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Biomedical subjects

A Dhall

Publications and source records attributed to A Dhall.

11 recordsLinked to original sources

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.

Adult↗

False-positive exercise stress electrocardiogram due to accessory pathway in the absence of manifest preexcitation.

False-positive exercise testing in patients with an accessory pathway has been described only in patients with manifest preexcitation during exercise. We describe a patient in whom marked ST-segment changes were seen during an exercise test in the absence of any preexcitation of the QRS complexes. The role of the accessory pathway in producing the ST changes was reaffirmed by absence of this abnormality following catheter ablation of the accessory pathway.

Catheter Ablation↗

Transcatheter device closure of ventricular septal defects: immediate results and intermediate-term follow-up.

BACKGROUND: Transcatheter closure is an accepted mode of treatment in selected cases of congenital heart disease. Lately, this technology has been applied to closure of ventricular septal defect (VSD). METHODS AND RESULTS: We performed percutaneous transcatheter closure of VSD in 30 patients. The location of VSD was perimembranous in 28 patients and muscular trabecular in 2. Two (7%) patients also had left ventricular-right atrial communication. There were 17 male subjects and 13 female subjects, with an age range of 5. 5 to 33 years (mean +/- SD, 12.9 +/- 5.7; median 12.2). The diameter of VSD ranged from 3 to 8 mm (mean +/- SD 4.7 +/- 1.3; median 4.5). In 5 (17%) patients, the pulmonary to systemic blood flow (Qp/Qs) was >/=2.1 (range 2.0 to 2.6). The defect was at least 6 or 8 mm from the aortic valve in patients in whom a 12- or 17-mm Rashkind double umbrella device was deployed, respectively. In 1 patient, the defect was closed with a detachable stainless steel coil, size 8 mm, with 4 loops (8 x 4). The devices were successfully deployed in 87% of patients. In 6 (20%) patients, the procedure had to be repeated primarily because of the use of undersized umbrella deices. Unsuccessful deployment of the device occurred in 4 (13%) patients. In one of these procedures, the coil embolized to the left pulmonary artery, and it was successfully retrieved. A minimal residual shunt seen as a thin streak on transthoracic color flow mapping persisted in 8 (30%) patients, which remained unchanged over a follow-up period of 5 to 28 (17.1 +/- 6.4) months. Both patients with left ventricular/right atrial communication showed complete abolition of the shunt. No patient developed new-onset aortic or tricuspid regurgitation or intravascular hemolysis. At follow-up, no patient had developed infective endocarditis, bundle branch block, or late valvular insufficiency. CONCLUSIONS: Transcatheter closure is safe and efficacious in selected cases of perimembranous and muscular VSD.

Adolescent↗

High altitude dives from 7000 to 14,200 feet in the Himalayas.

Indian Navy divers carried out no-decompression dives at altitudes of 7000 to 14,200 ft (2134-4328 m) in the Nilgiris and Himalayas from May to July 1988. Seventy-eight dives on air and 22 dives on oxygen were carried out at various altitudes. The final dives were at Lake Pangong Tso (4328 m) in Ladakh, Himalayas, to a maximum of 140 feet of sea water (fsw) [42.6 meters of sea water (msw)] equivalent ocean depth in minimum water temperature of 2 degrees C. Oxygen diving at 14,200 ft (4328 m) was not successful. Aspects considered were altitude adaptation, diminished air pressure diving, hypothermia, and remote area survival. Depths at altitude were converted to depths at sea level and were applied to the Royal Navy air tables. Altitude-related manifestations, hypoxia, hypothermia, suspected oxygen toxicity, and equipment failure were observed. It is concluded that stress is due to effects of altitude and cold on man and equipment, as well as changes in diving procedures when diving at high altitudes. Equivalent air depths when applied to Royal Navy tables could be considered a safe method for diving at altitudes.

Acclimatization↗

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.

Adolescent↗