Direct microvascular repair of an infant's transected coronary artery: case report

The authors report the direct, microvascular repair of a right coronary artery transected during reoperation fOr complications of arterial switch operation (ASO) in a 3 month-old child. This is the first documented use of direct microsurgical anastamosis in the repair of an infant's transected coronary artery. Deviation from standard coronary bypass graft repair was permitted by vessel characteristics, as well as close collaboration between plastic surgery and cardiac surgery services. Patency of repair was confirmed intraoperatively with Doppler ultrasound and through postoperative echocardiograms documenting stable right ventricular function. This case highlights the benefit of a multidisciplinary approach to an emergent clinical problem using microsurgical techniques.     

Decreased septal wall thickening in patients with left bundle branch block

OBJECTIVES: Septal wall motion abnormalities are frequently observed in patients with left bundle branch block (LBBB). However, septal wall thickening in LBBB patients has not been thoroughly evaluated. METHODS AND RESULTS: To investigate the relationship between septal wall motion and wall thickening, we studied 31 normal control subjects, 24 LBBB patients with normal wall motion (LBBB-NWM), and 24 LBBB patients with septal dyssynchrony (LBBB-SDS), all with a low likelihood (<15%) of coronary artery disease. The septal and lateral quadrants of the left ventricle were analyzed in stress 8-frame gated technetium 99m sestamibi tomograms. The percent wall thickening was calculated by use of a 25-segment polar map with the p-FAST software program by two independent methods: the regional count density increase from end diastole to end systole (CD method) and the geometric increase in the distance between the 50% thresholded endocardial and epicardial borders from end diastole to end systole (GD method). In addition, the ratio of septal/lateral percent wall thickening was calculated. The relative septal wall thickening in the entire LBBB population was decreased as compared with the normal control subjects (0.35 +/- 0.37 vs 0.81 +/- 0.17, P <.001). Decreased wall thickening was observed in not only LBBB-SDS patients but also to a lesser degree in LBBB-NWM patients (0.12 +/- 0.35, P <.001; 0.57 +/- 0.24, P =.005, respectively). This abnormality was most apparent when the CD method was used. CONCLUSIONS: Septal wall thickening is decreased in patients with LBBB even with normal wall motion. LBBB per se may compromise septal wall thickening, and dyssynchronous wall motion results in further deterioration of wall thickening.     

Genetic disruption of Kir6.2, the pore-forming subunit of ATP-sensitive K+ channel, predisposes to catecholamine-induced ventricular dysrhythmia

Metabolic-sensing ATP-sensitive K+ channels (KATP channels) adjust membrane excitability to match cellular energetic demand. In the heart, KATP channel activity has been linked to homeostatic shortening of the action potential under stress, yet the requirement of channel function in securing cardiac electrical stability is only partially understood. Here, upon catecholamine challenge, disruption of KATP channels, by genetic deletion of the pore-forming Kir6.2 subunit, produced defective cardiac action potential shortening, predisposing the myocardium to early afterdepolarizations. This deficit in repolarization reserve, demonstrated in Kir6.2-knockout hearts, translated into a high risk for induction of triggered activity and ventricular dysrhythmia. Thus, intact KATP channel function is mandatory for adequate repolarization under sympathetic stress providing electrical tolerance against triggered arrhythmia.     

Did Michelangelo (1475-1564) have high-functioning autism?

In this paper evidence is presented that Michelangelo met the criteria for Asperger's disorder, or high-functioning autism. The evidence relates to his single-minded work routine, unusual lifestyle, limited interests, poor social and communication skills, and issues of life control. Depression and various medical conditions, including gout, renal colic and renal stones, did not stop his obsessive working habits.     

A closer look at food allergy and intolerance

Food allergy is a condition prevalent in over 2 percent of the world's population. The topic has been subject to research from ancient Greek times and continues to attract modern scientific and medical communities. In susceptible individuals certain foods produce a wide spectrum of unwanted effects like eczema, asthma, and urticaria. The management of food allergy and intolerance chiefly involves elimination diets, accurate diagnosis and detecting the causative mechanism providing us with ample food for thought. In this article, we have attempted to summarize and simplify the research on the various aspects of food allergy and intolerance, and discuss the natural history, manifestations, mechanisms, diagnosis, and management of this condition affecting countless worldwide.     

Normal values for a clinical test of letter-recognition contrast thresholds

PURPOSE: To investigate the contrast thresholds (CTs) in normal subjects using a high-luminance, letter-recognition task under clinically relevant testing conditions. SETTING: Texas Tech University Health Sciences System, Lubbock, Texas, USA. METHODS: Sixty normal subjects aged 20 to 49 years with a best corrected visual acuity of 20/20 or better in both eyes participated. M & S Technologies software was used to display black-on-white Sloan letters at contrast levels of 25%, 20%, 15%, 12%, and 10% through 1% in 1% decrements. The effects of age, sex, optotype size, eye dominance, ambient illumination level (bright = 625 - 630 lux; dim = <3 lux), and direction of approach to threshold were analyzed using a multivariate, ordinary, least-squares analysis. RESULTS: Age and sex did not influence CTs. Ascending versus descending testing was not statistically significant (P>.5). The effects of room illumination and eye dominance were significant (P<.01). Significant differences were found between 20/30 and 20/50, 20/30 and 20/70, and 20/50 and 20/70 optotype sizes (P<.01 for all comparisons). CONCLUSIONS: A commercially available, computer-based test of CTs was easy to administer and apparently easy for inexperienced subjects to perform. The results suggest criteria for detecting visual problems concerned with familiar but complex spatial-image shapes. This information might be used to assess the effects of treatments such as laser refractive surgery on recognition contrast. Further study is warranted.