Biomedical subjects

A K Jacobs

Publications and source records attributed to A K Jacobs.

62 records · Page 4Linked to original sources

PubMed1991

Atypical MRI findings of venous sinus thrombosis in pregnancy: clinical significance relating to episodic vascular headache.

Two cases of headache during pregnancy were associated with MRI findings suggestive of venous sinus thrombosis. The findings, however, were atypical, and of uncertain clinical significance. Venous sinus thrombosis typically does not occur during the first and second trimesters (less than 10 percent of reported cases). Thus, these two cases are doubly unusual. The correct significance of these equivocal MRI findings of possible venous sinus thrombosis must be understood so that unnecessary and potentially harmful therapies are not employed, and so that appropriate management of what may otherwise be a typical vascular headache syndrome may be undertaken.

Adult↗

PubMed1990

Dynamic arm exercise during cardiac catheterization in the assessment of stenotic valvular disease.

Assessment of hemodynamic responses during some form of exertion or stress during cardiac catheterization is useful among patients suspected of having valvular stenosis who demonstrate normal or borderline valve gradients at rest. Leg raising exercise and drug administration are commonly used for this purpose, but each has inherent limitations. To evaluate the usefulness of dynamic arm raising exercise as a means of altering hemodynamics during cardiac catheterization, 23 such patients were studied. Measurements obtained during arm raising exercise were compared with those at rest. Heart rate rose by 34 +/- 4 beats/min (p less than 0.001), while cardiac output increased by 1.4 +/- 0.2 l/min (p less than 0.001). Stroke volume decreased slightly, although left ventricular filling pressures and pulmonary capillary wedge pressures rose in nearly all subjects. The change in valvular gradients was variable. These data were compared with those obtained in 11 similar patients receiving either dopamine or isoproterenol as an intervention. The changes in heart rate and cardiac output from the resting state were similar between the groups, with fewer side effects occurring during arm exercise. Dynamic arm exercise is a safe and effective maneuver which can be performed during cardiac catheterization in patients undergoing diagnostic evaluation of stenotic valvular disease.

Adult↗

PubMed1990

Long-term outcome of patients after percutaneous transluminal coronary angioplasty.

The efficacy of percutaneous transluminal coronary angioplasty (PTCA) in relieving symptoms of coronary artery disease is well established, and the technique has become widely used in patients with multivessel as well as single-vessel disease. The technique has only recently been widely applied, and long-term outcome is, therefore, not well defined. Studies of patients who underwent the procedure early in its development were primarily of patients with single-vessel disease. These studies demonstrated low mortality (1%/yr) and nonfatal myocardial infarction (MI) rates (1-3%/yr), with a majority of patients (85-90%) clinically improved after 5 years. More recent studies of patients with multivessel disease demonstrate higher mortality (2-4%/yr) and a similar incidence of nonfatal MI (2-3%/yr), with improvement in symptoms in the majority (70-80%). The degree of revascularization can be an important factor in symptomatic improvement as well as in the need for subsequent revascularization. A favorable outcome is most likely when all lesions attempted with PTCA are reduced by at least 20% and no significant residual lesions remain in any proximal vessels. The efficacy of PTCA as compared with bypass surgery in patients with multivessel disease is uncertain. The results of several large ongoing and planned clinical trials should provide the information necessary to more fully understand the use of angioplasty in this setting. Although no study has directly compared PTCA with coronary artery bypass surgery, nonrandomized comparisons indicate similar long-term outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗

PubMed1989

Factors predicting recurrent restenosis after percutaneous transluminal coronary balloon angioplasty.

To identify factors that predict a second restenosis after repeat percutaneous transluminal coronary balloon angioplasty (PTCA), the records of 196 consecutive patients undergoing redilation for treatment of a first restenosis were reviewed. Repeat PTCA was successful in 181 (92%) of these patients. After a successful second PTCA, 47 patients (26%) developed a second restenosis (recurrent restenosis group, group 1) and 134 (single restenosis group, group 2) did not. The 2 patient groups were compared with respect to clinical, angiographic and procedural factors at second PTCA. Univariate correlates of a second restenosis were younger age (54 +/- 10 vs 57 +/- 9 years, p less than 0.05), interval less than 60 days between initial PTCA and recurrence of anginal symptoms (55% of patients in group 1 vs 25% in group 2, p = 0.001), a greater number of inflations (6.3 +/- 4.2 vs 4.4 +/- 2.5, p less than 0.005) and a shorter maximal balloon inflation time (49 +/- 26 vs 69 +/- 36 seconds, p = 0.0006). With multivariate analysis, the 2 factors that emerged as independent predictors of recurrent restenosis were recurrence of symptoms less than 60 days after initial PTCA (p less than 0.004) and a greater number of inflations (p less than 0.04). These data suggest that younger age and rapid recurrence of anginal symptoms after first PTCA predict an increased likelihood that a second restenosis will occur after repeat PTCA and that certain procedural factors, in particular the greater number of balloon inflations and a shorter maximal balloon inflation time, may play an important role in the development of recurrent restenosis.

Angioplasty, Balloon↗

PubMed1989

Antecedent angina: a predictor of residual stenosis after thrombolytic therapy.

Patients with a significant residual stenosis after thrombolytic therapy are believed by many to be at increased risk for repeat ischemic events and may be candidates for prompt angiography and revascularization. To test the hypothesis that patients with antecedent angina (Canadian classes I to IV, greater than or equal to 24 h before myocardial infarction) are more likely to have a significant residual stenosis (greater than or equal to 60% diameter reduction) than are those without antecedent angina, the coronary angiograms of 82 consecutive patients undergoing routine angiography after thrombolytic therapy were reviewed. Compared with the patients without antecedent angina, the group with antecedent angina had an increased mean stenosis (74% versus 58%) and more multivessel disease (44% versus 5%). The sensitivity and specificity of a clinical history of antecedent angina predicting the presence of a significant residual stenosis were 75% and 96%, respectively; the positive predictive accuracy was 98%. These data suggest that antecedent angina can be used to identify a high risk subgroup whose condition may warrant routine coronary angiography.

Angina Pectoris↗

PubMed1989

Outcome in patients with recurrent restenosis after percutaneous transluminal balloon angioplasty.

The records of 1162 consecutive patients undergoing their first percutaneous transluminal coronary angioplasty at a centre between March 1980 and June 1987 were reviewed. Initial angioplasty was successful in 1011 patients (87%). In 202 (20%) symptomatic restenosis developed. Of these, 196 were treated with redilatation; this was successful in 181 (92%). After a second dilatation, restenosis developed in 47 patients (26%). Of these, 41 (87%) were treated with a third angioplasty, with primary success in 38 (93%). A further restenosis developed in 13 of these 38 patients (34%). Eight patients were treated with a fourth angioplasty with restenosis in four (50%). Two of these four patients underwent a fifth angioplasty (with continuing success at long term follow up in both). Overall, 14 of the 47 (30%) patients who developed restenosis twice were eventually treated with coronary bypass surgery. Most patients (33), however, were treated only with repeated angioplasties. Of these 33 patients, 27 were treated with a third angioplasty, four with a fourth procedure, and two with a fifth. Twenty-nine (88%) were symptom free at a mean follow up of 28 (range 8 to 86) months. The combined success rate for a third, fourth, and fifth angioplasty was 94%. These data suggest that most patients with recurrent restenosis after angioplasty may be managed successfully and safely with repeated redilatations.

Adult↗

PubMed1986

Spinal cord lesions in progressive supranuclear palsy: some new observations.

The spinal cord was examined in two cases of progressive supranuclear palsy. In both cases, cells with neurofibrillary tangles were seen in the anterior horn, posterior horn, lateral horn, Clark's column, and intermediate gray. The tangles were most frequently observed in the posterior horn. The results suggest that the spinal cord is involved in the pathological process of progressive supranuclear palsy.

Aged↗

PubMed1985

Coronary sinus occlusion pressure and its relation to intracardiac pressure.

The hemodynamic components of coronary sinus (CS) occlusion pressure in humans have not been well described. If no other outflow for venous blood were present, then after acute occlusion of the coronary sinus the pressure would increase and equal aortic pressure. However, if thebesian vein drainage between the left ventricle and the coronary veins has an important role in humans, then CS occlusion pressure might reflect left ventricular (LV) pressure through transmitted LV pressure or intramyocardial pressure. To study this relation, 27 patients who underwent routine diagnostic cardiac catheterization were evaluated. Occlusion was accomplished by sudden inflation of a No. 7Fr balloon-tipped catheter placed into the CS. LV end-diastolic pressure and end-diastolic CS occlusion pressure were simultaneously recorded at rest. LV end-diastolic pressure (16.7 +/- 5.6 mm Hg) was not significantly different from end-diastolic CS occlusion pressure (15.9 +/- 5.4 mm Hg). LV end-diastolic and end-diastolic CS occlusion pressures were positively correlated (p less than 0.001) over the entire range of pressures (9 to 27 mm Hg). In contrast, systolic CS occlusion pressure was significantly lower than LV systolic pressure and unrelated to right-sided heart pressures. It is concluded that in humans, end-diastolic CS occlusion pressure closely parallels LV end-diastolic pressure, and measurement of CS occlusion pressure to assess LV end-diastolic pressure may have clinical use. These findings also suggest the existence of hemodynamically important thebesian vessel connections that may have implications for retroperfusion or pressure-controlled intermittent CS occlusion in humans.

Blood Pressure↗