Multigated Radionuclide Ventriculography Research Articles

Right Ventricle Dysfunction in Patients With Adult Cystic Fibrosis Enlisted for Lung Transplant

Knowledge of preoperative right heart function of adult patients with cystic fibrosis (CF) awaiting lung transplant (LUTX) is limited. The echocardiography of adult patients with CF enlisted for LUTX was retrospectively analyzed and compared with standards and invasive analyses (right heart catheterization, multigated radionuclide ventriculography). We included 49 patients (reported as mean ± standard deviation; 29 ± 9 years of age; forced expiratory volume in first second of expiration, 31% ± 11% predicted; lung allocation score, 36 ± 5; invasive mean pulmonary artery pressure, 17 ± 5 mm Hg; multigated radionuclide ventriculography right ventricle [RV] ejection fraction, 50% ± 9%). Patients had increased RV end-diastolic area, RV wall thickness, and increased pulmonary artery acceleration time with subnormal tricuspid annular plane systolic excursion, tissue Doppler positive peak systolic velocity, and fraction area change. Subnormal tricuspid annular plane systolic excursion (< 23 mm), tissue Doppler positive peak systolic velocity (< 14 cm/s), and fraction area change (< 49%) had high sensitivity and negative predictive value in predicting impaired RV. ejection fractionA good correlation between echocardiographic estimated and invasively measured systolic pulmonary artery pressure was observed (R2 = 0.554, P < .001). Adults with CF awaiting LUTX have morphologic alterations of the right heart, with subclinical impairment of RV systolic function. Echocardiography may be used as a bedside, repeatable, and reliable noninvasive test to screen further deterioration in RV function while on the waiting list for LUTX. More prospective follow-up echocardiographic studies are necessary to confirm such a hypothesis.

Screening and intervention for treatment-related cardiac dysfunction in childhood cancer survivors.

10.2217/FON.15.108 © 2015 Future Medicine Ltd During the past four decades, marked advances have been made in the treatment of childhood cancers, such that long-term survival is an expected outcome for many children diagnosed with cancer today [1]. However, improvements in outcome have come at a cost. It is estimated that nearly a third of all childhood cancer survivors will develop a severe or life-threatening health condition years after completion of cancerdirected therapy [2]; these include second cancers, endocrinopathies, neurosensory impairment and cardiovascular disease [2]. Outcomes following onset of cardiovascular disease are especially poor; 5-year overall survival is less than 50% [3], emphasizing the need to develop early screening and prevention strategies in survivors at highest risk of developing cardiovascular disease. Research on survivorship issues has revealed a clear association between certain therapeutic exposures such as anthracycline chemotherapy and/or mediastinal radiation and risk of cardiovascular complications such as heart failure [4]. In these survivors, there is often a long latency between initial exposure to cardiotoxic therapies and onset of clinically overt heart disease [4]. This period is characterized by the development of asymptomatic systolic and/or diastolic cardiomyopathy that can be detected using a variety of imaging modalities [4,5]. Radionuclide angiography (multigated acquisition scan and radionuclide ventriculography) was historically considered the gold standard for assessment of cardiac function [4,5]. However, exposure to ionizing radiation, along with a limited ability to detect structural abnormalities and early cardiac dysfunction, has limited its use in childhood cancer survivors [4,5]. 2D echocardiography offers a readily available assessment of both structure and function without exposure to radiation, and has therefore been widely used to follow childhood cancer survivors. [4,5] Frequently measured echocardiographic parameters of cardiac function include ejection fraction, shortening fraction, velocity of fiber shortening corrected for heart rate, stress–velocity index, left ventricular end-systolic wall stress and more subtle measures of diastolic function [4–6]. More recently, cardiac MRI has emerged as a sensitive and reproducible alternative to echocardiography in nononcology populations and cancer survivors [7,8]. However, despite its diagnostic advantages, higher cost and limited availability impede its use for routine screening. Consequently, current guidelines continue to recommend 2D echocardiography as the screening modality of choice for childhood cancer survivors [6]. COMMENTARY Special Focus Issue: Cardio-oncology

Reliability of left ventricular ejection fraction calculated with gated myocardial perfusion single photon emission computed tomography in patients with extensive perfusion defect

Gated myocardial perfusion scintigraphy (g-MPS) provides functional information on the left ventricle (LV) apart from the perfusion status. Computer algorithm-based LV ejection fraction (EF) calculated from resting g-MPS has been found to be reliable in patients with normal perfusion. However, its role in patients with extensive perfusion defects is not clear. To find the reliability of LVEF calculated from resting g-MPS in patients with extensive perfusion defects (>25% of LV myocardium) and to correlate this with echocardiography and multigated radionuclide ventriculography (RNV). Thirty patients with fixed perfusion defect of size greater than or equal to 25% of LV myocardium on rest g-MPS study were included. EF was calculated using three software packages: Emory Cardiac Toolbox, Myometrix, and quantitative gated single photon emission computed tomography (SPECT)/quantitative perfusion SPECT. The patients underwent RNV (gold standard) and echocardiography within a week of the g-MPS. Agreement among the EF values obtained by different methods was determined using Bland-Altman analysis. Correlation among the EF values was measured using Spearman's rank correlation. Thirty patients (23 male; seven female; mean age 51 years, range 32-70 years) were included prospectively. The average size of perfusion defect was 38% of the LV myocardium (range 25-56% of LV). The average ejection fraction values were 33% for Emory Cardiac Toolbox (range 11-50%), 31% for Myometrix (range 18-46%), and 33% for quantitative gated SPECT/quantitative perfusion SPECT (range 17-49%). The mean EF on echocardiography was 37% (range 22-60%), whereas that of RNV was 33% (range 10-50%). The data were normally distributed. There was statistically significant positive agreement between algorithm-based EF measurements to the gold standard RNV. This study suggests that EF calculations, from g-MPS SPECT data using different software, have high agreement with the gold standard RNV even in patients with extensive perfusion defects.

Long-term effects of antilipidaemic therapy on left ventricular function in patients with dyslipidaemia: multigated radionuclide ventriculography study

It has been reported that dyslipidaemia impairs left ventricular systolic (LVs) and diastolic (LVd) functions, irrespective of atherogenic effects, in the setting of coronary artery disease. The aim of the present study was to evaluate the effects of anti-lipidaemic therapy on LVs and LVd functions by means of multigated radionuclide ventriculography (RNV) in subjects with signs of dyslipidaemia and with preserved left ventricular function. Eighteen patients with dyslipidaemia (eight men, 10 women, mean age 50+/-10 years) were included in the study. While the clinical examination and treadmill exercise test results were normal in all patients, low-density lipoprotein levels exceeded 160 mg . dl. Patients with medical conditions including coronary artery disease, hypertension, diabetes, cardiomyopathy and valvular heart disease which would influence left ventricular function were excluded from the study. RNV was performed in all subjects, taking into account the best septal position to differentiate the left ventricle from the right ventricle. The following parameters were calculated: ejection fraction, peak ejection rate (PER), time to peak ejection (TPER), a ejection rate (aER), a ejection fraction (aEF), Peak filling rate (PFR), time to peak filling rate (TPFR), a filling rate (aFR), a filling fraction (aFF). The low-density lipoprotein value decreased and the high-density lipoprotein value increased after statin therapy (P<0.001 and P<0.003, respectively). PER, aER and aFF significantly increased and TPER decreased as a consequence of statin therapy (respectively, P<0.05, P<0.05, P<0.05 P<0.05). Anti-lipidaemic therapy is effective in dyslipidaemic patients. RNV is a useful and non-invasive method for monitoring changes in ventricular function following anti-lipidaemic treatment strategies.

The extracellular matrix in hibernating myocardium--a significant factor causing structural defects and cardiac dysfunction.

Recently, we described chronic intracellular degeneration accompanied by fibrosis as typical structural features of hibernating myocardium and we concluded that cellular degeneration as a sign of the incomplete adaptation to the reduced blood flow is characteristic of hibernation. This study has been extended by analyzing the composition of the extracellular matrix proteins of the diseased myocardium. Areas of hibernating myocardium were identified in 38 patients by angiography, multigated radionuclide ventriculography, thallium scintigraphy with reinjection and low-dose dobutamine echocardiography. These areas were biopsied at cardiac surgery and were studied by electron microscopic and immunofluorescence techniques. Electron microscopy showed an enlarged extracellular space containing numerous particles of cellular debris, macrophages, fibroblasts, homogeneous matrix material and collagen fibrils. The basement membrane of the cardiomyocytes was thickened by an augmentation of laminin, fibronectin and collagen VI, but these proteins also were present in the matrix itself. Collagen fibrils were numerous and macrophages (CD68) and fibroblasts (vimentin) were increased. In situ hybridization showed an increase in mRNA for laminin, fibronectin and collagen. This observation is consistent with the conclusion that fibrotic scar formation was occurring continuously. It is postulated that fibrosis is the consequence of myocyte loss due to chronic underperfusion in the hibernating tissue. This will further injure myocytes so that a vicious cycle is established that leads to progressive loss of structural integrity and functional capacity. Since these changes are progressive, revascularization should be performed at the earliest time point possible in patients with areas of hibernating myocardium.

Hibernating myocardium: an incomplete adaptation to ischemia.

We tested the hypothesis that hibernating myocardium represents an incomplete adaptation to a reduced myocardial oxygen supply. In 38 patients, areas of hibernating myocardium were identified by angiography, multigated radionuclide ventriculography, thallium scintigraphy with reinjection, and low-dose dobutamine echocardiography. Biopsies removed at cardiac surgery showed structural degeneration characterized by a reduced protein and mRNA expression and disorganization of the contractile and cytoskeletal proteins myosin, actin, desmin, titin, alpha-actinin, and vinculin by electron microscopy, immunohistochemistry, and in situ hybridization. Additionally, an increased amount of extracellular matrix proteins resulting in a significant degree of reparative fibrosis was present. Dedifferentiation, ie, expression of fetal proteins, was absent. Apoptosis indicating suicidal cell death was found by the terminal deoxynucleotidyl transferase end-labeling method and electron microscopy. Radionuclide ventriculography showed improvement of regional function at 3 months postoperatively compared with preoperative values (mean values, 23.5% and 48%, respectively), and the echocardiographic wall-motion score index decreased from 3.4 to 1.8. The degree of severity of the morphological changes (three stages) correlated well with the extent of postoperative functional recovery: more advanced clinical improvement was observed in patients with slight and moderate morphological degeneration (stages 1 and 2), but recovery was only partial in severe degeneration (stage 3). Cellular degeneration rather than adaptation is present in hibernating myocardium. The consequence is progressive diminution of the chance for complete structural and functional recovery after restoration of blood flow. The practical consequence from this study should be early revascularization in patients showing areas of hibernating myocardium.

7. Influence of corticoids and injection technique on in vivo red blood cell labelling and image quality in multi-gated equilibrium radionuclide ventriculography (RNV)

7. Influence of corticoids and injection technique on in vivo red blood cell labelling and image quality in multi-gated equilibrium radionuclide ventriculography (RNV)

Comparison of multigated radionuclide ventriculography and 2 D Echocardiography in the detection of systolic abnormalities in children with Duchenne's muscular dystrophy

Comparison of multigated radionuclide ventriculography and 2 D Echocardiography in the detection of systolic abnormalities in children with Duchenne's muscular dystrophy

Cardiac involvement of progressive muscular dystrophy (Becker type, Limb-girdle type and Fukuyama type) evaluated by radionuclide method.

Tl-201 SPECT and Tc-99m-Human serum albumin (HSA) multigated radionuclide ventriculography were performed on 11 patients with progressive muscular dystrophy (Becker type 2, Fukuyama type 2, Limb-girdle type 7) to evaluate myocardial involvement. Hypoperfusion was detected in 8 patients on Tl-201 SPECT. Decreases in both systolic function (left ventricular ejection fraction; LVEF) and diastolic function (peak filling rate; PFR) were also seen in these patients. A high incidence of myocardial involvement of these kinds of progressive muscular dystrophy was suggested.

Equilibrium Radionuclide Venthculography in Duchenne??s Cardiomyopathy

Myocardial dysfunction in 14 patients with Duchenne's muscular dystrophy (DMD) was evaluated by Tc-99m HSA multigated radionuclide ventriculography (MGRV). Follow-up studies were performed on eight patients for 5 years. Left ventricular ejection fraction and standard deviation of the phase angle were abnormal in all patients older than 15 years. Hypokinetic changes and phase delay were recognizable in most patients older than 17 years. Peak filling rate decreased in patients older than 17 years. MGRV was considered an effective method for evaluating serial changes in cardiomyopathy of patients with DMD.

Arm Exercise Training in the Rehabilitation of Patients with Impaired Ventricular Function and Heart Failure

Although exercise training is an accepted part of comprehensive coronary care programs in patients with coronary artery disease, it still remains to be demonstrated whether or not exercise training should also be applied to patients with impaired ventricular function. Circumstantial evidence exists that patients with impaired ventricular function may eventually benefit from an individually adapted exercise training program provided that contraindications for acceptance of cardiac patients to such a program are well observed. Our study is based on 22 patients with impaired ventricular function, of which 18 were at least 6 months after a Q-wave myocardial infarction and the remaining 4 after coronary artery bypass grafting. Eleven patients with impaired left ventricular function performing upper extremity (arm) ergometry were followed up for 36 months. These patients were trained twice weekly with exercise periods of 30 min duration. The reason for choosing arm ergometry training was that the peak heart rate obtained in arm ergometry is higher when compared to leg ergometry. Rate-pressure product and heart rate were higher for given submaximal work tasks in arm ergometry, while maximal work aerobic capacity was found to be lower in comparison to leg work. The assessment of our patients was based on cardiopulmonary testing, continuous electrocardiographic monitoring (48 h), two-dimensional echocardiography and equilibrium multigated radionuclide ventriculography (99mTc). Group 1, consisting of 11 patients with left ventricular ejection fraction (LVEF) 30.1 +/- 9.5%, were trained by arm exercise for 3 years with a significant increase in work capacity and LVEF. Group 2 consisted of 11 patients with LVEF 25.5 +/- 6.8% who underwent a 12 months' calisthenic program. Peak work capacity and LVEF remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Silent ischemia: a relevant problem in patients with coronary artery disease?

Awareness of silent myocardial ischemia has greatly increased during the last few years in the medical community. Methods for its detection include exercise testing, Holter monitoring, and, more specifically, Thallium-201 scintigraphy, 2D-echocardiography, and multigated radionuclide ventriculography with phase analysis, all during rest and exercise. Cohn's classification of silent ischemia has proven very useful in highlighting the magnitude of the problem. It can be estimated that about 2% to 4% of apparently healthy middle aged males in industrialized European countries are prone to asymptomatic ischemic episodes. Prognosis of silent myocardial ischemia has been evaluated in prospective and retrospective studies. Most authors come to the conclusion that ischemia is the key finding, whether painful of asymptomatic. Even present understanding of pain perception from the ischemic myocardium is incomplete; the high prevalence and the relation with myocardial infarction and sudden cardiac death make silent myocardial ischemia one of today's most relevant problems.

Assessment of Cardiac Function in Patients with the Acquired Immunodeficiency Syndrome

We have assessed right and left ventricular function by multigated radionuclide ventriculography in 12 consecutive patients with acquired immunodeficiency syndrome (AIDS) grouped according to the CDC classification system for HIV infection. Results were correlated with clinical, electrocardiographic and echocardiographic findings. Clinical examination and chest x-ray films showed no evidence of acute cardiac or pulmonary pathology. Five patients had evidence of ventricular dysfunction by radionuclide ventriculography along with significant ECG abnormalities. Three patients had abnormal ECG findings with normal ejection fractions. Echocardiography showed no evidence of significant valvulopathy or pericardial disease except for one patient with fibrinous strands associated with the pericardium. Decreased ejection fractions did not correlate with disease classification, risk group or survival. This study suggests that a major percentage of AIDS patients have some evidence of cardiac abnormalities. We conclude that abnormal ECG findings in an AIDS patient should alert the clinician to possible underlying ventricular dysfunction.

Early intervention in acute myocardial infarction: Significance for myocardial salvage of immediate intravenous streptokinase therapy followed by coronary angioplasty

Sixteen patients with acute myocardial infarction underwent treatment with streptokinase up to 3 hours after the onset of chest pain. Nine patients (group I) received streptokinase within 1 hour of the onset of pain, and seven patients (group II) received it within 2 to 3 hours. All underwent multigated radionuclide ventriculography after streptokinase therapy and 1 week later. Percutaneous transluminal coronary angioplasty of the infarct artery was performed within 24 hours in all patients. An effort-limited treadmill stress test was performed before discharge. There was no mortality or serious complication. Mean peak total creatine kinase was 521 +/- 289 mU/ml in group I, and 1,614 +/- 709 mU/ml in group II (p less than 0.05). The mean initial left ventricular ejection fraction was 47 +/- 11% in group I and 37 +/- 10% in group II. After early angioplasty (within 24 hours) and at 1 week recovery, left ventricular ejection fraction increased to 53 +/- 9% in group I (p less than 0.05) and to 40 +/- 7% in group II (p = NS). Seven of the nine patients in group I had normal radionuclide ventriculograms at discharge compared with none of the seven patients in group II. Thrombolytic therapy administered less than 1 hour after the onset of symptoms of acute myocardial infarction followed by angioplasty of the infarct artery results in preservation of left ventricular function, whereas therapy given after 2 hours has only a limited effect.

Comparative effects of diltiazem, propranolol, and placebo on exercise performance using radionuclide ventriculography in patients with symptomatic coronary artery disease: Results of a double-blind, randomized, crossover study

The effects of oral diltiazem (120 mg), propranolol (100 mg), and placebo on exercise performance and left ventricular function were compared before and during symptom-limited supine bicycle exercise by means of multigated radionuclide ventriculography in 12 patients with documented, symptomatic coronary artery disease; a double-blind, randomized crossover protocol was used. Diltiazem increased ejection fraction (EF) at submaximal exercise (+7.0 absolute percentage points, p < 0.02) and maximal exercise (+8.1 percentage points, p < 0.01). Exercise EF was increased by 13.6 percentage points ( p < 0.02) in patients with decreased ventricular function (resting EF <50%). Propranolol had no effect on exercise EF at any stage, even when patients with EF <50% were excluded. The increase in total exercise time was significant after diltiazem (+27%, p < 0.01) but not after propranolol (+16%, p = NS). As expected, propranolol decreased both resting (−9 bpm, p < 0.01) and exercise heart rates (−27 bpm, p < 0.001), whereas diltiazem had no significant effect. Propranolol decreased resting diastolic blood pressure (−8 mm Hg, p < 0.02), exercise systolic (−27 mm Hg, p < 0.001) and diastolic (−9 mm Hg, p < 0.01) blood pressures, and rest ( p < 0.01) and exercise ( p < 0.001) double product. Diltiazem decreased resting systolic blood pressure (−9 mm Hg, p < 0.01) and both resting (−8 mm Hg, p < 0.001) and exercise (−9 mm Hg, p < 0.01) diastolic blood pressures. Diltiazem decreased double product at submaximal ( p < 0.005) but not maximal exercise. Angina limited exercise in four patients after diltiazem compared to eight and seven patients after placebo and propranolol respectively ( p < 0.05). Thus, diltiazem improved exercise performance with the use of radionuclide ventriculography during symptom-limited supine bicycle ergometry to a greater extent than did propranolol or placebo, and this effect was most apparent in those with decreased left ventricular function.

Quantitative phase analysis of exercise radionuclide left ventriculography in normals and patients with coronary artery disease

Using multigated radionuclide ventriculography (RNV), the left ventricular (LV) phase histogram (PH) was used to quantitate LV synchrony at rest and at submaximal and maximal supine exercise in 10 normal and 10 coronary (CAD) patients. Each LV PH was obtained by masking the phase image with an LV region, generated semiautomatically and modified if necessary to minimize ambiguity of LV delineation. The shape and spread of each histogram was characterized by its standard deviation (SD) and skewness (SK). Normals had a tight resting PH with slight negative skewness (SD = 9.06 ± 0.22 (x̄ ± SEM; SK = − 0.53 ± 0.05). CAD patients had a wider resting PH with a larger SD and a significantly more positive skewness reflecting greater contractile asynchrony (SD = 16.53 ± 2.26; SK = 0.35 ± 0.22). With exercise the PH distribution for the normals remained tight (SD = 8.1 ± 0.24) while SK changed little (SK = −0.29 ± 0.04). In contradistinction, with exercise CAD patients markedly increased the spread of their LV PH (SD = 27.42 ± 3.77) and increased the number of late pixels (SK = 0.75 ± 0.15). It is concluded that quantitative PH analysis is a useful adjunct for the analysis of regional asynergy during resting or exercise radionuclide left ventriculography.