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A Movahed

Publications and source records attributed to A Movahed.

54 records · Page 3Linked to original sources
PubMed1990

Quantification of acute aortic regurgitation by color Doppler flow in an experimental animal model.

Color Doppler flow studies were performed on ten anesthetized open-chest dogs. Acute aortic regurgitation was created in the dogs by a special valve-spreading catheter. The magnitude of valvular regurgitation was determined by aortic electromagnetic flow recordings of regurgitant fraction. Arbitrarily-designated grades of aortic regurgitation: mild (4%-10%), moderate (11%-30%), and severe ( greater than 30%) were assigned on the basis of electromagnetic flow. We attempted to obtain studies of varying degrees of AR in each animal. Mean regurgitant fraction for the three grades were 6.8 +/- 0.6% (n = 11), 22.0 +/- 2.4% (n = 7), and 40.4 +/- 2.5 (n = 20), respectively (each P less than 0.05). By color Doppler flow assessment, the ratio of regurgitant jet height to the left ventricular dimension at the junction of the left ventricular outflow tract and the aortic annulus (JH/LVOH) was measured in each study. AR was classified by Doppler as grade I (mild), 1%-24%; II (moderate), 25%-64%; and III (severe), greater than or equal to 65% jet height/left ventricular outflow tract height. Color Doppler flow correlated well with flowmeter assessment of regurgitant fraction. Color Doppler flow tests had a calculated sensitivity of 88%, specificity of 83%, and predictive value of 85% for significant (moderate + severe) aortic regurgitation. Our data support the concept that this method of color Doppler flow assessment provides a quantitative noninvasive evaluation of aortic regurgitation.

Animals↗
PubMed1989

Anginal chest pain in sarcoidosis.

Of 43 consecutive black patients (42 male) with sarcoidosis, 12 (28%) complained of chest pain that met the clinical criteria for typical (four patients) or atypical (eight patients) angina pectoris. These patients underwent cardiopulmonary assessment, which included exercise and redistribution thallium-201 scans and, if indicated, coronary angiography. Nine control patients with sarcoidosis matched for age and duration of disease, but without chest pain, were also studied by thallium-201 scintigraphy. Six of the 12 patients with chest pain had thallium scans indicative of myocardial ischaemia, but all had normal coronary angiograms; no patient from the control group had evidence of ischaemia on the thallium scan. Four additional patients with chest pain and one from the control group had other (non-specific) abnormalities on the thallium scan, so that scans were abnormal in 10 of the 12 patients with sarcoidosis who had chest pain. Most patients with anginal chest pain reported partial or complete relief of symptoms with nitrates. Anginal chest pain appears to be common in black male patients with sarcoidosis, is associated with abnormal myocardial perfusion scans, and may result from myocardial sarcoidosis.

Adult↗
PubMed1987

Current review of exercise testing: application and interpretation.

Exercise testing has changed dramatically in scope over the past 50 years. While initially used to assess functional capacity, it is now also utilized to detect the presence and severity of coronary artery disease (CAD), to evaluate postmyocardial infarction patients at risk for future cardiac events, to screen certain asymptomatic populations for CAD, and to evaluate dysrhythmias, peripheral vascular disease, and lung disease. Dynamic exercise in continuous multistage protocols is most popularly employed because of the more easily measured workload. The safety of exercise testing, its contraindications and termination end points are summarized. The sensitivity of exercise testing ranges between 60 and 70% while specificity has been reported between 85 and 90%. Both sensitivity and specificity are enhanced through use of radionuclide exercise thallium imaging and ventricular angiography.

Coronary Disease↗
PubMed1984

Secondary mania associated with diltiazem.

Diltiazem, a calcium-channel blocker, is an effective antianginal agent, particularly in treating the vasospastic type of angina pectoris. This drug has recently been released for use in the United States. Noncardiac untoward effects of diltiazem are few. We describe a case of mania with psychotic features that occurred while a patient was on diltiazem.

Angina Pectoris↗
PubMed1984

Electrocardiographic changes of acute lateral wall myocardial infarction: a reappraisal based on scintigraphic localization of the infarct.

To determine how often acute lateral myocardial infarcts may be electrocardiographically "silent," a new approach was utilized in which subjects were selected by admission thallium scintigraphy. Thirty-one patients with their first infarction were identified with moderate to severe perfusion defects of the lateral and posterolateral walls, persistent over 7 days and associated with severe wall motion abnormalities. Patients with involvement of the anterior, septal or "inferior" regions were not included. In nine patients, the perfusion defect extended to the anterolateral wall: all developed ST elevation and Q waves in at least one of the "lateral" leads (I, aVL or V6) but none showed changes in the "inferior" leads (II, III or aVF). In the other 22 patients, the perfusion defect was limited to the lateral and posterolateral walls: only 12 showed ST elevations (inferior leads only in 7, lateral leads only in 2, both leads in 3) and only 9 developed Q waves (inferior in all). In 8 of these 22 patients, the infarct was silent in the sense that no ST segment elevation or Q waves were seen, although ST depressions or T wave inversions, or both, in all but one patient were compatible with subendocardial infarction. The results indicate that the standard electrocardiogram is insensitive to changes in the lateral and posterolateral regions. Additional diagnostic studies are needed for proper localization and sizing of acute myocardial infarcts.

Adult↗
PubMedDate not supplied

The safety of adenosine pharmacologic stress testing in patients with first-degree atrioventricular block in the presence and absence of atrioventricular blocking medications.

BACKGROUND: Pharmacologic stress testing in conjunction with radionuclide myocardial perfusion imaging may be used in the diagnosis of coronary artery disease and risk assessment. Adenosine can cause atrioventricular nodal (AV) block during infusion. In this study, we evaluated whether patients with baseline first-degree AV block could safely undergo adenosine stress testing. METHODS AND RESULTS: We evaluated the frequency of second- and third-degree AV block in patients with baseline first-degree AV block during adenosine stress testing, in the presence and absence of AV blocking medications (digitalis, beta-blockers, diltiazem, verapamil). Six hundred consecutive patients underwent pharmacologic stress myocardial perfusion imaging with adenosine infusion at 140 microg/kg/min for 6 minutes. A total of 43 patients (7.16%) had baseline first-degree AV block (PR interval > 200 msec), and 557 patients had a baseline PR interval < 200 msec. Twenty-one of the 43 patients (48.8 %) had further prolongation of PR interval > 240 msec, compared with 58 of 557 patients (10.4%) in the control group (P < .0001). In 16 of the 43 patients (37.3 %), second-degree AV block developed, compared with 45 of 557 patients (8.0 %) in the control group (P < .0001). In 6 of the 43 patients (13.9%), third-degree AV block developed, compared with 6 of 557 patients (1.0%) in the control group (P < .0001). All types of AV block were short duration and were not associated with any specific symptoms. None of these episodes required specific treatment. The presence of AV blocking medications (digitalis, beta-blockers, diltiazem, verapamil) did not increase the incidence of AV block during adenosine infusion. CONCLUSION: In patients with baseline PR interval of more than 200 msec, the frequency of second- and third-degree AV block during adenosine stress testing was significantly higher than in patients with a normal baseline PR interval. AV blocking medications did not increase the incidence of second- and third-degree AV block during adenosine stress testing. We conclude that it is safe to perform adenosine pharmacologic stress testing in patients with baseline PR prolongation.

Adenosine↗
PubMedDate not supplied

The frequency of atrioventricular block during adenosine stress testing in young, middle-aged, young-old, and old-old adults.

The frequency of atrioventricular (AV) block was evaluated in 600 consecutive patients of different age groups referred for pharmacologic stress testing. Adenosine was infused at 140 mg/kg/min for a total of 6 minutes in conjunction with radionuclide myocardial perfusion imaging. Seventy-five patients (12.5%) were young adults (< 49 years old), 214 (35.6%) were middle-aged (50-65 years), 195 (32.6%) were young-old (66-75 years), and 116 patients (19.3%) were old-old (over 75 years). The frequencies of first-degree AV block in young adults, middle-aged, young-old, old-old, and all ages were 14.6%, 9.3%, 14.3%, 17.24%, and 13.16%, respectively. The frequencies of second-degree AV block were 14.65%, 7.0%, 8.7%, 15.5%, and 10.1%, respectively. The frequencies of third-degree AV block were 2.66%, 2.33%, 1.0%, 2.58%, and 2.0%, respectively. Comparison of the incidence of the three types of AV block for each age group vs. all patients showed no statistically significant difference (p > 0.08). All types of AV block were of short duration, were well tolerated, and did not require discontinuation of the adenosine infusion or specific treatment. This study confirms the safety of adenosine stress testing in all age groups for evaluation of coronary artery disease and risk assessment.

Adenosine↗
PubMedDate not supplied

Role of beta blockers in congestive heart failure.

Prolonged activation of the adrenergic nervous system has adverse consequences on the cardiovascular system in patients with congestive heart failure. Beta adrenergic receptor-blocker therapy modifies these deleterious effects. Beta blockers have been shown to improve myocardial function and survival when used in conjunction with conventional treatment with diuretics, angiotensin-converting enzyme inhibitors, and digoxin. Beta blocker therapy in mild-to-moderate heart failure should not be delayed because it causes some reversal of both neurohormonal compensatory mechanisms and the deleterious myocardial remodeling process. This paper reviews the beneficial effects of beta adrenergic receptor-blocker therapy on the pathophysiology, symptoms, left ventricular function, morbidity, and mortality in patients with congestive heart failure. (c)2000 by CHF, Inc.

Journal Article↗
PubMedDate not supplied

Reversible cardiomyopathy due to selenium deficiency.

Selenium is an essential trace element and a component of glutathione peroxidase, an enzyme that may help to prevent oxidative damage to cells. Selenium deficiency has been linked to the development of Keshan disease, a dilated congestive cardiomyopathy occurring primarily in children living in rural China. Sporadic cases have been reported in the United States in individuals with poor nutritional intake, mostly in individuals on long-term home parenteral nutrition. This report describes a young black woman with Crohn's disease in whom a congestive cardiomyopathy developed and was subsequently reversed following administration of selenium.

Adult↗
PubMedDate not supplied

A radioimaging technique for quantifying regional myocardial blood flow.

We developed a radioimaging technique for measuring regional myocardial blood flow (rMBF) in 5 mm2 myocardial tissue using canine closed-chest models. RMBF was measured in three groups: (1) total occlusion of left anterior descending (LAD) coronary artery with microfibrillar collagen, (2) fixed stenosis of LAD with angioplasty balloon, and (3) comparison of clinical dose response of adenosine (AD) and dipyridamole (DP) on rMBF. In these studies, rMBF in every 5 mm2 tissue was measured throughout the epicardium and endocardium. In groups 1 and 2, rMBF was also measured during adenosine-induced coronary hyperemia (ADICH). In group 1 (n = 7), rMBF measured at 6 hours post-LAD occlusion in epicardial infarct center (IC), peri-infarct (PI) and normal zone (NZ) were 17 +/- 7, 55 +/- 8, and 132 +/- 12 ml/min/100 tissue, respectively. The area and location of infarct seen in TTC staining matched with rMBF images. During ADICH, the corresponding rMBF were 16.2 +/- 13.9, 98.3 +/- 53.0, and 226.0 +/- 103.6 ml/min/100 g tissue, respectively. RMBF measured during ADICH in group 2 (n = 4) in areas of LAD stenosis (LS), surrounding stenosis (SS), and no stenosis (NS) were 120 +/- 58, 249 +/- 123, and 432 +/- 181 ml/min/100 gm tissue, respectively. In group 3, rMBF measured during 3 min into 0.14 mg/kg/min adenosine infusion in areas perfused by LAD, circumflex (CX) and right coronary artery (RCA) were 244 +/- 22, 238 +/- 19, and 215 +/- 19 ml/min/100 g tissue, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMedDate not supplied

Evidence for free-radical mediated injury during coronary artery bypass surgery.

Prolonged global ischemia followed by reperfusion during coronary artery bypass graft (CABG) surgery leads to a burst of oxygen free-radical generation and subsequent myocardial impairment. Blood samples were collected at different time periods from the right atrium of patients (n = 55) who underwent CABG surgery. Free-radical activity was measured by assays for thiobarbituric acid reactive species (TBARS), mainly malondialdehyde (MDA), at zero minute (before aortic cross-clamp), one minute and 10 minutes after declamping i.e. reperfusion. There was a significant increase (p < 0.001) in the level of MDA at one minute of reperfusion which continued to be elevated up to 10 minutes. This increase was significantly correlated with aortic cross-clamp time (r = 0.525, p < 0.05). The activity of CPK and CPK-MB was raised by two fold (p < 0.001) after release of the clamp. Plasma Troponin-T level was estimated in 10 patients during CABG surgery and a significant increase (p < 0.01) was observed at one minute as well as 10 minutes of reperfusion which correlated well (r = 0.81, p < 0.01) with the severity of ischemia. The concomitant rise in TBARS (marker of free-radical activity), CPK, CPK-MB and Troponin-T (indicators of myocardial damage) on reperfusion implies that there is free-radical mediated damage to the cardiac membrane during CABG surgery.

Biomarkers↗