Search PubMed⌕ Search

Biomedical subjects

A T Weiss

Publications and source records attributed to A T Weiss.

At least 37 records · Page 2Linked to original sources
PubMed1995

Emergency rotational ablation of a calcified left main coronary artery stenosis in a patient with ischemic induced cardiogenic shock.

High-speed rotational ablation is ideal in the treatment of chronic calcified atherosclerotic lesions. This report describes an elderly woman with a prior history of coronary artery bypass surgery, who developed cardiogenic shock secondary to occlusion of a saphenous vein graft to the obtuse marginal branch of the circumflex coronary artery. Her left main coronary artery was heavily calcified and almost completely occluded. She was treated successfully by high-speed rotational ablation of her left main stenosis.

Aged↗
PubMed1995

Acute myocardial infarction--the angiographic picture: new insights into the pathogenesis of myocardial infarction.

The angiographic appearance of the coronary arteries were examined in 302 patients with stable angina pectoris and compared to 308 patients with acute myocardial infarction, who received high-dose intravenous thrombolytic therapy, in order to elucidate the underlying angiopathological picture in the two diseases. In each group coronary lesions were present in proximal segments of the arteries and were closely related to bifurcations. Lesions were more extensively distributed in the coronary tree in patients with stable angina and they had an average of 5.4 lesions per patient, compared to the acute myocardial infarction group who had only 2.4 lesions. Also, in the acute myocardial infarction patients, four-fifths of the culprit arteries were patent, 104 (34%) had a ruptured plaque, 22 (7%) had an ulcerated plaque and in 190 (62%) the lesions were eccentric. The study shows that patients with myocardial infarction who are suitable for thrombolysis have a unique coronary angiographic picture and the acute episode is caused by sudden rupture of a localized atheromatous plaque which initiates an obstructive thrombotic cascade.

Angina Pectoris↗
PubMed1995

Early intravenous thrombolysis in acute myocardial infarction: the Jerusalem experience.

Myocardial damage in acute myocardial infarction is a time-dependent process. We examined the influence of very early thrombolytic therapy, comparing prehospital to hospital administration, in a consecutive group of patients with myocardial infarction on mortality, complications and the preservation of left ventricular function. Seven hundred sixty patients received early thrombolytic therapy: 114 at home (time delay to treatment 1.4 +/- 0.8 h) and 646 in hospital (2.1 +/- 1.0 h). Sixteen patients died in hospital and significant hemorrhage occurred in 15 (including three patients with hemorrhagic stroke). There was no difference between groups in hospital mortality or rate of complications. The duration of ischemia was shorter in patients with prehospital therapy (pain duration: 3.3 +/- 2.1 vs. 4.0 +/- 2.2; P < 0.05, and time to recovery of the ST segment in the electrocardiogram: 4.3 +/- 3.3 vs. 6.6 +/- 6.3; P < 0.002). Peak plasma creatine kinase was earlier in patients with prehospital therapy (11.2 +/- 5.0 vs. 13.0 +/- 5.8; P < 0.002), although there was no difference between groups in the absolute peak plasma level. Left ventricular function was assessed by contrast ventriculography 1 week after admission (616 patients). Ventricular function was better in patients with prehospital therapy: (ejection fraction of 58 +/- 13% vs. 54 +/- 15%; P < 0.05 and a left ventricular dysfunction index of 534 +/- 515 vs. 691 +/- 519 units; P < 0.05). We conclude that prehospital thrombolytic therapy is feasible and safe. Reperfusion is achieved earlier and more myocardium can be salvaged using this strategy without increasing the rate of complications.

Coronary Angiography↗
PubMed1994

The effect of overdrive pacing rate and duration on ventricular escape rhythms in patients with chronic complete atrioventricular block.

The effect of overdrive (OD) pacing rate and duration on subsidiary pacemakers was evaluated in 54 patients with third-degree AV block. They had a permanent pacemaker implanted 61 +/- 56 months earlier because of complete AV block in 38 patients and, in 16 patients because of second-degree AV block, which in the interim advanced to complete AV block. The patients had a reliable infranodal escape rhythm, with a mean cycle length of 2,022 +/- 603 msec, upon discontinuation of the ventricular OD pacing, at a rate of 40 beats/min. The escape interval and escape rhythm cycle length was evaluated after OD pacing at 40, 50, 60, 70, 90, and 100 beats/min for 30 seconds, at each rate. In 100% of the patients the subsidiary pacemaker recovered after OD pacing at 40 and 50 beats/min and the number decreased to 59% at a rate of 100 beats/min. The escape interval prolonged gradually between OD pacing at 40 and 100 beats/min, by 56%. The effect of OD pacing duration at 50 and 70 beats/min was evaluated. At an OD pacing rate of 70 beats/min there was a significant effect of the pacing duration on the escape interval. There were significant differences in the escape interval duration and escape rhythm cycle length between males and females, patients with or without coronary artery disease, and patients with narrow or wide QRS escape. However, the increase in the OD pacing rate had a similar effect on the escape interval in the above mentioned groups. There was no effect on the paced QRS duration and sinus cycle length at each OD pacing rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Total coronary artery occlusion late after successful coronary angioplasty of moderately severe lesions: incidence and clinical manifestations.

Coronary restenosis after balloon angioplasty is a slow process that develops over a few months. In some patients, with an initially successful angioplasty, an artery that originally had only moderate stenosis becomes totally occluded as a result of restenosis. This report describes 16 such patients out of 415 dilated lesions with late angiographic follow-up. Ten patients presented with stable angina pectoris, 5 had unstable angina and only one was admitted with a small myocardial infarction. Visible collaterals were present in 15 patients. Except for the patient who sustained myocardial infarction, none of the late angiograms showed the typical morphological features of acute lesion. We conclude that total coronary occlusion late after successful angioplasty of an artery that was moderately narrowed is rare. The 'restenotic' occlusion is a slow process that stimulates collateral formation and thus the risk of myocardial infarction is small.

Adult↗
PubMed1994

Value of dobutamine/nitrate radionuclide angiography in predicting revascularization effects on ventricular function.

OBJECTIVE: Dobutamine and Nitrate Radionuclide Angiography (RNA) may help to distinguish viable from nonviable myocardium and to predict revascularization effects on LV function. SETTING: Ambulatory. EXPERIMENTAL DESIGN: Prospective. PATIENTS AND METHODS: We studied 12 patients (11 male, 1 female; mean age 56 +/- 10 years) with three-vessel disease, severe LV dysfunction, and prior MI for a mean follow-up time of 10 +/- 3.4 months. Thallium-201 scintigraphy favored potential viability in all patients: inducible ischemia with satisfactory perfusion in more than one coronary arterial territory. Global and regional LVEF's were calculated from preoperative RNA (baseline rest study and with continuous dobutamine infusion with gradual rate increase plus oral nitrates) and postoperative RNA at 1 and 6 months. RESULTS: There was no operative mortality, but two late deaths occurred. Symptomatically, most patients showed improvement. Global LVEF increased during dobutamine and nitrates preoperatively (p < 0.01), but not at 1 and 6 months postoperatively (without pharmacological intervention). Mean LVED volume was not significantly changed postoperatively. Regional EF improvement was found in 4 out of 9 LV wall segments under dobutamine and nitrates, and this increase persisted postoperatively at 1 and 6 months. CONCLUSIONS: Mild but significant increase in global LVEF during dobutamine and nitrates administration is not predictive of postoperative LVEF improvement. However, regional EF improvement appears to be predictive of post-revascularization LV functional improvement.

Administration, Sublingual↗
PubMed1993

Early heart rate variability alterations after acute myocardial infarction.

In order to assess early changes in heart rate variability, we studied 81 patients with acute myocardial infarction during the initial 24 hours after thrombolytic therapy. The standard deviation of the mean heart rate and the low (0 to 0.05 Hz), mid (0.05 to 0.20 Hz), and high (0.20 to 0.35 Hz) frequency band power were evaluated with 24-hour ECG Holter recordings. We found diminished variance in the time domain and reduced power spectrum in the frequency domain compared with a group of 41 normal subjects (p < 0.01). Patients with anterior infarction had significantly (p < 0.01) higher heart rates and lower heart rate variability values than patients with inferior infarction. Reduction in heart rate variability occurred within the first 8 hours in patients with anterior infarction; a significant fall (p < 0.03) was especially noted in the high-frequency band after a decline in ST-segment elevation. Heart rate variability alterations in patients with inferior infarction were most evident in the final 8-hour interval. These findings may be viewed in terms of sympathovagal imbalance and may be related to clinical signs of intense autonomic nervous system activity that are observed early in the course of acute anterior and inferior myocardial infarction.

Aspirin↗
PubMed1993

Intra-aortic balloon counterpulsation improves survival in cardiogenic shock complicating acute myocardial infarction.

The impact of intra-aortic balloon counterpulsation (IABC) on survival of patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) has been evaluated in this study of 85 patients. IABC was available for the 24 group A patients (and used in 20 patients). IABC was not available for the 21 group B patients who presented simultaneously with similar clinical characteristics and received identical pharmacological treatment. In-hospital and one year survival was significantly higher in group A (46% and 38% vs 19% and 10%, P < 0.001). Sixteen out of the 20 (group A1) IABC patients received early coronary revascularization. During 1980-1984, 35 patients with AMI and CS received IABC (group C) but none underwent early revascularization. There was no difference in in-hospital or one-year survival between group A1 (50% and 40%) and group C (45% and 40%). We conclude that early IABC improves survival of patients with AMI complicated by CS.

Combined Modality Therapy↗
PubMed1993

Single physician approach to radiofrequency catheter ablation in patients with supraventricular tachycardia.

The minimal requirements for safe and effective performance of catheter ablation using radiofrequency current are still unclear. To determine the feasibility and safety of single physician approach to catheter ablation of supraventricular tachycardia substrate using radiofrequency energy, the results of the ablation procedure in 52 consecutive patients were evaluated. The procedures were performed during 1 year by the same physician and nurse. Twenty-one patients had selective atrioventricular (AV) nodal pathway ablation and 31 patients had accessory AV pathway ablation. Forty-eight patients (89%) had the diagnostic and the ablative procedure during the same electrophysiological test. In the 21 patients with AV nodal reentrant tachycardia, all had successful selective ablation of the fast (13) or the slow (8) pathways. Eight patients had recurrence of the clinical tachycardia and had a successful reablation. No patient developed complete AV block or other significant complications. The mean fluoroscopy time during the procedure was 16.0 +/- 8.6 minutes. In the eight patients with Wolff-Parkinson-White syndrome, all concealed accessory pathways were successfully ablated with a mean fluoroscopy time of 30.0 +/- 27.9 minutes. Two patients had recurrence of the conduction through the accessory pathway and had a successful reablation. Eighteen of 19 patients with a single overt accessory pathway had successful ablation, with a fluoroscopy time of 22.7 +/- 20.6 minutes. Three patients had an early recurrence of the conduction through the accessory pathway, reablation was successful in two of them. Ten accessory pathways were ablated in four patients with multiple pathways during nine procedures. Only two patients developed minor peripheral vascular complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Comparison between patients with and without reliable ventricular escape rhythm in the presence of long standing complete atrioventricular block.

The underlying heart rhythm was evaluated in 74 patients with complete atrioventricular block and had a permanent pacemaker implantation. The pacing was inhibited for 10 seconds or until the patient developed symptoms of presyncope or syncope. Fifty-six patients (74%) had a reliable escape with a mean cycle length of 2010 +/- 596 msec and a mean escape interval of 2335 +/- 971 msec. In 93% of these patients the escape interval was < 4 seconds. The patients without reliable escape (24%), developed symptoms only after a mean of 7153 +/- 1875 msec. The duration of the conduction disorder was longer in the patients without escape and the intraventricular conduction was slower. More patients without escape were treated and antiarrhythmic agents. Forty-eight patients were followed for 1 year and underwent at least two different studies and 13% had different results at different tests. In conclusion, patients without reliable escape have a longer history of conduction disorder, a slower intraventricular conduction, and are frequently treated with antiarrhythmic agents. Even patients with reliable escape occasionally may show a greater pacemaker dependence; therefore, they should also be considered as pacemaker dependent.

Aged↗
PubMed1991

Clinical, psychological and thallium stress studies in patients with chest pain and normal coronary arteries.

The clinical and psychological profiles of 36 consecutive patients with chest pain and normal coronary arteries (study group) were compared to those of 34 patients with chest pain and significant coronary arterial disease (control group). All 70 patients were hospitalized for chest pain at least once prior to coronary angiography. The features of a typical episode of chest pain were similar in the normal coronary arteries and coronary arterial disease groups, but the female patients with normal coronary arteries had a shorter duration of a typical episode of chest pain, and the male patients with normal coronary arteries had a lower frequency of positive effort tests. Psychological testing showed the women with normal coronary arteries to have a tendency to increased somatization, anxiety, and a lower ability to identify origin of difficulties. The patients in the normal coronary and coronary arterial disease groups had psychological profiles typical of patients with chronic somatic disease. A psychiatric interview demonstrated an increased frequency of depressive trait (score 0-2) in the normal women (0.6 +/- 0.8 vs 0, P less than 0.05), and a tendency to increased somatization, anxiety, and sleeping disorders. Increased somatization was found in the normal coronary men (1.1 +/- 0.7 vs 0.5 +/- 0.7, P less than 0.05). Twenty-five patients of the normal coronary group underwent quantitative thallium stress studies, and 13 patients (52%) had evidence of stress-induced myocardial perfusion defect. There were no differences in the clinical and psychological profiles of the patients with normal and those with pathological thallium stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Chest Pain↗
PubMed1990

Partial resistance to anticoagulation after streptokinase treatment for acute myocardial infarction.

This study examines the response of 3 different groups of patients to anticoagulants: 50 patients previously treated with streptokinase for acute myocardial infarction (AMI) (group 1), 24 patients with AMI who had received anticoagulants without prior thrombolysis (group 2) and 11 subjects who received anticoagulants for noncoronary indications (group 3). No significant differences were detected between groups 2 and 3; therefore, they were combined for analysis. After streptokinase, patients required 37,755 +/- 1,516 (mean +/- standard error of the mean) U of heparin per day to achieve the desired activated partial thromboplastin time (APTT). The dosage was 30,294 +/- 1,089 U/day in patients without antecedent thrombolysis (p less than 0.001). Group 1 patients required 5 +/- 0.4 days until adequate anticoagulation was achieved, compared with 3 +/- 0.2 days in the control group (p = 0.01). Despite higher heparin requirements, group 1 patients had a lower APTT value than the other subjects (87 +/- 5 vs 101 +/- 6 seconds, p = 0.08). Group 1 patients required 5 +/- 0.3 days to reach anticoagulation with warfarin versus 4 +/- 0.2 days in groups 2 + 3 (p = 0.05). Comparison of groups 1 and 2 yielded similar, although smaller, differences. Patients treated with streptokinase for AMI seem to be partially resistant to anticoagulation, which may increase the risk of reocclusion.

Anticoagulants↗
PubMed1990

Systemic embolization following thrombolytic therapy for acute myocardial infarction.

We describe a patient with acute inferior myocardial infarction who developed a "saddle" aortic embolus during streptokinase infusion. Three months previously, this patient had sustained an anterior infarction, and an apical aneurysm was found. This patient's embolus had most probably originated from a left ventricular mural thrombus that had been dislodged by streptokinase. As fibrinolytic treatment is gaining wide acceptance, physicians should be aware of this rare, but possible, complication.

Aged↗