Background: Cardiac amyloidosis is an infiltrative disease causing predominant diastolic dysfunction and systolic dysfunction at its advanced stage. Right ventricular (RV) dysfunction is an independent predictor of poor prognosis in congestive heart failure and cardiomyopathies. However, the assessment of RV function is still technically difficult because of the complicated geometry of the RV. The recently proposed Tei index, obtained from the cardiac time interval analysis, allows noninvasive and quantitative estimation of global ventricular function without geometric evaluation. Therefore, this study was designed to assess RV function for patients with cardiac amyloidosis.
Methods: Study patients consisted of 30 consecutive patients with biopsy specimen-proven cardiac amyloidosis and 50 control subjects. Patients were classified as having early or advanced stage of cardiac amyloidosis on the basis of mean left ventricular wall thickness < 15 mm or >/= 15 mm. Tei index, defined as the sum of isovolumetric contraction and relaxation time divided by ejection time, was obtained from tricuspid and pulmonary Doppler flow velocity.
Results: RV Tei index was significantly increased for patients with cardiac amyloidosis (0.54 +/- 0.16 vs 0.28 +/- 0.05, amyloidosis vs control, P <.001). The incidences of abnormal RV isovolumetric contraction time, ejection time, isovolumetric relaxation time, and Tei index in all patients with cardiac amyloidosis were 63%, 43%, 73%, and 83%, respectively. The same incidences were 50%, 13%, 63%, and 75% in the early stage and 68%, 54%, 77%, and 86% in the advanced stage, respectively.
Conclusion: Patients with cardiac amyloidosis frequently have RV dysfunction even in its early stage. Tei index allows simple, noninvasive, and nongeometric estimation of RV dysfunction in patients with cardiac amyloidosis.