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Biomedical subjects

H Blanke

Publications and source records attributed to H Blanke.

At least 73 records · Page 4Linked to original sources
PubMed1980

Combined medical and surgical procedure in acute myocardial infarction--a preliminary report.

The purpose of this investigation was to evaluate a new therapeutic approach, by which acutely ischemic human myocardium could be reperfused. The procedure was as follows: intracoronary application of nitroglycerine, intraluminal recanalization by catheters and intracoronary application of streptokinase. Before and after these interventions coronary angiograms were made. Surgical coronary revascularization was performed 1--64 days after reestablishment of flow through the occluded vessels. Seven patients with acute myocardial infarction were treated in this manner. The mean preoperation ejection fraction was 48.6%, the mean enddiastolic pressure was 17.5 mmHg and the mean maximal CPK activity was 616 units/liter (u/l). By the conservative regimen outlined, reopening of the occluded vessels was achieved in all cases. Critical stenoses of 80--85%, however, persisted. But, reperfusion appeared sufficient since in none of the patients hemorrhagic myocarditis was produced intra-operatively. There was no hospital mortality. The mean post-operative ejection fraction was 60% and the mean enddiastolic pressure was 10.6 mmHg. It is concluded that ischemic myocardium can be reperfused by the active conservative regime tested. Emergency revascularization performed after induced reperfusion appears to carry a low operative risk.

Aged↗
PubMed1980

Recanalization of an acutely occluded aortocoronary bypass by intragraft fibrinolysis.

Acute thrombotic occlusion of an aortocoronary bypass graft to the left anterior descending coronary artery (LAD) was successfully dissolved by selective infusion of streptokinase into the graft at 2000 U/min for 1 hour via catheter. There was partial recanalization of the graft and complete filling of the LAD within 15 minutes. After 1 hour of lysis, the graft was completely patent, although high-degree narrowing at the site of the proximal anastomosis was still present. Follow-up angiography 16 days later revealed persistent patency of the graft and disappearance of narrowing at the site of proximal anastomosis. The relatively low total dose of streptokinase (140,000 U) did not result in a systemic hyperlytic state. There were no complications. The technique may prove useful in acute graft occlusion but needs further evaluation.

Acute Disease↗
PubMed1980

[Myocardial scintigraphy with thallium-201 for evaluation of the patency of aorto-coronary bypasses in multiple vessel disease and multiple bypasses (author's transl)].

The reliability of myocardial scintigraphy with thallium-201 in evaluating the patency of aorto-coronary bypasses was examined. In addition to coronary angiography and ventriculography in 16 patients (42 stenosed vessels, 36 bypasses of which 22 were patent) quantitative myocardial scintigraphy was performed after maximum exercise and at rest, pre- and postoperatively. In general, 12 patients with postoperatively improved angina showed an improvement in their scintigram. The analysis of myocardial areas with a bypass showed a decrease of thallium uptake at rest in 39%, regardless of patency occlusion of the bypass. In 85% of these regions an increased thallium uptake was seen after exercise, again independent of the function of the bypass. The data show that myocardial scintigraphy with thallium-201 cannot be utilized in patients with multiple vessel disease and multiple bypasses to evaluate the patency of a particular bypass, but a general assessment is possible, whether myocardial perfusion has improved.

Adult↗
PubMed1980

Right ventricular function at rest and during exercise in patients with coronary heart disease.

Biplane cineventriculograms of the right ventricle at rest and during exercise were made of 16 patients with a right coronary artery stenosis of greater than 50% and less than 90% to explain the alteration of the volumes and function of the right ventricle during exercise-induced angina pectoris. The right ventricular enddiastolic volume increases from 113 +/- 6.6 ml/m2 to 133.9 +/- 9.8 ml/m2 (P less than 0.001). The endsystolic volume increases from 48.9 +/- 4.1 ml/m2 to 52.9 +/- 5.3 ml/m2. The stroke volume index increases from 64 +/- 5.5 ml/m2 to 81 +/-8.3 ml/m2 (P less than 0.001). At the same time the ejection fraction increases from 56.5 +/- 2.9% to 60.2 +/- 3.2% (P less than 0.05). The left ventricular enddiastolic pressure increases from 12.8 +/- 1.5 mm Hg to 26.6 +/- 1.6 mm Hg (P less than 0.001). The enddiastolic pressure of the right ventricle increases from 5.8 +/- 0.5 to 12.2 +/- 0.8 mm Hg (P less than 0.001). The mean velocity of diameter shortening, VD, increases from 0.9 +/- 0.06 D/s to 1.12 +/- 0.09 D/s (P less than 0.05). Exercise-induced angina pectoris leads to a considerable increase of the left ventricular enddiastolic pressure and therefore to an increase of the right ventricular afterload. The increase of afterload in patients with a right coronary artery stenosis is compensated by a considerable increase of the enddiastolic volume: the pump-function during exercise-induced angina pectoris is maintained by an increase of preload.

Angina Pectoris↗
PubMed1980

Comparison of nineteen quantitative models for assessment of localized left ventricular wall motion abnormalities.

The usefulness of 19 models (8 of half-axis models, 3 radial models, and 8 segmental area models) for detection of local left ventricular wall motion abnormalities was analyzed in biplane cineventriculograms of 14 normals, 12 patients with anteroseptal, 10 with inferior, and 8 with posterolateral infarction. Extent of shortening of 22 half-axes and decrease of 24 areas were calculated in each projection. Mean values and one-sigma deviation were calculated for all axes in the group of normals and for those axes which pertained to segments of myocardial infarction in the group of coronary artery disease patients. Area model 3.5 yielded the largest number of significantly different areas between normal and infarcted ventricles. Sensitivity for recognition of myocardial infarction was calculated at 90% specificity by means of receiver operating characteristic curves. The greatest sensitivities were obtained with radial model 2.3, which yielded 83.3% true positive results for anteroseptal infarction, 90% for inferior infarction, and 87.5% for posterolateral infarctions. The best area model 3.5 yielded sensitivity between 67.5 and 80% only. Thus, in contrast to the literature, receiver operating characteristic analysis revealed radial model 2.3 to be most accurate in the assessment of local wall motion abnormalities.

Coronary Disease↗
PubMed1980

[Results of quantitative myocardial scintigraphy with thallium-201 at rest and after maximum exercise--critical analysis of predictive value and clinical application (author's transl)].

In 20 normal individuals and 60 patients with CAD, myocardial scintigraphy with thallium-201 was performed after maximum exercise and two hours later at rest. The evaluation of digitized scintigrams was performed quantitatively by means of a 14-halfsegment model. Using ROC analysis, sensitivity and specificity were estimated. Furthermore the predictive value of a thallium scintigram was evaluated by means of the bayesian theorem, comparing the data with coronary angiography and partly also with exercise ventriculography. At a specificity of 90%, sensitivity of scintigraphy for CAD was 97% in 34 patients with previous myocardial infarction and 85% in 26 patients without infarction. Sensitivity for the extent of CAD was 93% for 44 vessels, perfusing infarcted myocardium and 67% for 96 vessels, perfusing non-infarcted myocardium. Sensitivity decreased with increasing extent of CAD and was higher for Cx than for LAD. The predictive value of a positive or negative scintigram was analyzed for different prevalences of CAD. At a low prevalence, e.g. 5%, the predictive value of a pathological scintigram is only 32%, consequently thallium scintigraphy is not applicable as a general screening procedure. At a high prevalence, e.g. 90%, the predictive value of a normal scintigram is only 40%. Therefore thallium scintigraphy seems not to be able to differentiate whether a coronary artery stenosis is hemodynamically significant or not. This was in agreement with the data from exercise cineventriculography. A high predictive value of thallium scintigraphy of about 85% is obtained only in the case of a medium prevalence of CAD, e.g. in asymptomatic patients with pathological Ecg or in patients with atypical angina pectoris. An improvement of the predictive value of myocardial scintigraphy would require other radionuclides than thallium-201, to use higher activities and to allow Ecg-gated myocardial scintigraphy.

Adult↗
PubMed1980

[Reduction in cardiotoxicity of ionic contrast media used in coronary angiography by added calcium--Clinical study (author's transl)].

In 16 patients with CAD, hemodynamic and electrophysiologic side effects were examined following selective coronary artery injections with Urografin 76%, a commonly used ionic contrast medium. A Millar transducer tipped catheter was placed in the left ventricle for continuous pressure recording also during injections. The unmodified contrast medium decreases peak left ventricular pressure (-22 +/- 8%) and dp/dt max (-27 +/- 13%) markedly at injection. With added calcium (22.5 mEq/l) this cardiodepressive reaction becomes diminished to -15 +/- 7% and -13 +/- 8% respectively with high significance (p < 0.001). This positive effect is even more marked using higher volumes of contrast material for injection. In contrast to animal experiments, calcium did not completely compensate the negative inotropic reaction even in higher concentration (33.75 mEq/l). The marked sinus slowing (-29 +/- 14%)--observed in patients and not influenced by the calcium addition--has an additional effect in the sense of a "negative frequency-inotropism" and is responsible for the residual cardiodepressive reaction. An influence on electrophysiologic side reactions can also be observed with added calcium but only in injections with higher volumes of contrast medium. QT-elongation, T-wave changes are reduced significantly. We did not see any unfavorable reactions caused by added calcium. The cardiodepressive side effects on the contractile force by commonly used ionic contrast media can be reduced by adding calcium in the above-mentioned concentration. This may be helpful when studying high risk patients and using high injection volumes.

Adult↗
PubMed1980

[Quantitative Tl-201 scintigraphy in diagnosis of severity and location of coronary artery disease. Comparison of a Tl-score to invasive and non-invasive parameters (author's transl)].

Thallium-201 scintigraphy was performed in 20 normals and 60 patients (pts) with angiographically proven coronary artery disease (CAD) at rest after maximal exercise for evaluation of severity and location of CAD. The Tl-scintigrams were quantified by a Tl-score. The results of the Tl-score were compared with invasive and non-invasive parameters. Sensitivity asnd specificity of the Tl-score in evaluation of CAD was 90%. In normals, there were no significant differences from rest to exercise (Tl-score less than or equal to 1.2). Twenty-six of the pts with CAD, who had no evidence of myocardial infarction, showed a significant increase of Tl-score from 5.0 +/- 1.7 to 8.7 +/- 2.6 after exercise (p < 0.001). In 34 pts with CAD and a history of MI, Tl-score increased from 24.9 +/- 3.1 to 33.3 +/- 3.8 (p < 0.001). Exercised-induced ischemia was assessed by exercise electrocardiography in 48%, by Tl-score in 62% and by angina pectoris in 77%. In 37 pts, the Tl-score was compared with the coronary score, ejection fraction (EF) and local wall motion derived from biplane cineventriculograms. There was a significant correlation between the Tl-score and the EF: y = 79.13 - 1.11 x, n = 74, r = 0.688 (p < 0.001). No correlation was found between the coronary score and the Tl-score. Hypokinetic wall motion disturbances were assessed by Tl-score in 34% only, whereas akinesia and dyskinesia were detected in 86% (p < 0.001). The data suggest that Tl-scintigraphy even with a quantitative Tl-score is not sufficient for exact assessment of extent and severity of CAD.

Adult↗
PubMed1980

[Qualitative and semi-quantitative analysis of local wall motion abnormalities by gated-blood-pool in comparison to biplane cineventriculography (author's transl)].

Left ventricular wall motion at rest was assessed by the following three methods in 37 patients of whom 12 patients had coronary artery lesions of > 75% and Ecg-signs of transmural MI: A) qualitative analysis of GBP, B) semi-quantitative analysis of GBP, C) qualitative analysis of a biplane cineventriculogram. Sensitivity and specificity of each method were evaluated based on the cineventriculographic findings. Specificity of method A was 83%, of method B 100%. Sensitivity of method A was 88%, of method B 84%. Concordance of methods B and C was 92.8% (167/180 left ventricular segments). Discordance between the two methods was found only in 1 segment judged to be akinetic and in 12 segments judged to be hypokinetic by one of the two methods.

Adult↗
PubMed1979

[Reopening of infarct-occluded vessel by transluminal recanalisation and intracoronary streptokinase application (author's transl)].

Coronary angiography was performed 2 hours after onset of complaints in a 57-year-old patient with acute anteroseptal infarction. Using a wire spiral in the coronary catheter the acutely occluded anterior interventricular branch was reopened. With intracoronary streptokinase (120 000 units in 50 minutes) the recanalisation canal was enlarged. The clinical picture and electrocardiographic findings improved under the influence of treatment. An aorto-coronary bypass operation was performed on the following day. The post-operative angiogram showed marked improvement of left ventricular function. The results indicate that this intervention prevented widespread necrosis.

Angiography↗
PubMed1979

[Recanalization by catheter of the occluded artery after acute myocardial infarction (transluminal recanalization (author's transl)].

Using guide-wires and special catheters the occluded infarct-related coronary artery was recanalized in 10 patients with acute myocardial infarction 6.6 +/- 7.1 hours after the onset of symptoms. There were no complications. Immediately after recanalization there were 80-95% lesions at the site of the previous occlusion. Angiography, performed in 9 patients in the chronic stage of myocardial infarction, revealed patency of the recanalized vessel in all instances. There was a marked decrease in the narrowing at the time of the second angiogram in 6 patients. Changes in left ventricular function from the acute to the chronic stage were assessed in 8 patients: the ejection fraction increased in 6. The results of this pilot study indicate that transluminal recanalization of acutely occluded coronary arteries is possible without harmful side-effects. Early restoration of flow may salvage the jeopardized myocardium. Further application of this method of treatment in selected patients and efforts to improve the technique seem to be justified.

Adult↗
PubMed1979

Initial experience with transluminal recanalization of the recently occluded infarct-related coronary artery in acute myocardial infarction -- comparison with conventionally treated patients.

In 7 patients, the recently occluded infarct-related vessel was recanalized by transluminal catheter techniques during acute myocardial infarction (Group A). 4 patients had single-vessel disease, 2 patients two-vessels disease and one, involvement of three vessels. Control angiography was performed in 6 patients, 8 days to 7 months later. Changes of coronary artery anatomy and left ventricular function were compared with a group of 9 conventionally treated patients, who were found to have occlusion of the infarct-related vessel in the acute stage (Group B). Five Group B patients had one-vessel disease, 3 patients two-vessel disease and 1 patient, involvement of all three vessels. In the chronic stage, all transluminally recanalized vessels were found to be patent in Group A. There was spontaneous recanalization of the infarct vessel in 4 of 9 Group B patients. In Group A, the length of the akinetic segment (AKS) decreased significantly (p less than 0.05) from 145.4 +/- 48.5 mm to 73.2 +/- 73.4 mm (mean +/- SD). Volume parameters did not change significantly. In Group B, length of the AKS did not change significantly, EDVI increased significantly from 81.1 +/- 19.8 to 106.8 +/- 4.6 ml/m2 (p less than 0.05); ESVI increased significantly from 41.7 +/- 13.7; ml/m2 to 66.8 +/- 37.9 ml/m2 (p less than 0.01). In the acute stage, length of the AKS and volume parameters did not differ significantly between the two groups. In the chronic stage, AKS was significantly shorter (A: 73.2 +/- 63.4 mm; 144.9 +/- 59 mm (p less than 0.0025) and EF was significantly higher (A: 54.6 +/- 11.6%; B: 40.9 +/- 14.5% (p less than 0.05) in Group A. Peak CPK was lower in Group A (A: 1009 +/- 827 U/l; B: 1324 +/- 655 U/l), but this difference did not achieve statistical significance. Results of this pilot study suggest that transluminal recanalization in the early phases of acute myocardial infarction might result in limitation of myocardial injury. However, further research will be needed to improve the technique and to test its results.

Adult↗
PubMed1979

Acute myocardial infarction: intracoronary application of nitroglycerin and streptokinase.

In five patients with acute myocardial infarction, the effects of both intracoronary nitroglycerin (NTG) and subsequent intracoronary streptokinase application were evaluated. In addition, transluminal recanalization was performed in one of these patients. Injection of NTG into the infarct-related coronary artery resulted in improved distal filling of the subtotally occluded left circumflex artery in one patient, and in transient patency of the completely occluded right coronary artery in a second patient. In a third patient patency of the totally occluded left anterior descending artery (LAD) was achieved by transluminal recanalization with a guide wire. In a forth patient with occulsion of the LAD, there was no response to intracoronary NTG and mechanical recanalization was not attempted. Subsequent intracoronary infusion of streptokinase (1,000--2,000 U/min for 15--60 min) resulted in a further and long-term reduction of narrowing at the site of acute occlusion in patients I-III and in opening of the completely occluded LAD in patient IV. Improvement of lumen was paralleled by alleviation of symptoms. In a fifth patient, in whom the LAD was subtotally occluded, the degree of coronary obstruction could not be changed by intracoronary application of NTG or by lysis. In this patient, symptoms and ECG changes improved with reduction of pathologically elevated blood pressure values. The findings suggest that myocardial infarction had been caused by thrombotic occulsion in four patients, and that spasm of the infarct vessel could have been an additional factor in two of these patients. In the fifth patient, an increase of afterload in the presence of a subtotal lesion might have caused the critical imbalance between oxgen supply and demand, resulting in cell death.

Cardiac Catheterization↗
PubMed1979

[The right ventricle at rest and during exercise. I. Pump-function of the normal right ventricle (author's transl)].

Right ventricular volumes and function were assessed by biplane cincventriculography at rest and during exercise in 7 normals. Simultaneously pressure in the left ventricle was measured. 1. Stroke volume index of the right ventricle increased from (x +/- SEM) 46.8 +/- R.R ml/m2 at rest to 66.8 +/- 5.5 ml/m2 (p less than .05) during exercise. Ejection fraction increased from 56.4 +/- 3 to 70.3 +/- 3.7% (p less than .02). Enddiastolic volume increased from 82 +/- 5.8 to 95 +/- 7 ml/m2. Enddiastolic right ventricular pressure increased from 5. +/- .8 to 8 +/- 1 mm Hg (p less than .05). Increase of R.V. stroke volume during exercise is achieved at least in part by increased fiber stretch. 2. Endsystolic volume decreased from 36 +/- 3.2 to 28 +/- 4 ml/m2 (p less than .02). Right ventricular mean velocity of diameter shortening (VD) increased from 1.2 +/- .08 to 1.65 +/- .14 D/s (p less than .05). Decrease of endsystolic volume may be caused by decrease of afterload or increase of contractility. Our data do not enable evaluation of these mechanisms.

Blood Pressure↗
PubMed1979

[Quantitative exercise scintigraphy of the myocardium with 201Tl--methods and normal values (author's transl)].

Quantitative myocardial scintigraphy was performed in 20 normal individuals after maximum exercise and after two hours of rest. A mobile Anger camera with converging collimator and a Data-General computer with a 128 x 128 matrix were used. Quantitative analysis of data was performed on the basis of a 14-halfsegment model. Quantitative normal values after exercise and after redistribution of activity during rest are presented.

Adult↗