From the Guidelines
Preoperative transthoracic echocardiography (TTE) for heart transplant candidates should evaluate left ventricular size, wall thickness, and systolic function, as well as right ventricular size and function, valvular structure and function, pulmonary artery pressure, left atrial size, and pericardial assessment. The evaluation should include assessment of regional wall motion abnormalities, estimation of pulmonary artery pressure to identify pulmonary hypertension, and measurement of left atrial size to indicate chronicity of heart failure 1. Key parameters to be assessed include:
- Left ventricular morphology, diameters, wall thickness, mass, function, and motion abnormalities
- Right ventricular morphology, diameters, and motion abnormalities
- Valvular morphology and function, including assessment for stenosis or regurgitation of all four cardiac valves
- Pulmonary artery pressure estimation
- Left atrial morphology and size
- Pericardial assessment for effusion or constriction
- Aortic root dimensions and presence of atherosclerotic disease These parameters help determine transplant candidacy, guide perioperative management, and predict post-transplant outcomes by providing a comprehensive picture of cardiac pathology and potential surgical challenges 1. The use of 2D and 3D echocardiography, as well as other imaging modalities such as cardiac magnetic resonance and coronary angiography, may be necessary to provide a complete assessment of cardiac structure and function 1. Overall, a comprehensive preoperative TTE evaluation is essential to ensure optimal outcomes for heart transplant candidates.
From the Research
Preoperative Transthoracic Echocardiography Parameters for Heart Transplant
The following parameters should be evaluated in a patient posted for heart transplant:
- Right ventricular function: Assessment of the pulmonary circulation and right ventricular function is crucial in the evaluation of a patient as a potential heart transplant recipient 2
- Pulmonary vascular resistance: Preoperative pulmonary vascular resistance is an independent risk factor for early death after heart transplantation 2
- Transpulmonary gradient: This parameter is predictive of successful heart transplantation in cases of severe postcapillary pulmonary hypertension 3
- Left ventricular function: Left ventricular ejection fraction (LVEF) should be assessed, as it can be increased during transesophageal echocardiography in patients with impaired ventricular function 4
- Diastolic function: Diastolic dysfunction is a major cause of morbidity in heart transplant recipients, and echocardiographic indices of left ventricular filling pressure should be evaluated 5
Parameters to Predict Postoperative Outcome
The following parameters can predict postoperative outcome:
- Preoperative paradoxical septal motion: This can identify single-lung transplant recipients who have the largest postoperative right ventricular area reduction and fractional area increase 6
- Reversibility of pulmonary vascular resistance and transpulmonary gradient: Survival after heart transplantation is strictly related to the reversibility of these parameters before assist implantation 3
Echocardiographic Indices
The following echocardiographic indices should be used to evaluate left ventricular filling pressure:
- Peak early mitral flow velocity divided by septal early mitral relaxation velocity (E/e'(septal)): This is the best correlate with invasively measured pulmonary capillary wedge pressure (PCWP) 5