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Biomedical subjects

V Wiegand

Publications and source records attributed to V Wiegand.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Short- and long-term results following implantation of the new Wiktor stent in acute coronary occlusion following PTCA].

Ten patients, two women and eight men, were treated with the new balloon-expandable Wiktor Stent for acute coronary occlusion after PTCA. Two patients presented with an acute myocardial infarction. Stents with a diameter of 3.0 or 3.5 mm were implanted into the right coronary artery (n = 7), the left anterior descending (n = 2) artery, and the left circumflex coronary artery (n = 1). Stent implantation in the target segment was successful in all cases. Afterwards, patients received coumadine for 3 months and 100 mg acetylsalicyclic acid per day. We observed one acute occlusion after 8 h. Late occlusion occurred in two patients after cessation of anticoagulation within 3 weeks. Control angiography after 6 months in seven patients revealed stenosis within the stent in two cases.

Aged↗
PubMed1990

[Spontaneous coronary artery dissection: a rare cause of myocardial infarct].

The case of a 52-year-old female is presented who suffered from myocardial infarction with a prolonged course of symptoms. The angiographic examination revealed a spontaneous dissection of the right coronary artery without evidence for atherosclerotic coronary artery disease. Under medical treatment no further complications occurred. Control angiography showed a spontaneous improvement of the dissection. The characteristic clinical features of this case are compared with the literature data on angiographically visualized spontaneous coronary artery dissections.

Aortic Dissection↗
PubMed1990

[Doppler echocardiography evaluation of left ventricular function in intra-aortic balloon counterpulsation].

Doppler-echocardiographic measurement of transaortic and mitral flow allows an assessment of systolic and diastolic left ventricular performance. To evaluate the hemodynamic effects of intra-aortic balloon counterpulsation (IABP) 10 patients were examined during IABP after myocardial infarction or cardiothoracic surgery. Doppler echocardiographic transaortic (VAo), early (VE) and late (VA) transmitral flow velocities, transaortic velocity time integral (VTIAo), acceleration and deceleration intervals and rates were obtained. The IABP augmentation was changed from 1:1, 1:2 to 1:4 causing no notable change in invasively measured arterial pressures (p greater than 0.05). With constant heart rate the VE/VA ratio was similar in 1:2 and 1:1 mode (1.44 +/- 0.42 vs 1.47 +/- 0.27; p greater than 0.2), whereas VAo and VTIAo were increased (p less than 0.01). A beat-to-beat analysis during 1:2 mode confirmed an increase in VAo (84.1 +/- 13.5 vs 98.3 +/- 16.5 cm/s; p less than 0.01) and VTIAo after the augmenting balloon inflation, but did not confirm any concomitant effect on diastolic transmitral parameters; acceleration and deceleration intervals were not changed. Thus, Doppler-echocardiography was able to detect an increase in transaortic flow during IABP augmentation by beat-to-beat analysis. The increase in VTIAo indicates an elevated cardiac output. A similar instantaneous effect on the diastolic transmitral flow could not be identified.

Blood Flow Velocity↗
PubMed1990

[Estimated relation of Doppler echocardiography parameters of diastolic ventricular function and pulmonary capillary pressure in acute ischemia].

A close relation between the Doppler-echocardiographic transmitral flow signal (TMF) and the left ventricular filling pressure in patients with coronary heart disease (CHD) was described in several reports. The present study investigated the validity of this relation during an episode of acute ischemia induced by coronary angioplasty (PTCA) by simultaneous recording of TMF and mean pulmonary capillary wedge pressure (PCm). Thirty-nine patients were examined at rest, and 33 of them were further studied during a subsequent PTCA of the left anterior descending artery (n = 22) or the right coronary artery (n = 11). The onset of ischemia was evaluated by electrocardiography. The Doppler-echocardiographic parameters of diastolic ventricular function were correlated with PCm; the closest correlation was obtained for the relation between PCm and the ratio of the early/atrial velocity integral (Ei/Ai: r = 0.59; p less than 0.0001), and between PCm and the relative share of the early diastolic velocity integral (Ei%: r = 0.58; p less than 0.0001). A wide confidence interval of individual values did not allow a calculation of PCm from Ei/Ai. By a semiquantitative approach an elevated PCm could be estimated from Ei/Ai greater than 1.5 with a high sensitivity (86%) and specificity (81%). During PTCA an increase of PCm was observed (start: 10.2 +/- 4.8; end: 15.0 +/- 6.5; p less than 0.0001), while Ei/Ai decreased slightly (start: 1.37 +/- 0.41; end: 1.27 +/- 0.51; p = 0.32). With increasing duration of inflation, the correlation between PCm and Doppler-echocardiographic parameters was attenuated.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1989

[Acute myocardial infarct caused by nicotine-induced erythrocytosis].

A 29-year-old heavy smoker presented with an acute myocardial infarction and hematocrit of 70%. At immediate coronary angiography a complete occlusion of the right coronary artery was found. After intracoronary urokinase the coronary arteries were found to be completely normal. Causes for the erythrocytosis other than smoking could be excluded. We conclude that thrombotic coronary occlusion with acute myocardial infarction was caused by erythrocytosis due to heavy smoking.

Adult↗
PubMed1989

[Excimer laser angioplasty in arterial obstructive disease. Clinical experience with guidewire-controlled catheter systems].

Percutaneous transluminal laser angioplasties (PTLA) were performed in nine patients (7 males, 2 females, aged 52-81 years) with peripheral vascular disease, stages IIB-IV (Fontaine's classification), with 75% stenosis (5 patients) or occlusion (4 patients) in the area of the superficial femoral artery. Two catheter systems were used. One was a monofiber catheter (600 microns) with eccentric guidewire, the other a multifiber catheter with 12 concentrically arranged fibres (200 microns each) and a central guidewire. An XeCl-excimer laser (308 nm), with a pulse duration of 50 ns and pulse frequency of 15-30 Hz, served as the laser source. It was possible in all patients to reduce the stenosis of 75-100% to 35-70% or reopen the occlusion without laser-associated complications. To remove the residual stenosis PTLA was followed by balloon dilatation in seven patients and by application of a Simpson atherectomy catheter in one patient: these measures reduced the degree of stenosis to 20-40%.

Aged↗
PubMed1989

Beneficial effects of long-term diltiazem treatment in dilated cardiomyopathy.

There is increasing evidence that chronic enhanced exogenous or endogenous catecholamine stimulation in patients with dilated cardiomyopathy may worsen hemodynamic status and prognosis. The cause of this deterioration may lie in myocellular calcium accumulation and microcirculatory disorders. In a prospective study, the calcium channel antagonist diltiazem was given to 22 patients with dilated cardiomyopathy (60 to 90 mg three times daily) in addition to conventional therapy of digitalis, diuretics and vasodilators. Twenty-five patients received the conventional therapy and served as historical controls. Eight additional patients who were not originally included in this control group received adjunctive diltiazem treatment after initially receiving conventional therapy alone. The three patient groups were similar in all hemodynamic and anamnestic features. Only patients with reduced myofibrillar volume fraction on myocardial biopsy were included in the trial, because they could be expected to show hemodynamic deterioration. The mean survival time was 29 months in the control group, whereas no patient in the diltiazem group died over a mean follow-up period of 15.4 months (p less than 0.001). Mean left ventricular ejection fraction increased from 0.34 to 0.44 (p less than 0.001) and New York Heart Association functional class improved significantly in the diltiazem group and during the diltiazem period in the crossover patients, but deteriorated in the control group. The results suggest that adjunctive diltiazem treatment in dilated cardiomyopathy has beneficial effects on mortality, hemodynamics and symptoms.

Adult↗
PubMed1989

Structure and function of contractile proteins in human dilated cardiomyopathy.

The pathogenesis of reduced systolic left ventricular function in dilated cardiomyopathy is yet unclear. To analyze a possible involvement of contractile protein, function and structure of left ventricular myofibrils were examined in hearts of patients with advanced cardiomyopathy undergoing heart transplantation and in normal control hearts (from renal transplant donors). Myosin and actin content of the left ventricular myocardium was slightly reduced in cardiomyopathic hearts. Myofibrillar polypeptide composition was determined using two-dimensional electrophoresis and immunoblotting. No differences in constituting polypeptides were apparent, including Z-line proteins and proteins of the endosarcomeric lattice. M-line-bound creatine kinase was identical in both groups. Further, basal and maximal myofibrillar adenosine triphosphatase (ATPase) activities were unaltered in dilated cardiomyopathy. The structure of purified myosin was identical in both groups by the following criteria: electrophoretic mobility of native myosin, identical pattern of light chains after isoelectric focusing, identical cleavage peptides of myosin's heavy chain, and identical patterns after immunoblotting of heavy chain cleavage peptides using polyclonal antibodies generated against myosin from normal and cardiomyopathic ventricles. Ca2+-activated, K+-EDTA-activated and actin-activated myosin ATPase activities were identical in control and cardiomyopathic hearts. A structural alteration or functional defect of myofibrils does not seem to be primarily involved in the pathogenesis of reduced myocardial contractility in dilated cardiomyopathy.

Actins↗
PubMed1989

Will emergency coronary bypass grafting after failed elective percutaneous transluminal coronary angioplasty prevent myocardial infarction?

An emergency aorto-coronary bypass grafting operation was performed within 12 hours after the development of acute myocardial ischemia due to partial or complete vascular occlusion in 34 of 950 (3.6%) patients who had received elective percutaneous transluminal coronary angioplasty (PTCA). Of the 34 patients, three (= 8.8%) died postoperatively in irreversible cardiogenic shock. Half of the surviving patients developed a Q-wave infarction after the operation, whereas the other half remained without transmural infarct. With comparable clinical data and times of operation up to placement of the aorto-coronary bypass vessel, an adequate residual perfusion must still have been present in the cases with non Q-wave infarction. Since in many cases a myocardial necrosis is unavoidable despite relatively early operative revascularization, the decisive role will be played by the remaining perfusion of the vessel concerned and any collaterals. It follows that treatment of an early PTCA complication, occurring in the catheter laboratory, ought to be the earliest possible aorto-coronary bypass operation unless available cardiological methods can reliably assure reperfusion. Treatment of a PTCA complication occurring later, however, e.g. after hours in the intensive-care unit, should be a repeat PTCA attempt: surgery at this stage will not prevent the transmural infarction but will increase risk of lethal complications.

Adult↗
PubMed1989

Contrary effects of acetylcholine on coronary arteries and aortocoronary venous grafts in man.

The endothelium-dependent vasomotor responses differ in arteries and veins, and the transfer of veins into the arterial circulation by venous grafting may change their endothelial function. The purpose of this study was to examine the responses to acetylcholine in aortocoronary venous grafts of coronary arteries in man which may indicate differences in the endothelial function of these vessels. Five patients with venous grafts (12 to 72 months after implantation) and five patients without any angiographic evidence for coronary artery disease (controls) were examined. The effect of local infusions of acetylcholine (7-70 nmol min-1) on the vessel diameters was assessed by quantitative angiography. In controls, acetylcholine caused no consistent reaction, but in patients with venous grafts the arterial segments distal to the bypass anastomoses were contracted (7 nmol min-1: 82 +/- 2%; P greater than 0.01). We observed that aortocoronary venous grafts reacted differently to acetylcholine compared with the coronary arteries (P less than 0.05): a slight but not significant dilatation of the venous graft occurred (7 nmol min-1: 103 +/- 1%). The contraction of atherosclerotic coronary arteries of patients with aortocoronary venous grafts is in accord with the assumption of a loss of endothelium-dependent vasodilatation in coronary artery disease. The cholinergic influence on the vasomotor control of venous grafts seems to be either of little importance or less affected by atherosclerotic endothelial lesions than in coronary arteries.

Acetylcholine↗
PubMed1989

Effect of intracoronary superoxide dismutase on regional function in stunned myocardium.

This study investigates the ischemic-time dependency of dysfunction in reversibly ischemic myocardium and the effect of postischemic oxygen free radical scavenging thereupon. In open chest pigs, occlusion of the distal left anterior descending coronary artery (LAD) for 4 (n = 5), 8 (n = 5), or 12 min (n = 5) resulted in paradoxical systolic and diastolic regional function, measured by ultrasonic crystals. With onset of reperfusion, systolic shortening (SS) and diastolic lengthening (DL) normalized completely in the 4- and 8-min groups, followed by a significant decrease to 50% control in the 8-min group. In the 12-min group, recovery of SS and DL was only partial. In two further groups, animals received an intracoronary infusion of either recombinant human superoxide dismutase (SOD, n = 6) or placebo (n = 6), starting with reperfusion after an 8-min LAD occlusion. SOD improved recovery of SS compared with placebo (p less than 0.05), but DL and the depression of SS during later reperfusion were not influenced. Mitochondrial function after 90 min of reperfusion was not impaired in ischemic-reperfused compared to control myocardium. We conclude that the degree of postischemic dysfunction increases with the duration of ischemia. Oxygen free radical scavenging by SOD, starting not before reperfusion, fails to prevent myocardial stunning. Mitochondrial function is intact in such myocardium.

Adenosine Diphosphate↗
PubMed1989

[Beneficial long-term effects of diltiazem on the course of dilated cardiomyopathy].

There is increasing evidence that chronic enhanced exogenic or endogenic catecholamine stimulation in patients with dilated cardiomyopathy may worsen hemodynamics and prognosis. The cause of this may lie in myocellular calcium accumulation and microcirculatory disorders. In a prospective study the calcium antagonist diltiazem was given to 22 patients with dilated cardiomyopathy (60-90 mg t.i.d.) in addition to conventional therapy of digitalis, diuretics, and vasodilators. Twenty-five patients received the conventional therapy and served as historical controls. Eight additional patients who were not originally included in the 25 controls changed over from conventional therapy to adjunctive diltiazem treatment. The patient groups compared were similar in all hemodynamic and anamnestic features. Further, only patients with reduced myofibril volume fraction in the myocardial biopsy were included in the trial, since hemodynamic deterioration could be expected in them. The mean survival rate was 29 months in the controls, while within a mean of 15.4 months no patient died in the diltiazem group (p less than 0.001). Mean left ventricular ejection fraction increased from 0.34 to 0.44 (p less than 0.001) and the New York Heart Association classification was significantly improved in the diltiazem group and during the diltiazem period in the crossovers, but deteriorated in the controls. Therefore, the results suggest that adjunctive diltiazem treatment in dilated cardiomyopathy has beneficial effects on letality, hemodynamics, and symptoms.

Adult↗
PubMed1989

[Use of the autoperfusion catheter in acute coronary occlusion within the scope of percutaneous transluminal coronary angioplasty (PTCA)].

The procedure of an autoperfusion catheterization after acute coronary occlusion by dissection during percutaneous transluminal coronary angioplasty (PTCA) is described. Multiple side holes proximal and distal to the dissection allow passive myocardial perfusion only by systemic blood pressure. In the case presented, the catheter immediately reestablished coronary blood flow and thereby produced resolution of symptoms and myocardial ischemia. This easy procedure made it possible to perform the subsequent coronary bypass operation as a controlled revascularization and it prevented myocardial necrosis.

Angioplasty, Balloon↗
PubMed1989

[Excimer laser coronary angioplasty in high-grade stenoses and chronic occlusion].

Excimer-laser-angioplasty offers the advantage of minimal thermal injury to adjacent tissue compared to other laser ablation techniques. Highly flexible glass-fiber-catheter systems are now available, and are capable of transmitting sufficient energy densities to ablate even calcified atherosclerotic coronary plaques. We report initial results of excimer-laser-ablation of severe coronary stenoses and occlusions in 17 patients. An excimer-laser (308 nm) with a pulse duration of 50 ns and a repetition rate of 10 to 40 Hz served as laser source. Eight patients had a chronic total occlusion (RCA, n = 4, RCx, n = 3, LAD, n = 1), nine patients had 90% to 95% stenoses (LAD, n = 7, RCA, n = 2). In all cases a laser-catheter consisting of 17 circumferentially orientated 100 microns glass-fibers and a central 15/1000-inch lumen could be advanced to the stenoses/occlusion over a guidewire that had been passed across the stenoses/occlusion. Stenoses diameter could be reduced by 41.5 +/- 10.1% in all patients and vessel lumen was further increased by subsequent balloon dilatation in 10 cases. After 24 h, 16 vessels were patent and showed no restenoses; one recanalized RCA was found reoccluded. We observed no complications, such as perforation, spasm, or thrombi.

Aged↗
PubMed1988

Coronary arterial embolism due to valvular debris after percutaneous valvuloplasty of calcific mitral stenosis.

A 74-year-old woman with refractory congestive heart failure due to long-standing calcific mitral stenosis who refused surgical intervention was treated with percutaneous balloon valvuloplasty. After an uneventful procedure, hemodynamic results were satisfactory with an increase in the mitral valve area from 0.4 to 1.1 cm2. Five hours after the procedure, the patient had a bout of vomiting followed by pulmonary aspiration. Electrocardiography, and in the further course, creatine kinase MB elevation, showed anterior myocardial infarction. Necropsy disclosed embolic material in the mid left anterior descending artery which unequivocally consisted of valvular material. This case demonstrates embolism of valvular debris as a life-threatening, procedure-related complication of percutaneous valvuloplasty of calcific mitral stenosis.

Aged↗