Limitations of multimodality imaging in the diagnosis of pannus formation in prosthetic aortic valve and review of the literature

Pannus formation is a rare complication and occurs almost exclusively in mechanical prosthetic valves.It consists of fibrous tissue that covers the surface of the prosthesis either concentrically or eccentrically,resulting in valve dysfunction.The pathophysiology seems to be associated to a chronic inflammatory process that explains the late and insidious clinical presentation.This diagnosis should be considered in patients with high transvalvular gradients on transthoracic echo,and workup should be completed with fluoroscopy and transesophageal echocardiography.Treatment is always surgical and recurrence is rare.We present a case of pannus formation in a prosthetic aortic valve and a review of the literature regarding this disorder.

Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy

AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.

Lamivudine resistance mutations in patients infected with hepatitis B virus genotype D

AIM: To determine the distribution of viral genotypes for primary or acquired lamivudine resistance. METHODS: A total of 283 patients with chronic hepatitis B virus (HBV) infection (245 patients with chronic hepatitis B and 38 inactive hepatitis B surface antigen carriers) were included in the study. The HBV geno-type was determined by using quantitative real-time polymerase chain reaction and sequence analysis, and tyrosine-methionine-aspartate-aspartate (YMDD) motif mutations were determined using the reverse transcriptase hybridization method. RESULTS: Lamivudine resistance was determined in a total of 25 (10.7%) chronic hepatitis B patients. Eight subjects (4%) had primary resistance to lamivudine, and 17 (53.1%) had secondary resistance to lamivudine. Genotype D, which was isolated from 267 of the patients with chronic HBV infection, was the dominant genotype in Turkey. CONCLUSION: Identification of YMDD motif mutations should have a positive impact on the selection of proper antiviral medication for patients, even for those who are nucleoside nave.