Severe aortic stenosis with high valvulo-arterial impedance (Zva) has more adverse cardiac changes on cardiovascular magnetic resonance

Methods Patients with severe AS had both pre-operative CMR and trans-thoracic echocardiography (TTE) within one week apart. From TTE, on top of the routine measurements, Zva was calculated as the sum of systolic blood pressure and the aortic valve continuous-wave Doppler mean gradient divided by the left ventricular stroke volume index. Patients were categorized into 2 groups according to their calculated Zva: (a) High Zva (≥4.5 mmHg/mL/m2), and (b) low Zva (<4.5). CMR parameters, namely left ventricle mass index (LVMI), ejection fraction (LVEF), enddiastolic volume (LVEDV), right ventricle end-diastolic volume (RVEDV) and left atrium volume index (LAVI), were compared between the 2 groups.