Arrhythmogenic myocardial scar localized through the combined use of 123I-mIBG SPECT and cardiac MRI

A 63-year-old male patient was referred to our Hospital due to sudden onset of palpitations and increased blood pressure, with basal ECG revealing a sinus tachycardia at 100 b/min and no other abnormalities. No history of cardiac symptoms or disease prior to this episode and no other relevant factors were reported. The patient underwent a dynamic ECG Holter monitoring that showed episodes of polymorphic not sustained ventricular tachycardia, preceded by tri-bigeminy ectopic ventricular beats. The patient was submitted to cardiac magnetic resonance (CMR) that was positive for myocardial scar localized in the proximal tract of infero-lateral wall of the left ventricle (LV) (Fig. 1). Since patient had not story of ischemic cardiopathy, this CMR finding was interpreted as myocyte injury caused by previous myocardial inflammation. Afterwards, the patient was administered with 185 MBq of 123I- mIBG (AdreViewTM, GE Healthcare) intravenously. Planar images were acquired at 15 min and 4 h after injection with dual-head -camera (Infinia®, GE Healthcare) equipped with low-energy, high-resolution collimators, and all acquisitions were performed with a 20% energy window centered at the 159-keV photopeak of 123 I. Furthermore, SPECT imaging of the chest was performed at 4 h, with a minimum of 30 projections per head, 20–30 s/projection, and a 64 × 64 matrix. Acquired images were transferred to a Xeleris® workstation (GE Healthcare) for elaboration. Heart to mediastinum (H/M) ratio, calculated on planar images according to the interna- tional guidelines, resulted of 1.94 at 15 min and 1.92 at 4 h. SPECT images demonstrated a segmental defect of 123I-mIBG uptake in the LV infero-lateral wall (Fig. 2). Emory Cardiac ToolboxTM wasapplied to obtain a 17-segment regional polar (bull’s-eye) map and a summed defect score (SDS) of 16 was calculated. Using a dedi- cated off-line co-registration software the corresponding SPECT and CMR slices were superimposed demonstrating a match between the scar tissue revealed by CMR and the regional abnormal uptake disclosed by SPECT (Fig. 3). After 2 weeks, the patient was submitted to CMR/SPECT-guided ablation of the ventricular arrhythmogenic focus. Dynamic ECG-monitoring performed 1 month after therapy revealed complete regression of the electrophysiological abnor- malities. Cardiac scintigraphy with 123I-mIBG is a well-established imag- ing method for predicting the arrhythmic events in chronic heart failure (HF).1 However, the phenomenon of sympathetic denerva- tion, consequent to post ischemic or phlogistic remodeling, resulted to be associated with increased risk of ventricular arrhythmia. In this context, the role of SPECT for the detection of regional defect of 123I-mBIG uptake has still to be defined.2 Of note, the ischemic and non-ischemic myocardial scars represent critical arrhythmo- genic substrates, whose early identification and treatment are of utmost importance. CMR represents an excellent imaging modal- ity, characterized by high anatomical contrast, for the localization of scar tissue. However, the usefulness of the combined use of 123I- mBIG SPECT and CMR for matching functional and structural data has not been still widely explored.3 The case we present confirmthe usefulness of this multimodality approach for the structural and functional identification of a non-ischemic arrhythmogenic focus, enabling a precise targeting for the ablative therapy

Effect of xyloglucan (tamarind seed polysaccharide) on conjunctival cell adhesion to laminin and on corneal epithelium wound healing

PURPOSE. To explore the role of a natural polysaccharide extracted from tamarind seed (xyloglucan, or tamarind seed polysaccharide, TSP) on the integrin-substrate recognition system and on repair of corneal wounds. METHODS. a) Cultured human conjunctival cells were labeled by addition of a tritiated amino acid mixture. Their adhesion to laminin-coated culture wells in the absence or presence of TSP was checked by radioactivity count, b) The corneal epithelium of albino rabbits was damaged by applying a paper disc soaked with n-heptanol. The eyes were then treated with TSP, with a hyaluronate reference formulation and with normal saline solution (controls). The diameter of corneal wounds was measured daily, after fluorescein staining. RESULTS. Compared to hyaluronate, TSP slighthly but significantly increased the wound healing rate. TSP 1.0% exerted a positive influence on cell adhesion to laminin, up to a certain laminin concentration. CONCLUSIONS. The ability of the polysaccharide to promote corneal wound healing might depend on its influence on the integrin recognition system

Burgalassi

Effect of xyloglucan (tamarind seed polysaccharide) on conjunctival cell adhesion to laminin and on corneal epithelium wound healing INTRODUCTION Various insults to the corneal and conjunctival epithelium are common in clinical ophthalmology. They may occur after trauma, ocular surgery, ocular surface diseases or as a result of environmental factors (1). Corneal/conjunctival surfaces can also be damaged by prolonged use of ophthalmic preparations: irritant effects, corneal lesions and alterations of conjunctival layer integrity produced by drugs and/or by common ingredients of eyedrops are well documented (2-5). Corneal or conjunctival wounds are commonly treated pharmacologically with the aim of promoting formation of an intact epithelial layer as rapidly as possible and then re-establishing the correct flow of biological information between corneal and conjunctival cells. Hyaluronic acid is reported to have a good effect on healing of clinical and experimental alkali wounds of the corneal epithelium, stroma, and endothelium (6-8). The epidermal growth factor (9), collagen lenses (10) and mucin extracted from bovine submaxillary glands (11) are also active in different models of corneal erosion. One of the first events in tissue repair is cell attachment and adhesion to specific substrates of the extracellular matrix, such as the glycoproteins laminin -PURPOSE. To explore the role of a natural polysaccharide extracted from tamarind seed (xyloglucan, or (Eur J Ophthalmol 2000; 10: 71-6