Quantitative criteria for the diagnosis of the congenital absence of pericardium by cardiac magnetic resonance.

BACKGROUND

Congenital absence of the left ventricular pericardium (LCAP) is a rare and poorly known cardiac malformation. Cardiac Magnetic Resonance (CMR) is generally used for the diagnosis of LCAP because of its high soft tissue contrast, multiplanarity and cine capability, but the diagnosis is usually made by only qualitative criteria. The aim of the present study was to establish quantitative criteria for the accurate diagnosis of LCAP on CMR.

METHODS

We enrolled nine consecutive patients affected by LCAP (mean age 26±8years, 7 males), 13 healthy controls, 13 patients with dilated cardiomyopathy (DCM), 12 patients with hypertrophic cardiomyopathy (HCM) and 13 patients with right ventricular overload (RVO). All patients underwent CMR. The whole-heart volume was measured in end-systole and end-diastole. Whole-heart volume change (WHVC), was the systo-diastolic change of volume, expressed percentage of the end-diastolic volume. The angle of clockwise-rotation of the heart was also measured in the end-diastolic phase of the axial cine stack.

RESULTS

The WHVC was significantly higher in LCAP (21.9±5.4), compared to healthy subjects (8.6±2.4, p<0.001), DCM (7.1±1.8, p<0.001), HCM (9.3±2.4, p<0.001) and RVO (8±2.4, p<0.001). The clockwise-rotation was significantly higher in LCAP (76±14°) than healthy controls (40±11°, p<0.001), DCM (41±5°, p<0.001), HCM (30±6°, p<0.001) and RVO (49±8°, p<0.001). WHVC had the highest sensitivity (100%) and specificity (100%) for diagnosing LCAP, using a threshold of >13%.

CONCLUSIONS

In LCAP the systo-diastolic WHVC was significantly higher than controls, DCM, HCM and RVO patients and resulted an optimal quantitative criteria for the diagnosis of LCAP.