Exercise Stress Test Late after Arrhythmic versus Nonarrhythmic Presentation of Myocarditis

Figures

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  Figure 1. Patient selection. The study flowchart is shown to highlight the selection of the 128 patients undergoing an exercise stress test. VT = ventricular tachycardia.

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  Figure 2. Exercise stress test findings. Representative examples of remarkable findings on exercise stress tests are shown. (Panel (A)). Female patient, 32-year-old, with evidence of frequent polymorphic ventricular ectopies on the effort at exercise stress test performed 12 months after cardiac magnetic resonance-proven acute myocarditis presenting with nonsustained ventricular tachycardia and syncope. After the exercise stress test, he underwent an endomyocardial biopsy and subsequent immunosuppressive treatment for virus-negative lymphocytic myocarditis. (Panel (B)). Male patient, 44-year-old (P123, Table 3) with evidence of sustained monomorphic ventricular tachycardia causing syncope during an exercise stress test performed late after presentation with arrhythmic myocarditis. The subsequent workup is shown in Table 3. (Panel (C)). Male patient, 68-year-old (P37, Table 3) with exercise stress test showing dynamic ST segment depression in inferolateral leads with ST elevation in lead aVR (exercise peak, bottom; compared to baseline, top). He was asymptomatic for angina or dyspnea. After normal coronary angiography, he had both cardiac magnetic resonance and endomyocardial biopsy with a…

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  Figure 3. Outcomes after exercise stress test. Kaplan-Meier curves are shown for the occurrence of adverse events after EST. Adverse events included cardiac death, disease-related hospital readmissions, malignant ventricular arrhythmia (sustained ventricular tachycardia, ventricular fibrillation, appropriate implantable cardioverter defibrillator treatment), and active myocarditis, proven by endomyocardial biopsy or myocardial imaging. For each graph, x-axis indicates follow-up months after EST, and y-axis indicates event-free survival. The continuous line refers to patients with EST positive for ventricular arrhythmia or ischemia (EST+), whereas the dashed line refers to patients with uneventful EST (EST-). Numbers at risk are reported below each chart. Curves are shown for the whole patient cohort (panel (A)) and arrhythmic and nonarrhythmic subgroups (panels (B,C), respectively). EFS = event-free survival; EST = exercise stress test; FU = follow-up.

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  Figure 4. Relationship between exercise stress test-induced ventricular arrhythmia and myocarditis staging. Representative examples of ventricular arrhythmia features on exercise stress test and subsequent myocarditis restaging are shown. (Panel (A)). Female patient, 40-year-old, with evidence of irregular nonsustained ventricular tachycardia immediately after exercise peak on stress test. She underwent cardiac magnetic resonance showing both T2 short-tau inversion recovery (mid panel, left) and late gadolinium enhancement sequences (mid panel, right) involving the subepicardial layer of the inferolateral left ventricular wall (arrows), fulfilling the Lake Louise criteria for active myocarditis. She underwent an endomyocardial biopsy showing multifocal lymphocytic inflammatory infiltrates (lower panel, arrows) confirming the diagnosis of chronically active virus-negative myocarditis, subsequently treated by immunosuppressants. (Panel (B)). Male patient, 66-year-old (P78, Table 3) with evidence of regular and monomorphic sustained ventricular tachycardia causing syncope during an exercise stress test performed late after presentation with arrhythmic myocarditis. Being an implantable…