Direct visualization of septal perforator coronary arterial blood flow during perflutren microsphere contrast...

A 62-year-old female with supraventricular tachycardia underwent a contrast echocardiogram to assess left ventricular structure and function due to sub-optimal images on conventional imaging. Multi-pulse, phase inversion, low mechanical index imaging was used (left ventricular opacification), combined with bolus dosing of a perflutren microsphere (Definity). In the parasternal short-axis view, during contrast imaging, flow within a septal coronary artery could be directly visualized. The corresponding coronary angiogram demonstrated prominent septal perforators arising from the LAD artery. By exploiting the non-linear oscillation properties of microbubbles and the linear oscillation properties of tissue, at low MI, contrast-specific imaging has the ability to enhance the contrast signal while suppressing the myocardial signal. This form of contrast imaging has high temporal and spatial resolution, enabling visualization of relatively small structures in real time. Clinical relevance of this finding includes the ability to enhance coronary blood flow evaluation, which would have utility in those studies where spectral Doppler is being used to evaluate coronary blood flow and coronary flow reserve and it may be beneficial in the identification of septal perforator arteries that should be injected with alcohol during percutaneous septal ablation for the management of hypertrophic obstructive cardiomyopathy.