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Biomedical subjects

A H Hakki

Publications and source records attributed to A H Hakki.

At least 73 records · Page 4Linked to original sources
PubMed1984

Left ventricular function in patients with coronary heart disease in the presence or absence of angina pectoris during exercise radionuclide ventriculography.

This study compares left ventricular (LV) performance during exercise in patients with angiographically documented coronary artery disease (CAD) based on the presence or absence of angina pectoris during the index exercise tests. The patients were divided into 2 groups: Group I included 31 patients who had angina pectoris during the test and Group II included 43 who did not. Multivessel CAD was present in 21 patients (68%) in Group I and 26 patients (60%) in Group II (difference not significant [NS]). There were no significant differences between the 2 groups in age, sex, history of diabetes mellitus, history of myocardial infarction and in the exercise duration, work load, heart rate and systolic blood pressure. Exercise-induced ST-segment depression was present in 48% of the patients in Group I and in 40% in Group II (NS). The mean LV ejection fraction at rest was 52 +/- 12% in Group I and 50 +/- 17% in Group II (NS). There were significant differences in the 2 groups in the change from rest to exercise in ejection fraction (-4.5 +/- 7.6% in Group I vs 1 +/- 9.4% in Group II, p less than 0.01), end-systolic volume (29 +/- 38 ml in Group I vs 9 +/- 23 ml in Group II, p less than 0.005), the change in systolic blood pressure-to-end-systolic volume ratio (-0.1 +/- 0.5 mm Hg/ml in Group I vs 0.3 +/- 1.1 mm Hg/ml in Group II, p less than 0.05), and wall motion score (-0.4 +/- 0.6 in Group I vs 0.09 +/- 0.7 in Group II, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1984

Location of myocardial necrosis as an independent determinant of left ventricular performance: analysis of 96 patients.

This study determines whether the location of myocardial scarring has an effect independent of its size on left ventricular (LV) ejection fraction (EF) in patients with coronary artery disease. Two groups of patients were studied: Group I (n = 44) had resting thallium-201 perfusion defects involving the anterior wall or septum or both, and Group II (n = 52) had perfusion defects involving the inferior wall or posterior wall or both. The thallium images were divided into 5 segments in each of 3 projections, and the thallium score was determined from the number of abnormal segments and the degree of reduction of thallium uptake; the higher the score, the more severe the perfusion deficit. If the thallium score was less than or equal to 10, EF was 45 +/- 14% (mean +/- standard deviation) in Group I and 47 +/- 11% in Group II (p = not significant [NS]). If the thallium score was greater than 10, EF was 30 +/- 12% in Group I and 32 +/- 11% in Group II (NS). Similarly, EF was not significantly different between the 2 groups when the perfusion defects were assessed by the number of abnormal segments. In each group EF was significantly lower as the number of abnormal segments increased or as the thallium score was higher (p less than 0.01). The results were unchanged when patients with resting ischemic defects or women were excluded. Thus, the location of myocardial scar itself is not important in determining LV function. However, the size of the scar is important in determining LVEF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Effects of angiographic contrast medium on left ventricular function: evaluation by contrast angiography and radionuclide angiography.

The purpose of this study was to evaluate the effect of angiographic contrast medium on left ventricular (LV) function in 26 patients undergoing diagnostic cardiac catheterization. Beat-by-beat analysis during contrast ventriculography showed that the ejection fraction (EF) was lower in the last beats than in the first beats (P less than .02). Radionuclide angiograms were obtained the day before, as well as 15 to 65 minutes after catheterization, which included contrast ventriculography and coronary anteriography. The EF by radionuclide angiography was lower after catheterization than before (43 +/- 14% vs 47 +/- 17%, P less than .01). The EF decreased by greater than or equal to 5% in 11 of the 26 patients (42%) after catheterization. The decrease in EF in some patients was observed up to 65 minutes after catheterization and was not associated with symptoms or ST-T changes. The EF decreased in only one of nine patients who received nitroglycerin during catheterization, whereas it decreased in 10 of 17 patients who did not receive nitroglycerin (P less than .05). The EF decreased in 9 of 14 patients (64%) who had normal resting LV function, whereas it decreased in only 2 of 12 patients (17%) who had abnormal resting function (P less than .05). Thus, contrast material may depress LV function up to 1 hr and is more frequent in patients with normal resting EF. The use of nitroglycerin during catheterization may mask this effect.

Adult↗
PubMed1984

Evaluation of patients with coronary artery disease during exercise: the relation between extent of disease and perfusion deficit.

The purpose of this study was to assess the relation between the extent of coronary artery disease (CAD) and size of exercise-induced myocardial hypoperfusion in 79 patients with angiographically documented CAD. None of the patients had Q-wave myocardial infarction. Fifty patients had one-vessel disease, ten had two-vessel disease, and 19 patients had three-vessel or left main disease. From a scintigraphic functional standpoint, patients were classified into two groups: 28 patients (35%) had large perfusion defects and 51 patients (65%) had small defects. The size of the thallium-201 perfusion defect during exercise was assessed as the perimeter of the defect in each projection expressed as a percentage abnormality of the total left ventricular perimeter in that projection. The average abnormality from the three projections was used in the final analysis. Eleven patients with large defects (39%) had one-vessel disease and 12 patients with small defects (24%) had multivessel disease. Stepwise multivariate discriminate analysis identified the number of diseased vessels (F = 13.9), the change in systolic blood pressure from rest to exercise (F = 10.8), the exercise heart rate (F = 9.1), and exercise electrocardiographic response (F = 7.8) as significant associates of the size of the perfusion defect (predictive accuracy = 70%). We conclude that the size of hypoperfused myocardium during exercise is variable in patients with CAD. Discriminate analysis identified the extent of CAD, exercise heart rate, change in systolic pressure from rest to exercise, and exercise electrocardiographic response as significant associates of the size of the defect.

Cardiac Catheterization↗
PubMed1984

Determinants of outcome following left ventricular aneurysmectomy.

UNLABELLED: The determinants of outcome after left ventricular aneurysmectomy are not well understood. We analyzed preoperative follow-up information on 38 patients who had undergone left ventricular aneurysmectomy. At a mean follow-up of 39 months (range 6 to 68), 25 patients (66%) improved by at least one functional class (New York Heart Association) (Group I), and 13 patients (Group II) either died (n: 8) or had persistent congestive heart failure (n: 5). Patients in Group I had significantly higher left ventricular ejection fraction before surgery than patients in Group II (38 +/- 12% vs. 29 +/- 14%, P less than 0.04). The volume of the aneurysm at end-diastole was smaller among patients in Group I than Group II (42 +/- 32 ml vs. 73 +/- 47 ml, P less than 0.04). The contractile indices of the nonaneurysm segment, contractile segment ejection fraction, basilar half ejection fraction, and basilar fractional area shortening were not significantly different between the two groups. There was no difference between the two groups in the preoperative left ventricular end-diastolic pressure, cardiac index, pulmonary artery wedge pressure, pulmonary artery pressure, extent of coronary artery disease, number of bypass grafts inserted, or aortic cross-clamp times. CONCLUSION: 1) The ejection fraction and volume of the aneurysm are more important predictors of outcome after left ventricular aneurysmectomy than the contractile indices of the nonaneurysmal left ventricle and 2) symptomatic improvement occurs in 66% of patients after left ventricular aneurysmectomy.

Adult↗
PubMed1984

Regulation of cardiac output during upright exercise in patients with aortic regurgitation.

The change in cardiac output during upright exercise in patients with aortic regurgitation (AR) is not well known. We measured left ventricular (LV) ejection fraction (EF) and volume, regurgitant fraction (RF), total cardiac output and forward cardiac output at rest, and peak upright exercise by means of radionuclide angiography in ten normal subjects and 15 patients with AR. In the normal subjects, there was no significant change in the end-diastolic volume but there was a significant decrease in the end-systolic volume (p = 0.0001) and a significant increase in EF (p = 0.0001). The increase in cardiac output during exercise was due to increases in both stroke volume and heart rate. In patients with AR, there was a significant decrease during exercise in RF (53 +/- 15% at rest, and 45 +/- 15% during exercise; p = 0.03), and in end-diastolic and end-systolic volume (p = 0.02, and p = 0.003, respectively). The EF increased during exercise (p = 0.003). The total stroke volume did not change (68 +/- 19 ml/m2 at rest, and 67 +/- 14 ml/m2 during exercise; p, NS). Thus, in patients with AR, individual changes in EF, RF, and volume are quite variable, but as a group a decrease in RF and an increase in heart rate contribute to the increase in forward flow. The total stroke volume may not increase during exercise, despite an increase in EF and a decrease in end-systolic volume because of a concomitant decrease in end-diastolic volume.

Adolescent↗
PubMed1984

Cardiac function in hyperthyroidism.

It is accepted that thyroid hormones, thyroxine and tri-iodothyronine have direct inotropic and chronotropic effects on the heart. However, the mechanisms of manifestations are still uncertain. The following discusses and evaluates some of the theories regarding the interaction of these hormones with cardiac function.

Adult↗
PubMed1984

Effect of intra-aortic balloon pumping on left ventricular function: evaluation by radionuclide ventriculography.

The purpose of this study was to evaluate the effect of intra-aortic balloon pumping (IABP) on left ventricular (LV) performance in ten patients (group I) with pump failure and in ten patients (group II) with angina pectoris. Left ventricular ejection fraction, regional ejection fraction, systolic chordal shortening and volumes were measured by first-pass radionuclide ventriculography using a computerized multicrystal gamma camera. Patients in group I had significantly lower ejection fractions, regional ejection fractions and systolic chordal shortening and larger end-diastolic and end-systolic volumes than patients in group II, both on (p greater than 0.0001) and off (p less than 0.004) IABP. With IABP, the ejection fraction increased by 0 +/- 0.5% in group I and 5.8 +/- 1.7% in group II (p = 0.004); the regional ejection fraction increased by 0.1 +/- 0.9% in group I and 10.3 +/- 2.1% in group II (p = 0.0004); the systolic chordal shortening increased by 1.1 +/- 0.6% in group I and 6.5 +/- 1.1% in group II (p = 0.0006); the end-diastolic volume decreased by -0.4 +/- 6% in group I and -14 +/- 4% in group II (p = 0.07); and the end-systolic volume decreased by -1 +/- 6% in group I and -21 +/- 5% in group II (p = 0.02). Thus, IABP results in improvement in left ventricular performance in patients with angina pectoris but not in patients with pump failure.

Aged↗
PubMed1984

Effects of resting ischemia assessed by thallium scintigraphy on QRS scoring system for estimating left ventricular function quantified by radionuclide angiography in acute myocardial infarction patients.

The purpose of this study was to determine whether resting ischemia limits the usefulness of the QRS scoring system in predicting left ventricular (LV) ejection fraction (EF) in patients with acute infarction. We studied 48 patients after acute infarction by means of 12-lead ECG, thallium-201 scintigraphy, and radionuclide angiography. The thallium-201 scintigrams showed fixed defects in 25 patients, perfusion defects with partial or complete redistribution in the delayed images in 19 patients, and normal images in the remaining four patients. In the 48 patients there was a significant correlation between the QRS score and LVEF (r = -0.67; p less than 0.001). Patients with fixed defects showed a better correlation than patients with resting ischemia (r = -0.77 vs r = -0.60). A QRS score of 3 or less was used to separate patients with LVEF of 40% or greater from those with lower LVEF in patients with fixed defects (p = 0.0005), but this cutoff did not categorize patients with resting ischemia as to LVEF. Thus the presence of rest ischemia in patients with acute infarction may affect the correlation between QRS score and LVEF.

Electrocardiography↗
PubMed1984

Correlation between changes in R wave amplitude and left ventricular volume induced by rapid atrial pacing.

To examine the Brody effect in humans, we studied 15 patients by means of coronary sinus pacing. We measured left ventricular (LV) volumes from the cardiac output (measured by the thermodilution technique) and LV ejection fraction (measured by radionuclide ventriculography). Pulmonary blood volume was determined by means of cardiac output and mean pulmonary transit time. In six patients, pacing was performed at two different rates, resulting in 21 pacing measurements. The heart rate increased with pacing from 73 +/- 11 to 119 +/- 19 bpm (mean +/- standard deviation, p less than 0.001). The end-diastolic volume (EDV) and the end-systolic volume (ESV) decreased with pacing (p less than 0.001 each). The R wave amplitude decreased with pacing (1.44 +/- 0.63 mV control vs 1.32 +/- 0.58 mV with pacing; p less than 0.01). R wave amplitude decreased in 19 of the 21 pacing studies (90%); EDV and ESV decreased in all 21 pacing studies, and pulmonary blood volume decreased in 14 of the 15 pacing studies (93%) performed in 11 patients. There was a significant correlation between the percentage of change in R wave amplitude with the percentage of change in EDV (r = 0.54, p less than 0.01) and with the percentage of change in ESV (r = 0.54, p less than 0.01). These results, therefore, validate Brody's hypothesis and indicate that changes in LV volumes affect the R wave amplitude.

Adult↗
PubMed1984

Thallium-201 myocardial scintigraphy and left ventricular function at rest in patients with rest angina pectoris.

The purpose of this study was to examine the rest thallium-201 perfusion pattern during angina-free periods in 40 patients with rest angina pectoris secondary to coronary artery disease (greater than or equal to 70% diameter narrowing). Seventeen patients had previous Q wave myocardial infarction. The perfusion defects were considered fixed or reversible, depending on the absence or presence of redistribution in the 4-hour delayed images. There were 40 perfusion defects (26 fixed and 14 reversible) in 27 patients whereas 13 patients had normal scans. Reversible perfusion defects were present in 10 patients (25%). Of the 26 fixed perfusion defects, 17 did not have corresponding Q waves. Occluded vessels (63%) had more perfusion defects than vessels with subtotal occlusion (30%) (p less than 0.01). The perfusion defect size was larger in patients with lower ejection fraction than in patients with higher ejection fraction. We conclude: (1) perfusion defects are common in patients with rest angina and are reversible in 25% of patients indicating reduced regional coronary blood flow; (2) the degree of stenosis affects the presence of perfusion defect; (3) fixed defects may be present without corresponding Q waves; and (4) global left ventricular function is related to the size of perfusion defects.

Adult↗
PubMed1984

Similarity between women and men in manifestation of myocardial ischemia during exercise.

We assessed the effect of gender on the electrocardiographic changes and thallium-201 myocardial perfusion during exercise in patients with coronary artery disease. Eighty-nine patients with coronary artery disease (50% or greater diameter narrowing of one or more major coronary arteries) who had undergone exercise thallium scintigraphy were retrospectively studied. There were 29 women and 60 men. Fifty-six patients had one-vessel disease, 11 patients had two-vessel disease, and 22 patients had three-vessel disease or left main disease. The extent of coronary artery disease was assessed by the Gensini score. There was no difference between men and women in age, medications, number of diseased vessels and the coronary artery disease score. Exercise tolerance was lower, although insignificantly in women compared to men. However, exercise heart rate, double product, and the electrocardiographic response were similar in men and women. Also, both the presence and size of exercise-induced perfusion defects were similar in men and women. Thus, the electrocardiographic response to exercise is not influenced by gender in patients with similar extent of coronary artery disease and comparable manifestations of myocardial ischemia.

Cardiac Catheterization↗
PubMed1984

Prognostic implications of rest and exercise radionuclide ventriculography in patients with suspected or proven coronary heart disease.

Rest and exercise radionuclide ventriculography were assessed for their value in predicting major cardiac events in patients with chest pain. Of 219 patients who were followed for up to 51 months, 42 had major cardiac events: 12 patients (5.5%) died, 5 (2.2%) sustained nonfatal myocardial infarction, and 25 (11.4%) had coronary arterial bypass grafting. Univariate and multivariate survival analysis revealed that exercise left ventricular ejection fraction was the best predictor for total major events and the resting ejection fraction to be the best predictor for death or nonfatal myocardial infarction. These two variables were strong predictors in the entire group of patients and in subgroups: patients with or without Q-wave infarction, patients with high probability of coronary artery disease and those with abnormal resting left ventricular function. Thus, radionuclide angiography provides important prognostic data that permits the physician to categorize patients with chest pain syndromes with respect to subsequent cardiac events. If validated, this model or a modification of it could identify patients at high risk of subsequent major cardiac events who are candidates for intensive follow up and therapy or further invasive evaluation, as well as patients at low risk of subsequent major cardiac events for whom standard follow up would be appropriate.

Angiography↗
PubMed1984

Effects of residual coronary artery disease on results of coronary artery bypass grafting.

To assess the effects of residual coronary artery disease (non-revascularized coronary vessels) after coronary artery bypass grafting on symptoms and exercise left ventricular function, we categorized 77 patients into 3 groups according to the extent of residual coronary artery disease: group I (n = 17) had no residual coronary artery disease (residual score = 0); group II (n = 30) had light residual coronary artery disease (score of 1 to 9, mean 4.7); and group III (n = 30) had moderate residual coronary artery disease (score greater than or equal to 10, mean 23). Sixty patients were asymptomatic after coronary artery bypass grafting (14 in group I, 24 in group II, and 22 in group III), but the remaining patients had occasional angina pectoris. The resting left ventricular ejection fraction was significantly higher in group I than in the remaining 2 groups (56 +/- 18% in group I, 47 +/- 19% in group II, and 43 +/- 16% in group III, P less than 0.05). The exercise left ventricular ejection fraction was also significantly higher in group I (61 +/- 16% in group I, 51 +/- 18% in group II and 45 +/- 18% in group III, P less than 0.01). The ejection fraction response to exercise was abnormal in 5 patients in group I, 15 patients in group II, and 19 patients in group III. Thus, coronary artery bypass grafting results in symptomatic improvement, even in patients with residual coronary artery disease. The presence of residual coronary artery disease, however, may be a determinant of exercise left ventricular function in these patients.

Adult↗
PubMed1984

R wave amplitude: a new determinant of failure of patients with coronary heart disease to manifest ST segment depression during exercise.

Patients with coronary artery disease may not manifest ST segment depression during exercise. Inadequate stress, mild coronary artery disease and severe left ventricular dysfunction have been postulated as mechanisms. The purpose of this study was to determine the influence of exercise R wave amplitude on ST segment depression in 81 patients with coronary artery disease (50% or greater diameter narrowing of one or more vessels). All patients underwent symptom-limited treadmill exercise testing and 71 patients (88%) had concomitant thallium-201 imaging. In 26 patients, the exercise R wave amplitude in electrocardiographic lead V5 was less than 11 mm (Group I), and in 55 patients it was 11 mm or greater (Group II). The two groups were similar with regard to age, sex, propranolol administration and left ventricular function. There was a significant difference in the incidence of positive exercise electrocardiograms in the two groups (2 patients [8%] in Group I and 27 patients [49%] in Group II; p = 0.002), despite similar exercise heart rate and extent of coronary artery disease. Myocardial ischemia, manifested by exercise-induced angina or exercise-induced thallium-201 perfusion defects, was similar in both groups. Thallium-201 imaging showed perfusion defects in 73% of patients in Group I and in 76% of patients in Group II (p = not significant). Thus, R wave amplitude is a new determinant of failure to develop ST depression during exercise. A low R wave amplitude (less than 11 mm) is rarely associated with ST depression, even in patients with multivessel coronary artery disease. Exercise thallium-201 imaging is a valuable diagnostic tool in patients with low R wave amplitude.

Adult↗
PubMed1984

Correlation among right ventricular preload, afterload and ejection fraction in mitral valve disease: radionuclide, echocardiographic and hemodynamic evaluation.

The relation among right ventricular preload, afterload and ejection fraction in patients with mitral valve disease has not been well elucidated. In this study, measurements were made of intracardiac pressures and forward cardiac output during cardiac catheterization (n = 43), the ejection fraction by radionuclide angiography (n = 43) and end-systolic radius and wall thickness by M-mode echocardiography (n = 22). There was a linear correlation between pulmonary artery pressure and right atrial pressure (r = 0.57, p less than 0.01). The right ventricular peak circumferential systolic wall stress was increased in 68% of the patients (in comparison with wall stress measurements obtained in 10 normal subjects). The right ventricular ejection fraction was abnormal in 38 patients (88%) and abnormal in 14 of the 15 patients with high wall stress. There was an inverse correlation between ejection fraction and end-diastolic volume (r = -0.61, p less than 0.001). The right ventricular ejection fraction measurement was repeated within 3 months after mitral valve replacement in 16 patients; the ejection fraction increased from 21 +/- 9 to 29 +/- 10% (mean +/- standard deviation) after surgery (p less than 0.01), but normalization of the ejection fraction was observed in only 3 patients (19%). Thus, abnormal right ventricular ejection fraction, which is observed in most patients with rheumatic mitral valve disease, results from inappropriate wall stress or depressed inotropic response of the right ventricle due to damage. Right ventricular dilation appears to be a compensatory mechanism to maintain the cardiac output.

Aged↗