WPW and preexcitation syndromes.

Wolff-Parkinson-White syndrome is a disorder characterized by presence of an accessory pathway which predisposes patients to tachyarrhythmias and sudden death. Among patients with WPW syndrome, atrioventricular reentrant tachycardia (AVRT) is the most common arrhythmia, accounting for 95% of re-entrant tachycardias. It has been estimated that one-third of patients with WPW syndrome have atrial fibrillation (AF). AF is a potentially life-threatening arrhythmia. If an accessory pathway has a short anterograde refractory period, then rapid repetitive conduction to the ventricles during AF can result in a rapid ventricular response with subsequent degeneration to ventricular fibrillation (VF). The accessory pathway may be located anywhere along the atrioventricular valve Most of the patients are young and do not have structural heart disease hence it is important to risk stratify these patients so as to prevent the sudden death. Management of asymptomatic patients with WPW syndrome has always remained controversial Catheter ablation of accessory pathways has become an established mode of therapy for symptomatic patients and asymptomatic patients employed in high-risk professions.

Conscious sedation as an anaesthetic technique in patients undergoing nonthoracotomy placement of automatic implantable cardioverter defibrillator: an initial experience.

Six adult patients with life threatening recurrent ventricular arrhythmias who underwent non- thoracotomy placement of automatic implantable cardioverter defibrillator under conscious sedation are reported. Our clinical experience, patient satisfaction, recovery profile, complications and cardiologist perception about the technique of conscious sedation is presented and discussed.

Cerebral venous thrombosis in a patient of paroxysmal nocturnal haemoglobinuria following aplastic anaemia.

A young lady who had aplastic anaemia presented for cerebral venous thrombosis after five years of follow up. She was diagnosed to have paroxysmal nocturnal haemoglobinuria. She had received immunosuppressive therapy with methylprednisolone, cyclosporine-A, anti-lymphocyte globulin, danazol and pregnenolone. The relation between aplastic anaemia, paroxysmal nocturnal haemoglobinuria and cerebral venous thrombosis is discussed. The role of immunosuppressive therapy for aplastic anaemia in causation of paroxysmal nocturnal haemoglobinuria is reviewed.

Transcatheter closure of secundum atrial septal defect with atrial septal defect occlusion system (ASDOS): initial experience and short-term follow-up.

Transcatheter closure of secundum atrial septal defect is a well known alternative to surgery. It was attempted in seven patients (age range 7-34 years, mean 20.1 +/- 6.5 years) with the double umbrella nitinol device (ASDOS, Dr. Ing Osypka, Germany). The interatrial septal anatomy and blood flow were examined by transthoracic and multiplane transoesophageal echocardiography. The size of atrial septal defect varied from 1.25-2.4 cm (mean 1.75 +/- 0.3 cm), minimal septal rim 0.5-1.0 cm (mean 0.75 +/- 0.20 cm), and Qp/Qs 1.6-3.2:1 (mean 2.4 +/- 0.6). One patient had an atrial septal defect following surgery for left atrial myxoma. The procedure which involved the use of monorail system for deployment of device under transoesophageal echocardiography guidance, was successful in six (86%) of the seven patients. The size of the implanted device ranged from 30-45 mm. In two patients, the right atrial umbrella had to be oversized in comparison to the left atrial umbrella for stability and adequate occlusion of the defect. The patient in whom the procedure failed had a defect size of 1.7 cm, with minimal septal rim (anterosuperior) of 5 mm; however, the device could be easily retrieved. Immediately after and at follow-up of one year, transoesophageal echocardiography-guided colour flow mapping revealed complete abolition of left-to-right shunt in five (83%) of the six patients. One patient had a small residual flow at the posterior rim of the defect; none had atrioventricular valve regurgitation. Although the procedure is complex, it is safe with the advantage of excellent control on the monorail system for proper positioning, repositioning and, if required, retrieval of the device.