TAILIEUCHUNG - THE ROLE OF SURGERY IN HEART FAILURE - part 3

qua một van chân, tay giả phụ thuộc vào loại, kích thước, và vị trí của chân tay giả cũng như sản lượng tim; hướng dẫn có sẵn cho các phạm vi chấp nhận được của Doppler gradients gặp phải trong hoạt động tốt van. Các hướng dẫn ACC / AHA [7] thực sự không đề nghị một siêu âm tim thường xuyên hàng năm ở những bệnh nhân có van cơ khí | EXPECTATIONS OF SURGEONS FROM AN IMAGER 133 across a prosthetic valve depends upon the type size and position of the prosthesis as well as the cardiac output guidelines are available for the acceptable range of Doppler gradients encountered in properly functioning valves. The ACC AHA guidelines 7 actually do not recommend an annual routine echocardiography in patients who have mechanical valves or during the first 5 years with bioprosthetic valves unless there is a change in clinical status. However patients who have bio-prosthetic valves may be considered for annual echocardiography after the first 5 years in the absence of a change in clinical status IIb . An echocardiography should be performed anytime if there is a change in clinical status. The most common prosthesis complications are extrinsic interference of function pannus thrombus vegetation resulting in obstruction or regurgitation perivalvular leak strut fracture and component escape leaflet tear of bioprosthesis and leaflet calcification stenosis of bioprosthesis. Because of its more anterior position aortic prosthesis can be imaged more efficiently by TTE than mitral prosthesis. Assessment of mechanical prosthetic malfunction is more difficult with TTE because acoustic shadowing caused by the prosthetic material may limit transthoracic visualization of prosthetic leaflets vegetations abscesses and thrombi. TEE should be performed when TTE does not clearly identify the site and or Duration of LVAD Support days Fig. 8. A Transesophageal echocardiogram of patient who had HeartMate vented electric LVAD showing volume unloading of left atrium and LV whereas right-sided chambers remain volume loaded. B Ex vivo LV end-diastolic pressure-volume relations EDPVR measured from normal hearts failing hearts and end-stage failing hearts supported with LVAD explanted at time of transplantation. C With heart size indexed by V30 volume on EDPVR at which pressure is 30 mm Hg it is seen that LV reverse structural .

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