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Biomedical subjects

S Mohiuddin

Publications and source records attributed to S Mohiuddin.

At least 19 recordsLinked to original sources

Arbutamine vs. exercise stress testing in patients with coronary artery disease: evaluation by echocardiography and electrocardiography.

Arbutamine is a new beta-adrenergic agonist with potent chronotropic and inotropic properties developed to pharmacologically induce stress. A prospective trial was conducted in five centers with a total enrolment of 45 patients with angiographically documented coronary artery disease. The primary purpose of the trial was to compare the efficacy of arbutamine with symptom-limited exercise in provoking clinical (angina), electrocardiographic (> or = 0.1 mV ST depression) and echocardiographic (induced wall motion abnormality) evidence of transient stress-induced ischemia. The secondary purpose was to assess the safety of arbutamine in patients with coronary artery disease. Ischemia was induced at a lower heart rate, systolic blood pressure and pressure-rate product during arbutamine infusion than during exercise. Using angina and/or electrocardiographic evidence of ischemia, arbutamine was more sensitive than exercise in detecting myocardial ischemia (77 vs. 58%, P = 0.021). Using echocardiography, the sensitivity for inducing wall motion abnormalities was 88% with arbutamine and 79% with exercise (P = not significant). Echocardiography in combination with angina and/or electrocardiographic evidence increased the sensitivity to 94% using arbutamine and to 88% with exercise. For the patients with multivessel disease, the sensitivity was 97% and 91%, respectively. No serious adverse events, either cardiac or noncardiac, were associated with arbutamine, and no patient had prolonged ischemia. Although exercise is the preferred method of stress for patients who are able to exercise adequately, arbutamine is at least as sensitive as exercise for the diagnosis of myocardial ischemia, and appears to be a safe and effective alternative to exercise testing in patients unable to exercise adequately.

Adrenergic beta-Agonists↗

Adenosine in myocardial perfusion imaging using positron emission tomography.

Because of its unique ability to demonstrate the metabolic consequences of myocardial ischemia, positron emission tomography (PET) is extremely valuable in assessing myocardial viability. PET imaging can identify the myocardial segments that are likely to improve after revascularization and may be more sensitive and specific for the detection of coronary artery disease compared with thallium perfusion imaging. Adenosine has several advantages over dipyridamole as a pharmacologic stress agent for use with PET. It produces maximal vasodilation in a significantly greater percentage of patients, is a more potent coronary vasodilator, and its very short half-life may be ideal for use with the very short half-life radioactive tracers used in PET. When combined with metabolic studies, adenosine may be useful for the assessment of patients who received thrombolytic therapy for an acute myocardial infarction.

Adenosine↗

Persistent hypoxemia due to patent foramen ovale in a patient with adult respiratory distress syndrome.

This report describes a patient in the recovery phase of the adult respiratory distress syndrome in whom the persistence of severe hypoxemia was not corrected by a high fractional concentration of oxygen in the inspired gas and positive end-expiratory pressure. A right-to-left interatrial shunt was diagnosed by M-mode and cross-sectional echocardiography with saline injection, and the presence of a patent foramen ovale was confirmed at the time of cardiac surgery.

Echocardiography↗

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↗

Hereditary progressive atrioventricular conduction defect.

New data on genetics, including an extensive pedigree and certain aspects of natural history, have been compiled on Family S, which is characterized by a hereditary progressive atrioventricular (A-V) conduction defect. Concordance analysis of heart block in affected parents and their offspring suggests as a working hypothesis transmission of diathesis for the defect by means of a Mendelian autosomal dominant factor. Regression of the defect in several relatives, including reversion from first degree heart block to normal A-V conduction, defies explanation at this time. However, rapport established with the unusually large (1,067 members) and cooperative kindred will permit longitudinal evaluation of these findings.

Adolescent↗

Management of acute aortic dissection.

The therapy for acute dissecting aneurysm of the aorta remains a difficult problem for thoracic surgeons. Because of an excessive operative mortality in patients with acute dissection who were operated on within 24 hours of hospital admission, we have utilized intensive medical management to delay surgical intervention. Even patients with acute aortic insufficiency can be supported medically, allowing their operations to be delayed at least 3 weeks or longer. Since this policy has been implemented, there has been no operative mortality in our last 13 patients with acute dissection. Medical therapy as the definitive treatment is now reserved solely for Type III dissections or for patients who cannot be operated on for other reasons. This report outlines our rationale for therapy and our current method of managing acute dissection.

Antihypertensive Agents↗