Biomedical subjects

C Landou

Publications and source records attributed to C Landou.

31 records · Page 2Linked to original sources

PubMed1982

Reconstruction of the anomalous left coronary artery within the main pulmonary artery.

Successful reconstruction of the anomalous origin of the left coronary artery from the pulmonary artery was performed in a 27-year-old man. A patch of glutaraldehyde-treated bovine pericardium was used to construct a tunnel within the main pulmonary artery, connecting a created aortopulmonary window to the ostium of the left coronary artery. Angiography one month after the operation demonstrated patency of the tunnel. The procedure is suitable when direct re-implantation of the left coronary artery into the aorta is impossible for technical reasons.

Adult↗

PubMed1981

Post exercise T wave changes in patients with normal and abnormal coronary arteriogram.

The pre- and postexercise ECGs of those with normal (n = 15) and those with abnormal (n = 66) coronary arteriogram (diameter reduction greater than or equal 50% regarded as significant) were compared in a series of 81 patients with effort angina. ECGs with other known causes of ST-T changes had been excluded. The ECGs 2 and 4 min after a bicycle exercise test were studied for an abnormal ST reaction, and the change in the T wave amplitude in lead V2 from before to 2 min after exercise was measured when there was no q wave, QS complex or negative T at rest in this lead. None of the 15 patients in the normal arteriogram group had abnormal ST reaction post exercise and 1 of 13 evaluable ECGs showed a reduction of T in V2 greater than or equal to 20%. In the abnormal arteriogram group, 37 of the 66 patients had an abnormal reaction and 17 of the remaining 26 evaluable ECGs showed a reduction of T in V2 greater than or equal to 20%. The sensitivity of an abnormal ST reaction for significant coronary obstructions was 56% at specificity of 100%. Addition of an alternative criterion of a reduction of the T amplitude in lead V2 greater than or equal to 20% from before to 2 min post exercise increased the sensitivity to 82% and decreased the specificity to 92%. Thus, it seems worthwhile to study the T V2 reaction in angina patients who do not show an abnormal ST reaction post exercise.

Adult↗

PubMed1981

Indications for the internal mammary artery graft.

Experience of 285 internal mammary artery (IMA) grafts inserted during a five-year period disclosed an operative mortality of 1.5% when patients with associated procedures were excluded. Two of nine patients undergoing concomitant intracardiac surgery died within one month. Thus the overall operative mortality was 2.1%. Preoperative IMA graft blood flow was significantly less than that through comparable aortocoronary saphenous vein grafts. Early IMA graft patency (two weeks) was 95% and the cumulative late patency (one year) was 91%. Early patency for IMA grafts with peroperative flow less than 20 ml was 70%. None of these grafts were occluded at late follow-up. Sixteen occluded IMA grafts were related to technical problems (six grafts), inadequate graft size (five), extensive disease of the recipient coronary artery (four) and to overestimated proximal stenosis with large competitive flow enhancing early graft failure (one graft). Retrograde filing of the IMA when contrast was injected into the recipient coronary artery, was observed in 7 patients (3%). Probable causes were proximal stenosis of the graft, small sized IMA with inadequate antegrade flow and overestimated proximal coronary obstruction. Prerequisites for performing optimal IMA grafting need pre- and peroperative caution. A good calibre IMA without proximal obstructions must be available. The technique of dissecting and handling the vessel and performing anastomosis must be careful. The recipient coronary artery should be selected with consideration in order to avoid unfavourable demand-supply ratios. The IMA is most suitable for low-flow situations supplying a small amount fo myocardium distal to a high-grade coronary obstruction.

Adult↗

PubMed1981

Early and late patency of aortocoronary vein grafts.

Early patency (two weeks) of 331 aortocoronary vein grafts was 89%. Late patency (one year) of 122 restudied grafts was 80%. A cumulative one year patency of 72% was calculated. Patency was similar for SV grafts, sutured distal to stenosis and segmental obstruction. Early patency was significantly decreased when the peroperative graft blood flow was 20 ml/min or less or the diameter of the recipient coronary artery was smaller than 1.5 mm. Cumulative one year patency was lower in symptomatic patients (54%) than in those who underwent consecutive reevaluation (80%). There was a trend towards improved patency rates for graft anastomosed to the left anterior descending coronary artery and grafts without pre-existing pathological changes. Patient parameters, such as at operation, sex, smoking habits, hypertension, lipid abnormalities, diabetes, previous myocardial infarction or depressed left ventricular function, had no bearing on patency. Graft failure occurring, despite refined surgical technique, is usually due to pathological changes of the vein graft per se or the recipient coronary artery and its vascular bed.

Adult↗

PubMed1981

Angiographic changes in internal mammary artery and saphenous vein grafts, two weeks, one year and five years after coronary bypass surgery.

Coronary angiography was performed two weeks after coronary bypass surgery on 112/121 consecutive operative survivors (93%), on 97/119 one-year survivors (82%) and on 79/108 five-year survivors (73%). Occlusions of the grafts were uncommon after the first year. The cumulative five-year patency, calculated with the actuarial method, was 89% for internal mammary artery (IMA) grafts and 77% for aortocoronary saphenous vein (SV) grafts. Almost 70% of the SV grafts exhibited a 15-50% reduced diameter after one year and 10% showed progressive narrowing at five years. Diffuse luminal narrowing did not predict graft failure. The incidence of localized narrowings present at two weeks after surgery was, however, significantly higher among SV grafts, which occluded within one year, than among those patent after five years. In 5% of the IMA grafts the diameter was reduced 15-80% after five years. This was related either to obstruction at the anastomotic site or to low-grade proximal coronary stenosis. No less than 12% of the IMA grafts increased 20-50% in diameter as an adaptation to good distal runoff.

Adult↗

PubMed1981

Exercise tolerance five years after coronary bypass surgery in relation to clinical and angiographic findings.

Exercise on a bicycle ergometer was used to assess symptom-limited working capacity (Wsl) five years after coronary bypass surgery. Ninety-six patients were evaluated with a sitting bicycle test using 10 Watt increments of work load every minute from an initial load of 10 Watt. Ninety-three per cent had less symptoms than before surgery and 32% said they had no angina. Angina was provoked at exercise in 1/31 asymptomatic patients (3%) and in 46/65 (71%) of those with residual symptoms. The Wsl of 50-250 Watt (mean 143 Watt) in a asymptomatic patients was significant higher than 30-220 Watt (mean 105 Watt) performed by patients with residual angina. In 61 patients, exercise tests were performed before, one year and five years after the operation. Average Wsl was significantly higher after one year (127; 36 Watt) than before surgery (90; 23 Watt). but declined significantly until the five-year evaluation (113; 37 Watt). After one year 82% had a higher Wsl than prior to operation compared to 69% five years after surgery. Angiography five years after surgery revealed that 60/76 subjects (79%) had all grafts patent and 16/76 (21%) one or more grafts occluded. In spite of one or more grafts occluded. 2/16 patients (13%) were asymptomatic, whereas 25/60 (42%) with all grafts patent were free from symptoms. Average Wsl was significantly higher in patient with all grafts patent (130; 44 Watt) compared to patients with one or more grafts occluded (102; 33 Watt). It is concluded that although subjective improvement after coronary bypass surgery persisted in about 90% of the patients for five years, bicycle exercise tests show a significant decline of Wsl after the first year, but five years after surgery was still better than before the operation.

Adult↗

PubMed1981

Changes in coronary artery disease five years after coronary bypass surgery.

Seventy-nine patients underwent repeat coronary angiographies five years after coronary bypass surgery. Ninety-eight of 122 inserted grafts (80%) were patent. Significant coronary obstruction (greater than 50% reduction of luminal diameter) developed in 43/79 patients (54%) and was associated with a longer duration of angina before surgery and a lower diastolic blood pressure at the five-year follow-up, but significantly related to such factors as age, sex, type of angina, previous myocardial infarction, hypertension, hyperlipaemia, diabetes or smoking. The total number of significant obstructions increased from 230 to 308 (34%). Progression of pre-existing changes to occlusion was common and the number of occlusions increased 95% in non-grafted arteries compared with 48% in grafted arteries until the five-year evaluation. Fifty-seven of 81 new significant obstructions (70%) were found in non-grafted coronary arteries. The proximal part of the right coronary artery was most commonly affected with 19/57 (33%) of these new obstructions. A significant stenosis regressed in three patients. At the five-year follow up, 74/79 patients (94%) had less symptoms than before operation and 27/79 patients (34%) were asymptomatic. Nine patients had no angina, despite non-bypassed significant obstructions. All grafts were patent in 25/27 asymptomatic patients (93%) and in 38/52 (73%) of those with angina. Two patients had no anginal symptoms, despite occluded grafts. One had sustained a myocardial infarction and the other had symptoms of left ventricular failure. Well-developed collateral vessels were observed in 15/27 asymptomatic patients (56%) and in 45/52 (87%) of those with angina. Recurrence of symptoms was related to progressive coronary disease, graft occlusions, obstruction of anastomoses, non-bypassed obstruction or combinations of these changes.

Adult↗

PubMed1980

Exercise electrocardiogram in patients with normal and abnormal coronary arteriogram.

The predictability of normal and significantly abnormal coronary arteriogram from history, symptoms during exercise test and post exercise ECG changes was examined in seventy patients with chest pain consistent with effort angina. The combined criteria (1) increasing chest pain until interruption of the exercise test plus (2a) appearance or increase of a biphasic T wave post exercise or (2b) a previous acute myocardial infarction, were found to have a sensitivity of 81% and a specificity of 94%. Substituting ST depression for the T wave criterion did not increase either figure, nor did adding ST depression as an alternative criterion to the T was biphasicity. As inspecting the T wave configuration is simpler than measuring the ST depression, T biphasicity seems to be an alternative to ST depression. The only factor found in all patients with abnormal coronary arteriogram was chest pain increasing continuously during the exercise test until its interruption. The pain pattern occurred only in 71% of patients with normal arteriogram, and thus the absence of this pain pattern may be used to avoid some normal coronary arteriographies.

Adult↗

PubMed1980

Left ventricular pump function before and after aortocoronary bypass surgery.

Ten patients with severe effort angina and with left ventricular dysfunction during exercise before operation underwent haemodynamic and angiographic studies in average 20 months after coronary artery bypass surgery. Five patients (50%) were completely asymptomatic after operation(group I). The other five (group II) were still limited physically because of anginal pain, although two were much improved. Pre-operatively there was no significant difference in the severity of the disease, as judged from case histories, work tests and haemodynamic and angiographic findings between the two groups. The working capacity of the patients in group II was not increased significantly post-operatively. Their coronary arteriograms revealed unsatisfactory surgical results. In two patients, one significantly stenosed vessel was not bypassed because of poor run-off. In the other three patients, one graft was closed. Left ventricular function curves showed no significant improvement of left ventricular pump function. In group I, working capacity increased significantly, all stenoses of major coronary vessels were bypassed and all grafts were patent. Left ventricular function showed an almost normal response during exercise. These findings suggest that left ventricular dysfunction due to ischaemia can be significantly improved by coronary bypass and that there is a good correlation between clinical, haemodynamic and angiographic findings.

Aged↗

PubMed1980

Late thrombotic malfunction of the Björk-Shiley tilting disc valve in the tricuspid position. Principles for recognition and management.

Among 52 consecutive patients surviving tricuspid valve replacement with the Björk-Shiley tilting disc valve, follow-up extends between 1/2-9 years, mean 4.9 years. Four patients suffered thrombotic obstruction of their tricuspid prosthesis on 8 occasions, an incidence of 3.2%/year. Ebstein's anomaly and deficient anticoagulation were identified as likely contributory factors, but the complication remained unexplained in 2/8 instances. Thrombotic malfunction of the tricuspid prosthesis seems to constitute a relatively benign clinical entity with mild manifestations and diagnostic possibilities by non-invasive methods. Relief by means of thrombolytic treatment in the form of streptokinase (Kabikinase) (4) or replacement of the clotted prosthesis (4) involved neither disabling complications nor mortality. Our clinical observations and experimental studies suggest that thrombolytic therapy is effective, provided that prosthetic malfunction is due to a recent red clot, whereas encapsulation of the prosthetic disc by organized white-grey pannus necessitates re-operation. Streptokinase treatment should be attempted before surgery, but it is hardly meaningful to proceed for more than 24 hours. Restored prosthetic function within this time limit indicates the likely resolution of a red clot.

Angiocardiography↗

PubMed1979

Coronary artery spasm--a case with fatal outcome.

The case of a 45-year-old man with nocturnal angina and angiographically verified spontaneous spasm of the left anterior descending and left circumflex coronary arteries is described. The patient died suddenly one month after investigation, despite treatment with a beta-blocker and nitroglycerin. Other forms of pharmacological treatment should be tried in such patients.

Angina Pectoris↗

PubMedDate not supplied

High density lipoproteins and coronary atherosclerosis. A strong inverse relation with the largest particles is confined to normotriglyceridemic patients.

The relations of high density lipoprotein (HDL) subclasses to severity and rate of progression of coronary atherosclerosis were investigated in 60 men who had survived a myocardial infarction before the age of 45 years and who had subsequently undergone two coronary angiographies, with an intervening time interval of 4-7 years between angiographies. Five HDL subclasses with different particle sizes were determined by gradient gel electrophoresis, and the major serum lipoprotein classes were separated by preparative ultracentrifugation in connection with the second angiography. Highly significant inverse correlations were found between the plasma levels of the largest HDL particles, the HDL2b subclass, and both disease severity as observed on the second coronary angiogram (r = -0.53, p less than 0.001) and progression of coronary lesions between angiographies (r = -0.38, p less than 0.01). Grouping the patients according to the presence or absence of very low density lipoprotein (VLDL) triglyceride elevation revealed striking differences in the relations of HDL subspecies to coronary atherosclerosis between normotriglyceridemic and hypertriglyceridemic subjects. There were strong inverse correlations between the plasma HDL2b concentration and both severity of lesions (r = -0.72, p less than 0.001) and rate of lesion progression (r = -0.58, p less than 0.01) in the normotriglyceridemic patients, whereas this relation was absent in subjects with hypertriglyceridemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Polar presentation of coronary angiography and thallium-201 single photon emission computed tomography. A method for comparing anatomic and pathologic findings in coronary angiography with isotope distribution in thallium-201 myocardial SPECT.

Individual results of coronary angiography were compared with tomographic myocardial scintigraphy (SPECT) in 99 patients. Coronary angiography findings were transferred to polar maps. Borders between arteries were assigned angles in a coordinate system constructed as a compass-rose. Areas perfused by different arteries were described by sectors. Findings were visually compared with the perfusion defects in a polar presentation of thallium-201 SPECT also described by angles. The mean values and SD for the angles representing arterial borders and perfusion defects were presented. The left ventricular myocardium was perfused by 3 coronary arteries in 92/99 patients. Dominant left artery was present in 7/99 patients; 79 perfusion defects were related to 118 arterial sectors 84 per cent had totally or partially matched stenotic arteries. Inter-individual differences in distribution of coronary arteries influence the localization of perfusion defects in myocardial SPECT and can be estimated with this polar presentation method.

Adolescent↗