Myocardial contrast echocardiography in biopsy-proven primary cardiac amyloidosis

Cardiac vasculature is affected in 88-90% of patients with primary cardiac amyloidosis (CA). Myocardial contrast echocardiography (MCE) relies on the ultrasound detection of microbubble contrast agents that are solely confined to the intravascular space, and are therefore useful in the evaluation of flow in the microvasculature. This is the first case report describing the use of MCE during vasodilator stress to evaluate coronary flow reserve in a patient with biopsy-proven primary CA and angiographically normal coronaries. Qualitative MCE demonstrated delayed replenishment of microbubbles during peak stress; quantitative analysis was consistent with a reduction in total myocardial blood flow and reserve values. Comparative imaging modalities including strain and strain rate imaging, magnetic resonance imaging, and myocardial scintigraphy were suggestive to the diagnosis of CA. In conclusion, MCE is a method for recognition of microvascular dysfunction, and might be considered as a useful tool to augment echocardiographic assessment in the early diagnosis of CA.