A new echocardiographic approach for the detection of non-ischaemic fibrosis in hypertrophic myocardium.

AIMS

Regional myocardial fibrosis detected by magnetic resonance imaging (MRI) using late enhancement (LE) indicates an unfavorable prognosis. We investigated in a prospective study whether regional non-ischaemic fibrosis in hypertrophic myocardium can also be detected by ultrasonic strain-rate imaging based on specific visual features of the myocardial deformation traces.

METHODS AND RESULTS

This diagnostic study aimed to define left ventricular fibrotic segments in 30 patients with hypertrophic cardiomyopathy (n = 10), severe aortic valve stenosis (n = 10), Fabry disease cardiomyopathy (n = 10), and 10 healthy controls. MRI and strain-rate imaging (=deformation imaging) was performed in all patients and controls to detect LE. In total, 42 segments showed LE according to MRI criteria. Using strain-rate imaging, all LE positive segments displayed a characteristic pattern consisting of a first peak in early systole followed by a rapid fall in strain rate close to zero and a second peak during isovolumetric relaxation. This 'double peak sign' was never seen in segments of healthy controls. However, it was detected in 10 segments without LE. These 'false-positive' segments belonged to Fabry patients who often develop a fast progressing fibrosis. In a follow-up MRI study after 2 years (available for 6/10 segments), all these segments had developed LE.

CONCLUSION

The 'double peak sign' in strain-rate imaging tracings seems to be a reliable tool to diagnose regional fibrosis.