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Biomedical subjects

V S Banka

Publications and source records attributed to V S Banka.

At least 19 recordsLinked to original sources
PubMed1992

Effectiveness of decremental diameter balloon catheters (tapered balloon).

Natural tapering of coronary arteries from larger proximal to smaller distal diameters often creates a dilemma for optimal balloon sizing during percutaneous transluminal coronary angioplasty (PTCA). To demonstrate the need for new dilating catheters suitable for tapered coronary anatomy, 100 consecutive coronary arteries were measured by videodensitometry, 1 cm proximal and distal to the stenosis. In 23 arteries there was a 1 mm or greater taper and 19 arteries showed a 0.5 to 0.99 mm taper. Only 50 arteries showed a nearly uniform diameter at the site of the stenosis, and 8 arteries demonstrated reverse taper, i.e., distal was greater than proximal diameter. To avoid balloon size mismatch with significant tapering, decremental diameter balloon catheters were developed. Series I tapers from 3.5 to 3.0 mm and series II from 3.0 to 2.5 mm over a balloon length of 25 mm. Tapered balloons were used in 80 patients with 94 tapered coronary arteries. Before PTCA, proximal, stenotic and distal mean diameters measured 3.6, 1.1 and 2.6 mm, respectively; after PTCA, proximal, stenotic and distal diameters measured 3.6, 2.8 and 2.5 mm, respectively, thus maintaining the natural tapering after effective dilatation. Only 2 arteries (2.1%) showed significant dissection, with no abrupt occlusions, and none requiring bypass surgery. In summary, decremental diameter balloon catheters provide optimal dilation in tapered arterial segments with few complications and offer a new approach to balloon sizing.

Angioplasty, Balloon, Coronary↗
PubMed1992

Coronary artery disease in women. How it is--and isn't--unique.

Various risk factors, such as smoking and diabetes, have an adverse effect on women's inherent biological protection from coronary artery disease (CAD). In women, CAD is most likely to present as angina. Although infarction as the initial event is less common in women than in men, it is more likely to be fatal. The prognosis for women with diabetes and CAD is especially poor. Differences in the therapeutic approach to CAD in men and women do not appear justified. Preventive strategies for women center around cessation of smoking, aspirin therapy, diet modification, and estrogen therapy.

Coronary Disease↗
PubMed1991

Prevention of restenosis by lovastatin after successful coronary angioplasty.

Prevention of restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) remains a major challenge. To determine whether lovastatin could prevent restenosis, between December 1987 and July 1988, a total of 157 patients undergoing successful PTCA were randomly and prospectively assigned to the lovastatin group or a control group. Seventy-nine patients received lovastatin (20 mg daily if the serum cholesterol level was less than 300 mg/dl and 40 mg daily if the serum cholesterol level was greater than or equal to 300 mg/dl) in addition to conventional therapy (lovastatin group). Seventy-eight patients received conventional therapy alone (control group). Fifty patients in the lovastatin group and 29 in the control group were evaluated with coronary angiography at an interval of 2 to 10 months (mean 4 months). The restenosis rate was evaluated according to the number of patients showing restenosis, the number of vessels restenosed, and the number of PTCA sites restenosed. Restenosis was defined as the presence of greater than 50% stenosis of the PTCA site. In the lovastatin group 6 of 50 patients (12%) had restenosis compared with 13 of 29 patients (44.4%) in the control group (p less than 0.001). When the number of vessels restenosed was considered, only 9 of 72 vessels (12.5%) restenosed in the lovastatin group compared with 13 of 34 vessels (38.2%) in the control group (p less than 0.002). Similarly, 10 of 80 (12.5%) PTCA sites restenosed in the lovastatin group compared with 15 of 36 (41.7%) in the control group (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1989

Long-term efficacy of percutaneous transluminal angioplasty on incidence of myocardial infarction, relief of symptoms and survival.

This study was conducted to determine the long-term effects of percutaneous transluminal coronary angioplasty (PTCA) on the incidence of myocardial infarction, survival, and relief of symptoms. A total of 124 patients were included in the study and were followed for 16 to 25 months. The success rate of PTCA was 91.2% and 160 stenoses were dilated. Fifty-nine patients had multivessel disease (MVD) and 54 had single-vessel disease (SVD). There was no difference in survival when patients with SVD were compared with those with MVD. The cardiac survival rate for both groups was greater than 98%. Nine patients had myocardial infarction in the area of the dilated artery: 3 patients (5.5%) with SVD and 6 patients (10.1%) with MVD. Ninety-six patients (84.9%) remained free of symptoms: 46 patients (85.2%) with SVD and 50 patients (84.7%) with MVD. These data demonstrate the long-term efficacy of PTCA in patients with SVD and MVD with regard to control of symptom of angina, improved survival, and prevention of myocardial infarction.

Adult↗
PubMed1987

Type Ia tricuspid atresia with extensive coronary artery abnormalities in a living 22 year old woman.

Type Ia tricuspid atresia, with extensive coronary artery abnormalities, is identified in the oldest living patient with this condition, a 22 year old woman. Clinical characteristics include severe cyanosis, effort dyspnea, myocardial infarction in the past and persistent angina pectoris. "Ideal" pulmonary flow and adequate left ventricular function, despite an akinetic apical segment, are substantive factors for this exceptional longevity. Coronary abnormalities consist of: 1) total proximal occlusion of the left anterior descending coronary artery; and 2) partial diversion of coronary artery flow to a segmental pulmonary artery branch. Nonvisualization of the coronary sinus is also noted. Factors other than atherosclerosis may account for total proximal occlusion of the left anterior descending coronary artery. Survival is threatened by adverse effects of ongoing ischemic coronary events.

Adult↗
PubMed1985

A sequential approach to the diagnosis of coronary artery disease using multivariate analysis.

There has been considerable interest in recent years in enhancing the accuracy of noninvasive tests in diagnosing coronary artery disease. The recognition that no currently available test is a perfect predictor has led to the use of probability analysis as a means of assessing the presence or absence of coronary disease. In this article we present a multivariate approach to the diagnosis of coronary disease. One hundred forty-seven patients undergoing coronary angiography, thallium-201 imaging, and exercise ECG were studied. Patients were classified according to age, sex, and typical vs atypical chest pain. Sequential stepwise logistic regression analysis was performed to develop probability statements prior to testing, after exercise ECG, and after exercise ECG and thallium-201. The results indicate that this sequential approach can be used to develop strategies for the diagnosis of coronary disease in the same way as Bayes' theorem, while permitting integration of multiple characteristics into one model.

Adult↗
PubMed1985

Influence of nitroglycerin on collateral blood flow during acute ischaemia in the dog.

To investigate the effects of nitroglycerin on collateral blood flow 10 open chest dogs underwent coronary occlusion followed by nitroglycerin infusion (80 to 300 micrograms . min-1) to lower mean systemic blood pressure by 20 mmHg, followed by phenylephrine infusion (10 to 40 micrograms . min-1) to restore blood pressure to the pre-nitroglycerin level. Myocardial blood flow was measured with microspheres. The contribution of overlapping normal zone tissue in the ischaemic zone was evaluated with the balloon perfusion technique. Collateral flow was measured with microspheres in the most ischaemic tissue. In addition "load line" analysis was used to calculate collateral flow from retrograde flow. Nitroglycerin lowered blood flow to non-ischaemic tissue, and tended to lower blood flow to ischaemic tissue. Phenylephrine restored blood flow to the value after coronary occlusion. Load line analysis data was similar to data on myocardial blood flow from the microspheres. Collateral resistance changed little during the experiment. Th effects of nitroglycerin on collateral blood flow are, thus, minimal. While it is possible that under special circumstances there may be some decrease in collateral resistance, the bulk of data from this study and others do not support the idea that systemic infusion of nitroglycerin in the setting of an acute myocardial infarction will affect collateral flow.

Animals↗
PubMed1979

Extent and severity of coronary heart disease. Determinations by thallous chloride Tl 201 myocardial perfusion scanning and comparison with stress electrocardiography.

Rest and exercise ECGs are the most widely used "noninvasive" tests for detecting coronary heart disease, but their sensitivity and specificity are suboptimal. Therefore, the diagnostic value of myocardial perfusion scanning using thallous chloride Tl 201 during rest and stress electrocardiography was examined in 95 patients with a chest discomfort syndrome. Overall, thallous chloride Tl 201 perfusion scanning had a sensitivity of 75% and a specificity of 91% for coronary heart disease compared with 56% sensitivity and 86% specificity with exercise-induced ST segment depression on the ECG. Combining rest and stress ECGs resulted in a sensitivity of 71%. In patients with coronary heart disease, perfusion scanning had a sensitivity of 93% for asynergy compared with 58% for exercise-induced ECG ST depression. Rest and stress myocardial perfusion scanning with thallous chloride Tl 201 provides improved sensitivity with good specificity in the diagnosis of coronary heart disease compared with exercise electrocardiography alone.

Arrhythmias, Cardiac↗
PubMed1979

Comparison of wall motion and regional ejection fraction at rest and during isometric exercise: concise communication.

The detection of regional abnormalities of left-ventricular wall motion provides strong evidence for the presence of coronary heart disease. In 129 patients undergoing coronary arteriography, the relative value of radionuclide angiographic assessment of wall motion was compared with computer-generated regional ejection fraction, at rest and during handgrip exercise. Wall motion was determined by superposition of computer-derived end-diastolic and end-systolic perimeters. Relative regional ejection fraction was determined using a computer-generated 16-color isocount image that permitted a quantitative assessment of zonal contribution to ejection fraction. Of the 129 patients, coronary arteries were normal in 31 and diseased in 98. Of 24 patients with single-vessel disease, wall-motion abnormalities were present, at rest or during exercise in 15, whereas regional ejection fraction detected 20 patients. Seventy-four patients had multivessel disease. Of these, wall-motion abnormalities occurred in 52 but regional ejection fraction was abnormal in 69 (p less than .01). Overall, sensitivity was 67% by wall motion and 91% by relative regional ejection fraction (p less than .001). Specificity was 94% by wall motion and 87% by regional ejection fraction (not significant). Thus, radionuclide angiographic assessment of regional ejection fraction during handgrip exercise is both highly sensitive and specific for coronary heart disease and significantly enhances detection of coronary heart disease compared with wall-motion assessment, with little loss in specificity.

Cardiac Output↗
PubMed1978

Ventriculographic-echocardiographic correlation in patients with asynergy.

The ability of echocardiography to detect segmental ventricular asynergy was evaluated in 41 patients before cardiac catheterization. Of 24 normal posterior wall segments by echocardiography, 23 were also normal by ventriculography, while one was hypokinetic. Of 17 asynergic posterior wall segments by echocardiography, 15 were asynergic and two were normal by ventriculography. Posterior wall excursion for the normal group was 1.30 +/- 0.18 cm (SD), while those demonstrating hypokinesis on ventriculography showed an excursion of 1.05 +/- 0.19 cm (P less than .005), and akinetic segments showed an excursion of 0.97 +/- 0.13 cm (P less than .005). In 15 patients, septal motion as determined by echocardiography was compared with the left anterior oblique ventriculogram. Of nine normal septal motions by echocardiography, seven were also normal by left anterior ventriculography (septal excursion, 0.84 +/- 0.25 cm). Of six patients with decreased echocardiographic septal motion, four were normal and two were abnormal by ventriculography. Although normal echocardiographic septal motion correlated well with ventriculography, decreased septal excursion by echocardiography did not.

Cardiac Catheterization↗