sodium-pertechnetate-tc-99m and Hypertension--Pulmonary

Advances in management of patients with congenital diaphragmatic hernia (CDH) have improved mortality rates but with a risk of increased pulmonary morbidity. The prognosis for CDH survivors remains difficult to predict owing to the lack of adequate methods. We used single photon emission computed tomography (SPECT) to measure the regional distribution of ventilation and perfusion in CDH infants to quantify the degree of lung function impairment and relate it to neonatal clinical disease severity.. Single photon emission computed tomography was performed in 12 CDH infants at the mean age of six months. Ventilation and perfusion were traced with 5 MBq Technegas and technetium-labelled albumin macro-aggregates, respectively. Neonatal clinical data collected during the patient's stay in the pediatric intensive care unit was correlated with the SPECT data.. Single photon emission computed tomography revealed varying degrees of ventilation-perfusion abnormalities which correlated with the presence of pulmonary artery hypertension, days on ventilator and days on extracorporeal membrane oxygenation.. The grade of clinical disease severity in infants following CDH repair is closely related to the ventilation-perfusion abnormality as seen using SPECT. The persistence of pulmonary artery hypertension into the postoperative neonatal period appears to be an important pathophysiological factor related to ventilation-perfusion abnormalities. Single photon emission computed tomography provides valuable clinical information for patient follow-up.

Topics: Extracorporeal Membrane Oxygenation; Hernia, Diaphragmatic; Hernias, Diaphragmatic, Congenital; Humans; Hypertension, Pulmonary; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Lung; Oxygen Inhalation Therapy; Pulmonary Ventilation; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Aggregated Albumin; Tomography, Emission-Computed, Single-Photon; Ventilation-Perfusion Ratio

Cross-sectional lung ventilation (V)-perfusion (Q) imbalance in primary pulmonary arterial hypertension (PAH) and passive pulmonary hypertension (PH) was characterized by automated V/Q single-photon emission computed tomography (SPECT).. Technegas/macro-aggregated albumin SPECT-derived V/Q SPECT and V/Q profile were automatically built to characterize cross-sectional lung V-Q imbalance in 12 patients with primary (idiopathic or familial) PAH and 15 patients with passive PH associated with left ventricular dysfunction or failure. The abnormality of V/Q distribution in these patients was correlated with PaO2 and pulmonary arterial pressure and with lung morphologic changes on computed tomography (CT).. Markedly low V/Q ratios (reverse V-Q mismatch) in the background lungs with heterogeneous V/Q distribution was seen in 12 of the 12 (100%) patients with primary PAH and in 10 of the 15 (66%) patients with passive PH, which were predominantly seen in the upper lung zone. Including these regions with reverse V-Q mismatch, the V/Q profile frequently showed flattened peaks with asymmetric and broadened V/Q distribution in all patients, with significant correlation between the standard deviation of V/Q ratios in the entire lungs and PaO2 and mean pulmonary arterial pressure (both; P<0.01). At the regions of the lungs with reverse V-Q mismatch, bronchial lumens compressed by dilated pulmonary arteries and heterogeneous lung attenuations were frequently seen on CT.. Patients with primary PAH and passive PH seem to characteristically have a high prevalence of reverse V-Q mismatch indicative of an inadequate hypoxic vasoconstriction reflex on V/Q SPECT, frequently accompanied with heterogeneous lung attenuations and compressed airways on CT.

Topics: Adult; Aged; Albumins; Automation; Case-Control Studies; Female; Humans; Hypertension, Pulmonary; Lung; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Ventilation-Perfusion Ratio; Young Adult

We report an initial investigation of a subtraction-based method to estimate right ventricle ejection fraction (RVEF) from ECG-gated planar equilibrium radionuclide angiography (ERNA) data. Twenty-six consecutive patients referred for scintigraphic evaluation of cardiac function prior to chemotherapy had ECG-gated first-pass (FP) imaging and ERNA imaging performed following the same radiotracer injection. RVEF was computed from FP images (RVEF

Topics: Cardiac-Gated Imaging Techniques; Computed Tomography Angiography; Electrocardiography; Female; Heart Ventricles; Humans; Hypertension, Pulmonary; Image Interpretation, Computer-Assisted; Linear Models; Male; Predictive Value of Tests; Radionuclide Angiography; Radiopharmaceuticals; Retrospective Studies; Sodium Pertechnetate Tc 99m; Stroke Volume; Ventricular Dysfunction, Right; Ventricular Function, Left; Ventricular Function, Right

Topics: Humans; Hypertension, Pulmonary; Lung; Reagent Kits, Diagnostic; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed

Topics: Adult; Cardiac Catheterization; Female; Hemodynamics; Humans; Hypertension, Pulmonary; Lung; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Time Factors

A 5-week-old infant presented with signs of severe congestive heart failure and pulmonary hypertension. Injection of technetium-99m pertechnetate demonstrated anomalous perfusion of the right lung. Subsequently, anomalous origin of the right pulmonary artery from the ascending aorta was proven at cardiac catheterization and repaired. Repeat injection of radionuclide 1 week postoperatively demonstrated normal flow to the right lung.

Topics: Aorta, Thoracic; Cardiac Catheterization; Heart Septal Defects, Atrial; Humans; Hypertension, Pulmonary; Infant; Male; Pulmonary Artery; Pulmonary Circulation; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The acute effects of intravenously administered hydralazine on pulmonary hemodynamics and ejection radionuclide angiography were evaluated in 9 patients with chronic airflow obstruction (forced expiratory volume in one second, 1.2 +/- 0.8 L, mean +/- SD), pulmonary hypertension (mean pulmonary artery pressure (PAP), 29 +/- 13 mmHg), and sleep hypoxemia (maximal sleep desaturation, 20 +/- 16%). The effect of hydralazine was measured during both normoxia and hypoxia and compared with the effect of hyperoxia. Hydralazine increased cardiac index from 3.7 +/- 0.2 to 4.5 +/- 0.8 L/min/m2 (mean +/- SE, p less than 0.05, n = 9), but there were no significant changes in PAP (29 +/- 4 to 32 +/- 4 mmHg), mean pulmonary vascular resistance index (PVRI) (390 +/- 80 to 360 +/- 80 dyn.s.cm.-5.m2), mean right ventricular stroke work index (12.7 +/- 2.7 to 15.0 +/- 2.2 g.m/m2), and mean pulmonary capillary wedge pressure (12 +/- 1 to 12 +/- 2 mmHg). Mean right ventricular ejection fraction and mean right ventricular end diastolic volume also were not changed after treatment with hydralazine. Hyperoxia was used to assess the reversibility of pulmonary hypertension and to compare this with hydralazine. Hyperoxia increased arterial oxygen saturation (SaO2) from 91 +/- 1 to 96 +/- 1% and decreased the cardiac index from 3.8 +/- 0.1 to 3.1 +/- 0.2 L/min/m2 (p less than 0.02, n = 6) but, as with hydralazine, there was no significant change in PAP (28 +/- 6 to 25 +/- 6 mmHg) and PVRI (350 +/- 120 to 360 +/- 80 dyn.s.cm-5).m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Angiography; Female; Hemodynamics; Humans; Hydralazine; Hypertension, Pulmonary; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen; Pulmonary Wedge Pressure; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Vascular Resistance

Topics: Adult; Aged; Cardiac Catheterization; Diastole; Female; Heart Septal Defects, Atrial; Heart Ventricles; Hemodynamics; Humans; Hypertension, Pulmonary; Male; Middle Aged; Postoperative Period; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Systole; Technetium

Radionuclide angiocardiography was used to assess pulmonary vascular reactivity in eight patients (nine studies) with a large, relatively unrestrictive intracardiac defect and pulmonary arterial hypertension. Radionuclide angiocardiograms, using technetium-99m pertechnetate, were performed first with the patient breathing room air and then after 10 minutes of breathing a mixture containing 90 percent or more of oxygen. The pulmonary to systemic flow ratios obtained by gamma variate analysis of the radionuclide time-activity curves were compared with those calculated with the Fick principle at the time of cardiac catheterization. There was a good correlation between the two methods both in room air studies (r = 0.88) and in those obtained with 90 percent or more of oxygen (r = 0.94). All six studies (in five patients) with a reactive pulmonary vasculature (judged by a pulmonary vascular resistance at cardiac catheterization of less than 6 units/m2 with oxygen or after tolazoline) had a radionuclide pulmonary to systemic flow ratio of 3.0 or greater with oxygen. The three patients with a nonreactive pulmonary vasculature had a radionuclide pulmonary to systemic flow ratio of 2.3 or less with oxygen, a value that was unchanged from the room air value. These data suggest that radionuclide angiocardiography may be a useful, relatively noninvasive method of assessing pulmonary vascular reactivity in patients with a large, relatively unrestrictive intracardiac defect.

Topics: Angiocardiography; Cardiac Catheterization; Child, Preschool; Heart Defects, Congenital; Heart Septal Defects, Ventricular; Hemodynamics; Humans; Hypertension, Pulmonary; Infant; Pulmonary Artery; Pulmonary Circulation; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Vascular Resistance

In 49 patients in whom gated equilibrium ventriculography and cardiac catheterization were performed within a 6 day interval, total and fractional portions of global and regional right ventricular ejection fraction (RVEF) were correlated with pulmonary arterial systolic pressure. Pulmonary arterial systolic pressure was normal (30 mm Hg or less) in 27 patients (Group I) and elevated (31 mm Hg or greater) in 22 patients (Group II). The second-half regional RVEF was 38 +/- 8% (mean +/- standard deviation) with a range of 30 to 54% for Group I and 22 +/- 6% with a range of 13 to 32% for Group II. The difference between the means was statistically significant (p less than 0.001). Use of a second-half regional RVEF of 30% as the criterion of elevated pulmonary arterial systolic pressure resulted in a sensitivity of 0.86 and a specificity of 1.00. A power curve fit in which pulmonary arterial systolic pressure = 10.91 (second-half regional RVEF)-0.87 allowed accurate estimation (r = -0.85) of pulmonary arterial systolic pressure from the second-half regional RVEF. It is concluded that second-half regional RVEF may be used to accurately detect pulmonary arterial hypertension and to estimate its extent.

Topics: Adult; Aged; Blood Pressure; Cardiac Catheterization; Cardiac Output; Coronary Disease; Erythrocytes; Female; Heart; Humans; Hypertension, Pulmonary; Male; Middle Aged; Myocardial Contraction; Oxygen Inhalation Therapy; Pulmonary Artery; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium