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Biomedical subjects

A E Raizner

Publications and source records attributed to A E Raizner.

At least 73 records · Page 4Linked to original sources
PubMed1986

Quantitative analysis of thallium-201 uptake and washout before and after transluminal coronary angioplasty.

Transluminal coronary angioplasty has become an important therapeutic modality in the treatment of coronary artery disease. The effects of coronary angioplasty on regional myocardial perfusion have been reported in only a small series of patients, employing subjective analysis of thallium-201 perfusion scintigrams. Thus, we studied 61 patients with quantitative analysis of thallium-201 uptake and washout before and after undergoing angioplasty. Prior to angioplasty, there were 105 areas in 47 patients with abnormal thallium-201 uptake during exercise, with a mean uptake of 49 +/- 1.3%. The uptake of thallium-201 in these same areas increased to 71.3 +/- 1.9% post angioplasty (P less than 0.0001), and 68 (65%) of the areas showing abnormal uptake returned to normal. Abnormalities in washout of thallium-201 before angioplasty were seen more frequently than in uptake (150 vs 105 areas, P less than 0.05), with 8 patients having abnormal washout in the presence of totally normal uptake. Thallium-201 washout in the abnormal areas improved from 16 +/- 2.8 pre angioplasty to -23 +/- 1.8% post angioplasty (P less than 0.001). Normalization resulted in 6 of the 8 patients with exclusively washout abnormality. Residual abnormalities in uptake and/or washout were seen in 53% of the patients, usually in areas with prior myocardial infarction or supplied by a vessel with significant stenosis which did not undergo angioplasty. Improved thallium-201 uptake and washout corresponded to reductions in percent coronary area stenosis (89 +/- 1.0 to 36 +/- 2.0%, P less than 0.001) and transstenotic pressure gradient (42 +/- 3.0 to 9.0 +/- 2.0 mm Hg, P less than 0.001). Thus, quantitative analysis of thallium-201 uptake and washout provided objective evidence for improved myocardial perfusion after coronary angioplasty. Due to a fairly high prevalence of residual perfusion abnormalities after this procedure, optimal assessment of benefits requires quantitative comparison of thallium uptake and washout before and after coronary angioplasty.

Adult↗
PubMed1985

Intracoronary thrombolytic therapy in acute myocardial infarction: a prospective, randomized, controlled trial.

A prospective, randomized trial was designed to assess the efficacy of intracoronary thrombolytic therapy with streptokinase (STK) in acute myocardial infarction. Sixty-four patients with acute myocardial infarction were randomized within 6 hours of onset of symptoms to 1 of 3 groups. Sixteen patients were treated by conventional means (control group). Nineteen patients underwent coronary arteriography and received corticosteroids and intracoronary and intravenous nitroglycerin (NTG group). Twenty-nine patients received management identical to that of the NTG group, with the addition of intracoronary STK therapy (STK group). Recanalization was demonstrated in 21 of 29 patients (72%) in the STK group. Global and regional ejection fraction (EF) was determined by radionuclide ventriculography before any intervention and 7 to 10 days later. No significant improvement in global EF was achieved in the control and NTG groups. In STK patients as a group, global EF did not increase significantly; however, in patients recanalized with STK, EF improved from 42 +/- 17% to 49 +/- 16% (p = 0.023). All groups showed wide variability of response. Improvement in global EF of more than 5% was noted in 44% of patients recanalized with STK. When subgrouped on the basis of initial global EF of 45% or less or more than 45%, only patients recanalized with STK with an initial EF of 45% or less had an improved global EF (from 30 +/- 10% to 42 +/- 10%, p = 0.015).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

Effects of transluminal coronary angioplasty on left ventricular systolic and diastolic function at rest and during exercise.

The left ventricular global and regional systolic function, ventricular volumes, and peak diastolic filling rate (PDFR) were studied in 30 patients with coronary artery disease, before and 2 to 5 days after transluminal coronary angioplasty (PTCA), utilizing equilibrium radionuclide angiography at rest and during exercise. At rest, the global ejection fraction (EF) was unchanged before (60 +/- 9%) and after PTCA (62 +/- 10%). During exercise, global EF increased from 59 +/- 11% pre PTCA to 67 +/- 10 post PTCA (p less than 0.001). Twenty-two patients had abnormal EF response to exercise pre PTCA, versus seven post PTCA (p less than 0.001). Improvements in exercise regional EF paralleled the changes in global EF. End-systolic volume was unchanged at rest but decreased significantly with exercise post PTCA (60 +/- 36 ml pre vs 49 +/- 32 ml post PTCA, p less than 0.01). At rest, the PDFR was unchanged post PTCA (2.4 +/- 0.9 end-diastolic volume (EDV)/sec pre vs 2.5 +/- 0.8 EDV/sec post). During exercise, PDFR increased from 2.1 +/- 0.7 EDV/sec pre PTCA to 2.5 +/- 0.7 EDV/sec post PTCA (p less than 0.02). In conclusion, in patients with coronary artery disease, successful PTCA improves global and regional systolic function during exercise. Diastolic function is improved during exercise, a fact not previously demonstrated.

Adult↗
PubMed1985

Effect of coronary artery recanalization on right ventricular function in patients with acute myocardial infarction.

The effects of coronary artery recanalization by intracoronary administration of streptokinase on left ventricular function during acute myocardial infarction have received increasing attention in recent years. Although myocardial dysfunction is often more pronounced in the right ventricle than in the left ventricle in patients with acute inferior wall myocardial infarction, the effect of coronary artery recanalization on right ventricular dysfunction has not been previously addressed. Accordingly, in this investigation, 54 patients who participated in a prospective, controlled, randomized trial of recanalization during acute myocardial infarction were studied. Among 30 patients with inferior wall infarction, 19 had right ventricular dysfunction on admission; 11 of these 19 had positive uptake of technetium-99m pyrophosphate in the right ventricle, indicative of right ventricular infarction. Patients with successful recanalization (n = 6) exhibited improved right ventricular ejection fraction from admission to day 10 (26 +/- 7 to 39 +/- 14%, p less than 0.03). However, control patients (n = 6) and patients who did not undergo recanalization (n = 7) also exhibited improvement (20 +/- 7 to 29 +/- 11% [p less than 0.02] and 30 +/- 8 to 40 +/- 6% [p less than 0.03], respectively). Improvement in several other variables of right ventricular dysfunction evolved at an equal rate with the ejection fraction changes. Patients with or without right ventricular infarction improved similarly. These data indicate that the right ventricular dysfunction commonly associated with inferior wall infarction is often transient, and improvement is the rule, irrespective of early recanalization of the "infarct vessel."

Aged↗
PubMed1984

Accelerated junctional rhythms during oral verapamil therapy.

This study examined the frequency of atrioventricular (AV) dissociation and accelerated junctional rhythms in 59 patients receiving oral verapamil. Accelerated junctional rhythms and AV dissociation were frequent in patients with supraventricular tachyarrhythmias, particularly AV nodal reentry. Verapamil administration to these patients led to an asymptomatic increase in activity of these junctional pacemakers. In patients with various chest pain syndromes, verapamil neither increased the frequency of junctional rhythms nor suppressed their role as escape rhythms under physiologically appropriate circumstances.

Administration, Oral↗
PubMed1983

Inhibition of airway reactivity by nifedipine in patients with coronary artery disease.

Nine patients with coronary artery disease were challenged with aerosolized methacholine before and 3 days after the daily oral administration of 30 mg of nifedipine. Resting airway tone appeared to be generally unaffected by nifedipine, as there were no significant changes in the baseline ventilatory functions. Serial measurements of spirometry and airway resistance were made after cumulative methacholine doses of 1.25, 3.75, and 8.75 mg. Identical doses of methacholine induced smaller changes in specific airway conductance (p less than 0.02), airway resistance (p less than 0.001), FEV1 (p less than 0.02), and FEF25-75% (p less than 0.01) after nifedipine therapy than before. These differences were significant at all methacholine dosage levels by paired t test except for FEV1 at the 3.75 mg dose. This study demonstrated that the bronchospastic response to methacholine in patients with coronary artery disease is reduced after the administration of nifedipine. This salutary effect on ventilatory function may be of importance to cardiac patients with concomitant chronic airway obstruction who are intolerant of beta-adrenergic blocking agents.

Airway Resistance↗
PubMed1981

Early post-myocardial infarction treadmill stress testing. An accurate predictor of multivessel coronary disease and subsequent cardiac events.

Limited (heart rate to less than or equal to 120 beats/min) standardized treadmill stress testing was done before hospital discharge in 40 survivors of uncomplicated acute myocardial infarction. Each patient had subsequent coronary arteriography. Twenty-one had inferior, 10, anterior, and nine, nontransmural infarctions; in 30 patients this was their first infarction. A positive electrocardiographic response or angina, or both, occurred in 15 patients and correctly detected most patients with multivessel disease (sensitivity 67%, predictive value 87%) and patients at risk for coronary events: 35% of positive responders admitted for angina in the first month after discharge versus 4% of patients with a negative test (p less than 0.05). During a 7-month follow-up period, 73% of patients with a positive test result developed angina versus 16% of those with negative test results (p less than 0.001). Thus, predischarge post-myocardial infarction limited stress testing correctly identifies the high-risk subset of patients with multivessel coronary disease and thereby allows intelligent selection of patients for early coronary arteriography.

Adult↗
PubMed1980

Exercise-induced coronary arterial spasm: angiographic demonstration, documentation of ischemia by myocardial scintigraphy and results of pharmacologic intervention.

Exercise-induced coronary arterial spasm is an infrequently recognized phemonemon whose mechanism and management are not well established. In two patients with reproducible exercise-induced S-T segment elevation and angina pectoris thallium-201 scintigraphy showed areas of reversible anteroapical hypoperfusion, and gated radionuclide ventriculography revealed anteroapical hypokinesia with a decrease in left ventricular ejection fraction at peak exercise. During coronary arteriography supine exercise provoked occlusive spasm of the left anterior descending coronary artery, which at rest had only minimal plaques. Consequently, treadmill testing was performed with five different pharmacologically provoked interventions: direct vasodilatation (nitrates), alpha adrenergic blockade (phenmoxybenzamine), beta adrenergic blockade (propranolol), calcium flux blockade (verapamil), and prostaglandin inhibition (indomethacin). Exercise-induced coronary arterial spasm, manifested as S-T segment elevation and angina, was prevented by nitrates, but was not eliminated by short-term oral administration of an alpha or beta blocking agent, a calcium antagonist or a prostaglandin inhibitor. Further, beta adrenergic blockade appeared to be detrimental. Thus, this study demonstrates (1) that coronary arterial spasm may be the underlying mechanism of at least some cases of exertional angina associated with transient perfusion deficits and left ventricular dysfunction, and (2) that it may be prevented by oral nitrates.

Angina Pectoris, Variant↗
PubMed1979

Trainees' retention of cardiopulmonary resuscitation. How quickly they forget.

Lay persons trained in cardiopulmonary resuscitation (CPR) were evaluated six months after completion of a four-hour basic life support course to determine the degree to which CPR cognitive and psychomotor performance skills were retained. Evaluation criteria were based on the American Heart Association's recommended standards. The data disclosed a significant decrease in the resuscitators' retention of CPR knowledge and skills.

American Heart Association↗
PubMed1979

The magnitude of exercise-induced ST segment depression and the predictive value of exercise testing.

The assess whether the magnitude of exercise induced ST segment depression improves the predictive values of symptom limited exercise tests, and helps in the recognition of patients with more severe coronary heart disease, 90 consecutive patients with positive treadmill tests who also underwent selective coronary arteriography were reviewed. The predictive value improved progressively with the increasing ST depression and was most reliable in a select group of patients with normal electrocardiographic baseline who were not receiving digitalis (73% with ST depression greater than or equal to 1 mm to 100% with ST depression greater than or equal to 4 mm). The incidence of 2 and 3 vessel disease increased from 61% with ST depression greater than or equal to 1 mm in the overall population to 100% with ST depression greater than or equal to 4 mm in the select group, and the incidence of left main trunk lesions increased, respectively from 6 to 30%. The prediction of 2 and 3 vessels disease was found to be significantly greater when patients were dichotomized into those with ST depression greater than or equal to 4 mm compared to less than 4 mm. It is concluded that the magnitude of ST segment depression definitely improves the predictive values of exercise tests as well as the ability to recognize the patients with more severe disease. However, the markedly positive exercise tests cannot be utilized to accurately predict the presence of 2 or 3 vessel disease in individual cases unless ST depression attains 4 mm or more in patients with normal electrocardiographic baseline who are not taking digitalis. In this group, the ability to predict left main trunk lesion is approximately 30%.

Coronary Angiography↗