Biomedical subjects
Publications and source records attributed to H S Bush.
Despite isolated reports of myocardial infarction and sudden cardiac death in men taking sildenafil for erectile dysfunction, clinical evidence shows the drug to be safe, effective, and well tolerated in most men with coronary artery disease. Nevertheless, caution is advised in specific instances.
The Greenfield filter is an effective device which provides protection against emboli to the lungs from the deep veins of the lower half of the body. Specific complications, such as perforation, may occur following the placement of caval filters. We report a case of inferior vena cava perforation by a Greenfield filter diagnosed at the time of surgery. With the increasing use of caval filter placement, specific complications such as this will be encountered.
OBJECTIVES: The purpose of this study was to determine whether a low procedural activated coagulation time is associated with a high rate of in-hospital complications and to identify whether there is an activated coagulation time range that may be associated with a low rate of complications. BACKGROUND: In recent years the activated coagulation time has come into widespread use for monitoring anticoagulation in the catheterization laboratory. However, considerable controversy exists as to the standards by which to judge "adequate" anticoagulation for interventional procedures. METHODS: From a total of 1,469 consecutive patients with percutaneous transluminal coronary angioplasty, we retrospectively identified 103 (Group I, 7% of the overall population) with major complications of death or emergency or urgent coronary artery bypass graft surgery and compared them with 400 patients without complications (Group II). Group I patients had more high risk clinical characteristics, such as type B and C lesions, class III and IV angina, recent myocardial infarction and recent thrombolytic treatment. Activated coagulation times were compared between Groups I and II at baseline, after administration of 10,000 U of heparin and at the end of the procedure. RESULTS: There were no differences in baseline activated coagulation times between Groups I and II. Group I had significantly lower activated coagulation times after heparin therapy and at the end of the procedure: 61% < 250 s, 20% between 250 and 275 s, 11% between 275 and 300 s and 8% > 300 s; 279 of Group II had activated coagulation times 27% < 250 s, 17% between 250 and 275 s, 35% between 275 and 300 s and 21% > 300 s (p < 0.0001). Complications occurred in all patients with final activated coagulation times < 250 s but in only 0.3% of patients with final activated coagulation times > 300 s. CONCLUSIONS: A diminished activated coagulation time response to an initial bolus of heparin is associated with major in-hospital complications after coronary angioplasty, although patients with complications did have a higher risk before the procedure. It remains to be determined whether there is an ideal "target" activated coagulation time for interventional procedures.
The accurate assessment of coagulation status is an important part of interventional procedures performed in the cardiac catheterization laboratory. While the traditional clinical means of assessing heparin anticoagulation has been with the activated partial thromboplastin time (APTT), the activated coagulation time (ACT) has come into widespread use in the catheterization laboratory as an assay of whole blood clotting time which can be performed rapidly at the bedside. The purpose of the present study was to (1) assess the anticoagulant effect of a 10,000 U bolus of heparin in PTCA patients and (2) document the relationship between ACTs and APTTs in a subset of these patients. Baseline and postheparin ACTs were measured using a HemoTec coagulation timer in 545 unselected PTCA patients. The average baseline ACT was 120 +/- 22 sec. After a 10,000 U bolus of heparin the average ACT was 249 +/- 44 sec; 58% of patients had an ACT less than 250 sec, 17% had an ACT between 250 and 275 sec, 12% had an ACT between 275 and 300 sec, and 13% had an ACT greater than 300 sec. A total of 175 paired ACT and APTT measurements were obtained in a random subset of these patients at baseline, after heparinization, and at 4-6 hr intervals after the procedure. The APTT was limited by absolute upper and lower limits of 150 and 22 sec; there were no such limits on the ACT. When limiting values were excluded, there was a strong overall correlation between ACT and APTT measurements (r = 0.92, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
The sensitivity of the surface 12-lead electrocardiogram and that of standard (limb-lead) monitoring for the detection of ischemia during percutaneous transluminal coronary angioplasty were compared in 115 patients. The purpose was to identify the electrocardiographic leads that provide the most sensitive indicators of coronary ischemia during percutaneous transaluminal coronary angioplasty and to evaluate the "ischemic fingerprint" that is obtained with 12-lead electrocardiogram during balloon inflation as a predictor of abrupt reocclusion after successful percutaneous transaluminal coronary angioplasty procedures. During balloon inflations of 30 seconds, ischemia was detected in 61 of 145 vessels (42%) by limb-lead monitoring alone versus 130 of 145 vessels (90%) by 12-lead electrocardiography (p less than or equal to 0.001). In the nine patients (7.8%) who experienced abrupt reocclusion within 24 hours, the electrocardiogram during chest pain after percutaneous transaluminal coronary angioplasty was identical to that obtained during percutaneous transaluminal coronary angioplasty ("ischemic fingerprint"). None of the six patients who had chest pain after percutaneous transaluminal coronary angioplasty without evidence of abrupt reocclusion reproduced their ischemic fingerprint. The suggested optimal leads for monitoring ischemia are as follows: left anterior descending coronary artery, V2, and V3; circumflex artery, V2, and V3; and right coronary artery, III and aVF.
The time to systolic murmur peak is a clinical index that is useful in assessing the severity of valvular aortic stenosis. To determine whether phonocardiography could be used to detect a change in the timing of the murmur and thus to measure hemodynamic improvements in elderly balloon aortic valvuloplasty patients, we retrospectively reviewed phonocardiographic tracings of 18 patients taken before and after the procedure. Ten men and 8 women were included in the study; the mean age was 80.7 +/- 11.2 years (range, 64 to 90). Phonocardiographic signals were digitized, and the R-wave to murmur peak interval (R-MP) was measured. In 11 patients, the R-MP decreased (mean decrease, 16% +/- 11%): of these, 10 had a significant (> 25%) decrease in mean gradient; 10 had a significant (> 25%) decrease in peak-to-peak gradient; and the average increase in aortic valve area was 38%. Seven patients had an increase in R-MP (mean increase, 10% +/- 9%): of these, 6 had a decrease in mean gradient of less than 25%; 6 had a decrease in peak-to-peak gradient of less than 25%; and the average increase in aortic valve area was 21%. Pre- and post-balloon aortic valvuloplasty heart rates were not significantly different (71 +/- 8 beats/min versus 73 +/- 5 beats/min). In this study, hemodynamic improvements after valvuloplasty were manifested by a reduction in the R-MP interval. We conclude that phonocardiography may be a practical, noninvasive method of assessing the hemodynamic response to balloon aortic valvuloplasty.
Explore the source record for details and available documents.
To evaluate the effect of balloon aortic valvuloplasty on left ventricular ejection dynamics, simultaneous left ventricular and aortic pressures were obtained by use of a micromanometer catheter in nine patients before and after the procedure. Ejection times, stroke volumes (thermodilution), ejection rates, and pressure gradients were measured. For each parameter, ejection was then divided into two components: accelerative (onset systole to peak gradient) and decelerative (peak gradient to end systole). After valvuloplasty, there was 1) a decrease in overall ejection time and in mean and peak pressure gradients; 2) an increase in overall ejection rate; 3) no change in stroke volume or heart rate; 4) an increase in both accelerative and decelerative ejection rates and a decrease in the decelerative ejection time (expressed as a percentage of the R-R interval); and 5) a decrease in the time for the ejection of the final 25% of stroke volume (P less than 0.01) and time occupied by the final 25% of the gradient. Immediately following balloon aortic valvuloplasty, there is a decrease in ejection time and in increase in ejection rate. Balloon aortic valvuloplasty has a significant effect on the dynamics of left ventricle ejection, with changes primarily expressed in late systole. By improving the mobility of calcified leaflets, balloon aortic valvuloplasty may reduce the forces opposing forward blood movement during the decelerative phase of ejection.
In order to evaluate the effects of balloon aortic valvuloplasty on left ventricular systolic function and ejection dynamics, Doppler echocardiographic studies were performed on 29 patients before and following valvuloplasty. Continuous wave aortic velocity signals were digitized and (with catheterization laboratory before and after valvuloplasty valve areas) were used to calculate: stroke volume; ejection time; ejection rate; time to 25%, 50%, and 75% ejection; accelerative (onset systole to peak velocity) ejection volume, time, and rate; and decelerative (peak velocity to end systole) ejection volume, time, and rate. Following valvuloplasty, there were no significant changes in heart rate; time to 25%, 50%, and 75% ejection; accelerative ejection time; and decelerative ejection time. There were significant increases in stroke volume, total ejection rate, accelerative ejection volume, decelerative ejection volume, accelerative ejection rate, and decelerative ejection rate, and a significant decrease in total ejection time. Balloon aortic valvuloplasty has a significant effect on the dynamics of left ventricular ejection. There is an increase in stroke volume and a decrease in ejection time, with relatively little effect on early systole, and a more pronounced effect in late systole. There are significant increases in accelerative and decelerative ejection volumes and rates, and a decrease in the time required for the last 25% of ejection. By improving the mobility of calcified leaflets, balloon aortic valvuloplasty may reduce the forces opposing forward blood movement during the decelerative phase of aortic ejection.
This report describes the 1st use of percutaneous transluminal coronary angioplasty in a posttransplant patient at the Texas Heart Institute. The patient, a 44-year-old man, experienced 3 episodes of moderate allograft rejection, hypercholesterolemia, transient severe hyperglycemia, and transient severe renal insufficiency in the posttransplant period. His cholesterol levels became elevated immediately and remained between 200 and 250 mg/dL, despite treatment with gemfibrozil. He had increasing lower-extremity claudication that was treated with bilateral femoral-popliteal bypass grafting. At 5-year follow-up, a discrete 75% stenosis was found in the right coronary artery. He was treated successfully with percutaneous transluminal coronary angioplasty on 20 February 1989 and was able to return to work thereafter.
Brachial artery injuries are a well-described complication of cardiac catheterization. Traditional therapy has involved surgical repair. We report a case treated with balloon angioplasty followed by streptokinase. This procedure may provide a treatment alternative in a select group of patients.
The recent approval of tissue plasminogen activator (tPA) by the Food and Drug Administration has opened a new era in the management of acute coronary occlusions. Absolute contraindications are well established. A case of intracranial bleeding as a complication of thrombolytic therapy in an intravenous substance abuser is presented. This may represent a relative contraindication to thrombolytic therapy.
During a four-year period, an instrument to identify stress was developed from items suggested by students from a search of related literature, and from a jury of experts. The 100-item instrument, including four subcategories, was administered to more than 1,200 students at 23 colleges. Means were computed to the total test, subcategories, and individual items according to frequency and intensity. Responses of men and women were sufficiently different to warrant establishing separate means; women scored higher than men. The degree of stress reported by women decreased with each grade level, but peaked in the sophomore year for men and declined thereafter. Academic factors were cited most frequently as a source of stress, while Relationships and Home and Community factors ranked high in stress intensity. The instrument provides a valuable tool to assist students identify factors that could be targeted for stress management. The instrument also could be used as a tool for further stress management research.
Explore the source record for details and available documents.
Explore the source record for details and available documents.