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Biomedical subjects

N L Coplan

Publications and source records attributed to N L Coplan.

45 records · Page 3Linked to original sources
PubMed1985

Mechanism underlying the absence of ischemic changes on the exercise electrocardiogram in patients with abnormal exercise thallium-201 imaging and coronary artery disease.

Patients with coronary artery disease may have reversible abnormalities on a thallium myocardial perfusion study without simultaneous ischemic changes on the exercise electrocardiogram, but the mechanisms responsible for this disparity have not been fully elucidated. A group of 37 patients with angiographically demonstrated coronary artery disease and abnormal thallium perfusion imaging were divided into two groups on the basis of their exercise electrocardiographic ST segment response. Thirteen patients (Group A) had no significant electrocardiographic changes with exercise, while 24 patients (Group B) had ST changes consistent with ischemia during the test. There were no significant differences in clinical or angiographic characteristics between the two groups. Stress test results showed a similar mean duration of exercise in the two groups (6.2 +/- 1.8 versus 6.7 +/- 2.5 min, p = NS), but the patients in Group A achieved a significantly lower mean maximal heart rate (117 +/- 26 versus 132 +/- 21 beats/min, p less than 0.05) and mean maximal double product (19,650 +/- 5116 versus 22,650 +/- 4871, p less than 0.05). There was no consistent pattern of thallium perfusion abnormality noted in Group A to suggest that a particular region of electrically silent myocardium was responsible for ischemia in the absence of electrocardiographic changes. These results suggest that exercise thallium-electrocardiogram discordance is mediated by the level of myocardial workload achieved. An abnormal perfusion scan accompanying an exercise electrocardiogram which does not demonstrate any ischemic ST change may occur when there is sufficient increase in myocardial oxygen demand to result in differential augmentation of myocardial blood flow, but insufficient imbalance of supply and demand to result in signs of ischemia on the surface electrocardiogram.

Cardiac Catheterization↗
PubMed1985

Unilateral neck pulsations in a patient with a permanent pacemaker.

An asymptomatic patient with a permanent pacemaker presented with unilateral accentuated neck pulsations. Evaluation revealed tricuspid insufficiency, a massively dilated right internal jugular vein, and obstruction of the left internal jugular vein. There was no evidence of aneurysm, vascular tumor, or fistula. The most likely explanation for this constellation of findings is tricuspid regurgitation occurring in the setting of unilateral internal jugular vein occlusion. Such a combination should be considered in the differential diagnosis of asymmetrical neck pulsations in a patient with a transvenous pacemaker.

Humans↗
PubMed1985

Ostial left main stenosis following repair of a ruptured sinus of Valsalva aneurysm.

A patient complained of angina pectoris nine months after surgical repair of an aortic right atrial fistula and mitral valve replacement. Subsequently, he was shown to have a new obstruction of the ostium of the left main coronary artery. This case illustrates the need to consider this syndrome in the differential diagnosis of postoperative complaints of chest pain, especially following an operation which involves direct cannulation of the coronary arteries.

Angina Pectoris↗
PubMed1985

Natural history of idiopathic dilated cardiomyopathy. Implications for future therapy.

Idiopathic dilated cardiomyopathy can present in a number of different ways, with the majority of patients having heart failure. Natural history studies show a poor prognosis for most patients with this disease. However, a substantial number may stabilize or even improve, and have a survival curve similar to patients without the disease. Patients can be stratified for relative risk of mortality by age, cardiomegaly on chest roentgenograph, ventricular function, and quantitative assessment of ventricular arrhythmias. Therapy can be divided into three categories: alteration of factors associated or contributors to ventricular dysfunction, supportive therapy, and investigational therapy. The efficacy of therapy should be judged by its effect on functional capacity and survivorship. The first category includes controlling hypertension and abstaining from alcohol. This often leads to improved functional status, and may improve survival. The second category includes anticoagulant therapy and, most importantly, medications for heart failure (digoxin, diuretics, vasodilators, nonglycoside inotropes, etc.). These agents may improve functional status, but in general have had little impact on survival. Investigational medical therapy for future use depends upon identification of factors involved in the genesis of the disease and the pathophysiologic mechanisms responsible for morbidity and mortality. The inflammatory component in the genesis and/or maintenance of cardiomyopathy, the importance of frequent ventricular arrhythmias in prognosis and the influence of endogenous vasoconstrictors on heart failure and arrhythmias, have been mentioned as such areas of interest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1984

Carotid sinus hypersensitivity. Case report and review of the literature.

Carotid sinus hypersensitivity is a potentially treatable cause of recurrent neurologic symptoms. Diagnosis depends upon recognizing the variable presentation of symptomatic carotid sinus hypersensitivity, and noting an exaggerated cardiovascular response to carotid sinus massage associated with neurologic symptoms. Once the diagnosis of symptomatic carotid sinus hypersensitivity has been established, it is important to delineate the type of hypersensitivity present, because identification of the vasodepressor response has important therapeutic implications.

Carotid Artery Diseases↗
PubMed1984

Pericardial mesothelioma masquerading as a benign pericardial effusion.

A 53 year old asymptomatic man presented with a primary pericardial mesothelioma masquerading as a benign pericardial effusion. Although M-mode echocardiography showed an echo-free space, two-dimensional echocardiography and thoracic computed tomography demonstrated that the suspected effusion was caused by a mass surrounding the heart. Newer noninvasive techniques can be valuable for the early detection of pericardial tumor.

Diagnosis, Differential↗