PubMed Health⌕ Search

Biomedical subjects

Nikolaos Demakopoulos

Publications and source records attributed to Nikolaos Demakopoulos.

7 recordsLinked to original sources
PubMed2006

Early post-stress pulmonary uptake of 99mTc tetrofosmin during exercise (SPECT) myocardial perfusion imaging: correlation with haemodynamic, perfusion and function parameters.

OBJECTIVE: To test the association of early post-stress lung/heart ratio (LHR) of 99mTc tetrofosmin radioactivity with gated-SPECT findings and angiographic results. METHODS: We studied 158 consecutive patients, with stress/rest 99mTc tetrofosmin myocardial SPECT and coronary angiography. Rest scans were obtained as gated SPECT and the left ventricular ejection fraction and end diastolic volume were calculated. To evaluate myocardial ischaemia, we calculated the summed stress score, summed rest score and summed difference score indices. For the LHR calculation, we acquired an anterior image, 4-6 min after radiotracer injection at stress; LHR was defined as mean counts/pixel in the lung region of interest divided by the mean counts/pixel in the myocardial region of interest. RESULTS: An early post-stress LHR value of 0.500 was defined as the upper normal limit. The most significant correlation (P<0.001) was observed among early post-stress LHR, summed stress score and the number of stenosed vessels. The incidence of multi-vessel coronary artery disease in the subgroup of patients with increased values of early post-stress LHR, was significantly higher than in the normal group (81% vs. 42%, P<0.001). There was a significant difference (P<0.001) of the early post-stress LHR value between patients with normal coronary arteries or one-vessel disease and patients with multi-vessel disease. Early post-stress LHR was an independent predictor of multi-vessel coronary artery disease (coefficient 1.85, SD 0.16, P<0.001), with an incremental value for its identification. CONCLUSIONS: Our results suggest that early post-stress 99mTc tetrofosmin LHR appears to be a useful index of extensive myocardial ischaemia dysfunction and multi-vessel coronary artery disease.

Aged↗
PubMed2005

Stress fracture of the ulnar styloid protuberance.

Stress fractures of the upper extremities are uncommon but can be a serious source of morbidity if not correctly diagnosed. We present a rare case of a 49-year-old female typist, who reported a 4-month history of a pain located in the region of the left lower ulnar epiphysis and extended to the left portion of the wrist. The patient did not mention any injury. The pain was exacerbated during typing and the clinical diagnosis of tendonitis was made initially. Because of the patient's persistent symptoms, she underwent a plain radiograph investigation in the region of the left lower forearm and wrist, which did not reveal any bone lesion. Consequently, we performed a 3-phase bone scan that showed findings consistent with a fracture of the left ulnar styloid protuberance. The fracture was thought to have a stress origin attributed to the patient's tough working.

Arthralgia↗
PubMed2003

Tc-99m tetrofosmin myocardial SPECT combined with a modified exercise protocol in an unusual case of steal phenomenon.

A 61-year-old diabetic woman was referred for myocardial perfusion single photon emission computed tomographic (SPECT) imaging 4 years after coronary artery bypass grafting to the left anterior descending (LAD) artery using a left internal mammary artery (LIMA) graft. She had 3 months' angina associated with fatigue of her left upper extremity (the patient is left-handed). Stress myocardial imaging using a Bruce protocol did not exhibit significant myocardial ischemia, but because of her typical angina symptoms, she underwent repeat stress myocardial imaging in combination with exercise of her left arm. During the aforementioned modified stress protocol, the patient reported angina, and radionuclide perfusion imaging showed extensive myocardial ischemia. The patient underwent coronary angiography and arteriography of the left subclavian artery, which revealed severe stenosis before the origin of the LIMA, resulting in reversed blood flow from the LAD artery through the LIMA graft to the left subclavian artery.

Exercise Test↗
PubMedDate not supplied

Abnormal heart rate recovery immediately after treadmill testing: correlation with clinical, exercise testing, and myocardial perfusion parameters.

BACKGROUND: The increase in heart rate during exercise is considered to be attributed to sympathetic system activation combined with parasympathetic withdrawal. The prognostic importance of the chronotropic response to exercise and heart rate recovery 1 minute after exercise has already been established. The purpose of this study was to evaluate heart rate recovery as an index of myocardial ischemia, by correlating heart rate recovery with known parameters of myocardial ischemia. METHODS AND RESULTS: Included in the study were 304 consecutive patients (73% men), aged 34 to 82 years. Patients whose heart rate recovery value or myocardial perfusion imaging could have been influenced by factors other than ischemic disease were excluded from the study. The patients underwent single photon emission computed tomography myocardial perfusion imaging combined with symptom-limited exercise testing with thallium 201 or technetium 99m tetrofosmin. The value for heart rate recovery was defined as the decrease in heart rate from peak exercise to 1 minute after termination of exercise. For semiquantitation of the scintigram, the uptake of the radiotracer was graded on a scale from 0 to 4. Twenty-one beats per minute was defined as the lowest normal value for heart rate recovery. We found 74 patients (24%) with an abnormal value. We also found a significant correlation between heart rate recovery 1 minute after exercise and stress myocardial perfusion score. In addition, there was a statistically significant relationship between heart rate recovery and chronotropic variables. Patients with an abnormal value of heart rate recovery were generally of an older age, were more likely men, had a higher frequency of risk factors for coronary artery disease, were mostly taking cardioactive medications, had lower efficiency during treadmill testing, and had more pathologic findings on the scintigram. CONCLUSIONS: Myocardial ischemia, as assessed by myocardial perfusion imaging, is an important correlate of heart rate recovery. There is a significant correlation between chronotropic variables during exercise testing and heart rate recovery 1 minute after exercise. It seems that the heart rate recovery value 1 minute after peak exercise may be considered a reliable index of the severity of myocardial ischemia.

Adult↗