technetium-tc-99m-tetrofosmin and Pulmonary-Disease--Chronic-Obstructive

Regadenoson (REG) is a A2a receptor selective pharmacologic SPECT imaging agent. Its safety in unselected chronic obstructive pulmonary disease (COPD) or asthma (AM) undergoing SPECT imaging has not been well evaluated. We retrospectively identified 228 patients (COPD n = 126 and AM n = 102, Grp 1) undergoing REG SPECT from Jan to Nov 2009 and compared to 1,142 patients without COPD and AM (control, Grp 2). A standard 400 μg REG bolus was used and gated Tc-99 m tetrofosmin SPECT done. Patient demographics, REG SPECT data, side effects, arrhythmia occurrences, and any exacerbation of COPD or AM leading to treatment, hospitalization or death were evaluated. The side effect profile of Grp 1 was also compared to a historical cohort who underwent intravenous dipyridamole thallium-201 imaging and adenosine SPECT. Both groups were comparable with regards to baseline characteristics. There was 0% incidence of clinical exacerbation of COPD or AM after REG. COPD patients had more non-significant arrhythmias (58.3% vs. Grp 2, 43%, P = 0.004). There was 0% incidence of any atrio-ventricular block and only 2 instances of brief supraventricular tachycardia. When compared to the historical cohort of COPD who underwent IV dipyridamole thallium imaging, COPD in Grp 1, had more dyspnea and flushing and when compared to COPD/AM patients who underwent adenosine SPECT, Grp 1 pts had more of flushing and headache (24.9% vs. 2.8%, P = <0.001) but less of bronchospasm (1.3% vs. 6.9%, P = 0.022) and AV block (0% vs. 4.2%, P = 0.014). REG SPECT can be safely performed in COPD and AM population.

Topics: Adenosine A2 Receptor Antagonists; Aged; Asthma; Atrioventricular Block; Bronchoconstriction; Chi-Square Distribution; Female; Heart Diseases; Hemodynamics; Humans; Male; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Pulmonary Disease, Chronic Obstructive; Purines; Pyrazoles; Radiopharmaceuticals; Retrospective Studies; Risk Assessment; Risk Factors; Tachycardia, Supraventricular; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

On the basis of our hypothesis that lipophilic cations may be more suitable for ventilation lung scintigraphy than the conventional technetium-99m diethylenetriamine penta-acetic acid (Tc-DTPA), comparative studies were carried out.. The nebulization potential of nine routine radiopharmaceuticals was compared on medical and scintigraphy-specific nebulizers. This was followed by ventilation scintigraphy in 14 patients with chronic obstructive airway disease (n=13) or pulmonary embolism (n=1) where either 99mTc-methoxyisobutylisonitrile (n=10) or Tc-tetrofosmin (n=4) was used. Same-patient comparison with 99mTc-DTPA ventilation scan was available in six patients using the same acquisition protocol. Comparison with 99mTc-DTPA was made with respect to the nebulization rates, radioactivity delivered per unit of radioactivity available for inhalation, and regional distribution of inhaled counts.. Lipophilic cation solutions had a significantly higher nebulization rate compared with 99mTc-DTPA using the medical nebulizer (235%, P<0.01) and 370% on scintigraphy-specific nebulizer (P<0.01). More than three times the counts of 99mTc-methoxyisobutylisonitrile or 99mTc-tetrofosmin was deposited in the body compared with Tc-DTPA aerosol per megabecquerel activity inhaled (1.5 vs. 0.4 kcounts/MBq) (P<0.001), preferentially in the lungs (75.2 vs. 65.2%), at the expense of oropharynx and stomach. Within the lungs, about 50% more counts were deposited in the outer one-third lung with lipophilic cations. Overall, therefore, more than 12 times the radioactivity deposition was achieved in the peripheral one-third of the lungs with the lipophilic cations.. Ventilation lung scanning with lipophilic cations is a viable substitute of nanoparticle scintigraphy (technegas and pertechnegas, which are expensive and technically far more demanding).

Topics: Adult; Humans; Male; Middle Aged; Nebulizers and Vaporizers; Organophosphorus Compounds; Organotechnetium Compounds; Pulmonary Disease, Chronic Obstructive; Pulmonary Embolism; Pulmonary Ventilation; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Pentetate; Technetium Tc 99m Sestamibi

Evaluation of possible cardiac complications is essential for safe and effective respiratory rehabilitation of patients with chronic respiratory diseases (CRDs). The aim of this study is to clarify the pathophysiology of electrocardiographic (ECG) changes during exercise and the prevalence of coronary artery disease (CAD) in CRD patients without a history of myocardial ischemia.. We studied 42 CRD patients with exercise-induced ST depression by cardiopulmonary exercise testing (CPET). They were selected from 249 consecutive CRD patients without any history of CAD who underwent CPET between January 1999 and December 2001. Thirty-three patients without respiratory diseases who had positive ST depression during exercise were selected as disease control subjects. Exercise myocardial SPECT was performed to evaluate myocardial ischemia and right ventricular (RV) overload as measured by increased RV uptake.. Among the 249 consecutive CRD patients without any history of CAD, positive ST depression during exercise was found in 42 (16.9%). Only 2 of the 42 patients (4.8%) had an ST depression other than in II, III, or aVF leads. The incidence of myocardial ischemia by perfusion SPECT was significantly lower in CRD patients (26.2%) than in disease control subjects (78.8%). The most common finding in the CRD patients during exercise was RV overload but without ischemia (26 cases; 61.9%). Ischemia was found in 11 patients (26.2%), with 10 of these patients also having RV overload. Neither ischemia nor RV overload was found in 5 patients (11.9%); these patients were eventually diagnosed as normal.. The incidence of myocardial ischemia as determined by perfusion SPECT was low in CRD patients with positive exercise-induced ECG changes. On the other hand, RV overload was observed in most such cases. Cardiac perfusion SPECT is a useful technique to evaluate cardiac ischemia and RV overload simultaneously. CPET with 12-lead ECG monitoring is necessary in CRD patients before respiratory rehabilitation. Further examination for ischemia should be done if positive ST depression is found.

Topics: Aged; Coronary Circulation; Coronary Disease; Electrocardiography; Exercise Test; Female; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Pulmonary Disease, Chronic Obstructive; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Right