A strain on the diagnosis.

A 68-year-old female presented with acute lower extremity deep vein thrombosis and dyspnoea. The patient had no other symptoms. Transthoracic echocardiogram (TTE) with global longitudinal strain (GLS) showed preserved left ventricular ejection fraction, normal wall motion, Grade II diastolic dysfunction, and mild concentric left ventricular hypertrophy (LVH). The GLS was −17.5% (normal >−18%) with relative apical sparing on the Bull’s eye plot, suggestive of cardiac amyloidosis ( and ; GE EchoPAC, GE Medical Systems, Milwaukee, WI, USA).

(A) Apical four-chamber longitudinal strain study from the initial transthoracic echocardiogram shows myocardial contours that fail to encompass the endocardial and epicardial borders. This study also fails to demonstrate the true apex due to foreshortened images, as outlined by the arrow. (B) Bull’s eye strain plot from the initial transthoracic echocardiogram demonstrates decreased strain within basal and mid-segments with apical preservation. (C) Cardiac magnetic resonance of the heart in standard long-axis three-chamber view demonstrates apical-predominant hypertrophy in diastole. (D) Cardiac magnetic resonance of the heart with TRUFI PSIR sequence shows circumferential diffuse late gadolinium enhancement within the apex. (E) Apical four-chamber apical longitudinal strain study from the subsequent transthoracic echocardiogram shows myocardial contours that encompass the endocardial and epicardial borders and incorporate the true apex. Also notable is the ‘spade-like’ configuration of the left ventricular cavity at end-diastole (outlined by the arrow), which was missed during the initial read. (F) Bull’s eye strain plot from the follow-up transthoracic echocardiogram demonstrates decreased apical strain, which is seen in patients with apical hypertrophic cardiomyopathy.

Cardiac magnetic resonance imaging (cMRI) was obtained, demonstrating apical-predominant hypertrophy and apical circumferential diffuse late gadolinium enhancement, consistent with apical hypertrophic cardiomyopathy (HCM; and ). A second TTE revealed moderate apical LVH (rather than mild and concentric). The GLS was −11.1%, with decreased apical strain (rather than relative apical sparing), consistent with apical HCM ( and ). There was no systolic anterior motion or LV obstruction.

We describe apical HCM misdiagnosed as cardiac amyloidosis due to improper strain technique. In the first TTE, inaccurate landmark placement resulted in contours tracking inside the ventricular chamber that does not encompass the endocardial and epicardial borders, leading to faulty GLS measurements. Moreover, the true apex was not appreciated due to foreshortened apical views, leading to abnormal apical thickening. These technical mistakes ultimately produced an erroneous apical-sparing Bull’s eye plot and diagnosis, with additional tests for the patient. On the second study, not only is the contouring more accurate, but the true apex is also better appreciated, leading to an opposite strain pattern on the Bull’s eye plot.[1]

Case teaching points are: (i) LV contouring verification is required by operator and interpreting physician, (ii) recognition that apical foreshortening can lead to abnormal apical thickening, contributing to higher endocardial GLS measurements and false apical-sparing patterns,[2] and (iii) patients with HCM echo phenotypes benefit from cMRI, especially when the Bull’s eye pattern appears discordant.

Consent: The authors confirm that written consent for submission and publication of this case report including images and associated text has been obtained from the patient in line with COPE guidance.

Conflict of interest: None declared.

Funding: None declared.

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