Tumor lysis syndrome (TLS) is an oncological emergency characterized by a classic tetrad of hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. Risk assessment and prophylactic therapy is critical in preventing this oncological emergency. Treatment of established TLS involves aggressive hydration, electrolyte management, and the use of hypouricemic agents.
Multiple variables contribute to the delivered tidal volume during high-frequency oscillatory ventilation, including ventilator model selection and endotracheal tube size. It is possible that real-time, clinical monitoring of delivered tidal volume during high-frequency oscillatory ventilation would allow better titration and maximize performance of these ventilators in caring for critically ill patients.
ObjectiveDue to its circular shape, the area of the proximal left ventricular tract (PLVOT) adjacent to aortic valve can be derived from a single linear diameter. This is also the location of flow acceleration (FA) during systole, and pulse wave Doppler (PWD) sample volume in the PLVOT can lead to overestimation of velocity (V1) and the aortic valve area (AVA). Therefore, it is recommended to derive V1 from a region of laminar flow in the elliptical shaped distal LVOT (away from the annulus). Besides being inconsistent with the assumptions of continuity equation (CE), spatial difference in the location of flow and area measurement can result in inaccurate AVA calculation. We evaluated the impact of FA in the PLVOT on the accuracy of AVA by continuity equation (CE) in patients with aortic stenosis (AS).MethodsCE-based AVA calculations were performed in patients with AS once with PWD-derived velocity time integral (VTI) in the distal LVOT (VTILVOT) and then in the PLVOT to obtain a FA velocity profile (FA-VTILVOT) for each patient. A paired sample t-test (P < 0.05) was conducted to compare the impact of FA-VTILVOT and VTILVOT on the calculation of AVA.ResultThere were 46 patients in the study. There was a 30.3% increase in the peak FA-VTILVOT as compared to the peak VTILVOT and AVA obtained by FA-VTILVOT was 29.1% higher than obtained by VTILVOT.ConclusionAccuracy of AVA can be significantly impacted by FA in the PLVOT. LVOT area should be measured with 3D imaging in the distal LVOT.
Patients with concomitant severe aortic stenosis (AS) and left ventricular outflow tract (LVOT) obstruction undergoing transcatheter aortic valve replacement (TAVR) are at risk for hemodynamic collapse due to a sudden decrease in afterload causing worsening LVOT obstruction. We present a case of an 88‐year‐old female with symptomatic, severe AS, and LVOT obstruction with systolic anterior motion (SAM) of the mitral leaflet in whom alcohol septal ablation was contraindicated secondary to a chronic total occlusion of the right coronary artery that filled retrograde via septal collaterals. MitraClip at the time of TAVR was successfully performed to treat SAM with subsequent stabilization of LVOT gradients despite treatment of the patient's AS. This novel approach may represent a feasible option to prevent hemodynamic complications after TAVR in patients with significant LVOT obstruction secondary to SAM and AS.
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