Quantitative assessment of endomyocardial biopsy in arrhythmogenic right ventricular cardiomyopathy/dysplasia: an in vitro validation of diagnostic criteria.

AIMS: To provide a standardized endomyocardial biopsy (EMB) protocol and diagnostic quantitative parameters for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). The Task Force criteria for the in vivo diagnosis of ARVC/D include tissue characterization by EMB as a major criterion. METHODS AND RESULTS: EMBs were simulated in vitro with a Cordis bioptome in explanted hearts from six groups: diffuse (n = 10) and segmental (n = 10) ARVC/D, dilated cardiomyopathy (DC) (n = 10), controls (n = 10), adipositas cordis (n = 10), elderly >80 years (n = 10). Sampling sites were the RV inferior-subtricuspid, antero-apical, and mid-outflow tract (RVOT), the septum, and the left ventricle (LV). Histomorphometry was performed to evaluate the amount of myocardium and fibrous and fatty tissues. Myocyte diameters and abnormalities were also assessed. By selecting a 95% specificity, the ARVC/D diagnostic cut-offs on cumulative RV EMB samples are myocardium <59%, fibrosis >31% and fat >22% (80, 50, and 50% sensitivity, respectively). By excluding elderly and obese people groups a lower cut-off for fat was found (>9%). A high variability between different RV sampling sites was observed; the antero-apical was the most informative region although fat at this level is non-specific. No useful diagnostic cut-off for fatty tissue was identified at the antero-apical and RVOT area. No significant difference was found for any tissue parameter either in septal or in LV EMB. Increased RV myocyte diameters and cytological changes were detected in ARVC/D and DC. CONCLUSION: The residual myocardium is the main diagnostic morphometric parameter in ARVC/D, whereas fat at the apex is non-specific. Sensitivity and specificity vary according to the RV region. Target sampling of the triangle of dysplasia is required, although only a single region is often informative, emphasizing the usefulness of imaging-guided EMB. There is no diagnostic value of either septal or LV EMB. Cardiomyopathic changes of the myocytes also appear important for establishing a pathological diagnosis.

Morphologic validation of reperfused hemorrhagic myocardial infarction by cardiovascular magnetic resonance.

The purposes of this study were to assess the ex vivo cardiovascular magnetic resonance (CMR) signals of pathologically proved hemorrhagic myocardial infarction (MI) and to correlate these with in vivo CMR findings. Late gadolinium hypoenhancement within a hyperenhanced area in reperfused acute MI is ascribed to severe microvascular obstruction. The hearts of 2 patients, who died from cardiogenic shock after acute MIs and who had undergone coronary recanalization and in vivo CMR, were examined by T(2) and T(1) late enhancement sequences as well as by gross and histologic investigation. Four corresponding short-axis slices of each cardiac specimen from the base to the left ventricular apex were selected to assess the extent of MI and hemorrhage and were compared with the in vivo T(2) and late enhancement CMR scans. On pathologic examination, the extent of MI was 57 +/- 30% and 44 +/- 24%, and the extent of hemorrhage was 23 +/- 13% and 19 +/- 8% of the left ventricular area, respectively, showing progressive increases from the base to the apex. The low-signal intensity areas observed by ex vivo T(2) CMR strongly correlated with the hemorrhage quantified on histology (R = 0.93, p = 0.0007). Using ex vivo late gadolinium sequences, bright areas surrounded by thin dark rims, consistent with magnetic susceptibility effects, were detected, corresponding with hemorrhage. On in vivo CMR images, low-signal intensity and hyperintense areas with peripheral susceptibility artifacts were observed within the MI core on T(2) and late gadolinium sequences, respectively. In conclusion, in reperfused MI, CMR hypointense T(2) signal and susceptibility effects within the late gadolinium hypoenhanced areas are consistent with interstitial hemorrhage due to irreversible vascular injury, as proved by pathologic study.

Spontaneous coronary artery dissection mimicking aortic dissection.

A 51-year-old woman suffered rapidly irreversible cardiogenic shock with left hemiparesis. Transesophageal echocardiography, which represents an essential imaging tool in the emergency room, ruled out aortic dissection involving branch vessels but did not allow an in vivo diagnosis of spontaneous coronary dissection. The in vivo diagnosis of spontaneous coronary dissection is rather difficult because of the dramatic clinical presentation and selective coronary angiography requirement.

Recurrence of idiopathic pulmonary hemosiderosis in a young adult patient after bilateral single-lung transplantation.

BACKGROUND: Idiopathic pulmonary hemosiderosis (IPH) is a rare disease of unknown etiology characterized by hemoptysis, diffuse pulmonary infiltration, and anemia. Diagnosis requires a detailed clinical history and transbronchial lung biopsy (TLB). METHODS AND RESULTS: A 19-year-old man developed progressive dyspnea, hemoptysis, and anemia. The chest x-rays showed bilateral opacities. IPH was diagnosed on the basis of clinical findings and TLB. The patient was treated with corticosteroidal therapy. His respiratory function worsened, and he underwent lung transplantation in 1997. The pathological examination on native lungs confirmed the previous histologic diagnosis. In 2000, the patient again developed hemoptysis, fever, and hypoxemia. A recurrence of the disease was established by TLB. CONCLUSIONS: This is the first report of recurring IPH. The possibility of recurrent IPH raises the question whether these patients should be disqualified from lung transplantation. This question is unanswerable because incidence of recurrence, time course, and impact on the graft function are presently unknown and unpredictable.