Parachute-Like Structure Oscillating Between Left Ventricular Outflow Tract and Sinus of Valsalva

An asymptomatic 56-year-old male presented to hospital because of newly diagnosed Levine III/IV systolic ejection murmur in his right intercostal sternum. Transthoracic echocardiography (TTE) demonstrated a slightly accelerated blood flow in the left ventricular outflow tract (LVOT) without aortic valve (AV) stenosis (AV area 1.51 cm²; AV peak velocity 2.2 m/s). Furthermore, TTE and transesophageal echocardiography revealed an oscillating mobile membranous structure in the patient’s LVOT (Figure A–C; Supplementary Movies 1,2), crossing over the AV reaching to the sinus of Valsalva during the systolic phase. To further understand the 3-dementional structures,¹ we performed an additional contrast-enhanced coronary computed tomography angiography (CCTA) examination, which showed that the structure got closer to the right coronary artery (RCA) ostium during the systolic phase (Figure D,E). Although this raised concerns regarding myocardial ischemia, CCTA revealed no evidence for obstruction of the RCA based on disturbed coronary blood flow (Figure D). Based on the specific images available on CCTA and echocardiography, the differential diagnosis was giant fenestration, valve strand of the AV, or subaortic membrane accompanied by elongation² (Supplementary Movie 3). Although open heart surgery to prevent sudden cardiac death was discussed, the patient was managed with a careful watching strategy with echocardiography. At the 1-year follow-up, echocardiography confirmed the absence of the LVOT obstruction and other complications, supporting the conservative management strategy.

Figure.

Parachute-like structure flailing back and forth between the left ventricular outflow tract and the sinus of Valsalva. (A) Transthoracic echocardiography (TTE). The arrowhead indicates parachute-like structure. (B,C) Transesophageal echocardiography (TEE). Arrowheads indicate parachute-like structure. (C,D) Cardiac computed tomography (CT) during the systolic (D) and diastolic (E) phases. Insets show short axis images of the aortic valve. Arrowheads indicate parachute-like structure. LA, left atrium; RA, right atrium; RCA, right coronary artery.

Acknowledgment

The authors acknowledge fruitful discussions with Yukihiro Shimizu, Honorary Director of Fujiikai Kashibaseiki Hospital.

Disclosures

None declared.

Supplementary Files

Supplementary Movie 1. A TTE image of parachute-like structure.

Supplementary Movie 2. TEE images of parachute-like structure.

Supplementary Movie 3. 3D CCTA images of parachute-like structure.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circrep.CR-21-0044

References

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