Biomedical subjects

T K Kaul

Publications and source records attributed to T K Kaul.

43 records · Page 3Linked to original sources

PubMed1979

Failure of pacemaker electrode leads.

With the application of new power sources to pacemakers, considerable improvement has been achieved in the theoretical implant lifetime of current pulse generators, and equally reliable electrode leads will be necessary to ensure long-term pacing. The durability of the electrodes implanted in the past ten years in this centre has been carefully studied. The findings suggest that the use of a more durable conductor material and development of the concept of a 'fail safe' lead (using multi-filament conductors or a secondary conductive pathway along the electrode) will be necessary to match with the implant lifetime of the newer pulse generators. The diagnosis and management of broken conductors is discussed.

Electrodes, Implanted↗

PubMed1977

Radiographic appearances of implanted transvenous endocardial pacing electrodes.

It is important to ensure correct positioning of long-term pacing electrodes. Electrocardiograms and the radiographic appearance of pacing electrodes are conventionally used to confirm the site of the pacing electrode. Electrocardiographic patterns from stimulation of the right ventricle and left ventricle of the heart through the coronary venous system and the limitations in the interpretations of these patterns have been well documented in the past. The appearances of chest x-ray films can also be misleading. In the present study performed on cadavers, detailed appearances of pacing electrodes placed electively in different sites in the right ventricle and in the coronary sinus and its radicles are described, and the limitations in the interpretations of such appearances are discussed.

Coronary Angiography↗

PubMed1976

Mitral valve replacement in the presence of severe pulmonary hypertension.

Thirty patients with severe preoperative pulmonary hypertension (pulmonary artery pressure range 90-165 mmHg, mean 118 mmHg) were reviewed following single mitral valve replacement, with prosthetic valves, within the last 10 years (1964-74). The early and late mortality for this group was no different from that of the total series of mitral valve replacements performed over the same period. Marked postoperative clinical improvement was accompanied by corresponding radiological and electrocardiographic changes. In addition there was a statistically highly significant haemodynamic improvement in the 21 survivors (mean survival time 5 1/2 years). At recatheterization the mean pulmonary artery pressure was 41-5%, the mean wedge pressure 46-3%, and the transpulmonary gradient (PAm-LAm) 36-1% of the preoperative values. It is concluded that gross pulmonary hypertension is not per se a contraindication to mitral valve replacement surgery.

Adult↗

PubMed1976

Chylothorax: report of a case complicating ductus ligation through a median sternotomy, and review.

An unusual case of chylothorax is described in a 4-year-old child after repair of a ventricular septal defect and ligation of a patent ductus arteriosus through a median sternotomy. Left chylothorax developed after a latent period of six days and was treated initially with continuous drainage and parenteral supplementation of proteins and lipids. Operative intervention with oversewing of the site of the leak in the anterior mediastinum proved necessary after three weeks. The anatomical variations of the thoracic duct are outlined to explain the occurrence of chylothorax after diverse intrathoracic operations. The physiological effects of a thoracic duct fistula and various aspects of management are reviewed.

Child, Preschool↗

PubMedDate not supplied

Results of combined valve replacement and myocardial revascularization. Relation to method of myocardial protection.

One hundred and twenty-three patients underwent combined valve and coronary artery bypass surgery, between 1974 and 1985. Seventy patients had aortic valve replacement, 53 had mitral valve replacement; 63.4% were male and 45% were over 60 years (mean 59 +/- 2 years). Ischaemic cardiac arrest was used in 21 patients (Group I), cold crystalloid cardioplegia in 51 (Group II), and cold blood cardioplegia in 51 (Group III). Group III had a greater number of patients with poor preoperative functional status and left ventricular function. Early mortality was 19%, 17.6% and 11.7% in Groups I, II and III respectively (NS), and was not influenced by patients age, number of vessels with critical coronary artery disease and the type of the valve procedure. There was a significant decrease in the release of LDH and AST in Group III when compared with Group II (p less than 0.02 and p less than 0.01) respectively. The linearized rate of recurrence of angina (% per patient year) was 0.4, 0.95 and 0.07; and late mortality (% per 100 years) was 5.8, 3.2 and 2.6 in Groups I, II and III respectively. Patient survival and the quality of life has been improved since the introduction of cold blood cardioplegic protection.

Adult↗

PubMedDate not supplied

A modified technique for mitral valve replacement.

Between 1976 and 1983 254 mitral valve prostheses (243 Björk-Shiley and 14 bioprostheses) were implanted in 252 patients using a modified technique. The age of patients varied from 26-72 years (mean 56 +/- 18 years). This technique allows an equidistant placement of sutures and accurate stitching of mitral valve annulus to the prosthetic valve ring. Follow-up averaged 67 +/- 21.6 months (3-7 years). Linearized aseptic dehiscence was 0.17 per 100 patient years. This technique was especially useful in patients with small left atrium and minimised the risk of a major prosthetic detachment.

Bioprosthesis↗

PubMedDate not supplied

Sinoatrial disorders, the "sick sinus" syndrome. Experience with implanted cardiac pacemakers.

The long term results of permanent pacemaker implantation in patients with disorders of the sinoatrial node and atrial conduction pathways were studied. In a consecutive series of 300 patients treated by pacemaker implantation, 68 ((22.3%) had sinoatrial disorders. Mean age of the group was 54 years (33-82 years); 37 were male, 31 female. Diagnosis was confirmed by serial electrocardiography with overdrive suppression of sinoatrial node function as indicated. Twenty-two patients presented with sinus bradycardia alone (Type I disorder) and 46 with bradycardia-tachycardia syndrome (Type II disorder) were completely controlled. of the 46 Type II patients, in 30 (65.2%) tachyarrhythmias were controlled by pacing alone and in 14 (30.4%) by pacing and antiarrhythmic drug therapy. Congestive cardiac failure was relieved in 80% and anginal pain in 70% of patients with rate control alone. Systemic embolisation did not recur after pacemaker implantation. The average duration of pacemaker therapy was 52 months (12-96 months). In this series, long term ventricular demand pacing proved beneficial in both types of sinoatrial disorders.

Adult↗