Electroanatomical Mapping May Identify Concealed Arrhythmogenic Cardiomyopathy in Endurance Athletes With Complex Ventricular Arrhythmias

Figures

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  Figure 1. Resting, Exercise, and Ambulatory ECGs of Athlete 1 (A) Resting 12-lead ECG with biphasic T-waves in V2 and V3. (B) ECG during cycle ergometry testing showing ectopy during mild to moderate workloads, consisting of isolated beats and couplets likely originating from the right ventricular outflow tract (left bundle branch block in V1, QRS >130 ms, inferior axis). (C) A persistently high burden of PVBs confirmed by a 7-day ambulatory single-lead ECG monitor (14,324 PVBs, 134 couplets, and 1 triplet). ECG = electrocardiogram; PVB = premature ventricular beat.

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  Figure 2. EAM of Athlete 1 With Bipolar and Unipolar Mapping Demonstrating Patchy Low-Amplitude Zones Surrounding the RVOT and the Inferior Wall, With Unipolar Mapping Suggesting a Deeper, Potentially Epicardial Substrate (A) Left anterior oblique view. (B) Posterior view. (C) Right anterior oblique view. (D) Inferior wall view showing patchy zones of abnormal unipolar signal amplitude, suggesting the presence of a deeper epicardial substrate. EAM = electroanatomical mapping; RVOT = right ventricular outflow tract.

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  Figure 3. Nonsustained Ventricular Tachycardia Lasting 29 Seconds at 232 beats/min in Athlete 1 Documented on Implantable Loop Recorder 1 Month After Placement

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  Figure 4. Resting ECG of Athlete 2 Showing Early Repolarization, T-Wave Inversion in V1, and V2, and a Rightward Axis ECG = electrocardiogram.

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  Figure 5. Frequent Premature Ventricular Beats and Recurrent Nonsustained Ventricular Tachycardia Progressing to Ventricular Tachycardia Storm in Athlete 2 Note the highly unusual lead configuration on this electrocardiogram (leads I, II, III, V1, V2, aVR, aVL, and aVF).

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  Figure 6. Epicardial EAM of Athlete 2 With Bipolar and Unipolar Mapping Demonstrating Patchy Low-Amplitude Zones Surrounding the RVOT, Basal Posterior Tricuspid Annulus, and Large Parts of the RV (A) Left anterior oblique view. (B) Posteroanterior view. (C) Right anterior oblique view. (D) Inferior wall view. EAM = electroanatomical mapping; RV = right ventricle; RVOT = right ventricular outflow tract.

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  Figure 7. Resting, Exercise, and Ambulatory ECGs of Athlete 3 (A) Resting ECG showing multiple ventricular beats with left bundle branch block morphology in V1, inferior axis, and QRS duration <130 ms, with slightly variable morphology, probably of right ventricular outflow tract origin. (B) ECG during exercise testing revealing frequent PVBs with similar morphology, including couplets at peak exercise and during recovery. (C) Ambulatory 24-hour Holter ECG showing frequent PVBs (3,262) with left bundle branch block morphology in V1, multifocal, short coupled, 130 couplets, 42 triplets, and 1 polymorphic run of nonsustained ventricular tachycardia of 4 beats at 193 beats/min. ECG = electrocardiogram; PVB = premature ventricular beat.

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  Figure 8. EAM of Athlete 3 With Bipolar and Unipolar Mapping Demonstrating Patchy Low-Amplitude Zones Surrounding the RVOT, With Unipolar Mapping Suggesting a Deeper, Potentially Epicardial Substrate (A) Left anterior oblique view. (B) Posterior view. (C) Right anterior oblique view. (D) Additional image of epicardial mapping and ablation. Left: activation map in sinus rhythm; right: bipolar voltage map in sinus rhythm, both in right anterior oblique view. The red paravalvular region is consistent with fat in the atrioventricular groove along the right coronary artery. EAM = electroanatomical mapping; RVOT = right ventricular outflow tract.

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  Visual Summary. Diagnostic Workflow Summary Three highly trained cyclists presented with palpitations and heart rate “spikes.” Despite normal conventional imaging (TTE, CMR), symptoms and ventricular arrhythmias persisted, prompting electroanatomical mapping, which revealed concealed arrhythmogenic substrates. The combination of clinical findings and mapping results ultimately led to a diagnosis of ACM in all 3 athletes, underscoring diagnostic gaps in current ACM criteria. ACM = arrhythmogenic cardiomyopathy; CMR = cardiac magnetic resonance; HRM = heart rate monitor; PVB = premature ventricular beat; SCA = sudden cardiac arrest; TTE = transthoracic echocardiography; VA = ventricular arrhythmia.