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Biomedical subjects

P Spiller

Publications and source records attributed to P Spiller.

At least 55 records · Page 3Linked to original sources
PubMed1981

[Long-term results of coronary revascularization--clinical, angiographic and hemodynamic findings (author's transl)].

Clinical angiographic, and hemodynamic examinations were performed in 37 patients (mean age 54 +/- 6.5 years) with coronary heart disease 5.4 +/- 5.3 months and 57.0 +/- 15.3 months after coronary revascularisation. The results were compared with those of a preoperatively performed examination (8.1 +/- 5.9 months). Early postoperatively 57 per cent of the patients were free of angina and 32 per cent had marked relief, whereas preoperatively 73 per cent had severe angina (class III and class IV). Late postoperatively 51 per cent had no angina and 49 per cent had only slight or moderate angina. The patency rate of the aorto-coronary bypass grafts was 90 percent early and 83 per cent late postoperatively. Occlusions of the native coronary arteries proximal to the anastomosis were found in 26 per cent preoperatively, in 55 per cent early and in 84 per cent late postoperatively. The parameters of left ventricular function showed no significant alterations early and late postoperatively. The results demonstrate that the relief of angina, the patency rate of the aorto-coronary bypass grafts and the resting function of the left ventricle are approximately unchanged five years after coronary revascularisation.

Adult↗
PubMed1981

[Examination of the effect of aorto-coronary revascularisation by means of exercise tests (author's transl)].

The purpose of this study was to determine the value of exercise tests in the examination of the effect of aorto-coronary revascularisation. 48 patients (mean age 52 +/- 6 years) were examined 5.0 +/- 1.9 months before and 4.9 +/- 3.0 months after coronary revascularisation by means of coronary and left ventricular angiography. Left ventricular function at rest was unchanged. 122 grafts were constructed, the patency rate was 86%. Preoperatively two exercise tests with a bicycle ergometer were performed, some days before angiography and some days before operation, respectively. A third test was performed postoperatively (again some days before angiography). During exercise at identical work load, heart rate and systolic blood pressure did not change significantly pre- and postoperatively. At the second preoperative examination, pulmonary artery pressure (31.6 +/- 11.3 mm Hg) was significantly lower than at the first examination (36.3 +/- 10.8 mm Hg). Postoperatively there was a further decrease of mean pulmonary artery pressure (27.6 +/- 6.5 mm Hg). At the highest work load, mean pulmonary artery pressure was significantly lower at the second preoperative and at the postoperative examination (34.4 +/- 11.6 and 31.3 +/- 8.1 mm Hg versus 39.6 +/- 9.8 mm Hg). The explanation of the preoperative reduction of pulmonary artery pressure is not clear. The pressure decrease must be considered in the examination of the effect of aorto-coronary revascularisation by means of exercise tests.

Coronary Angiography↗
PubMed1981

[Experimental studies of the effects of contrast medium on left ventricular function (author's transl)].

The influence of contrast medium (0.63 ml/kg body weight Natrium-Methylglucamin-Jothalamat, Conray 70) on pressures and volumes of the left ventricle were studied in six anesthetized mongrel dogs (mean body weight 36 +/- 6 kg). Under closed-chest conditions radiopaque markers were implanted into the endocardium of the left ventricle by means of a special catheter via the right carotid artery. The positions of the markers were calibrated in terms of volume by injections of contrast medium during diastole (flow rate 14 ml/s). Thus it was possible to determine left ventricular volumes without additional administration of contrast medium. Before and during injection, volumes determined from the position of the markers and pressure (catheter-tip manometer) were evaluated in each cycle. After injection, the parameters were determined every minute over a period of ten minutes. Immediately after injection of contrast medium there was a short period in which the following parameters changed: decrease of ventricular systolic pressure, of mean aortic pressure, of maximal dp/dt, of minimal dp/dt, and, after a short increase, of enddiastolic pressure. About one minute after the end of injection, the parameters were about the initial values. These transitory changes were explained by the initial negative and vasodilating effect of the contrast medium. The chamber volumes and stroke volume did not change during and after injection. Because of the constant heart rate cardiac output did not change. The ejection fraction was diminished even before injection, no further changes were found. These experimental results show that, even in ventricles with reduced function, contrast medium injected with a slow flow rate during diastole only leads to small and transient changes of left ventricular hemodynamics.

Animals↗
PubMed1981

[Clinical and hemodynamic results in patients with left ventricular aneurysm after surgical therapy (author's transl)].

The clinical and hemodynamic results of 87 patients (average age 49 years, range 22 to 65 years) with left ventricular aneurysm were retrospectively investigated before and after (1-87 months) surgical treatment. 34 patients underwent aneurysmectomy only (group 1), 35 patients additionally underwent coronary revascularisation (group II), and 18 patients underwent--because of findings during operation--coronary revascularisation only (group III). The size of aneurysm was not significantly different in the three groups. Postoperatively it decreased only in groups I and II. The majority of the patients in group I (with predomination of one-vessel disease) had no angina pectoris. There was no significant change early and late (more than 12 months) after the operation. The patients in groups II and III (the majority with multi-vessel disease) showed an improvement of angina pectoris. Preoperatively most of all the patients claimed to have exertional dyspnea. On the whole, there was no significant change after operation. The majority of the patients showed an improvement in their angina pectoris and dyspnea when those symptoms were the major indications for the operation. Heart rate, systolic and end-diastolic pressure in the three groups did not significantly change after the operation. End-diastolic and end-systolic volumes decreased significantly in groups I and II. The ejection fraction increased significantly. In group III these parameters did not change. Circumferential fiber shortening velocity in the residual ventricle significantly increased only in group I. Hemodynamic studies during exercise were performed in total on 32 patients. In group I, there was a significant smaller increase of the mean pulmonary artery pressure, no significant change in groups II and III. At rest, only the patients with aneurysmectomy showed an improvement of the global and residual left ventricular function. The patients with an angiographically presumed aneurysm and viable myocardium found intraoperatively showed no improvement in function at rest or during exercise even after coronary revascularisation. The hospital mortality was 6%. Three patients died during the follow-up period because of ascertained cardiac reasons. The high mortality of non-operated patients with similar clinical and hemodynamic findings as in operated patients warrants an indication for aneurysmectomy without even taking into account the symptomatic and functional improvements.

Adult↗
PubMed1980

[Videodensitometric and electromagnetic flow measurements in aorto coronary bypass grafts (author's transl)].

Electromagnetic flow measurements in aorto coronary bypass grafts and cine angiography were performed simultaneously during bypass surgery. Using the front velocities of injected boli of contrast medium the videodensitometric measurement (QVD) overestimates the electromagnetically measured flow (QEM) systematically about 20% (QVD = 1.26 . QEM = 4 ml/min; Syx = 10.8 ml/min; r = 0.97). During the passage of the front of the contrast medium through the videodensitometric measuring windows, the flow is altered by the injection about + 13.6 ml/min on an average.

Blood Flow Velocity↗
PubMed1980

[Maximum rate of left ventricular volume change--a parameter of ventricular function (author's transl)].

Peak left ventricular ejection rate (dV/dtsyst) and peak left ventricular filling rate (dV/dtdiast) were determined from biplane cineangiographies in patients with normal left ventricular function (n = 8), pressure overload (n = 11), aortic regurgitation (n = 7), mitral regurgitation (n = 9), mitral stenosis (n = 6), hypertrophic obstructive cardiomyopathy (n = 10), congestive cardiomyopathy (n = 9) and coronary heart disease (n = 17). dV/dtsyst (normal 642 +/- 187 ml s-1) was reduced in mitral stenosis (447 +/- 77 ml s-1) and was increased significantly in aortic regurgitation (1085 +/- 162 ml s-1) and mitral regurgitation (744 +/- 232 ml s-1). dV/dtsyst/EDV was correlated linearly with ejection fraction and was reduced significantly in mitral stenosis, aortic and mitral regurgitation, congestive cardiomyopathy and coronary heart disease. Ventricles with pressure overload and coronary heart disease could be separated better from normal ventricles by dV/dstsyst/EDV than by ejection fraction. dV/dtdiast (normal 549 +/- 205 ml s-1) was decreased significantly in mitral stenosis and increased in aortic regurgitation (1141 +/- 557 ml s-1) and mitral regurgitation (946 +/- 349 ml s-1). Peak left ventricular filling rate and diastolic stiffness were correlated by a hyperbolic function. The results show that peak left ventricular ejection and filling rates allow a more detailed analysis of ventricular function than the usually applied parameters. Quantification of the factors which determine the rate of change of left ventricular volume was only partially possible.

Aortic Valve Insufficiency↗
PubMed1979

Flow measurements and simultaneously performed angiography of aorto-coronary bypass grafts during bypass surgery.

The function of aorto-coronary bypass grafts is usually assessed by the run-off, determined from postoperatively performed cineangiograms. The reliability of this method was tested by comparing the electromagnetically measured graft flow with the run-off, qualitatively estimated from cineangiograms. The electromagnetic flow measurements and cineangiography were performed simultaneously during bypass surgery. The run-off was classified by three independent observers into three classes (poor, moderate, and good). The average mean flow rates corresponding to the three classes were: poor: Q = (43 +/- 11)ml/min; moderate: Q = (48 +/- 14)ml/min; good; Q = (63 +/- 22)ml/min. Although the differences between the flow rates of the three classes were found significant (except between poor and moderate run-off), there was a wide range of overlapping. Especially in grafts with low flow rates (Q less than 70 ml/min) there were pronounced disagreements between the qualitative estimation of flow and the electromagnetically measured flow. Using videodensitometric flow measurements as a check test, the uncertainties in classification proved to be caused by the lack of reliability of the observer. The flow rates in aorto-coronary bypass grafts can be determined reliably only by means of quantitative methods, e.g., electromagnetic or videodensitometric flow measurements.

Angiography↗
PubMed1979

[Ventricular and myocardial function in mitral regurgitation (author's transl)].

Left ventricular and myocardial performance were analyzed in 9 patients with chronic volume overload by mitral regurgitation from biplane cineventriculograms, simultaneous pressure recordings and cardiac output (thermodilution method) determinations. In spite of a considerable regurgitant fraction (49 +/- 17% of total stroke volume) cardiac index on the average is normal (CI = 3.3 +/- 0.7 l . min-1). The main compensatory mechanism to maintain cardiac ouput in hypertorphy (WED = 1.1 +/- 0.2 cm; LVMI = 216 +/- 62 g . m-2; LVMI/EDVI = 1.3 +/- 0.3 g . ml-1) and dilatation (EDVI = 163 +/- 37 ml . m-2). An increase of preload is of minor importance (PLVED = 15 +/- 7 mmHg; sigma ED = (40 +/- 19) x 10(3) dyn . cm-2). Left ventricular enlargement and wall mass are related to the degree of clinical heart failure (NYHA). Enddiastolic volume on the average is more increased than total stroke volume (89 +/- 31 ml . m-2). Ejection fraction (EF = 54 +/- 7%) was depressed despite a normal afterload (sigma tej = (171 +/- 37 x 10(3) dyn. cm-2; sigma max = (247 +/- 48 x 10(3) dyn . cm-2). The reduced ejection fraction and diminished myocardial power are related to an impairment of myocardial function (VMW . sigma tej = (83 +/- 39) x 10(3) dyn . cm-2 . s-1; VMW . sigma tej/ln sigma ED = 7.9 +/- 3.6 x 10(3) dyn . cm-2 . s-1). In comparable degrees of heart failure myocardial function is more compromised in patients with mitral than with aortic regurgitation.

Adult↗
PubMed1979

[Ventricular and myocardial function in aortic regurgitation (author's transl)].

The influence of chronic volume load on ventricular function and myocardial load and shortening was investigated in 10 patients with chronic aortic regurgitation by means of biplane ventriculography and simultaneous pressure measurements. The regurgitant fraction was 63 +/- 15 per cent. Enddiastolic volume (EDVI 227 +/- 37 ml/m2), systolic (161 +/- 18 mm Hg) and enddiastolic ventricular pressure (30 +/- 12 mm Hg) were elevated, ejection fraction was reduced (54 +/- 7 per cent). Myocardial mass related to EDV was normal (1.2 +/- 0.2 g/ml). Contractility as measured from dp/dt max (1736 +/- 492 mm Hg s-1) and dp/dtmax/PI (22.2 +/- 4.3 s-1) was slightly reduced. Mean velocity of equatorial midwall fiber shortening VMW 0.45 +/- 0.13 cir X s-1) was significantly diminished, equatorial midwall fiber stress during ejection (sigma tej 267 +/- 44.5 X 10(3) dyn X cm-2) was elevated. In spite of a very high enddiastolic stress (sigma ED 96 +/- 36 X 10(3) dyn X cm-2) mean systolic power (sigma tej X VMX 123 +/- 43.2 X 10(3) dyn X cm-2 X s-1) was normal. Compensation of chronic volume load in aortic regurgitation is not compensated by an increased contractility but by ventricular enlargement and a pronouned increase in preload. Myocardial load and shortening in chronic aortic regurgitation are altered in the same way (increased stress and reduced shortening) as in chronic pressure overload.

Adult↗
PubMed1978

[Results of endarterectomy in coronary artery surgery (author's transl)].

In a series of 432 aortocoronary bypass procedures endarterectomies were performed in 58 patients (13.4%) on 60 coronary arteries. Except of two vein patch grafts all endarterectomized arteries were bypassed with a saphenous vein graft. The majority of the patients had an endarterectomy of the right coronary artery. Clinical control investigations were performed in 43 out of 47 survivors including 30 with coronary angiograms 5.2 months (mean) after surgery. 26 out of 31 endarterectomized arteries (83.9%) were open angiographically whereas the patency rate to non-endarterectomized arteries of the same patients was 86.4%. The hospital mortality was high; 11 out of 58 patients (19%) deceased. All patients who died postoperatively had a three vessel disease with diffuse coronary sclerosis. Only three had no myodardial infarction prior to surgery, seven had one to four infarctions before surgery. The relatively high mortality intends for the future a more strict revision of the indications for coronary surgical procedures. But not in all cases the preoperative coronary angiograms and ventriculograms allow a clear estimation of the local arterial conditions.

Coronary Artery Bypass↗
PubMed1978

[Correction of left coronary artery to pulmonary artery fistula on the occasion of pulmonary embolectomy (author's transl)].

In a 42 year old woman a left coronary artery to pulmonary artery fistula was proved by catheterization and coronary angiography. During this investigations a right femoral hernia became symptomatic, and surgical correction was carried out. Three days postoperatively a massive pulmonary embolism occurred causing shock and fibrillation of the heart. After intubation the patient was brought to the operating theatre under external massage, and a pulmonary embolectomy using ECC was performed. The fistula in the main pulmonary artery was closed by suture. The vascular convolute was left in place. A primarily additional ligature of the fistula artery at the starting point was reopened because of a failing right ventricle under the assumption of a possible partial vascular supply of the right ventricular myocardium which could not be proved.

Adult↗