Geometric remodeling of the left ventricule (LV) following myocardial infarction and ischemic insult is associated with myocardial load redistribution. Regional curvatures based on 3-D reconstructions of the LV are used to calculate the regional loads. The technique uses surface normals to derive local circumferential and meridional curvatures. Following the validation of the procedure on simple geometric shapes, the effect of acute ischemia on the regional load redistribution was studied in six open chest dogs. Short axis magnetic resonance imaging (MRI) scans were used to reconstruct end-diastolic (ED) and end-systolic (ES) LV images by applying our helical shape descriptor, before and after acute coronary occlusion. Regional curvatures as well as local wall thickness by the volume element method were calculated before and after acute ischemia, and were used to approximate regional loads, by a regional stress index (sigma/P). Postmortem evaluation using monastral blue staining was used to divide each LV to normal (NZ), ischemic (IZ), and border (BZ) zones in the ischemic case, and to the anatomically matched regions in the preischemic LVs. Ischemia affects the local curvatures and loads both at ED and ES. At ED, sigma/P rose significantly only in the IZ. Similarly, at ES, the highest increase in load was detected in the IZ, but increases in circumferential and meridional load were seen in all regions. Identifying the load redistribution following acute ischemia helps delineate the mechanisms affecting geometric LV remodeling following myocardial infarction.

Animals↗

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Interpretation of echocardiographic data: are physicians and sonographers violating the law?

When a sonographer renders diagnostic interpretations from echocardiographic data, the possibility exists that state statutes concerning the unauthorized practice of medicine may be violated. Problems likely exist in this regard when the sonographer renders such interpretations without proper physician interaction or when the physician delegates such responsibilities to the sonographer. In such situations the physician may be guilty of aiding and abetting the unauthorized practice of medicine. Such practices may also violate various reimbursement rules and policies. Given such a situation, even the rendering of preliminary results by sonographers without appropriate supervision by the physician may be in violation of various state statutes and rules governing reimbursement procedures.

Echocardiography↗

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Dipyridamole echocardiography in the detection of vulnerable myocardium in the early postinfarction period.

To evaluate the effect of dipyridamole on regional wall motion after myocardial infarction two-dimensional echocardiograms were obtained on 21 postinfarction patients immediately before and 7 to 10 minutes after the intravenous infusion of ddipyridamole (0.60 mg/kg). All patients underwent coronary angiography, and 20 patients underwent scintigraphy with dipyridamole thallium immediately subsequent to dipyridamole echocardiography. Dipyridamole augmented noninfarct zone regional wall motion in 20 of 31 regions supplied by nonstenotic coronary arteries. In contrast, only one of eight regions of noninfarct zone myocardium supplied by coronary arteries with greater than a 70% luminal diameter narrowing (vulnerable myocardium) was able to augment the regional wall motion subsequent to dipyridamole administration (p = 0.05). Dipyridamole echocardiography appears to be a safe and sensitive technique that may be useful in the detection of vulnerable myocardium in the early postinfarction period.

Adult↗

PubMedDate not supplied

Bacterial endophthalmitis following penetrating keratoplasty suture removal.

A case of bacterial endophthalmitis following suture removal after penetrating keratoplasty is presented. The sutures were removed 10 months postoperatively, and the endophthalmitis became apparent 2 days following suture removal. The patient was chronically immunosuppressed and was found to have a chronic dacryocystitis, which was felt to be the source of the bacterial infection.

Adult↗