Unexplained Syncope in Athletes

Figures

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  Figure 1. Case 1, Football Player: Resting LVOT Gradient Continuous-wave Doppler across the aortic valve displaying no significant LVOT gradient (<20 mm Hg). LVOT = left ventricular outflow tract.

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  Figure 2. Case 1, Football Player: Stress LVOT Gradient Continuous-wave Doppler across the aortic valve during stress displaying late-peaking dagger signal and significant LVOTO, with peak gradient near 150 mm Hg. LVOT = left ventricular outflow tract; LVOTO = left ventricular outflow tract obstruction.

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  Figure 3. Case 2, Runner: Resting LVOT Gradient Continuous-wave Doppler across the aortic valve displaying no significant LVOT gradient (<20 mm Hg). LVOT = left ventricular outflow tract.

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  Figure 4. Case 2, Runner: Isoproterenol-Provoked TEE Gradient Using isoproterenol for provocation, continuous-wave Doppler across the aortic valve demonstrated dynamic LVOTO with peak gradient >100 mm Hg. LVOTO = left ventricular outflow tract obstruction; TEE = transesophageal echocardiography.

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  Figure 5. Case 3, Masters Athlete: Electrocardiogram Electrocardiogram demonstrating sinus rhythm with borderline left ventricular hypertrophy.

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  Figure 6. Case 3, Masters Athlete: Resting LVOT Gradient Continuous-wave Doppler across the aortic valve displaying no significant LVOT gradient (<20 mm Hg). LVOT = left ventricular outflow tract.

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  Figure 7. Case 3, Masters Athlete: Cardiac MRI Cardiac MRI demonstrating maximal wall thickness of 11 mm. There was no evidence of LGE. LGE = late gadolinium enhancement; MRI = magnetic resonance imaging.

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  Figure 8. Case 4, Track Athlete: Resting TTE Gradients Continuous-wave Doppler across the aortic valve with Valsalva maneuver showed 2 discrete profiles: an early peaking signal consistent with fixed obstruction and a late peaking signal suggestive of dynamic obstruction. TTE = transthoracic echocardiography.

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  Figure 9. Case 4, Track Athlete: Cardiac MRI Three-chamber view demonstrating subaortic flow acceleration and presence of subaortic membrane (arrow). MRI = magnetic resonance imaging.

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  Figure 10. Case 4, Track Athlete: TEE Gradients (A) Continuous-wave Doppler across the aortic valve demonstrating early peaking gradient consistent with fixed obstruction secondary to subaortic membrane. (B) With isoproterenol, dynamic late peaking signal (150 mm Hg) was obtained, consistent with significant LVOTO. LVOTO = left ventricular outflow tract obstruction; TEE = transesophageal echocardiography.

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  Visual Summary. Key Points When Evaluating the LVOT in Athletes With Syncope The figure highlights the importance of considering the intrinsic anatomy of mitral valve, recognizing limitations of rest imaging and importance of provocation, and how detection of LVOTO can drastically change management. AML = anterior mitral valve leaflet; CW = continuous wave; ICD = implantable cardioverter-defibrillator; LVH = left ventricular hypertrophy; LVOT = left ventricular outflow tract; LVOTG = left ventricular outflow tract gradient; LVOTO = left ventricular outflow tract obstruction; SAM = systolic anterior motion; Iso-TEE = isoproterenol-provoked transesophageal echocardiography; TTE = transthoracic echocardiography.