Combined physiologic and anatomic assessment of percutaneous revascularization using a Doppler guidewire and ultrasound catheter.

Previous investigations have established the utility of intravascular ultrasound (IVUS) examination for the evaluation of arterial dimensions and qualitative changes following percutaneous revascularization. More recently, the feasibility of obtaining intravascular physiology findings before and/or after percutaneous revascularization by use of an intravascular Doppler Flowire (Cardiometrics) has been demonstrated. Accordingly, we investigated the feasibility of using this combined physiologic/anatomic approach to evaluate individuals undergoing percutaneous revascularization of stenotic or occluded coronary and peripheral arteries.

Clinical issues related to discontinuing digoxin therapy in elderly nursing home patients.

Digoxin is commonly used to treat congestive heart failure. Digoxin augments ventricular systolic performance, but does not benefit patients whose congestive heart failure is caused by poor diastolic function. We studied 47 elderly nursing home patients who were receiving long-term digoxin therapy.

Three-dimensional reconstruction of human coronary and peripheral arteries from images recorded during two-dimensional intravascular ultrasound examination.

Background: Intravascular ultrasound provides high-resolution images of vascular lumen, plaque, and subjacent structures in the vessel wall; current instrumentation, however, limits the operator to viewing a single, tomographic, two-dimensional image at any one time. Comparative analysis of serial two-dimensional images requires repeated review of the video playback recorded during the two-dimensional examination, followed by a "mind's eye" type of imagined reconstruction.

Methods And Results: Computer-based, automated three-dimensional reconstruction was used to generate a tangible format with which to assess and compare a "stacked" series of two-dimensional images.

Combination balloon-ultrasound imaging catheter for percutaneous transluminal angioplasty. Validation of imaging, analysis of recoil, and identification of plaque fracture.

Background: We investigated the hypothesis that an ultrasound transducer positioned within an angioplasty balloon could be used to perform quantitative assessment of arterial dimensions before and after percutaneous transluminal angioplasty (PTA) and to identify certain mechanical alterations consequent to PTA, including vascular wall recoil and the initiation of plaque fractures.

Methods And Results: A combination balloon-ultrasound imaging catheter (BUIC) that houses a 20-MHz ultrasound transducer within and halfway between the proximal and distal ends of an angioplasty balloon was used to perform PTA in 10 patients with peripheral vascular disease. Each PTA site was also evaluated before and after PTA by standard (nonballoon) intravascular ultrasound (IVUS) technique.

Catheter-based intravascular ultrasound discriminates bicuspid from tricuspid valves in adults with calcific aortic stenosis.

A catheter-based intravascular ultrasound transducer was used to study aortic valve morphology in adults with calcific aortic stenosis. Examination of 14 postmortem specimens disclosed that intravascular ultrasound consistently identified the number of cusps or the presence of a calcified median raphe in the conjoined cusp, or both, and thereby distinguished a calcified bicuspid from a calcified tricuspid aortic valve. These postmortem findings were then employed to identify valvular morphology in 15 patients undergoing diagnostic cardiac catheterization or balloon aortic valvuloplasty, or both.

Percutaneous intravascular US as adjunct to catheter-based interventions: preliminary experience in patients with peripheral vascular disease.

Catheter-based ultrasound (US) transducers may be introduced into the vascular system to record high-resolution images of the vessel wall and lumen. The potential advantages and existing liabilities of percutaneous intravascular US as an adjunct to transluminal vascular recanalization were investigated. A 6.

Clot-selective coronary thrombolysis with pro-urokinase.

Recognition that myocardial infarction is caused by coronary thrombosis has stimulated a search for a safe, rapidly acting, and effective thrombolytic regimen. Tissue plasminogen activator (t-PA) can provide relatively clot-selective thrombolysis, but one quarter of patients fail to achieve reperfusion, lysis speed is not optimal, and higher doses have been associated with an increased incidence of hemorrhagic stroke. We report the results of a multicenter study of pro-urokinase, a second naturally occurring plasminogen activator that has structural similarities to t-PA but has a different mechanism of action.

Lipids, lipoproteins, fibrinogen and fibrinolytic activity in angiographically assessed coronary heart disease.

Plasma lipids, lipoproteins, fibrinogen and fibrinolytic activity (FA) were measured in 202 consecutive patients undergoing coronary angiography. Twenty-one patients, 13 men and 8 women with a mean age of 52.8 years and 56.

Effect of local lidocaine anesthesia on ventricular escape intervals during permanent pacemaker implantation in patients with complete heart block.

Transient asystole is often noted during the course of permanent pacemaker implantation in patients with complete heart block. Since subcutaneous lidocaine is frequently used as the local anesthetic agent for permanent pacemaker implantation, the effect of this drug on ventricular escape intervals was studied. Ventricular escape intervals after transient cessation of pacing were studied in 9 patients with complete heart block before and 10, 30, and 45 minutes after subcutaneous lidocaine administration for permanent pacemaker implantation.

Transfemoral temporary pacing and deep vein thrombosis.

The incidence of deep vein thrombosis following transfemoral temporary pacing was prospectively assessed in 20 consecutive patients using serial 125I-fibrinogen scanning, impedance plethysmography, and measurements of fibrin degradation products. Four patients underwent venography. Of the twenty patients, five (25%) had definite evidence of deep vein thrombosis, six demonstrated equivocal abnormalities, and nine had no evidence of thrombosis.

Results and complications of intraaortic balloon pumping in surgical and medical patients.

The intraaortic balloon was attempted for therapy in 94 patients and successfully placed in 86. The balloon catheter could not be passed through the femoral or iliac artery in 12 patients (13 percent) of the group; in 4 of these the balloon was inserted through an aortic arch graft. The medical indications were cardiogenic shock and preinfarction angina.

Multilevel atrioventricular block.

Arrhythmias displaying conduction disturbances consistent with block at more than one level within the atrioventricular conduction system were seen in 36 patients during a two year period in a community hospital. Two levels of block were postulated in each patient; one patient also demonstrated a third level of block. In 24 patients (Type A), there was an integral conduction ratio at the upper level of block.