Search PubMed⌕ Search

Biomedical subjects

C S Thomas

Publications and source records attributed to C S Thomas.

122 records · Page 7Linked to original sources

A randomized study of the safety and efficacy of reused angioplasty balloon catheters.

BACKGROUND: To lower costs, many centers around the world utilize previously used, resterilized balloon catheters to perform coronary angioplasty There are no controlled trials regarding their safety and efficacy. METHODS AND RESULTS: We performed the first randomized, double-blind, controlled, single-center clinical trial comparing the safety (clinical success) and efficacy (angiographic success) of reused versus new coronary angioplasty balloon catheters. A total of 377 procedures were included, 178 in the reused catheter arm and 199 in the new catheter arm. There were no significant differences in clinical or lesion characteristics among the two arms. The incidence of first balloon failure in the reused catheter arm was similar to that of the new catheter arm (12 cases [7%] v. 10 cases [5%], respectively). The angiographic success rate was also similar-176 cases (98.9%) in the reused catheter arm and 196 cases (98.5%) in the new catheter arm. The number of balloon catheters used per lesion, amount of contrast, and procedural and fluoroscopy time were similar in the two arms. At 30 days, the incidence of major adverse cardiac events was similar in both arms, 8 cases (4.5%) in the reused catheter arm and 10 cases (5%) in the new catheter arm. The incidence of fever was also similar. CONCLUSIONS: When performing coronary angioplasty, reused catheters are as effective (similar angiographic success) and safe (similar clinical success) as new catheters.

Adult↗

Sizing of balloons in balloon mitral valvotomy.

In twenty six consecutive patients who underwent balloon mitral valvotomy (BMV) by the transseptal double balloon technique, the mitral valve area (MVA) increased from 0.78 +/- 0.1 cm2 to 1.80 +/- 0.3 cm2, (p < 0.001). Effective balloon dilating area (EBDA) of each combination of balloons used was calculated using a standard formula. Patients were classified into 4 subgroups with approximate EBDAs of 3.3, 4.0, 4.9 and 5.7 cm2 and they had mean post-BMV MVAs of 1.28, 1.78, 1.89 and 1.98 cm2 respectively (ANOVA F = 3.32, p < 0.05). Patients were reclassified after normalisation of EBDA and post-BMV MVA to square metre of body surface area. Three subgroups with mean normalised EBDAs of 2.32, 2.96 and 3.62 cm2/m2 had mean normalised post-BMV MVAs of 0.99, 1.17 and 1.40 cm2/m2 respectively (ANOVA F = 6.85, p 0.01). A trend towards increasing mitral regurgitation with increasing balloon size was noted. Three cases of mitral regurgitation including one case of severe mitral regurgitation occurred in the subgroup of 9 patients with largest normalised EBDAs. The overall correlation between normalised EBDAs and normalised post BMV MVA was strong r = 0.67, p < 0.01). The optimal normalised EBDA for Indian patients undergoing BMV is around 3.6 cm2/m2. Balloons used should be sized accordingly.

Adolescent↗

Phase analysis of radionuclide ventriculograms in patients with coronary artery disease.

Phase analysis of radionuclide ventriculograms were performed in eighty patients with coronary artery disease (CAD) and in sixteen healthy subjects. The phase image in the normal group revealed a homogeneous pattern and a narrow bell shaped histogram. In forty one patients with CAD whose Left ventriculogram showed hypokinetic segments, phase image was abnormal in twenty six revealing well demarcated areas of contraction abnormality and a histogram showing broad base with multiple peaks. The mean phase angle and the standard deviation (S.D.) of phase histogram of the abnormal segments was significantly different from normal. Eighteen patients with CAD had akinetic segments. Phase analysis was abnormal in all. Six patients with CAD had dyskinetic segments. It is concluded that phase image analysis is very useful in detecting segmental wall motion abnormalities.

Adult↗

Tetralogy of Fallot with absent pulmonary valve: diagnostic features and management.

Tetralogy of Fallot with absent pulmonary valve is a rare congenital malformation. The diagnostic features and surgical management in ten patients with this malformation have been described. There were five male and five female patients, (age 3 1/2 to 26 years). The common symptoms were recurrent respiratory tract infection and cyanosis. Examination revealed hyperdynamic precordial pulsations, single second heart sound and an early diastolic murmur along the left sternal border in all. Electrocardiograms were indistinguishable from typical tetralogy of Fallot. Chest X-ray revealed cardiomegaly, prominent pulmonary conus and dilated pulmonary arteries in all cases, lung vascularity being variable. Echocardiographic findings were diagnostic and are discussed in detail. Cardiac catheterization and angiocardiography revealed annular stenosis in all, along with aneurysmal dilatation of main and branch pulmonary arteries. Eight patients underwent intracardiac repair. There was no perioperative mortality. All patients have been followed up for 350 months (mean 29 months).

Adolescent↗

Dipyridamole radionuclide ventriculography for localisation of coronary artery disease.

Nineteen consecutive patients who had coronary arteriography underwent dipyridamole stress testing with 0.14 mg/kg/min infusion over 4 minutes during computer assisted radionuclide ventriculography. Global ejection fraction, diastolic function and regional ejection fraction were calculated by a semiautomatic method. There were 17 patients with severe left anterior descending disease of which 12 involved the proximal segment of the LAD, 15 patients with left circumflex disease and 13 patients with right coronary artery disease. Abnormalities in resting or stress induced regional ejection fraction was used for localisation of severe coronary artery disease. The overall sensitivity was 75 per cent with a specificity of 75 per cent, a positive predictive value of 90 per cent and a negative predictive value of 45 per cent. For LAD disease the sensitivity was 94 per cent with a 100 per cent specificity while proximal segment of LAD had a sensitivity of 100 per cent and a specificity of 57 per cent. Identification of left circumflex disease had a sensitivity of 47 per cent and a 100 per cent specificity and right coronary artery had a 85 per cent sensitivity and a 50 per cent specificity. Four patients developed ST changes, 6 developed chest discomfort and 1 patient developed giddiness. All 7 were promptly reversed with intravenous aminophylline. Thus dipyridamole radionuclide ventriculography is a highly sensitive and specific method for localisation of CAD.

Adult↗

Distribution of Body Mass Index in Indian patients with coronary artery disease.

To study the distribution of overweight and obesity among Indian patients with coronary artery disease (CAD), a cross-sectional analysis of computerized data on patients, proved to have CAD by selected coronary arteriography, was carried out. There were 1078 patients, with 1052 males (mean age +/- SD:50 +/- 7.5) and 26 females (mean age +/- SD:47.7 +/- 8). Of these, 22 percent had single vessel disease, 38 percent two vessel and 40 percent three vessel disease. The Body Mass Index (BMI) was calculated from the height and weight data. BMI over 27 kg/m2 was defined as overweight and that over 30 kg/m2 as obese. Data analysis revealed that only 8.2 percent of patients with CAD were overweight, of whom 2.2 percent were obese. CAD was seen in Indians with BMI from 15 kg/m2 onwards. The BMI in the risk factor groups of smoking, diabetes and hypertension was not different when compared to those without the risk factors. However, the BMI was higher in those with a positive family history (p < 0.01). BMI was higher in the businessmen and executives but did not qualify for overweight or obesity group. BMI did not correlate with the various lipid fractions studied. It is concluded, that in Indian patients, angiographically proved coronary artery disease can be seen with low BMI.

Adult↗

Management of infectious waste in the home care setting.

Adaptation of infection control into practical protocol for the home care setting continues to present a challenge for home care nurses. Most information published on the management of infectious waste in home care is based on hospital protocols, and does not apply to home practice. Reasonable practices for disposal of infectious waste are not addressed by any authoritative resources. This presentation will identify principles of infection control, requirements, laws of regulating bodies, and steps that are measured chronologically to write administrative waste control policies.

Centers for Disease Control and Prevention, U.S.↗