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Biomedical subjects

R Balcon

Publications and source records attributed to R Balcon.

At least 55 records · Page 3Linked to original sources
PubMed1982

Isolated disease of left anterior descending coronary artery. Angiocardiographic and clinical study of 218 patients.

The angiocardiographic and clinical findings in 218 patients with significant obstruction confined to the left anterior descending coronary artery were reviewed to study the influence of the site of obstruction and of the collateral circulation on clinical presentation and prognosis. One hundred and fifty-six patients had been managed medically, 51 had had aortocoronary bypass operations, and 11 had had left ventricular aneurysms excised. The artery was divided into three segments: left anterior descending 1 (LAD1) from its origin to the first septal branch, left anterior descending 2 (LAD2) from the first septal to the first diagonal branch, and left anterior descending 3 (LAD3) the remaining distal vessel. Cardiogenic shock occurred only in patients with LAD1 lesions, but apart from this the clinical presentation bore no consistent relation to the site of disease. Patients with proximal lesions were more likely to have a "positive" exercise test, had more severely impaired left ventricular function, and had a worse prognosis than those with more distal disease. Non-visualisation of collateral vessels in patients with left anterior descending occlusion was associated with extensive infarction, and patients who presented with infarction had more severely impaired ventricular function than those who presented with angina and subsequently had an infarction. Left ventricular function was poor at the time of angiography in 11 of 12 of those who subsequently died; it is therefore unlikely that the prognosis of patients with isolated left anterior descending obstruction could be improved by expanding the indication for aortocoronary bypass from that of severe angina.

Adult↗
PubMed1981

Cardiac pain at rest. Management and follow-up of 100 consecutive cases.

One hundred consecutive patients, admitted to the coronary care unit with cardiac pain at rest but no evidence of recent myocardial infarction have been followed up for nine to 26 (mean 14) months. They were treated initially with bed rest, beta-adrenergic blockade, and nitrates. In 54 patients pain subsided within 24 hours. Coronary angiography was carried out in 46. Thirty-five had coronary artery lesions and three had spasm in normal coronary arteries. One had hypertrophic cardiomyopathy and seven had normal findings. Seventeen patients with previous angina and severe coronary disease were operated on, with one death and one perioperative infarction; two died late, 12 were symptom free, and two had angina. Seven of 18 patients treated medically had recurrent angina and underwent operation. Of the 11 unoperated patients, one died, three had angina, and seven were symptom free. Two of the eight patients who were not catheterised developed infarction, four had angina, and three were symptom free. Recurrent pain continued for more than 24 hours in 46 patients, and all underwent angiography. Forty-three had coronary artery disease and 34 underwent early bypass surgery; there were two operative deaths and three perioperative infarctions. Twenty-six symptom free at follow-up. Of the nine unoperated patients with coronary disease, four developed infarction, two were operated on for recurrent angina, two were symptom free, and one had mild angina. Optimal management of patients with pain at rest can be determined only with knowledge of the coronary artery anatomy and of left ventricular function. Many respond initially to intensive medical treatment and coronary angiography can be performed electively. In those with continuing pain, urgent angiography is required and can be done safely.

Adult↗
PubMed1980

Observations on exercise testing and coronary arteriography.

Exercise tests were performed on 551 patients with a clinical diagnosis of coronary artery disease during their admission for angiography. A computer-generated index (CI, 0-100%) was used to describe the coronary anatomy, and additional data on left ventricular contraction abnormalities were recorded. Significant correlations exist between exercise performance and angina grade, coronary pathology, left ventricular function, and prognosis.

Angina Pectoris↗
PubMed1979

Reoperation for recurrent angina.

Forty patients with persistent or recurrent angina after an aortocoronary bypass procedure underwent a second operation. The cause of recurrent angina, defined by angiography, was thought to be isolated graft failure in 13 patients, progression of disease in ungrafted vessels in 4, incomplete revascularisation in 2, and stenoses distal to patent grafts in 1. More than one factor was responsible in 20 patients. There was 1 early postoperative death and 3 perioperative myocardial infarctions. Thirty-four patients have been followed for more than 3 months (4 to 63 months). Of these, 17 had previously bypassed vessels regrafted and 5 are sympton free, 4 have mild angina, and 8 have severe angina. Ten patients had previously ungrafted vessels grafted and 4 are sympton free, 3 have mild angina, 2 have severe angina, and 1 is limited by breathlessness. Seven patients had a combined procedure and 4 are sympton free, 1 has mild angina, and 2 have severe angina. Reoperation can be carried out safely but the results are less satisfactory than for a primary procedure.

Adult↗
PubMed1978

Haemodynamic effects on the myocardial blood flow supply/oxygen demand ratio in pacing induced angina pectoris.

Angina pectoris results from an imbalance between oxygen supply and demand in the subendocardium. The haemodynamic effects contributing to this imbalance have been studied in 10 patients with coronary artery disease. Myocardial oxygen demand was estimated from the tension time index (TTI), potential subendocardial flow from a diastolic pressure time index (DPTI), and the oxygen supply/demand ratio from (DPTI/TTI. With progressively increasing pacing rates up until induction of angina, no significant change in TTI was found whereas a significant fall in DPTI and DPTI/TTI occurred (P less than 0.001). During pacing runs with induction of angina DPTI/TTI reached a minimum value 5 s before,and at the onset of angina. No such relationship was seen for TTI or DPTI alone. A significant rise in LVEDP (P less than 0.05) and fall in dP/dt min (P less than 0.01) occurred at angina both contributing to a further reduction in DPTI and DPTI/TTI. Changes in DPTI/TTI may then reflect changes in the myocardial blood flow supply/oxygen demand ratio in the presence of coronary artery disease and haemodynamic changes before and at the induction of angina lead to a further reduction of this ratio.

Angina Pectoris↗
PubMed1978

A computer generated index for the assessment of coronary angiography.

Mortality in patients with coronary artery disease is related to its severity. The commonly used classification of 1, 2 or 3 vessel disease is relatively insensitive. We have designed a new classification which takes into account site, severity and effect of multiple lesions in the coronary circulation. Data is recorded on Mark Sense computer cards and a coronary index (CI) obtained. We have collected data from 1100 patients and shown correlations of the index with clinical variables, ventricular function and in particular, mortality.

Angina Pectoris↗
PubMed1978

Results of aortocoronary bypass operations. Follow-up in 343 patients.

Three hundred and forty-three patients who had aortocoronary bypass graft operations for disabling angina were followed up for from 6 months to 5 years (average 2 years). 80 per cent had multiple grafts and 20 per cent had additional endarterectomy. The overall mortality within one month of operation was 5 per cent, and in those who had vein graft procedures only was 4 per cent. 11 per cent had a postoperative myocardial infarction (6% perioperative) and there were 3 per cent late deaths. At 3 years 90 per cent are surviving. 80 per cent are asymptomatic without treatment. The mean angina grade was 0.3 at the latest follow-up, compared with 2.5 before operation; maximum exercise tolerance was also significantly improved (P less than 0.001). When angina recurred, it did so in 80 per cent of the cases within 12 months of operation and was usually attributable to inadequate revascularisation. Ventricular function as assessed by preoperative ventriculography was the factor most clearly related to survival rate and the early excellent results of coronary bypass operations seem to be maintained up to 5 years. It is, therefore, reasonable to continue to advise operation if only for relief of angina.

Adult↗
PubMed1978

Angina following aortocoronary bypass surgery.

43 patients (group A) who had a recurrence of angina after aortocoronary bypass surgery were compared with 93 (group AF) who remained symptom free for at least 1 yr in order to assess the effects of pre- and intraoperative factors on the outcome of surgery. Age and sex distribution, severity and duration of preoperative angina, incidence of preoperative infarction, known coronary risk factors and severity of coronary artery disease assessed angiographically, were similar in the 2 groups. Group A had a lower preoperative exercise tolerance (434 V, 517 ppm/min; P less than 0.05) and a greater proportion of patients with cardiac enlargement (33% V, 14%; P less than 0.05). Fewer grafts were implanted in this group (1.65 V, 2.05; P less than 0.01) which consequently had a higher postoperative coronary score (2.47 V, 1.69; P less than 0.05). It appears that the extent of myocardial revascularization may influence the symptomatic result of aortocoronary bypass surgery.

Angina Pectoris↗
PubMed1977

Haemodynamic observations with KO. 1366 (bunitrolol), a new beta-adrenergic blocking agent.

The haemodynamic effects of a new beta-adrenergic blocking agent KO.1366 (bunitrolol) were assessed in 10 males admitted to hospital for investigation of chest pain. Measurements were made at rest, during atrial pacing at 100 beats/min, and during hand grip exercise, before and afterintravenous administration of KO.1366 at a dosage of 0.05 mg/kg body weight. There was a 12% (p less than 0.01) slowing in resting heart rate and alpha 4% (p less than 0.05) slowing in exercise heart rate after drug administration. Resting left ventricular end diastolic pressure rose by 2.2 mm Hg (p less than 0.01) following the drug, but there was no significant change during pacing or exercise. Left ventricular systolic pressure and its first derivative did not change significantly. Cardiac output rose slightly, and stroke volume at rest and during exercise showed a considerable increase. In the dosage used, KO.1366 has an important chronotropic effect on the heart without causing significant myocardial depression.

Adrenergic beta-Antagonists↗
PubMed1976

Effect of isoprenaline and nitroglycerine on pressure time indices and coronary graft blood flow in man.

In five patients studied 1 to 3 d after coronary artery surgery isoprenaline and nitroglycerine have been used to alter the systolic (TTI) and diastolic (DPTI) pressure time indices. A close correlation with the predicted relationship between diastolic coronary graft flow and the DPTI/TTI ratio has been demonstrated during isoprenaline-induced tachycardia. Nitroglycerine reduced diastolic coronary graft resistance and increased the DPTI/TTI ratio, effects which are desirable for the relief of angina.

Adult↗
PubMed1976

Clinical experience with left main coronary artery stenosis.

We report the clinical features and the results of investigation and surgery in 20 patients with significant left main coronary artery stenosis. All had moderate to severe angina; 8 had pain at rest. Three had dyspnoea as a major symptom. The electrocardiogram was abnormal in 17, with evidence of previous myocardial infarction in 10. Of the 11 patients exercised, 8 developed chest pain. Nine patients had a normal left ventriculogram. At coronary angiography all patients had major disease elsewhere in addition to the left main coronary artery stenosis. There were no deaths or major complications associated with this investigation. One patient was unsuitable for surgery because of diffuse left ventricular hypokinesia, one had a fatal myocardial infarction while awaiting operation, and there was one preoperative death. Sixteen of the 17 surgical survivors are free from angina. There has been a significant improvement in the maximum exercise capacity in the 10 patients who had pre- and postoperative exercise tests.

Adult↗
PubMed1976

Surgical treatment of postinfarction left ventricular aneurysm in 32 patients.

Thirty-two patients with large postinfarction left ventricular aneurysms shown at operation to consist of fibrous tissue are reported. All had angina and/or breathlessness, and none had a history of embolism. Thirty were correctly diagnosed by left ventricular cineangiography. Two of the 3 patients with inferior and 1 with an anterior aneurysm had associated ventricular septal defects, and 3 patients with an anterior aneurysm had mitral regurgitation. All had major coronary arterial lesions and 68 per cent had double or triple vessel disease. The aneurysm was excised in all patients; in 15 this was combined with saphenous vein bypass grafting of coronary arteries supplying surviving myocardium, in 3 with closure of a ventricular septal defect, and in 3 with mitral annuloplasty or replacement. Operative mortality was 6-2 per cent, and 79 per cent of the survivors are asymptomatic with average follow-up period of 18 months after operation.

Adult↗
PubMed1975

Coronary arteriographic study of mild angina.

The results of coronary arteriography, exercise, and pacing stress testing in 50 young patients with mild angina are analysed. There was a significant correlation between the results of stress tests and the secerity of disease. There were, however, patients with severe disease and negative tests. Fifty-six per cent of patients had disease which potentially could have been surgically treated. It is concluded that coronary arteriography is indicated in these patients with mild symptoms.

Adult↗