PubMed Health⌕ Search

Biomedical subjects

G M Ansel

Publications and source records attributed to G M Ansel.

11 recordsLinked to original sources
PubMed2000

Renal artery angioplasty and stent placement: predictors of a favorable outcome.

BACKGROUND: Renal artery stenosis is a common disorder and is an established cause of hypertension and renal insufficiency. Although treatment with renal artery stents has been shown to improve blood pressure and renal function for some patients, the patient population most likely to benefit is unknown. The current study was designed to determine which factors are predictive of improved blood pressure and renal function when patients with renal artery stenosis are treated with renal artery angioplasty and stent placement. METHODS: In a prospective evaluation 127 consecutively enrolled patients with renal artery stenosis in 171 vessels were treated with angioplasty and intravascular stents. Blood pressure and serum creatinine concentration were measured before stent placement and during the follow-up period. RESULTS: The mean length of the follow-up period was 15 +/- 14 months. Mean systolic blood pressure improved among patients with hypertension (from 177 +/- 26 mm Hg before stent placement to 151 +/- 24 mm Hg 6 months after stent placement (P <.001). The greatest improvement occurred among those with the highest baseline systolic blood pressure. This beneficial effect on blood pressure was sustained for 3 years. Sex, age, diastolic blood pressure, number of vessels into which stents were placed, serum creatinine concentration, presence of bilateral disease, race, and severity of stenosis were not predictive of improved blood pressure. Mean creatinine concentration was not significantly changed for the group as a whole. A significant decrease in serum creatinine concentration occurred among 43% of patients with baseline renal insufficiency. None of the examined variables was predictive of improvement. CONCLUSIONS: Renal artery angioplasty and stent placement produced a significantly greater reduction in systolic blood pressure among patients with the highest baseline systolic blood pressure. Other examined variables were not predictive of a significant improvement in blood pressure. No examined variable was predictive of improved renal function. We concluded that management of renal artery stenosis with renal artery angioplasty and stent placement is most likely to result in significant improvement in systolic blood pressure among patients with the highest baseline systolic blood pressure.

Aged↗
PubMed1998

Rheolytic thrombectomy in the treatment of acute limb-threatening ischemia: immediate results and six-month follow-up of the multicenter AngioJet registry. Possis Peripheral AngioJet Study AngioJet Investigators.

We tested the efficacy of rheolytic thrombectomy in treating 21 patients (mean age 68+/-12 years; 66% male) and 22 vessels (limbs) who presented to the hospital within 2 weeks of the development of limb-threatening ischemia. Fifty-two percent had contraindications to use thrombolytics, and 57% had severe comorbidities. All of the vessels were occluded with thrombus on the initial angiogram. Procedural success was achieved in 20 limbs (91%). Three patients expired in the hospital, and one expired at follow-up due to nonvascular causes. Acute limb salvage was achieved in 18 of 19 limbs (95%) in the 18 survivors, and 6-month limb salvage was achieved in 16 of 18 limbs (89%) in the 17 survivors. Rheolytic thrombectomy is effective in restoring immediate blood flow in acute limb-threatening ischemia, especially in high-risk surgical patients or patients with contraindications to thrombolytic therapy.

Aged↗
PubMed1995

Current status of percutaneous vascular procedures.

The current nonsurgical therapeutic options for patients with peripheral vascular disease are rapidly expanding. No longer is conservative management the only alternative for patients with significantly symptomatic but noncritical limb ischemia. Certainly for vascular disease above the inguinal ligament interventional procedures especially with adjunctive stent placement have excellent success and long term patency. Femoropopliteal vascular disease of relatively limited nature also is well-treated with interventional procedures. Infrapopliteal vascular disease treated with a surgical venous bypass appears to have superior results than intervention. However, for poor surgical risk patients or in patients without the necessary venous conduit, limb salvage is still good with a percutaneous approach. Renal artery stenosis appears now to be well treated with interventional techniques. Early data with up to one year follow-up shows that even ostial stenoses respond well when vascular stents are utilized. Extending the life of failing hemodialysis grafts is another area where interventional techniques are of benefit. In the future, more extensive vascular disease and other vascular disease entities such as cerebrovascular disease and abdominal aortic aneurysm may be successfully treated by a percutaneous approach.

Angioplasty, Balloon, Coronary↗
PubMed1994

Prevention of tricyclic antidepressant-induced ventricular tachyarrhythmia by a specific bradycardic agent in a canine model.

Sinus tachycardia facilitates ventricular conduction delay and sustained ventricular tachyarrhythmias during tricyclic antidepressant overdose. We hypothesized that impeding sinus tachycardia with the specific bradycardia agent, UL-FS 49, would reduce the incidence of ventricular tachyarrhythmia caused by tricyclic antidepressant overdose and tested this hypothesis in a canine model of ventricular tachycardia (VT) induced by graded amitriptyline infusion (0.5-1.0 mg/kg/min) during continuous hemodynamic monitoring. Three groups were studied. A control group (group A, n = 8) received amitriptyline infusion alone. A pretreated group (group B, n = 8) received UL-FS 49 (1 mg/kg intravenously, i.v.) 45 minutes before amitriptyline infusion. A treatment group (group C, n = 5) received UL-FS 49 (1 mg/kg) during amitriptyline infusion after onset of ventricular tachyarrhythmia. Seven (88%) in group A had ventricular tachyarrhythmia at 35 +/- 6 min of amitriptyline infusion. Ventricular tachyarrhythmia did not occur in any (0%) animal in group B. Peak sinus heart rate (HR) was significantly higher in group A (160.0 +/- 9.8 beats/min) than in group B (92.8 +/- 5.3 beats/min; p < 0.0001). Unimpeded sinus tachycardia in group A was associated with a significantly longer QRS duration (158.8 +/- 7.4 ms) as compared with group B (101.0 +/- 2.3 ms; p < 0.0001). UL-FS 49 did not influence systolic blood pressure (SBP) at baseline or during amitriptyline infusion. In group C, 3 of 5 dogs with nonsustained VT (NSVT) had effective sinus rate slowing and suppression of all NSVT after UL-FS 49. UL-FS 49 did not terminate SVT in 2 of 5 group C dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Amitriptyline↗
PubMed1993

Cardiac catheterization and coronary angiography using 5 French preformed (Judkins) catheters from the percutaneous right brachial approach: a comparative analysis with the femoral approach.

This study describes a method for the performance of cardiac catheterization using 5 French preformed Judkins catheters from a percutaneous right brachial approach, and compares that technique to the more traditional percutaneous right femoral approach with 6 French catheters. One hundred consecutive patients requiring diagnostic left heart catheterization and selective coronary angiography were randomized according to femoral versus brachial arterial technique. Procedural efficiency, radiation exposure, and diagnostic film quality favored the femoral approach, while patient comfort, hemostasis time, time to ambulation, and decreased need for post-procedure nursing care favored the brachial approach. No differences were identified in complications. Cardiac catheterization from a right brachial artery percutaneous approach with 5 French preformed catheters has both advantages and disadvantages when compared with a more traditional femoral approach with 6 French catheters. Multiple factors should be considered before selecting an approach to diagnostic cardiac catheterization and each patient should be individually evaluated for determination of the optimal technique.

Brachial Artery↗
PubMed1993

Mechanisms of ventricular arrhythmia during amitriptyline toxicity.

The ventricular tachycardia (VT) caused by high-dose tricyclic antidepressants has been hypothesized to be due to a quinidinelike effect with generation of repolarization abnormalities and afterdepolarizations. To test this hypothesis further, we infused amitriptyline in a graded fashion (0.5-1 mg/kg/min) in 23 chloralose-anesthetized dogs during endocardial monophasic action potential (AP) recording and continuous hemodynamic monitoring. Three groups of dogs were studied: group A (n = 5), crushed sinus node and fixed atrial pacing at 100 beats/min; group B (n = 12), crushed sinus node and fixed atrial pace plus intermittent accelerated pacing to mimic group C; and group C (n = 6) intact sinus node and unimpeded sinus tachycardia. Amitriptyline infusion induced VT in no (0 of 5) group A dogs, all (12 of 12) group B dogs during accelerated pacing, and 83% (5 of 6) of group C dogs. Dogs with VT had significantly higher heart rates (HR 184.8 +/- 39.3 beats/min) as compared with dogs without VT (115.2 +/- 12.5 beats/min, p = 0.0015). There was a strong positive correlation between the last RR coupling interval to the first VT interval (r = 0.85; p = 0.0033). Amitriptyline infusion caused rate-dependent QRS prolongation in each group, especially group C (p < 0.001). Action potential duration at 50% and 90% of repolarization (APD50, APD90) showed a biphasic response with progressive shortening followed by prolongation as amitriptyline serum concentrations increased. Afterdepolarizations were not detected from any monophasic AP recording, even in dogs with VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1982

Effects of syringe material and needle size on the minimum plunger-displacement pressure of arterial blood gas syringes.

We determined the minimum systolic pressures required for blood to enter and begin to displace the plungers of four brands of 3-ml and 5-ml plastic and glass arterial blood gas syringes by combining samples of each syringe size with three sizes of short-beveled needles--25 gauge, 5/8"; 22-gauge, 1"; and 20-gauge, 1 1/2". We measured pressures by use of an arterial-vessel model that incorporated whole human blood and simulated the conditions of a percutaneous arterial puncture. We concluded that all the arterial blood gas syringes that we studied would self-fill in most clinical situations when they were combined with 20- or 22-gauge needles, but that 22-gauge needles with glass syringes were preferable for persons whose systolic pressures were less than 70 mm Hg, for persons in shock, and for persons undergoing CPR. Only glass 3-ml syringes should be used with 25-gauge needles, as two brands of plastic 3-ml syringes with 25-gauge needles required systolic pressures greater than 158 mm Hg and all brands of plastic and glass 5-ml syringes with 25-gauge needles required systolic pressures greater than 247 mm Hg. Because we found no clinical or statistical differences between 20- and 22-gauge needles, we do not recommend use of the larger 20-gauge needle. The syringe-needle combinations that we do recommend should negate the need for, and the potential trauma of, manual aspiration of the syringe plunger.

Blood Gas Analysis↗