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Biomedical subjects

A N Mooss

Publications and source records attributed to A N Mooss.

32 records · Page 2Linked to original sources
PubMed1983

Tocainide kinetics in congestive heart failure.

Our subjects were 20 patients with life-threatening or symptomatic ventricular arrhythmias refractory to standard oral antiarrhythmic drugs but responsive to intravenous lidocaine. After evaluation of arrhythmias and treatment with intravenous lidocaine, oral tocainide dosage regimens were based on age, weight, and clinical status. During initial tocainide treatment, six plasma tocainide concentrations were recorded within a single dosing interval in 17 of 20 patients, by which standard kinetic parameters were calculated. Eventual trough steady-state tocainide plasma concentrations were predicted from the derived patient-specific kinetic parameters. Mean daily tocainide dose was 1800 mg (1200 to 2400). Mean daily tocainide doses (milligram per kilogram) did not differ significantly among responders and nonresponders or among patients with or without congestive heart failure. Mean peak and trough plasma concentrations 48 hr after initiation of therapy were 9.8 and 7.5 mcg/ml. Tocainide plasma concentrations did not correlate with responders and nonresponders or identify patients who were developing adverse reactions to tocainide. There were no significant differences in any of the calculated kinetic parameters as a function of response to tocainide or the presence of congestive heart failure, but there was a trend toward smaller volumes of distribution and higher average plasma concentrations at steady state in patients with congestive heart failure. There were no significant kinetic differences among patients with and without congestive heart failure, but a trend toward higher plasma concentrations in patients with congestive heart failure and the small number of patients suggests that further data collection is necessary before dosage recommendations can be made.

Adult↗
PubMed1982

Ventricular fibrillation complicating pacemaker insertion in acute myocardial infarction.

Temporary transvenous pacing catheters were placed in 101 patients with acute myocardial infarction (MI) for the management of bradyarrhythmias or conduction disturbances. Fourteen (14%) patients (group A) developed ventricular fibrillation (VF) at the time of pacing catheter manipulation in the right ventricle. Compared to the remaining 87 (86%) patients (group B), the patients in group A were younger (56.1 vs 65.8 yrs, P = 0.007). Thirteen (92.8%) of 14 patients in group A had inferior MI compared to 58 (66.6%) of 87 patients in group B (P = 0.04). All but one patient in group A had pacemaker insertion within 24 h of the onset of symptoms of MI compared to 55 (63%) of 87 in group B (P = 0.02). In 12 of the 14 patients in group A, following defibrillation and intravenous bolus administration of lidocaine, the pacing catheter was positioned in the right ventricle without further episodes of VF. It is concluded that 1) in patients with acute MI temporary transvenous pacemaker insertion may be complicated by VF; 2) VF is most likely to occur in younger patients with inferior MI infarction when the pacing catheter is inserted within 24 h of the onset of symptoms of infarction; and 3) administration of an intravenous bolus of lidocaine may be effective in preventing the induction of VF by catheter manipulation.

Adult↗
PubMed1981

Digoxin-induced positive exercise tests: their clinical and prognostic significance.

To evaluate the influence of digoxin on the results of exercise testing and the prognostic significance of digoxin-induced positive exercise tests, 98 healthy men, aged 22 to 70 years, were studied. All had normal initial exercise test results. All took digoxin, 0.25 mg daily, for 14 days, and then performed daily exercise tests until each had a negative test response. Five years after these initial tests, a medical history was obtained from 92 of the 98 subjects, and 76 subjects performed repeat exercise tests. Six subjects were lost to follow-up study. Twenty-five percent of subjects (22 of 98) had a digoxin-induced positive exercise test. There was a direct relation between age and the incidence of digoxin-positive tests. The incidence of digoxin-positive tests in men over age 60 years was 100 percent. By 30 seconds after exercise no subject had greater than 1.9 mm S-T depression. No test remained positive for more than 6 minutes after exercise was discontinued. No test was positive 12 days after digoxin was withdrawn. With logistic regression analysis, it was possible to estimate the probability that a subject would have a digoxin-induced positive test. No subject had had a cardiovascular event at follow-up study, but five subjects had a positive repeat exercise test. Four of these subjects had had a digoxin-positive test initially. It is concluded that (1) useful information can be obtained from exercise studies of patients who receive digoxin, (2) the probability that a positive exercise test is due to digoxin can be estimated, (3) to remove the exercise-induced electrocardiographic effect, the drug should be withdrawn for 12 days, and (4) digoxin may unmask subclinical coronary arterial stenosis.

Adult↗
PubMed1980

Automated and nomographic analysis of exercise tests.

A study was conducted to evaluate the validity and usefulness of a commercially available microprocessor for automated exercise ECG analysis and to develop a nomogram for estimating the severity of coronary artery disease. Results of visual analysis, automated analysis, and coronary arteriography were correlated for the 107 patients studied. Automated analysis was shown to be valid and useful. The ST integrals (area of ST depression) recorded after exercise were superior to those recorded during exercise because they manifested higher specificity and predictive value, even though their sensitivity was slightly lower. Using postexercise integrals, it was possible to differentiate mild and severe disease. From multiple-regression analysis of ST integrals, duration of exercise, and the severity of coronary artery disease, a nomogram was derived to estimate severity of coronary artery disease.

Angiography↗
PubMed1979

Unstable angina.

Explore the source record for details and available documents.

Angina Pectoris↗
PubMedDate not supplied

Long-term antiarrhythmic therapy with cibenzoline.

This single-blind, placebo-controlled study evaluated long-term therapy with cibenzoline in 19 patients with chronic ventricular arrhythmias. Antiarrhythmic efficacy, defined as greater than or equal to 75% reduction in single premature ventricular complexes (PVCs), greater than or equal to 90% reduction in paired PVCs, and total abolition of ventricular tachycardia (VT), was established after dose titration in 14 of 19 (74%) patients. Mean frequency of single PVCs was reduced by 65%, mean paired PVC frequency was reduced by 68%, and mean VT event frequency was reduced by 82%. Antiarrhythmic efficacy was maintained during long-term therapy in five of the 14 (36%) short-term responders. Of the nine patients who discontinued cibenzoline during long-term follow-up, five had a loss of arrhythmia control, three failed to redevelop arrhythmias during placebo reintroduction, and one developed an adverse reaction. Three patients (16%) experienced a proarrhythmic effect. Echocardiographic evaluation did not reveal any deleterious effect of cibenzoline on left ventricular function in the group as a whole. In six patients with preexisting left ventricular dysfunction, left ventricular ejection fraction and fractional shortening improved significantly (P less than .05) during cibenzoline therapy. Adverse effects occurred in seven patients (37%) but necessitated drug discontinuation in only one patient (5%). Cibenzoline provides effective short-term therapy for patients with chronic ventricular arrhythmias. Long-term therapy must be assessed periodically to ensure continued efficacy. Drug-related adverse effects occur infrequently. Cibenzoline can be used safely in patients with compensated left ventricular dysfunction.

Adult↗
PubMedDate not supplied

Economic impact of inappropriate histamine2-receptor antagonist use.

Histamine2 (H2)-receptor antagonists are widely prescribed for a variety of acid-mediated gastrointestinal disorders. The objective of the present study was to quantify the frequency of inappropriate H2-receptor antagonist use and its economic impact in patients who were admitted to a critical care bed at our hospital and followed as outpatients for 1 year. Eighty-eight (72%) of 123 patients admitted to the coronary care unit (CCU) or the intensive care unit over a 14-day period received H2-receptor antagonists. Forty-five (51%) of the 88 patients did not have a documented indication for H2-receptor antagonist therapy. Most of the patients without indications were admitted to the CCU for cardiac diagnoses. Thirty-eight patients (43%) were discharged on oral H2-receptor antagonist therapy. Twenty (53%) of the 38 patients had no documented indication for therapy; 17 of these patients continued H2-receptor antagonist therapy for 1 year, whereas the remaining 3 patients received therapy for 1, 2, and 3 months, respectively. The cost of therapy for the 45 patients receiving inappropriate therapy during hospitalization was $5,084.31. Outpatients costs for the 20 patients remaining on inappropriate therapy was $8,619.75. The total cost of inappropriate therapy was $13,704.06. If data collected during this 2-week period were extrapolated to 1 year, the projected annual cost of inappropriate therapy would be $356,305.56. The economic impact of inappropriate H2-receptor antagonist therapy at our institution is great. Programs designed to reduce such inappropriate use must be implemented and evaluated for their ability to decrease the associated costs.

Aged↗
PubMedDate not supplied

A comparison of sublingual nifedipine versus nitroglycerin in the treatment of acute angina pectoris.

The administration of nifedipine by the sublingual rather than the oral route has been suggested to provide a more rapid onset of effect. We compared the safety and efficacy of sl nifedipine to sl nitroglycerin in patients who developed anginal chest pain during diagnostic exercise stress testing. Consecutive patients undergoing diagnostic Bruce treadmill exercise who had not had a recent myocardial infarction or undergone coronary bypass graft surgery and who were not taking nitrates, beta-blockers, digoxin, or calcium antagonists were eligible. Seventy-eight patients meeting the inclusion/exclusion criteria consented to participate. Of these 78, 13 developed chest pain necessitating exercise cessation and were randomized to either nitroglycerin or nifedipine. Nitroglycerin was initially given to seven patients and nifedipine to six patients. Complete pain relief was observed in five of seven (71 percent) nitroglycerin patients at two minutes postdose. At four minutes postdose, the remaining two nitroglycerin patients were essentially pain-free. At two minutes postdose, no patient receiving nifedipine had complete pain resolution, and only one patient (17 percent) had partial (greater than 50 percent) pain relief. At four minutes postdose, four of the nifedipine patients were crossed over to nitroglycerin. At two minutes after the nitroglycerin dose, all four patients had total pain relief. The remaining two nifedipine patients had partial pain relief and were not crossed over to nitroglycerin. Subjective side effects and changes in heart rate and blood pressure were not significantly different between nitroglycerin and nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMedDate not supplied

Double-blind, randomized, placebo-controlled evaluation of atropine to prevent vasovagal reaction during removal of femoral arterial sheaths.

STUDY OBJECTIVE: To evaluate the efficacy and safety of atropine in preventing vasovagal reactions (VVRs) during removal of femoral arterial sheaths after diagnostic left heart catheterization. DESIGN: Prospective, double-blind, randomized, placebo-controlled study. SETTING: University-affiliated, 450-bed teaching hospital. PATIENTS: One hundred sixty-five patients undergoing left heart catheterization. INTERVENTIONS: Eighty-eight patients were assigned to receive atropine 0.5 mg intravenously and 77 received placebo 5 minutes before sheath removal. MEASUREMENTS AND MAIN RESULTS: The frequency of VVRs was significantly reduced in the atropine group compared with the placebo group, 2.3% and 10.4%, respectively (overall relative risk in the atropine group 0.22, 95% CI 0.12-0.41, p=0.03). Significant decreases in systolic (35.2 +/- 5.8 mm Hg, p<0.001) and diastolic blood pressures (12.6 +/- 12.6 mm Hg, p=0.002) occurred in the 10 patients with VVRs compared with those without VVR. No cardiac arrhythmias occurred after atropine administration. Dry mouth was the only side effect reported with atropine (8/88, 9%). CONCLUSION: Atropine significantly reduced the frequency of VVRs associated with removal of femoral arterial sheaths after diagnostic left heart catheterization. The drug should be studied in a larger series of patients to assess its ability to decrease the morbidity and costs associated with VVR.

Atropine↗
PubMedDate not supplied

Restenosis, the Achilles' heel of coronary angioplasty.

Coronary angioplasty is widely performed for the management of symptomatic coronary artery disease. With improvements in technique, operator experience, and tools, more complex lesions are being treated. Unfortunately, luminal renarrowing continues to limit the long-term success of the procedure, resulting in the need for repeat revascularization in approximately 30% of patients within 6 months. As the pathophysiologic process of restenosis is better defined, various pharmacologic and mechanical interventions have been tried to attenuate the process. Some agents are antithrombotics, antiplatelets, angiotensin-converting enzyme inhibitors, lipid-lowering drugs, and calcium channel blockers. Improvement has been noted with the newer glycoprotein IIb- and IIIa-blocking agents, mechanical stents, and radioactive materials. Whether these new compounds will withstand the test of time is unknown.

Angioplasty↗