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Biomedical subjects

A Greengart

Publications and source records attributed to A Greengart.

32 records · Page 2Linked to original sources
PubMed1984

Methemoglobin levels produced by organic nitrates in patients with coronary artery disease.

To determine if ordinary doses of nitrates produce a significant increase in methemoglobin, methemoglobin levels were measured in 59 randomly selected patients with coronary artery disease and unstable angina pectoris who were receiving organic nitrate therapy. Patients were taking isosorbide dinitrate, 2% nitroglycerin ointment, or a combination of the two. Patients were subdivided according to whether they were using one (group A) or more than one (group B) organic nitrate preparations. These results were compared with 17 control patients. Mean methemoglobin levels in group B were 1.78 +/- 1.29%, and this differed significantly (P less than 0.05) from both group A mean methemoglobin, 1.13 +/- 0.92%, and controls, 0.99 +/- 0.55%. The proportion of patients with elevated methemoglobin concentration increased from the control to group A to group B. It is concluded that commonly used dosages of nitrates are capable of causing elevations of methemoglobin which are probably not of routine clinical significance. However, these elevations may be of import in certain patient populations such as those with coronary insufficiency or anemia.

Aged↗
PubMed1984

High mortality early reinfarction with first nontransmural myocardial infarction.

Thirty-eight patients with first nontransmural myocardial infarction were studied to determine prognosis and clinical markers of a high-risk subgroup. We found a high incidence of reinfarction (18%) at a median time of 16 days post nontransmural infarction (seven patients). Reinfarction was uniformly associated with death within 24 hours. A total of 14 patients (37%) either died (eight patients) or required urgent revascularization (six patients). Predominant ST segment depression with presenting nontransmural infarction and a history of prior angina were associated with increased mortality (p less than 0.05 and p = 0.05, respectively). We conclude that patients with nontransmural infarction are at high risk for early recurrent infarction. Patients with history of prior angina and predominant ST segment depression may be at particularly high risk. Reinfarction in these patients is frequently extensive. We recommend that these patients be considered for early coronary angiography.

Aged↗
PubMed1984

Dilated cardiomyopathy in identical twins.

Identical twins had dilated cardiomyopathy and evidence of an autoimmune process involving both the heart and thyroid gland. An inherited abnormality of immune regulation is suggested as a possible basis for these unusual findings.

Adult↗
PubMed1983

Single catheter technique for accurate cardiac outputs from left ventricle.

We report our experience in cardiac output measurements using a single catheter for left ventricular green dye injection with sampling from the side arm of a femoral artery introducer sheath. This technique is compared to thermal dilution (20 patients) and pulmonary artery green dye injection (20 patients). There were no significant differences between the single catheter left ventricular method and the other two accepted methods for measuring cardiac output.

Cardiac Catheterization↗
PubMed1983

Bundle branch block in acute myocardial infarction.

The management of patients with acute myocardial infarction complicated by bundle branch block is a significant clinical problem and represents 8% to 13% of patients with acute infarction. This study reviews the records of 606 patients with myocardial infarction admitted to our coronary care unit. Forty-seven (8%) had complete bundle branch block. The risk of developing high-degree AV block in these 47 patients was reviewed. There are no established therapeutic guidelines for patients with pre-existing bundle branch block and left bundle branch block in acute myocardial infarction. We found a high risk of progression in patients with pre-existing bifascicular block in the presence of anterior wall infarction (25%) as well as in patients with left bundle branch block with acute anterior wall infarction (100%). On the basis of our data and careful review of the literature, we recommend prophylactic pacemaker insertion in these high-risk groups.

Bundle-Branch Block↗
PubMed1983

Clinical significance of slow paroxysmal atrial tachycardia.

This study examines the clinical setting, characteristics, and follow-up of 173 patients who had slow paroxysmal atrial tachycardia (SPAT) (greater than 4 beats, rate less than 150 bpm) during 24-hour Holter monitoring. These episodes were classified by probable mechanism according to recognized ECG criteria and included AV nodal reentry (AVNR), sinoatrial nodal reentry (SANR), and automatic (A). There were 76 males (44%) with a mean age of 72 years and 97 females (56%) with a mean age of 73 years. The indications for Holter recording revealed that the SANR and A subgroups had a higher frequency of cerebral symptoms compared to AVNR (p less than 0.01). Chest pain was more common in the SANR group as compared to the other two groups (p less than 0.01). There was no difference in the frequency of palpitation in the three subgroups. The mean rate of SPAT for the entire group was 115.2 +/- 14 and these episodes had a mean duration of 5.58 +/- 3.07 seconds. The SANR subgroup had a significantly slower rate (107.1 +/- 9.2) as compared to the AVNR subgroup (p less than 0.01). One hundred fourteen patients were available for follow-up. The average period of follow-up was similar for all three groups. At follow-up the frequency of sick sinus syndrome as determined clinically and permanent pacemaker insertion was significantly greater in the SANR subgroup (p less than 0.01) as compared to the other subgroups which did not differ from each other.

Aged↗
PubMed1983

Efficacy of sustained-release buccal nitroglycerin in patients with angina pectoris. New and long-acting therapy demonstrated by exercise.

The antianginal efficacy of a single sustained-release buccal nitroglycerin (BNTG) tablet was assessed in 16 patients with known coronary artery disease. Patients were trained in bicycle ergometry to induce angina pectoris within three to five minutes. A hemodynamically effective dose of BNTG was identified. Patients were tested at baseline and given placebo and BNTG in a randomized, double-blind manner on consecutive days. They were tested at 0.5, 1, 3, and 5 hours after drug administration. The average increase in exercise duration with BNTG compared with placebo at 0.5 hours was 40 percent (p less than 0.01); at 1 hour was 31 percent (p less than 0.01); at 3 hours was 27 percent (p less than 0.01); at 5 hours was 15 percent (p = NS). In a subset of ten patients in whom the tablet was maintained in the buccal pouch for five or more hours before dissolving, increase in exercise duration was significant at all times tested (p less than 0.05). We conclude that BNTG is an effective modality of administering nitroglycerin for rapid and prolonged effect with reduction in angina pectoris and increase in exercise duration which may persist for at least five hours.

Adult↗
PubMed1982

Current incidence of postmyocardial infarction (Dressler's) syndrome.

This study examines the current incidence of postmyocardial infarction (Dressler's) syndrome. During 1980, 282 patients with documented myocardial infarction were admitted to our coronary care unit. Early postmyocardial infarction pericarditis was present in 18 patients (6.4%). Six of these patients received steroids and the remainder were treated with salicylates or other anti-inflammatory drugs. Anticoagulation was used in 149 patients (53%) during hospitalization. One hundred forty-four (51%) were receiving heparin and 133 (47%) received no anticoagulation. Information on the patient's status at 6 months was available in 229 patients who were discharged alive. Sixteen patients had died within 6 months after discharge and 4 patients were lost to follow-up study. There were no documented cases of Dressler's syndrome. It is concluded that Dressler's syndrome has decreased in incidence and perhaps disappeared. This decrease is most likely related to decreased use of oral anticoagulants and to more aggressive treatment of postmyocardial infarction pericarditis.

Anti-Inflammatory Agents↗
PubMed1982

Relationship between QRS width and the presence of neoplasm.

This study examines the relationship between QRS width and the presence of neoplasia. The QRS width was measured in 236 consecutive ambulatory patients. The patients' body surface area, CBC, SMA 6, and SMA 12 were also recorded. There were 17 out of 34 (50%) patients with neoplasia in the group with QRS less than 0.08 seconds. There were only 19 out of 78 (24%) with neoplasia in the group with QRS greater than or equal to 0.08 seconds (P less than 0.01). We conclude that there is a higher incidence of neoplasia in patients with a QRS less than 0.08 seconds than in patients with a QRS greater than or equal to 0.08 seconds. This difference cannot be explained by age, body surface area, hemoglobin, or any variable in SMA 6 or SMA 12.

Aged↗
PubMed1982

Natural history of severe sinus bradycardia discovered by 24 hour Holter monitoring.

This study follows patients with severe sinus bradycardia (40 beats per minute for 6 seconds or greater) in order to evaluate mortality and the effectiveness of permanent pacemaker insertion. Severe sinus bradycardia was noted on a 24-hour Holter in 95 patients. There were 64 males and 31 females with a mean age of 69 +/- 10 years. All were available for follow-up at 26 +/- 13 months. Twenty-eight required a permanent pacemaker at an average of 2 +/- 3 months after the Holter. Of this group 12 had the Holter for arrhythmia, 11 for cerebral symptoms, 4 for palpitations and 1 for chest pain. Only 1 was taking digitalis and no patients were taking Inderal. Six (21%) died at a mean interval of 21 +/- 15 months following pacemaker insertion. Sixty-seven did not require pacemaker insertion. The indications for Holter monitoring were arrhythmia in 16, palpitations in 19, cerebral symptoms in 20 and chest pain in 12. Four of these patients were on digitalis, 8 on Inderal, and 4 on both. Eleven (16%) died at a mean interval of 12 +/- 7 months after the initial Holter recording. Dizziness and/or syncope reoccurred in 22. Five had these symptoms even after pacemaker insertion. We conclude that severe sinus bradycardia is associated with a significant mortality. Insertion of a permanent pacemaker may decrease recurrent symptoms and slightly increase time of survival, but does not appear to influence the overall survival rate.

Aged↗
PubMed1982

Coronary artery spasm appearing as syncope.

A 56-year-old man had coronary artery spasm. The initial manifestation of the disease was syncope that occurred at night. Coronary artery spasm was documented by Holter recording and cardiac catheterization. The patient was effectively treated with nitrates and calcium-blocking agents.

Angina Pectoris, Variant↗
PubMedDate not supplied

Treatment of severe left ventricular dysfunction with calcium chloride in patients receiving verapamil.

This report describes two patients who received verapamil because of supraventricular arrhythmias. The patients both developed severe hypotension and signs of left ventricular compromise. The hypotension and left ventricular compromise were promptly reversed by administration of intravenous calcium chloride. The dramatic improvement was documented clinically and in one case by two-dimensional echocardiography.

Arrhythmias, Cardiac↗