The differences between userand system-centered design practice have been discussed broadly in the literature for a long period. The value of user-centredness has even been taken for granted occasionally, though there is clear evidence implying that broader participation of users should be evaluated relative to the situation in hand. In this paper, both userand system-centered conducting of a d...

We report herein a case of benign cardiac schwannoma in the interatrial septum. A 42-year-old woman was transferred from a clinic because of cardiomegaly as determined by chest X-ray. A transthoracic echocardiography and chest computed tomography examination revealed a huge mass in the pericardium compressing the right atrium, superior vena cava (SVC), left atrium, and superior pulmonary vein. ...

A 35-year-old man presented with progressive exertional dyspnea (3 months) and syncopal attacks (1 week). He had tachypnea, tachycardia and hypotension. Examination revealed a mid-diastolic plop at the apex. Clinical suspicion was a left atrial mass with a ball valve-like mechanism (LA thrombus or LA tumors). Echo and cardiac MRIs with gadolinium enhancement (to differentiate between a tumor an...

Unroofed coronary sinus (URCS) is a rare cardiac anomaly, in which communication occurs between the coronary sinus (CS) and the left atrium (LA) because of partial or complete absence of the CS roof. A 30-year-old woman was scheduled for surgical closure of atrial septal defect, mitral valve repair and tricuspid annuloplasty. The intraoperative transesophageal echocardiography (TEE) revealed le...

Figure 1 a: Surface ECG recorded during atrial tachycardia (AT). P-wave polarity during the AT was positive in leads II, III, aVF, and V1 and negative in leads I and aVL. The AT cycle length was 510 ms. b: Findings from ablation in the pulmonary artery. The earliest local atrial potential preceded P-wave onset by 52 ms. Ablation from that site temporarily accelerated the AT rate (116 to 159 bpm...

A 31-year-old man with prior step-wise ablation for persistent atrial fibrillation presented with atrial tachycardia (AT). Linear lines for the mitral isthmus, left atrial roof, and the cavo-tricuspid isthmus had previously been performed in addition to pulmonary vein (PV) isolation and defragmentation on the left atrium. The patient was in sinus rhythm (SR) at the beginning of the procedure, s...

Evolution of Surgical Ablation of Atrial Fibrillation T he success of catheter ablation of atrial fibrillation has continued to increase with the introduction of new technology, additional experience, and advances in our understanding of the targets of ablation. Nevertheless, patients with symptomatic drug refractory long-standing atrial fibrillation present a particular challenge for treatment...

PAES DE CARVALHO, ANTONIO, WALMOR CARLOS DE MELLO AND BRIAN F. HOFFMAN. Electrophysiological evidence for specialized Jiber types in rabbit atrium. Am. J. Physiol. I g6(3):483-488 I g59.-Intracellular microelectrodes have been used to study the site of origin and direction of spread of activity in the rabbit atrium. In this study a number of fiber groups have been found which possess specialize...

Offices and retail spaces are among the most energy-intensive building typologies. Designing office buildings without proper consideration of their form, orientation, envelope, and other variables can lead to a considerable increase in energy usage. This research investigates how integrated usage of an atrium and courtyard can improve a building’s energy performance. Thermal performance of both...