Unusual flow patterns in a left ventricular aneurysm in hypertrophic cardiomyopathy: a case report

Apical aneurysms are a recognized complication of hypertrophic cardiomyopathy (HCM), reported in up to 30% of cases with apical and mid-ventricular involvement. They carry significant arrhythmic and thrombo-embolic risk, but the spectrum of associated intracavitary flow abnormalities is not fully described.

An 86-year-old woman presented with ventricular tachycardia, successfully cardioverted to sinus rhythm. Echocardiography demonstrated preserved ejection fraction with severe mid-ventricular and apical hypertrophy, and a large apical aneurysm (5 cm) confirmed on contrast echocardiography without thrombus. Global longitudinal strain was reduced (-5.6%). Cardiac magnetic resonance revealed mid-cavity hypertrophy and aneurysm formation, with patchy late gadolinium enhancement at the right ventricular septal insertion site, predominantly in the basal and mid-anteroseptal walls. Doppler interrogation identified a novel bifid systolic jet directed into the aneurysm during isovolumic contraction, as well as a paradoxical early diastolic jet from apex to base. Colour Doppler showed swirling intra-aneurysmal flow with a Yin-Yang appearance. The patient was stabilized on antiarrhythmics and advised implantable cardioverter-defibrillator therapy.

While paradoxical diastolic flow has been previously described in HCM with mid-ventricular obstruction, paradoxical bifid systolic jets have rarely been reported. These findings likely reflect transient pressure gradients between the contracting ventricle and the compliant aneurysm. The Yin-Yang Doppler pattern, more commonly associated with pseudoaneurysms, here reflected abnormal haemodynamics within a true aneurysm. This case highlights the importance of multimodality imaging not only for structural characterization and thrombus exclusion but also for identifying atypical intracavitary flow dynamics that may expand understanding of HCM pathophysiology.