c-TTE and c-TEE with "Curtain effect" for detecting right-to-left shunt in patients with cryptogenic stroke

Area of Science:

• Cardiology
• Neurology
• Diagnostic Imaging

Background:

• Cryptogenic stroke (CS) often involves right-to-left shunts (RLS), necessitating accurate detection methods.
• Patent foramen ovale (PFO) is a common cause of RLS in CS patients.
• Contrast transthoracic echocardiography (c-TTE) and contrast transesophageal echocardiography (c-TEE) are used to identify RLS.

Purpose of the Study:

• To compare the efficacy of c-TTE and c-TEE in detecting and grading RLS in CS patients.
• To evaluate the impact of different physiological states (Rest, Valsalva Maneuver, "Curtain effect") on RLS detection.
• To determine the optimal echocardiographic method for RLS assessment in CS.

Main Methods:

• 150 CS patients underwent both c-TTE and c-TEE.
• Echocardiography was performed at Rest, during Valsalva Maneuver, and during the "Curtain effect" (post-Valsalva).
• RLS detection and semiquantitative grading were based on microbubble characteristics in the left atrium.

Main Results:

• c-TTE during Valsalva maneuver detected significantly more RLS than c-TEE (83.3% vs 65.3%, P < .05).
• c-TTE during the "Curtain effect" revealed more PFO-RLS and higher grades than at Rest (91.8% vs 72.7%, P < .05).
• c-TTE consistently showed higher grades of PFO-RLS compared to c-TEE across all states (P < .05).

Conclusions:

• c-TTE, particularly during Valsalva maneuver or "Curtain effect", demonstrates superiority over c-TEE for RLS detection and PFO-RLS grading in CS patients.
• These enhanced c-TTE states can serve as a practical and effective screening approach for suspected RLS in CS.
• Improved RLS detection may aid in identifying stroke etiology and guiding therapeutic strategies.