PURPOSE: To investigate the neointimal response to poly(organo)phosphazene- and amphiphilic polyurethane-coated, oversized, stainless steel stents implanted in porcine peripheral arteries. METHODS: Nonarticulated, stainless steel, slotted-tube stents were coated with 1) a biodegradable poly-(organo)phosphazene with aminoacid ester side groups and 2) a biostable polyurethane prepared from an amphiphilic polyether, diphenyl methane-4,4'-diisocyanate and butane diol as chain extender. The stents were deployed in porcine peripheral arteries using an oversized balloon. RESULTS: The neonintimal response to amphiphilic polyurethane-coated stents was similar to the uncoated metallic stents. Poly(organo)phosphazene-coated stents, however, induced a severe histiolymphocytic and fibromuscular reaction resembling a foreign body reaction. CONCLUSIONS: Amphiphilic polyurethane is very promising as a biocompatible stent coating. Poly-(organo)phosphazene, however, appears unsuitable for this purpose.

Angioplasty, Balloon↗

PubMedDate not supplied

Right atrial tumor arising on an atrial septal aneurysm. Assessment by MR imaging.

An elderly women presenting with transient ischemic events underwent transesophageal echocardiography, which detected an aneurysm of the interatrial septum. A tumor protruding from the right atrial aspect of the aneurysm also was found incidentally. Not only was magnetic resonance (MRI) imaging helpful in better characterizing the aneurysm, but also the use of gadolinium diethylaminetriamine pentaacetic acid permitted differentiation between the tumor and adherent thrombus. To the best of our knowledge, this represents the first report of a tumor arising from an atrial septal aneurysm.

Aged↗

PubMedDate not supplied

Diagnostic value of transesophageal echocardiography in platypnea.

Platypnea is a rare syndrome of orthostatic dyspnea frequently caused by an interatrial right-to-left shunt. The diagnosis is difficult. Assessment of arterial blood gases reveals orthostatic desaturation. In the past, definite diagnosis necessitated catheterization in the supine and upright position. Now transesophageal echocardiography on a tilt table combined with a peripheral venous contrast study provides correct diagnosis in a safe and easy way.

Aged↗

PubMedDate not supplied

Assessment of the optimal atrioventricular delay in dual chamber-paced patients by a portable scintillation probe (VEST).

BACKGROUND: The optimal atrioventricular delay in dual-chamber pacing differs from patient to patient. The availability of a portable scintillation probe (VEST) enables noninvasive monitoring of left ventricular function. METHODS AND RESULTS: Hemodynamic variations were measured in 10 patients with programmable DDD pacemakers. The ejection fraction, stroke volume, and diastolic and systolic volume were evaluated, programming six different atrioventricular delays ranging from 75 to 200 msec, to determine the most favorable atrioventricular delay. Comparing left ventricular ejection fraction (LVEF), stroke volume, and end-diastolic and end-systolic volume at each DVI mode with a preceding DVI setting of 75 msec, all parameters at 200 msec were statistically different from those at 100 msec. An increase of LVEF and stroke volume and a decrease of end-systolic volume was found. In only five patients a switch of VVI mode to the optimal DVI mode results in an increase of LVEF of more than 5%. CONCLUSIONS: Our study stresses the importance of optimizing atrioventricular delay. The VEST system permits these measurements, increasing the accuracy of the determination of optimal atrioventricular delay, and appears to be valuable in the management of patients with cardiac dual-chamber pacemakers.

Aged↗

PubMedDate not supplied

Ischemic and reperfusive release of the endogenous purines and its influence on the myocardial viability during beta-adrenergic blockade.

The aim of this study was to estimate ischemic and reperfusive release of myocardial adenosine degradation products (MADP) during beta-adrenergic blockade and its relation to infarct size (IS) and viable myocardium size (VM). In a group of 24 shepherd-mongrel dogs, randomly assigned to a metoprolol (M-) and placebo-group (P-group), occlusion of the left anterior descending coronary artery (LAD) followed by reperfusion with recombinant tissue plasminogen activator was performed. Regional myocardial blood flow (MBF) was measured by the radiolabelled microsphere technique. Blood samples from aorta and great cardiac vein were collected to evaluate the concentrations of MADP. The triphenyltetrazolium chloride perfusion and fixation technique was used for infarct size measurement. MBF in the area at risk decreased in both groups during ischemia, but it was significantly higher (p = 0.013) in M-group. Recanalization of LAD was associated with an increase in flow in postischemic vascular bed. MBF was significantly higher (p = 0.024) in P-group during late reperfusion. In M-group IS was smaller (p = 0.007) and VM was bigger (p = 0.007). The correlation between arterial adenosine concentration during early reperfusion and IS (p = 0.044, r = -0.588) or VM (p = 0.036, r = 0.607) in M-group was noted. Values of net MADP balances significantly increased during early reperfusion. The correlation between reperfusive net MADP balance and IS (p = 0.00005, r = 0.906) or VM (p = 0.016, r = -0.675) in M-group was observed. The amount of MADP released during reperfusion correlates with the IS and is inversely proportional to the area of VM. The endogenously released adenosine may have additional cardioprotective effect during beta-adrenergic blockade.

Adenosine↗

PubMedDate not supplied

Surgical treatment of acute, massive lung embolism. Results and follow-up.

Between 1970 and 1984 the diagnosis of acute, massive lung embolism was made 30 times in our department. In 29 patients the clinical diagnosis was correct and a Trendelenburg operation under extra-corporeal circulation was performed. In 18 cases there was an operation in the immediate preoperative course. In 1 case there was a combination of operation and the use of contraceptives. 3 cases were immobilized by a plaster of Paris cast. In 4 cases the use of oral contraceptives and in 3 patients the history of chronic recurrent lung embolism were evident. The mean immobilisation time was 15 days. In 24 cases the diagnosis was made only on the base of the clinical anamnesis, and examination, E.C.G. and chest radiography. In 4 cases angiography and in 1 patient the scintigraphy confirmed the diagnosis. Preoperatively 28 patients were in severe shock. One patient was operated electively. 14 patients needed external cardiac massage. In all cases clots were found in the left pulmonary artery, 28 in the right pulmonary artery, in 3 cases clots in the right atrium, 3 in the right ventricle and three in the inferior caval vein. Nine De Weese caval vein clips were inserted and one Mobin-Uddin filter. Postoperatively 18 patients were alive and well without sequelae. Two patients developed a cerebro-vascular accident (CVA) with one complete recovery. Ten patients died. Postoperative treatment consisted of I.V. heparin administration immediately after surgery and 6 months of oral anticoagulants. Except for chronic recurrent lung embolism the pulmonary function tests were excellent postoperatively without recurrence of the disease.

Acute Disease↗

PubMedDate not supplied

Indications for surgical treatment of left ventricular aneurysm.

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Angina Pectoris↗

PubMedDate not supplied

The influence of automatic vascular suturing and arterio-venous shunting on the patency of small dacron grafts in dogs.

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Angiography↗

PubMedDate not supplied

Dobutamine stress echocardiography after heart transplantation.

Dobutamine stress echocardiography was performed in 28 heart transplant recipients to study its value in the detection and staging of transplant vasculopathy. Fourteen patients had angiographic evidence of coronary artery disease (group 1), and 14 had angiographically normal coronary arteries (group 2). The dobutamine stress protocol called for a dose increase of dobutamine every 3 minutes until the age-predicted maximal heart rate was achieved. In groups 1 and 2, the mean maximal dose of dobutamine was, respectively, 24 +/- 9 micrograms/kg min and 29 +/- 8 micrograms/kg min, and the mean rate-pressure product was, respectively, 12386 +/- 1777 mm Hg/min and 10753 +/- 1085 mm Hg/min at rest, increasing to 20987 +/- 4020 mm Hg/min and 19795 +/- 2728 mm Hg/min at maximal dose. No patient in group 1 or 2 had deterioration of global or regional wall motion under dobutamine stress. In group 1, seven patients had wall motion abnormalities at rest, normalizing in five of them under dobutamine stress. In group 2, four patients had wall motion abnormalities at rest, normalizing in all patients under dobutamine stress. Consequently, this protocol of dobutamine stress echocardiography is unsuitable for the early detection of transplant vasculopathy despite its proven value in the general population. Conversely, these data suggest that the functional sequelae of transplant vasculopathy are not necessarily prominent, despite the known angiographic underestimation of the extent of the disease.

Blood Pressure↗