The response of excitable cells to inhibitory nerve impulses has already been studied with intracellular electrodes in several preparations. In the spinal cord of the cat an inhibitory volley sets up a transient polarization of the motoneuron, preventing it from discharging (Brock, Coombs, and Eccles (4)). In the crustacean nerve muscle junction inhibitory impulses have a dual effect. They atte...

Introduction Atrial arrhythmia is common in patients with an atrial septal defect (ASD). Atrial fibrillation (AF) is the main cause of morbidity in older patients with ASD. An unroofed coronary sinus (CS) is rare (in,1% of all types of ASD) and is often associated with persistent left superior vena cava (PLSVC) and other forms of complex congenital heart disease and heterotaxy syndromes. Unroof...

We examined the cases of 702 patients found to have isolated atrial septal defect of the secundum or sinus venosus type at catheterization from 1953 to 1978. Forty patients (6%), 34 women and six men, had pulmonary vascular obstructive disease, with a total pulmonary resistance greater than 7 U/M2; of these patients 26 (mean age 47 years) underwent surgical closure and 14 (mean age 44 years) re...

OBJECTIVE To assess early and later results after surgery for sinus venous atrial septal defects (ASDs). METHODS Forty-four patients of sinus venosus ASDs with anomalous drainage of the right superior pulmonary vein into the superior vena cava, were operated upon between January 1985 and June 1995. Defects were approached by an incision starting from the tip of the right atrial appendage then...

BACKGROUND Inferior sinus venosus defects (SVD) are very rare and difficult to image from transthoracic echocardiography. Surgical errors were occasionally reported in the repair of inferior SVDs. RESULTS The authors have operated on 12 inferior SVD patients using bicaval cannulation with unsnared inferior vena cava (IVC) and proved successful. CONCLUSION This technique guaranteed a better ...

The ultrasound examination is a diagnostic tool of choice for ante mortem evaluation of heart diseases. Specific anatomical features of the ophidian heart such as mobility in the coelomic cavity, a single ventricular cavity, a tubular sinus venosus opening into the right atrium, and the presence of three arterial trunks, have direct consequences on the echocardiographic examination. We propose ...

Defects in the atrial septum cause left to right shunt because the left atrial pressure is higher than that in the right atrium. This causes volume overloading of the right ventricle. While this is generally well tolerated in infancy and childhood, development of exercise intolerance and arrhythmias in later childhood and adolescence, and the risk for development of pulmonary vascular obstructi...