Factors influencing acute high-grade restenosis in emergency percutaneous transluminal coronary angioplasty for acute myocardial infarction.

We studied the factors which may induce acute high grade restenosis in emergency percutaneous transluminal coronary angioplasty (PTCA). PTCA was attempted in 50 patients with acute myocardial infarction, and the balloon catheter passed successfully across the occlusion site in 47 (94%) of the patients. These 47 patients were analyzed. &#34;Acute restenosis&#34; was defined as a lesion which was revascularized to less than 50% luminal reduction narrowed again to more than 75% luminal reduction 5 min after the balloon inflation. Univariate and multivariate analyses were used for determining factors which significantly influenced acute restenosis. The incidence of at least one restenosis episode was 45%. Multiple regression analysis selected 5 factors associated significantly with an increased rate of acute restenosis: 1) angiographic evidence of dissection, 2) lesion in the right coronary artery (RCA), 3) lack of or insufficient administration of thrombolytic agent preceding PTCA, 4) curved lesion and 5) relatively small balloon/artery diameter ratio. Acute restenosis correlated significantly with late reocclusion. This study indicates that it is important to administer a thrombolytic agent prior to emergency PTCA, and to use an adequately sized balloon to the artery when the acute restenosis occurs by using relatively smaller sized balloon. The present data also demonstrated that patients with RCA and a curved lesion have a relatively high risk of acute restenosis. This study indicates how patients with relatively high risk of acute restenosis may be identified.</p

Studies on 24-hour Holter electrocardiography Part I: Bradyarrhythmias and pacemaker indication

Studies of 2216 24-hour Holter electrocardiograms of 1549 patients revealed bradyarrhythmias in 33 cases of advanced atrioventricular block, 169 cases of sick sinus symdrome and 32 cases of atrial fibrillation with slow ventricular response. The underlying diseases were mostly idiopathic, but included ischemic heart diseases and cardiomyopathy as well. The findings of Holter electrocardiography showed a significant difference between the bradyarrhythmia group and control group as to the minimum heart rate, maximum heart rate, the longest ventricular pauses and total number of QRS's during a 24-hour period. There were 55 cases of bradyarrhythmias with longest ventricular pauses of 3.0 seconds or longer. The incidence of atrial fibrillation with slow ventricular response was significantly different from other bradyarrhythmias. There were 64 cases of bradyarrhythmias with the total number of QRS's during a 24-hour period equaling 70,000 beats/day or less. The incidence of sick sinus syndrome group I was significantly different from other bradyarrhythmias. As regards severity of bradyarrhythmias, these two findings were inconsistent. Comparative studies of paced and unpaced groups showed that the patients were older and had more subjective symptoms in the paced group. In all Holter findings, the total number of QRS's during a 24-hour period and the longest ventricular pauses were significantly different from other findings. No correlation was observed between the longest ventricular pauses and the maximum sinus node recovery time (or maximum automaticity recovery time). In consideration of subjective symptoms and underlying diseases, severity and pacemaker indication of bradyarrhythmias should be determined by longest ventricular pauses and total number of QRS's during a 24-hour period shown on 24-hour Holter recordings

Studies on 24-hour Holter electrocardiography Part Ⅱ: Pacemaker function, arrhythmias and hemodynamics of cases with permanent pacemaker implantation

One hundred twenty-four patients with unipolar permanent pacemaker implantation (advanced atrioventricular block, 62 cases; sick sinus syndrome, 51 cases; and atrial fibrillation with slow ventricular response, 11 cases) were studied by 24-hour Holter electrocardiography. Analysis of pacemaker function and arrhythmias with various pacing modes (VVI pacing, 70 cases; AAI pacing, 19 cases; and DDD pacing, 35 cases) and measurement of hemodynamics revealed the following. In all pacing modes, atrial contraction was observed in cases of advanced atrioventricular block. However, in the VVI pacing mode with sick sinus syndrome, atrial contraction was often lost. In sick sinus syndrome group Ⅲ, pacemaker non-mediated arrhythmias were often recorded. Pacing failure was not noted with any atrial or ventricular pacing. Undersensing was observed in 26% of the AAI pacing group and 7% of the VVI pacing group. Myopotential inhibition was observed in 11-24% of all pacing modes, but only two patients complained of subjective symptoms. DDD pacing with atrial sensing yielded effective increase of heart rate, but caused pacemaker tachycardia and pacemaker mediated tachycardia. In making these diagnosis and managing of pacemaker mediated arrhythmias, 24-hour Hotter recordings were the most effective. In comparison of hemodynamics in any pacing mode, physiological pacing was significantly different from VVI pacing as to blood pressure, left atrial pressure and cardiac index. Patients who require improvement of hemodynamics should be treated with physiological pacing. As for the optimal choice of pacing modes, patients with advanced atrioventricular block without underlying disease do not always require physiological pacing. However, the patients with sick sinus syndrome should receive physiological pacing

Wide field-of-view x-ray imaging optical system using grazing-incidence mirrors

A field-curvature-corrected imaging optical system for x-ray microscopy using only grazing-incidence mirrors is proposed. It combines a Wolter type I (WO1) mirror pair, which forms a real image, with field curvature correction (FCC) optics—a convex hyperbolic mirror pair—that form a virtual image; compensation of the field curvatures realizes a wide field-of-view (FOV) and high magnification. Ray-tracing and wave-optics simulations verified the efficacy of the design, for which a FOV width was 111 µm—4.7 times larger than that for the uncorrected WO1 design. The addition of FCC optics also produced a 2.3-fold increase in magnification

Combined resection of lung cancer and invaded aorta with the use of simple temporary bypass : A case reort

Left pneumonectomy and concomitant resection of the invaded aorta were performed by the simple temporary bypass method. The patient was a 59-year-old male with the chief complaint of left thoracic pain. The 57×43×35 mm tumor was in a region centering on segment 6 of the left lung and had infiltrated the descending aorta. It was diagnosed as T4NOMO, Stage IIIb. A bypass for blood flow was established between the aortic arch avobe the invasion and the left femoral artery, after ligation of the pulmonary artery and vein and closure of the left bronchial stump. Vascular blocking forceps were applied to the descending aorta above and below the tumor infiltration, and two thirds of the circumference of the invaded aortic wall, 4.0×3.0 cm, along with the tumor, was resected. Reconstruction was performed with an 18mm Cooly double velour graft. Blood pressure was monitored with a pressure probe inserted into the right femoral artery. It did not fall below 60 mmHg during the operation. Local recurrence was observed 10 montns post-operatively, and the patient is now receiving radiation therapy