (p = 0.005). Higher biventricular systolic function (p < 0.001) and greater LGE extent (p = 0.033) at diagnosis had a protective effect. Conclusions: In our single-center cohort of rigorously defined myocarditis patients, higher biventricular systolic function and greater LGE extent on CMR at diagnosis identified patients with better functional class and higher left ventricular ejection fraction at follow-up. Conversely, larger biventricular volumes, CMR-based DCM features, and the presence of an ischemic LGE pattern at diagnosis were predictors of worse functional class and LV systolic dysfunction at follow-up. Larger prospective studies are warranted to extend our findings to multi-center cohorts.

Although ultrasound-guided axillary vein access (USGAVA) has proven to be a highly effective and safe method for cardiac electronic implantable device (CIED) lead placement, the collapsibility of the axillary vein (AV) during tidal breathing can lead to narrowing or complete collapse, posing a challenge for successful vein puncture and cannulation. We investigated the potential of the Valsalva maneuver (Vm) as a facilitating technique for USGAVA in this context. Out of 148 patients undergoing CIED implantation via USGAVA, 41 were asked to perform the Vm, because they were considered unsuitable for venipuncture due to a narrower AV diameter, as assessed by ultrasound (2.7 ± 1.7 mm vs. 9.1 ± 3.3 mm, p < 0.0001). Among them, 37 patients were able to perform the Vm correctly. Overall, the Vm resulted in an average increase in the AV diameter of 4.9 ± 3.4 mm (p < 0.001). USGAVA performed during the Vm was successful in 30 patients (81%), and no Vm-related complications were observed during the 30-day follow-up. In patients with unsuccessful USGAVA, the Vm resulted in a notably smaller increase in AV diameter (0.5 ± 0.3 mm vs. 6.0 ± 2.8 mm, p < 0.0001) compared to patients who achieved successful USGAVA, while performing the Vm. Therefore, the Vm is a feasible maneuver to enhance AV diameter and the success rate of USGAVA in most patients undergoing CIED implantation while maintaining safety.

While ultrasound assistance for accessing the axillary vein has been established as a reliable method for cardiac pacemaker and cardioverter-defibrillator leads implantation, there is a lack of information regarding the utilization of portable handheld ultrasound devices within this context. We describe our experience with the systematic use of a pocket-sized handheld ultrasound device during the implantation of transvenous cardiovascular implantable electronic devices.