Is it aortic stenosis or left ventricular outflow tract obstruction? The complementary role of four-dimensional flow cardiac magnetic resonance imaging

Trans-thoracic echocardiography (TTE) is the primary imaging modality for diagnosing any left ventricular outflow tract obstruction (LVOTO), estimating hemodynamic severity and timing of surgical intervention1 4 . Multi-parametric cardiac magnetic resonance imaging (CMR) provides additional details on tissue characterisation and cardiac haemodynamics. We present a case of a 74-year-old gentleman with a history of hypertrophic cardiomyopathy (HCM), where four-dimensional flow identified the mechanism of obstruction in the outflow tract when Doppler methods proved challenging.