No abstract available.
Arteries ; Cardiac Imaging Techniques ; Heart Defects, Congenital ; Transposition of Great Vessels

OBJECTIVETo explore safety, indications and advantages of mapping and ablation of arrhythmia in children guided by Carto and Ensite system.

METHODSGuided by Carto system, radiofrequency catheter ablation (RFCA) was performed on 8 pediatric patients with tachycardia whose mean age was (6.2 + or - 1.7) years, mean weight was (18.0 + or - 2.0) kg. Guided by Ensite system, RFCA was performed on 10 pediatric patients with arrhythmia, 8 of them were ablated guided by Ensite Array system: 6 cases with premature ventricular contractions (PVCs), 2 cases with right atrial tachycardia, their mean age was (11.3 + or - 1.2) years, and mean weight (40.0 + or - 5.0) kg. The other two cases with W-P-W syndrome were ablated guided by Ensite Navx system.

RESULTGuided by Carto system, 8 cases were successfully mapped and ablated: 6 cases had incision atrial tachycardia, 1 case had left atrial tachycardia and 1 case had right atrial tachycardia. In 1 case with incision atrial tachycardia the condition recurred after 3 months, and was ablated again successfully. Guided by Ensite Array system, 6 cases with PVCs (in 2 originating from the right ventricular inflow tract and in 4 originating from the right ventricular outflow tract) and 2 cases with right atrial tachycardia were successfully mapped and ablated, PVCs of the first 6 cases were reduced from (32 333 + or - 4509) 24 h to (0-4)/24 h after ablation. In 1 case with automatic atrial tachycardia, mapping could not be done by Ensite Array system, because P wave could not be identified from T wave. Single bolus of adenosine 20 mg was given within 30 s to let ventricles stop for 2 s (cardio-ventricular pacing standby) until T wave vanished, mapping and ablation were operated again successfully, but another atrial tachycardia occurred 1 day later. Guided by Ensite Navx system, 2 cases with W-P-W syndrome were successfully ablated, operation under X-rays lasted for 8 and 10 min. In none of the 9 patients the disease recurred after follow-up for 6 months.

CONCLUSIONCarto system is suitable for mapping and ablation in pediatric patients with continuous tachycardia, especially with incision atrial tachycardia; Ensite Array system fits children older than 10 years with right heart discontinuous arrhythmia; and Ensite NavX system can set up model and display endocardial anatomic structure quickly. Compared with two-dimensional mapping system, the three-dimensional mapping system (Carto and Ensite) can display the origin of arrhythmia and activation sequence clearly, decrease difficulty of operation efficiently and diminish operation time under X-ray.

Arrhythmias, Cardiac ; physiopathology ; surgery ; Catheter Ablation ; methods ; Child ; Child, Preschool ; Electrophysiologic Techniques, Cardiac ; methods ; Humans ; Imaging, Three-Dimensional ; Treatment Outcome

Myocardial perfusion imaging is one of the common diagnostic modalities used today for non-invasive diagnosis and evaluation of ischemia and myocardial infarction. However, this study may be time consuming due to delays mostly caused by diaphragmatic and intraabdominal artifacts. In this study, the effectiveness of different diets given to 120 patients pre-resting scan were evaluated through heart to liver ratio. Results showed that chocolate milk (H:L= 1.35 plus minus 0.28) is superior to water (H:L = 0.98 plus minus 0.32), null (H:L = 0.95 plus minus 0.39) and milk diet (H:L = 0.95 plus minus 0.27). However, lemon juice (H:L =1.14 plus minus 0.40) and milk with water (H:L = 1.16 plus minus 0.24) has no significant difference in effect with chocolate milk group. Thus patient may be given the choice of taking lemon juice, chocolate milk, or milk with water. This will help give good quality images while decreasing the waiting time of the patient.
Human ; Male ; Female ; Aged 80 and over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; MYOCARDIAL PERFUSION IMAGING ; DIAGNOSIS ; DIAGNOSTIC TECHNIQUES AND PROCEDURES ; DIAGNOSTIC IMAGING ; CARDIAC IMAGING TECHNIQUES ; MYOCARDIAL REPERFUSION

The study aims to determine the relationship of body mass index (BMI) and related anthropometric measurements on the image quality of Tl-201 and Tc-99m sestamibi myocardial perfusion scans (MPS). A total of 163 scans were analyzed. A blinded experienced physician performed visual analysis on the scans image quality on two different occasions. Quantitative parameter used was the heart-to-lung ratio (HLR). Regression analysis was done to determine the association of HLR with BMI and myocardial tracer uptake, ROC curves were generated to establish BMI and HLR cut-off points. Increasing BMI was associated with visually poorer images in the Tl-201 MPS group (p 0.003) but not for the Tc-99m MPS group (p 0.065). It was also associated with decrease HLR and myocardial tracer upatake for both tracers (p <0.001). ROC curves revealed BMI cut-off points of 28 (Tl-201 p 0.000; Tc99m sestamibi p 0.004) for both procedures; HR cut-off values of 3.0 for Tl-201 )p 0.295) and 2.5 for Tc-99m sestamibi (p 0.875). the image quality of Tl-201 scans begins to deteriorate at a BMI of 28 and HLR of 3.0 with myocardial count density reduction (less than or equal to 6000 counts) translating to visually poorer images. On the other hand , image quality of Tc-99m sestamibi scans also tend to deteriorate similarly at a BMI of 28. However, in contrast to Tl-201, the lower HLR cut-off of 2.5 suggests a relatively higher myocardial count density (greater than or equal to 9000 counts) rendering the image quality to be still satisfactory for subjective assessment.
Human ; Male ; Female ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; MYOCARDIAL PERFUSION IMAGING ; MYOCARDIAL SCINTIGRAPHY ; DIAGNOSIS ; DIAGNOSTIC TECHNIQUES AND PROCEDURES ; DIAGNOSTIC IMAGING ; CARDIAC IMAGING TECHNIQUES ; BODY MASS INDEX

imaging (dynamic CTP) with a 10.5-cm z-axis coverage. Although the increased radiation exposure associated with the 50% wider scan range compared to second-generation DSCT (2nd-DSCT) may be suppressed by using a tube voltage of 70 kV, it remains unclear whether image quality and the ability to quantify myocardial blood flow (MBF) can be maintained under these conditions. This study aimed to compare the image quality, estimated MBF, and radiation dose of dynamic CTP between 2nd-DSCT and 3rd-DSCT and to evaluate whether a 10.5-cm coverage is suitable for dynamic CTP.MATERIALS AND METHODS: We retrospectively analyzed 107 patients who underwent dynamic CTP using 2nd-DSCT at 80 kV (n = 54) or 3rd-DSCT at 70 kV (n = 53). Image quality, estimated MBF, radiation dose, and coverage of left ventricular (LV) myocardium were compared.RESULTS: No significant differences were observed between 3rd-DSCT and 2nd-DSCT in contrast-to-noise ratio (37.4 ± 11.4 vs. 35.5 ± 11.2, p = 0.396). Effective radiation dose was lower with 3rd-DSCT (3.97 ± 0.92 mSv with a conversion factor of 0.017 mSv/mGy·cm) compared to 2nd-DSCT (5.49 ± 1.36 mSv, p < 0.001). Incomplete coverage was more frequent with 2nd-DSCT than with 3rd-DSCT (1.9% [1/53] vs. 56% [30/54], p < 0.001). In propensity score-matched cohorts, MBF was comparable between 3rd-DSCT and 2nd-DSCT in non-ischemic (146.2 ± 26.5 vs. 157.5 ± 34.9 mL/min/100 g, p = 0.137) as well as ischemic myocardium (92.7 ± 21.1 vs. 90.9 ± 29.7 mL/min/100 g, p = 0.876).CONCLUSION: The radiation increase inherent to the widened z-axis coverage in 3rd-DSCT can be balanced by using a tube voltage of 70 kV without compromising image quality or MBF quantification. In dynamic CTP, a z-axis coverage of 10.5 cm is sufficient to achieve complete coverage of the LV myocardium in most patients.]]>
Cardiac Imaging Techniques ; Cohort Studies ; Cytidine Triphosphate ; Humans ; Image Enhancement ; Multidetector Computed Tomography ; Myocardial Perfusion Imaging ; Myocardium ; Perfusion Imaging ; Radiation Dosage ; Radiation Exposure ; Retrospective Studies

Patients with LV dysfunction are known to have a high risk for future coronary events. This study aimed to determine the incremental prognostic value of perfusion defects in patients with scintigraphic evidence of LV dysfunction. Patients showing either transient ischemic dilatation or Tl-201 lung:heart ratio of >0.5 on exercise or dipyridamole SPECT Tl- 201 myocardial perfusion scan were included in the study. Perfusion defects were scored semiquantitatively using a 17 -segment, 5-point scale (0 = normal, 4 = absent uptake). The extent and severity of defects were quantified using number of abnormal segments (NAS) and the summed stress score (SSS). Defect reversibility was quantified using the summed difference score (SDS) between stress and rest defects. Patients were followed up for the development of coronary events over a period of 12 - 30 months. There were 6 cardiac deaths and 7 myocardial infarctions in the 65 patients included in the study (20% overall event rate). ROC curve analysis of the scores revealed the following suggested cut-off values for predicting cardiac event: NAS ~ 7 (85% sensitivity, 56% specificity), SSS ~ 19 (77% sensitivity, 67% specificity) and SDS ~ 7 (31 % sensitivity, 60% specificity). ,Event rate was significantly higher above the cut-off value in SSS «19 = 9%, >19 = 32%,p = 0.04). With NAS, the event rate was higher above the cut-off value, with the difference approaching significance (NAS 7 = 26%, P = 0.06). There was no statistically significant difference in the event rate with high or low SDS (SDS 7 = 16%, P = 0.32). The odds ratios for NAS and SSS (5.8,4.9, respectively) were higher compared with SDS (0.56). The extent and severity of stress perfusion defects provided incremental prognostic information in patients with LV dysfunction. Our data suggest that the degree of defect reversibility showed no prognostic value in this subset of patients.

Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Dilatation ; Dipyridamole ; Myocardial Infarction ; Tomography, Emission-computed, Single-photon ; Myocardial Perfusion Imaging ; Thallium ; Radionuclide Imaging ; Diagnosis ; Cardiac Imaging Techniques

Over the past three decades, radionuclide myocardial perfusion scintigraphy (MPS) has become established as the main functional cardiac imaging technique for ischemic heart disease. It is currently appropriate for all aspects of detecting and managing ischemic heart disease, including diagnosis, risk assessment and stratification, assessment of myocardial viability, and evaluation of left ventricular function. The purpose of this article was to review recent trends in nuclear cardiology practice, excluding positron emission tomography. The past few years have brought several rapid developments that have increased photon sensitivity in nuclear cardiology scanner hardware. Additionally, software applying new methods of single photon emission tomography (SPECT) reconstruction on conventional and dedicated systems has preserved or even improved SPECT image quality with lower count statistics. On the other hand, much interest has been shown in lowering the radiation dose by the stakeholders of MPS.
Cardiac Imaging Techniques ; Cardiology ; Hand ; Myocardial Ischemia ; Myocardial Perfusion Imaging ; Perfusion Imaging ; Positron-Emission Tomography ; Risk Assessment ; Tomography, Emission-Computed, Single-Photon ; Ventricular Function, Left

OBJECTIVE: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. MATERIALS AND METHODS: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 +/- 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. RESULTS: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 +/- 0.306 [group A] vs. 1.084 +/- 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 +/- 0.16 mSv in group A and 7.1 +/- 1.05 mSv in group B (p = 0.001). CONCLUSION: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.
Arrhythmias, Cardiac/*diagnosis ; Artifacts ; *Cardiac-Gated Imaging Techniques ; *Coronary Angiography ; *Electrocardiography ; Female ; *Heart Rate ; Humans ; Male ; Middle Aged ; *Tomography, Spiral Computed

No abstract available.
*Cardiac-Gated Imaging Techniques ; Coronary Vessel Anomalies/*radiography ; Female ; Humans ; Male ; Sinoatrial Node/*radiography ; Tomography, X-Ray Computed/*methods

The aims of this study were to determine the prognostic value and the accuracy of nitrate-augmented Tc-99m myocardial SPECT for myocardial viability detection. Patients with angiographic CAD and LV wall motion abnormality by MUGA were included in the study. Rest Tc-99m sestamibi SPECT MPS was performed on two consecutive days, once with 0.6 mg sublingual nitroglycerin and once without. Perfusion was graded semi-quantitatively. Reversibility score was calculated as the difference between nitrate-augmented and rest imaging perfusion scores. Repeat rest SPECT MPS was performed after at least 6 months and all patients were followed up for at least 12 months to determine the occurrence of cardiac events. Thirty-five patients were included in the study. Five patients died from myocardial infarction during the follow-up period. Eleven patients had follow-up SPECT, with five of them done after revascularization. Defect score improved significantly after revascularization compared without revascularization (7.4 versus 0.3, p=0.02). Reversibility scores correlated poorly with the subsequent occurrence of cardiac events in patients treated medically. There was no significant increase in LVEF detected after revascularization even if the patients had a positive reversibility score. By this parameter, nitrate-augmented MPS could not accurately assess myocardial viability. However, with nitrate-augmentation, defect scores significantly improved and were more predictive of post-revascularization scores compared to the rest scores. These suggest the possibility for enhanced detection of potentially viable myocardium with nitrate MPS. And due to its simplicity and safety, the routine use of nitrate-augmentation in clinical practice may be recommended.

Human ; Male ; Female ; Diagnostic Techniques And ; Procedures ; Diagnostic Imaging ; Image Interpretation, Computer-assisted ; Tomography, Emission-computed ; Cardiac Imaging Techniques ; Myocardial Perfusion Imaging ; Myocardial Infarction ; Myocardium ; Nitroglycerin ; Technetium Tc 99m Sestamibi ; Tomography, Emission-computed, Single-photon