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Biomedical subjects

P R David

Publications and source records attributed to P R David.

36 records · Page 2Linked to original sources

Failure of diltiazem to prevent restenosis after percutaneous transluminal coronary angioplasty.

This prospective randomized trial was carried out in 92 patients who underwent a successful percutaneous transluminal coronary angioplasty (PTCA) and had no evidence of coronary spasm before PTCA. All patients were premedicated with calcium antagonists and platelet inhibitors and received platelet inhibitors (aspirin and dipyridamole) for 6 months after PTCA. The diltiazem group (46 patients with 50 stenoses successfully dilated) received diltiazem, 90 mg three times a day by mouth for 3 months after PTCA; in the control group (46 patients, 53 stenoses), calcium antagonists were discontinued immediately after PTCA. All patients underwent a control angiogram 5 to 10 months after PTCA unless recurrence of angina dictated its need earlier. Baseline characteristics were similar in both groups, except for the number of diseased vessels greater than or equal to 70%, which was higher in the control group (1.2 +/- 0.55 vs 0.9 +/- 0.39 for the diltiazem group, p less than 0.05). In the diltiazem group, the degree of stenosis increased from 38 +/- 15% immediately after PTCA to 42 +/- 23% at repeat angiography 8.24 +/- 4.79 months after PTCA and there were seven restenoses. In the control group, the degree of stenosis increased from 37 +/- 12% to 44 +/- 23% at repeat angiography 8.26 +/- 4.91 months after PTCA and there were 10 restenoses (NS vs the diltiazem group). In conclusion, in patients without variant angina before PTCA, adjunction of diltiazem to platelet inhibitors does not decrease the incidence of restenosis. These data suggest that coronary spasm is not the major mechanism of restenosis.

Adult↗

Percutaneous transluminal coronary angioplasty for the treatment of variant angina.

Among 268 patients undergoing percutaneous transluminal coronary angioplasty between February 1980 and January 1983, a total of 21 patients had variant angina, documented before angioplasty in 14 and after angioplasty in 7. Before angioplasty, all 21 patients had rest angina and 17 also had effort angina; single vessel coronary artery disease with 60 to 95% stenosis was present in all patients and the left anterior descending coronary artery was involved in all but 3 patients. Coronary angioplasty was successful in 19 patients (90%). Eight of the 19 patients remained symptom-free without coronary restenosis after successful angioplasty; in the other 11 patients, angina reappeared within 4 months, usually in association with restenosis. Of the nine patients with coronary restenosis, six had repeat angioplasty (five successful procedures and one failure), two received medical therapy and one underwent coronary bypass surgery. Patients in whom calcium channel antagonists were discontinued immediately after angioplasty had an exceedingly high coronary restenosis rate (8 [80%] of 10 successful attempts), but when calcium antagonists were continued for an average of 6 +/- 4 months after angioplasty, the restenosis rate was low (3 [21%] of 14 successful attempts). After a mean (+/- SD) follow-up period of 33 +/- 13 months, 1 patient had died and the 20 others (95%) were symptom-free; among these 20, 15 patients (75%) had been taking no antianginal drugs for more than 1 year, 2 still received calcium channel antagonists and 3 had had coronary bypass surgery. Repeat coronary arteriography performed 14 +/- 7 months after angioplasty in the 17 patients without angioplasty-related infarction or surgery showed 50% or less coronary stenosis in 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Clinical and angiographic assessment 6 months after double vessel percutaneous coronary angioplasty.

Percutaneous transluminal coronary angioplasty is an accepted treatment for selected patients with single vessel disease but has not been rigorously evaluated in patients with double vessel disease. Among 769 patients undergoing transluminal coronary angioplasty between 1980 and 1984, 74 with double vessel stenosis of 50% or more underwent double vessel coronary angioplasty. Primary success was obtained for both lesions in 63 patients (85%), for one lesion in 11 patients (15%) and for 137 (93%) of 148 segments overall. Except for myocardial infarction in one patient, no serious complication occurred. Before coronary angioplasty, 15 patients had unstable angina, 14 had Canadian Cardiovascular Society class III and 32 class I to II effort angina and only 2 were asymptomatic. Six months after coronary angioplasty, 27 were asymptomatic, 27 had class I to II and 5 had class III effort angina and 2 had sustained an episode of unstable angina. During the follow-up study, two patients had an infarction and one had coronary artery bypass surgery. Coronary arteriography was performed at a mean of 5.5 +/- 2.1 months after coronary angioplasty in all but three patients. Restenosis was found in 30 (23%) of 132 segments with angiographic control. Restenosis was present in one vessel in 17 patients and in both vessels in 4; 40 patients (66%) had no restenosis. Of the 34 patients with definite or probable angina, 50% had restenosis and 19% of patients with restenosis were symptom free.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Multifocal percutaneous transluminal coronary and aortic angioplasty. Apropos of a case].

The authors report a case of percutaneous transluminal angioplasty performed successfully in 2 stages on the right coronary artery and the abdominal aorta in a woman with a post-infarction angina and intermittent claudication. The invasive and non-invasive control investigations at 6 and 18 months after coronary dilatation confirmed good clinical results and the stability of the excellent result of the immediate postoperative angiographic control. As for the aortic dilation, the persistent functional improvement nearly 2 years later was sufficient evidence of the success of the procedure.

Angina Pectoris↗

Myocardial revascularization after failure of percutaneous transluminal coronary angioplasty.

From 1980 to 1983, 299 procedures for percutaneous transluminal coronary angioplasty were performed in 265 patients. The procedure failed in 88 patients, 72 of whom underwent myocardial revascularization within 1 week following the angioplasty attempt. Operation on an emergency basis was required in 35 patients because of a major complication during or after coronary artery dilatation, whereas the remaining 37 patients underwent elective operation following failure without complication. Coronary occlusion occurred in 23 patients, coronary dissection without occlusion in four, perforation of the coronary artery in one patient, and no visible angiographic changes accounted for the severe myocardial ischemia in the remaining 7 patients. Signs of acute myocardial infarction were present preoperatively in 13 of the 35 patients (37.1%) who underwent emergent operation. Among the factors analyzed, only the absence of collateral circulation and the extent of coronary disease were directly related to the development of complications with percutaneous transluminal coronary angioplasty. There were no early or late deaths in this series. Postoperative complications occurred in seven patients (20%) of the group undergoing emergency operation and in none of the group having elective operation. New postoperative myocardial infarction developed in three patients (8.6%). In six of the 13 patients with preoperative evidence of necrosis, the electrocardiogram returned to normal without other signs of acute infarction after the operation, whereas myocardial infarction was complete in the remaining seven patients. Thus, patients who have complications from percutaneous transluminal coronary angioplasty should undergo immediate operation; for those in whom the procedure fails without complication, surgical treatment can be postponed and performed electively later on if indicated by the clinical incapacity of the patient.

Adult↗

Exercise, electrocardiographic and functional responses after percutaneous transluminal coronary angioplasty.

Exercise testing after successful PTCA showed improved cardiac functional status on examination of electrocardiographic and symptomatic responses, myocardial perfusion and global and regional left ventricular function. Sixty-six patients were studied before and after persistently successful PTCA. Follow-up studies an average of 8 months after the successful procedure showed an incidence of abnormal testing of only 7% using both electrocardiographic and subjective symptomatic criteria during treadmill studies and no abnormal studies with thallium scintigraphy. Radionuclide cineangiography demonstrated similar left ventricular ejection fractions at rest before and after PTCA, but an improvement of 9 +/- 10% (p less than 0.001) in the exercise ejection fraction at follow-up. However, 52% of patients with paired data still had an abnormal radionuclide cineangiographic study after successful PTCA, raising the question of the presence of subclinical ischemia or a false-positive result.

Angioplasty, Balloon↗

[Socioeconomic benefits of coronary dilatation].

The socioeconomic benefits of coronary artery dilatation to the individual and the society in general, were assessed in a review of our first 158 cases in which we studied the length of in-patient treatment, the period off work and the number of patients returning to work after six months and one year. The population included 114 men and 44 women with an average age of 50 +/- 10 years, a history of anginal pain of 18.10 +/- 26.13 months, and of resistant angina of 4.33 +/- 5.72 months. Only one artery was diseased in 130 patients (82%), the remaining patients having multivessel disease. Left ventricular function was normal in 76% of the patients under study. Fifteen patients had already finished working at the time of dilatation and were excluded from the study. One hundred and nineteen (84%) of the 142 patients followed-up were still working before dilatation and 112 (79%) returned to work after 6 months. Of the 94 patients with a good initial result of dilatation, 76 returned to work (81%); 12 initial failures were treated medically, and 6 (50%) returned to work (p less than 0.05); 36 initial failures underwent aorto-coronary bypass surgery and 30.83% are back at work. At one year, 89% of the 103 patients followed-up were working, whilst only 83% of this subgroup were working before dilatation. The 91% of the 69 initial successes have returned to work; 71% of the 7 failures treated medically and 95% of the 27 failures who then underwent bypass surgery, have also returned to work.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Clinical experience with ioxaglate (Hexabrix) in selective coronary arteriography.

This prospective nonrandomized study was performed to evaluate the safety and efficacy of, as well as patient tolerance for, a new low osmolality contrast medium, ioxaglate (Hexabrix), in 90 adult patients of both sexes who were referred to our cardiac catheterization laboratory for angiocardiography including selective coronary arteriography. Ioxaglate did not cause any major adverse effects; side effects were rare and mild. Hemodynamic changes were minimal, even in patients with severe coronary artery disease, and no arrhythmias were seen. The radiographic quality of angiograms was scored as good to excellent for each examination, and was equal to that of films performed using a conventional contrast medium. Ioxaglate may be the contrast medium of choice for angiocardiography, especially in patients at high risk, i.e., those with severe coronary artery disease or severe left ventricular dysfunction.

Adult↗

Symptomatic coronary artery spasm following radiotherapy for Hodgkin's disease.

Four years after mediastinal radiation for Hodgkin's lymphoma, a 32-year-old man developed angina at rest and with varying levels of physical activity. At coronary arteriography, 40 percent to 50 percent stenoses were seen in the left coronary artery; ergonovine induced severe coronary spasm. Treatment with diltiazem eliminated all anginal attacks.

Adult↗

Percutaneous transluminal coronary angioplasty in patients with variant angina.

Among the first 83 patients treated with percutaneous transluminal coronary angioplasty (PTCA) at our institution, typical variant angina was recognized beforehand in five cases and was discovered within 4 months of PTCA in six others. All patients had a 65-95% proximal left anterior descending coronary artery stenosis and only one had a coronary lesion greater than 50% in other coronary arteries. Before PTCA, all patients were premedicated with calcium-antagonist drugs. Thirteen of 15 PTCAs, including three of four repeat PTCAs, were technically successful. However, variant angina recurred after successful PTCA in three of the five patients in whom it was documented beforehand and in an additional two of two patients with variant angina before a successful repeat PTCA. Overall, among the nine patients with variant angina after successful PTCA, five had restenosis at the site of PTCA and two others developed severe lesions adjacent to the site of PTCA within 4 months of the procedure. The three patients without restenosis have been treated with calcium-antagonist drugs from soon after PTCA and have remained angina-free. These results suggest that PTCA is technically feasible in patients with variant angina who have organic lesions, but symptoms due to coronary spasm usually persist or recur, often with restenosis.

Adult↗

Magnitude and distribution of trunk stresses in telecommunications engineers.

The incidence of back injuries has been shown to be greater in occupations as heavy manual work than light manual work. To plan a programme aimed at reducing the incidence of back injuries in industry those workers at high risk of incurring handling accidents and back injuries need to be identified and a knowledge of the specific occupational factors causing such injuries sought. This has been achieved for telecommunications engineers using epidemiological and radio pressure pill methodologies. The results verify the correlation between the back injury rates and physical work stresses of different occupational groups. The magnitude and relative frequency of trunk stresses in hazardous tasks has been determined and compared with those with lower incidences of back disorders. The study has confirmed that in examining manual handling hazards in industrial male populations a critical value of truncal stress can be applied and used to determine the safety of occupational factors in relation to their potential causing or contributing to degenerative back diseases.

Accidents, Occupational↗

Coronary artery disease in young women: clinical and angiographic features and correlation with risk factors.

Coronary arteriography was performed because of suspected coronary disease in 239 women less than 45 years of age. Normal coronary arteries were found in 112 women, and a further 23 had insignificant stenosis (less than 50 percent narrowing of luminal diameter). Of the remaining 104 women, 56 had one vessel, 22 two vessel and 26 three vessel disease. Hyperlipidemia, hypertension, diabetes, smoking and a family history of coronary disease were significantly more frequent in women with significant stenosis than in women with normal arteries. Significant coronary disease was found in 55 percent (100 of 182) of women with more than two risk factors but in only 7 percent (4 of 57) of those with less than two risk factors (P less than 0.0001). Evaluation of symptoms and the resting electrocardiogram also discriminated between women with and without coronary disease, but exercise testing was of little value. Only 4 of the 46 women with previous myocardial infarction had normal or near-normal coronary arteries. Among women with segmental wall motion abnormalities on ventriculography, the site was anterior in 90 percent (19 of 21) of women who used oral contraceptive drugs but in only 60 percent (21 of 35) of nonusers (P less than 0.05). However, in most respects, coronary artery disease in young women does not appear to differ from coronary disease in other patients.

Adult↗