Transesophageal echocardiography in children with cardiac assist

Perioperative echocardiographic examination for ventricular assist device implantation

Ventricular assist devices (VADs) are systems for mechanical circulatory support of the patient with severe heart failure. Perioperative transesophageal echocardiography is a major component of patient management, and important for surgical and anesthetic decision making. In this review we present the rationale and available data for a comprehensive echocardiographic assessment of patients receiving a VAD. In addition to the standard examination, device-specific pre-, intra-, and postoperative considerations are essential to the echocardiographic evaluation. These include: (a) the pre-VAD insertion examination of the heart and large vessels to exclude significant aortic regurgitation, tricuspid regurgitation, mitral stenosis, patent foramen ovale, or other cardiac abnormality that could lead to right-to-left shunt after left VAD placement, intracardiac thrombi, ventricular scars, pulmonic regurgitation, pulmonary hypertension, pulmonary embolism, and atherosclerotic disease in the ascending aorta; and to assess right ventricular function; and (b) the post-VAD insertion examination of the device and reassessment of the heart and large vessels. The examination of the device aims to confirm completeness of device and heart deairing, cannulas alignment and patency, and competency of device valves using two-dimensional, and color, continuous and pulsed wave Doppler modalities. The goal for the heart examination after implantation should be to exclude aortic regurgitation, or an uncovered right-to-left shunt; and to assess right ventricular function, left ventricular unloading, and the effect of device settings on global heart function. The variety of VAD models with different basic and operation principles requires specific echocardiographic assessment targeted to the characteristics of the implanted device.

The Role of Echocardiography in the Evaluation of Patients With Left Ventricular Assist Devices

The growing population of heart failure patients and the corresponding increase in demand for donor hearts has led to the need of alternate medical therapies. The availability of donor hearts is scarce, transplant is expensive, and many patients are too ill to withstand the transplant operation. Left ventricular assist devices (LVADs) have aided in the treatment leading up to heart transplantation and the recovery of reversible myocardial damage. With the increasing use of LVADs, echocardiography has become an extensive diagnostic aid in the evaluation of patients with LVADs. Because of this growing use of LVADs, it is necessary for sonographers to have a complete and current awareness of these devices. This literature review aims to expand the echocardiographer's knowledge of LVADs and to offer suggestions and techniques that may help in the evaluation of a patient with an LVAD.

Clinical utility of echocardiography in the management of implantable ventricular assist devices

BACKGROUND

The high mortality rate of congestive cardiac failure, the cost and complications of cardiac transplantation, and the waiting list mortality rate resulting from donor organ scarcity have encouraged the development of surgical techniques as bridges to transplantation or as long-term palliative therapy. Implantable left ventricular assist devices are now routinely used as such a bridge, and within the REMATCH Trial, as permanent palliative devices in nontransplant candidates. These are mechanical managements with myriad mechanical complications and pitfalls. Echocardiography has been extensively used in our institution to detect and diagnose previously documented and hitherto unencountered complications of these procedures.

METHODS AND RESULTS

The role of echocardiography in these procedures, including preoperative patient selection, intraoperative transesophageal echocardiography, and postoperative troubleshooting and late follow-up, is discussed. We describe our clinical echocardiographic approach, which has developed over 91 assist-device procedures. The relative frequency and clinical impact of specific anatomic, physiologic, hemodynamic, and mechanical features are described. New techniques such as the Doppler quantification of assist device inflow obstruction are illustrated, as are the device cannula position, the detection of device valve failure, and the parameters related to the remodeling procedure.

CONCLUSIONS

Echocardiography in heart failure surgery has proved to be an invaluable tool in the diagnosis and management of mechanical complications. The experience gained in our institution may serve as an aid to new surgical programs treating these critically ill patients.

Usefulness of Transesophageal Echocardiography in Diagnosing and Guiding Correct Placement of a Right Ventricular Assist Device Malpositioned in the Left Atrium

In this report, we describe how transesophageal echocardiography was used not only to diagnose incorrect cannula position of a right ventricular assist device in the left atrium through a patent foramen ovale, but also to guide and to confirm correct cannula placement. (ECHOCARDIOGRAPHY, Volume 13, March 1996)