"Hypersynchronization" by Tissue Velocity Imaging in Patients with Cardiac Amyloidosis

Diego Bellavia ¹, Patricia A Pellikka ¹, Theodore P Abraham ¹, Ghormallah Al-Zahrani ¹, Angela Dispenzieri ¹, Jae Oh ¹, Raul E Espinosa ¹, Christopher G Scott ¹, Chinami Miyazaki ¹ and Fletcher A Miller Jr.^1*

¹ Mayo Clinic, United States

^* To whom correspondence should be addressed. E-mail: miller.fletcher{at}mayo.edu.

Accepted 15 April 2008

Abstract

Objective It is unknown if some patients with cardiac amyloid have mechanical dyssynchrony, as has been demonstrated in patients with ischemic and dilated cardiomyopathies. The aim of this study was to assess mechanical dyssynchrony in patients with CA using tissue velocity imaging (TVI) and define its usefulness for risk stratification.

Design and Patients We included 121 patients with primary amyloidosis and 37 age- and sex-matched controls. Patients were divided into two groups: 60 with advanced-CA and 61 with no-advanced-CA, according to left ventricular (LV) wall thickness and diastolic dysfunction. Dyssynchrony assessment included: 1) atrio-ventricular dyssynchrony (dys), 2) interventricular dys, 3) intraventricular dys assessed longitudinally, using the standard deviation of time to systolic peak velocity (Ts-SD) of the 12 basal and mid level LV segments, and 4) intraventricular dys assessed radially, using the difference in radial Ts between mid anteroseptal and mid posterior segments.

Outcome Primary end-point was all-cause death. During a median follow-up of 13 months there were 35 events among patients.

Results Contrary to the hypothesis, the intraventricular dys indices in advanced-CA patients were reduced compared to either no-advanced-CA group or controls (Ts-SD: 12.1 ± 9.0; 35.1 ±18.6; 24.5 ± 14.1 respectively, p < 0.001). This reduction was primarily due to decreased ejection time (ET). Moreover, ET was the most significant predictor of survival (HR = 0.98, p <0.001).

Conclusions The regional timing of systolic motion measured by TVI was abnormally synchronized in the patients with advanced-CA. ET reduction plays a prominent role in this process and should be considered an essential parameter for assessment of patients with cardiac amyloidosis.