Resultado del cierre incompleto de defecto tipo Gerbode con coil Nit-Occlud Lê VSD: hemolisis grave que precisa reintervención / Effect of incomplete closure of a Gerbode defect with the Nit-Occlud Lê VSD Coil: severe hemolysis requiring a second procedure

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Clinical significance of right ventricular activity on treadmill thallium-201 myocardial single-photon emission computerized tomography using cadmium-zinc-telluride cameras.

OBJECTIVE: Identification of right ventricular (RV) abnormalities is important in patients with suspected coronary artery disease (CAD). RV activity can be better visualized on myocardial single-photon emission computerized tomography (SPECT) using a higher sensitivity cadmium-zinc-telluride (CZT) detector. The aim of this study was to investigate the clinical significance of RV/left ventricular (LV) uptake ratios during exercise thallium-201 SPECT using CZT detectors. PATIENTS AND METHODS: A total of 102 patients underwent treadmill ECG-gated SPECT, coronary angiography, and echocardiography. SPECT myocardial perfusion was interpreted using a 17-segment model and a 0-4-point scale. RV/LV uptake ratios were calculated on the basis of maximum counts per pixel within the entire RV and LV walls. The relationships between RV/LV uptake ratio and gated SPECT, presence of CAD (≥50% stenosis in the left main or ≥70% in the main branches), demographics, and echocardiographic parameters were analyzed. RESULTS: Stress RV/LV ratios correlated positively with the presence of left main or multivessel disease, and tricuspid regurgitation maximum pressure gradient. After multivariate regression, stress/rest RV/LV ratios correlated positively with mitral flow deceleration time, age, female sex, and use of ß-blockers. CONCLUSION: RV/LV uptake ratios on the basis of exercise myocardial perfusion SPECT imaging using CZT cameras are useful for the detection of severe CAD and could serve as an indicator of pulmonary hypertension and LV diastolic dysfunction.

Clinical validation of the planar radionuclide ventriculography in patients with right ventricular dysfunction

Objetivos: La ventriculografía con radionúclidos (RNV) se puede utilizar para la evaluación de la función ventricular derecha, pero debe ser validada clínicamente en pacientes con patología específica del ventrículo derecho (RV) y con posible interacción del ventrículo izquierdo (LV). Métodos: Tres grupos de 15 pacientes cada uno, con diagnóstico de displasia arritmogénica del ventrículo derecho (ARVD), hipertensión arterial pulmonar (PAH) o defecto del septum auricular (ASD) se comparan con un grupo de sujetos normales. Se valoran parámetros de ambos ventrículos por separado (fracción de eyección: LVEF, RVEF y sincronismo intraventricular, cuantificado como la desviación estándar de la fase: LVPSD y RVPSD) así como la relación o interdependencia del RV con el LV (RV/LV volumen, LV/RV fracción de eyección y sincronismo interventricular). Se analizaron también todas las variables en conjunto para identificar grupos de pacientes según su comportamiento funcional. Resultados: Se encontraron diferencias significativas entre los pacientes y el grupo control para la función del RV mientras que la del LV se mantiene dentro de los límites normales. Cuando se considera la función del RV, el grupo control y los pacientes con ASD muestran diferencia con los pacientes ARVD y PAH. Cuando se valora la relación RV/LV hay diferencia entre el grupo control y el grupo ASD. En el grupo de PAH, la función del LV muestra diferencias con el resto de los grupos. Conclusión: La RNV es una herramienta clínica fiable para valorar la función del RV en pacientes con patología del RV (AU)

Objectives. Gated radionuclide ventriculography (RNV) may be used for the evaluation of the right ventricular function. However, the accuracy of the method should be clinically validated in patients suffering from diseases with specific pathology of the right ventricle (RV) and with possible left ventricular (LV) interaction. Methods. Three groups of 15 patients each, diagnosed with arrhythmogenic right ventricular dysplasia (ARVD), pulmonary artery hypertension (PAH) or atrial septal defect (ASD) were compared to a group of normal subjects. The parameters for both ventricles were evaluated separately (ejection fractions: LVEF and RVEF, and intraventricular synchronism quantified as phase standard deviation: LVPSD and RVPSD) as well as the relation or interdependence of the right to left ventricle (RV/LV volume ratio, LV/RV ejection fraction and stroke volume ratios, and interventricular synchronism). All the variables as a whole were analyzed to identify groups of patients according to their functional behaviour. Results. Significant differences were found between the patients and control group for the RV function while the LV function remained mostly within normal limits. When the RV function was considered, the control group and ASD patient group showed differences regarding the ARVD and PAH patients. On evaluating the RV/LV ratios, differences were found between the control group and the ASD group. In the PAH patients, LV function showed differences in relation to the rest of the groups. Conclusion. RNV is a reliable clinical tool to evaluate RV function in patients with RV abnormality (AU)

Dedicated radial ventriculography pigtail catheter.

A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The "short" dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The "long" dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

Pigtail catheter fracture and embolization into the abdominal aorta: an extremely rare angiographic complication.

Coronary angiography is a widely used diagnostic method for coronary artery disease. In clinical practice, although complications of the procedure often involve the vascular access point, there is no previous report of the fracture and embolization of the distal tip of a pigtail catheter. Herein, we present the case of a 51-year-old woman whose left ventriculography was interrupted by fracture of the curved tip of a pigtail catheter, which remained at the renal artery level in the abdominal aorta.

Determinación de la fracción de eyección del ventrículo izquierdo realizada con 4 programas de cálculo distintos / Calculation of the left ventricular ejection fraction. Comparison between 4 different instruments

Objetivo. Analizar la relación existente entre los valores de la fracción de eyección (FE) del ventrículo izquierdo obtenidos mediante ventriculografía isotópica en equilibrio utilizando cuatro equipos de procesado distintos. Material y métodos. Se han estudiado 85 FE. Las adquisiciones se realizaron en una única gammacámara (Sopha®) mediante sincronización con el electrocardiograma (ECG) y utilizando hematíes marcados con Tc-99m. Se ha obtenido cada una de las FE por cuatro sistemas de procesado: NXT (Sopha®), Entegra (Gems®), Odissey (Philips®) y Esoft (Siemens®). El modo empleado por defecto era el de cálculo automático. Se aplicó la prueba de comparación de medias para datos apareados agrupando las 4 series de datos dos a dos. Asimismo, se buscó la correlación de Spearman y se aplicó la prueba de Bland-Altman para intercambiabilidad y se analizó su regresión por el método de Deming. Resultados. Los valores medios ± desviación estándar según cada programa fueron: NXT: 61 ± 9, Entegra: 60 ± 10, Odyssey: 60 ± 9, Esoft: 60 ± 10. No se han detectado globalmente diferencias, pero los 4 programas generan valores no intercambiables entre sí. Conclusiones. Aunque linealmente relacionados y sin diferencias significativas, se concluye que si se han de comparar estudios de un mismo paciente se emplee el mismo programa, cosa actualmente factible mediante el formato DICOM

Aim. The aim of this study was to analyse therelationship between left ventricular ejection fractions (EF) obtained using four different instruments.Material and methods. Eighty-five EF values were analysed. Gated acquisition was performed with the same gammacamera (SOPHA®) using 99mTc-labelled red cells. Each EF was obtained using four processing systems: NXT (SOPHA®), Entegra (Gems®), Odyssey (Philips®) and Esoft (Siemens®), always working in automated mode.The paired student’s t-test, Spearman correlation andBland-Altman analysis were used to compare methods,and Deming regression was applied. Results. Mean values and standard deviations for each program were: NXT: 61 ± 9; Entegra: 60 ± 10; Odyssey: 60 ± 9; Esoft: 60 ± 10.Although no significant differences were found as a wholeand the values were linearly related, the methods are not interchangeable. Conclusions. The same program should be used in the follow- up of each patient, which is now easily achievable by means of the DICOM standard (AU)

Accuracy of 4 different algorithms for the analysis of tomographic radionuclide ventriculography using a physical, dynamic 4-chamber cardiac phantom.

UNLABELLED: Various automatic algorithms are now being developed to calculate left ventricular (LV) and right ventricular (RV) ejection fraction from tomographic radionuclide ventriculography. We tested the performance of 4 of these algorithms in estimating LV and RV volume and ejection fraction using a dynamic 4-chamber cardiac phantom. METHODS: We developed a realistic physical, dynamic 4-chamber cardiac phantom and acquired 25 tomographic radionuclide ventriculography images within a wide range of end-diastolic volumes, end-systolic volumes, and stroke volumes. We assessed the ability of 4 algorithms (QBS, QUBE, 4D-MSPECT, and BP-SPECT) to calculate LV and RV volume and ejection fraction. RESULTS: For the left ventricle, the correlations between reference and estimated volumes (0.93, 0.93, 0.96, and 0.93 for QBS, QUBE, 4D-MSPECT, and BP-SPECT, respectively; all with P < 0.001) and ejection fractions (0.90, 0.93, 0.88, and 0.92, respectively; all with P < 0.001) were good, although all algorithms underestimated the volumes (mean difference [+/-2 SDs] from Bland-Altman analysis: -39.83 +/- 43.12 mL, -33.39 +/- 38.12 mL, -33.29 +/- 40.70 mL, and -16.61 +/- 39.64 mL, respectively). The underestimation by QBS, QUBE, and 4D-MSPECT was greater for higher volumes. QBS, QUBE, and BP-SPECT could also be tested for the right ventricle. Correlations were good for the volumes (0.93, 0.95, and 0.97 for QBS, QUBE, and BP-SPECT, respectively; all with P < 0.001). In terms of absolute volume estimation, the mean differences (+/-2 SDs) from Bland-Altman analysis were -41.28 +/- 43.66 mL, 11.13 +/- 49.26 mL, and -13.11 +/- 28.20 mL, respectively. Calculation of RV ejection fraction correlated well with true values (0.84, 0.92, and 0.94, respectively; all with P < 0.001), although an overestimation was seen for higher ejection fractions. CONCLUSION: Calculation of LV and RV ejection fraction based on tomographic radionuclide ventriculography was accurate for all tested algorithms. All algorithms underestimated LV volume; estimation of RV volume seemed more difficult, with different results for each algorithm. The more irregular shape and inclusion of a relatively hypokinetic RV outflow tract in the right ventricle seemed to cause the greater difficulty with delineation of the right ventricle, compared with the left ventricle.

Validation of planar and tomographic radionuclide ventriculography by a dynamic ventricular phantom.

Although there is increasing interest in the automatic processing of tomographic radionuclide ventriculography (TRV) studies, validation is mainly limited to a comparison of TRV results with data from planar radionuclide ventriculography (PRV) or gated perfusion single photon emission computed tomography (SPECT). The aim of this study was to use a dynamic physical cardiac phantom to validate the ejection fraction (EF) and volumes from PRV and TRV studies. A new dynamic left ventricular phantom was constructed and used to obtain 21 acquisitions in the planar and tomographic mode. The directly measured volumes and EFs of the phantom during the acquisitions were considered as the gold standard for comparison with TRV and PRV. EFs were calculated from PRV by background-corrected end-diastolic and end-systolic frames. Volumes and EFs were calculated from TRV by region growing with different lower thresholds to search for the optimal threshold. EF from PRV correlated significantly with the real EF (r=0.94, P=0.00). The optimal threshold value for volume calculation from TRV in 336 cases was 50% (r=0.98, P=0.00) yielding the best slope after linear regression. When considering these calculated end-diastolic and end-systolic volumes, EF correlated well (r=0.99, P=0.00) with the real EF, and this correlation was significantly (P=0.04) higher than that of the EF from PRV. Our experiments prove that EF measured by TRV yields more accurate results compared with PRV in dynamic cardiac phantom studies.

Single crystal biplane equilibrium radionuclide ventriculography: an improved planar imaging technique.

Radionuclide ventriculography in the best septal view is an established method to assess both global and regional ventricular function. Additional projections may be used to delineate the wall motion of inferior myocardial segments. Radionuclide ventriculography was performed in 65 patients using both a single plane (in the best septal view) and a biplane technique. The biplane collimator allowed simultaneous assessment in two planes 40 degrees apart, allowing simultaneous visualization of all four myocardial walls. Seventeen patients with regional wall motion abnormalities were detected with the single plane best septal view and a further 18 patients with impaired wall motion were identified with the biplane collimator (51% of the abnormal ventricles). The additional abnormal segments were seen in only the steep lateral projection. Left ventricular ejection fraction estimation with the biplane technique remains highly reproducible and correlates well with that derived from the best septal view. Biplane radionuclide ventriculography improves the detection of inferior wall motion abnormalities at no expense of time, and offers the possibility of performing two-view stress ventriculography with inotropic agents.

Continuous ambulatory radionuclide monitoring of left ventricular function: effect of body position during ergometer exercise.

UNLABELLED: We assessed the reliability of a continuous ambulatory radionuclide monitoring system (the VEST system, Capintec, Inc., Ramsey, NJ) for measurement of left ventricular performance during exercise in the upright and supine positions. METHODS: Sixteen healthy male volunteers (aged 32-46 yr; mean age 37 +/- 4 yr) were studied. All volunteers underwent ergometer exercise testing in both the upright and supine positions, and left ventricular performance was determined with the VEST system. RESULTS: The resting heart rate, systolic blood pressure, pressure rate product, relative end-diastolic volume, relative end-systolic volume and left ventricular ejection fraction (LVEF) all showed no differences between the upright and supine positions. At peak exercise, the heart rate, systolic blood pressure and pressure rate product showed no differences between the upright and supine positions. In the upright position at peak exercise the relative end-diastolic volume was increased (83% +/- 9% to 91% +/- 11%, p < 0.001); the relative end-systolic volume remained unchanged (34% +/- 3% to 33% +/- 15%), and LVEF was significantly increased from 58% +/- 6% to 66% +/- 11% (p < 0.01). In the supine position at peak exercise, the relative end-diastolic volume remained unchanged (85% +/- 5 to 83% +/- 7%), the relative end-systolic volume was increased (35% +/- 5% to 43% +/- 13%, p < 0.01), and LVEF was decreased from 58% +/- 5% to 48% +/- 17% (p < 0.01). These results indicated inferior data collection by the VEST system in the supine position. CONCLUSION: Since the detector of the VEST system may be too small, the data collection is impaired during exercise in the supine position by shifting the heart with deep respiration. The VEST system is very useful for determining left ventricular performance when applied in the sitting or upright position. However, in the supine position during exercise, the use of the VEST system should be avoided because it might indicate an artifactual deterioration of left ventricular performance.

Monitoring of left ventricular ejection fraction with a miniature, nonimaging nuclear detector: accuracy and reliability over time with special reference to blood labeling.

BACKGROUND: The purpose of this study was to determine the accuracy of determinations of left ventricular ejection fraction (LVEF) by a nonimaging miniature nuclear detector system (Cardioscint) and to evaluate the feasibility of long-term LVEF monitoring in patients admitted to the coronary care unit, with special reference to the blood-labeling technique. METHODS AND RESULTS: Cardioscint LVEF values were compared with measurements of LVEF by conventional gamma camera radionuclide ventriculography in 33 patients with a wide range of LVEF values. In 21 of the 33 patients, long-term monitoring was carried out for 1 to 4 hours (mean 186 minutes), with three different kits: one for in vivo and two for in vitro red blood cell labeling. The stability of the labeling was assessed by determination of the activity of blood samples taken during the first 24 hours after blood labeling. The agreement between Cardioscint LVEF and gamma camera LVEF was good with automatic background correction (r = 0.82; regression equation y = 1.04x + 3.88) but poor with manual background correction (r = 0.50; y = 0.88x - 0.55). The agreement was highest in patients without wall motion abnormalities. The long-term monitoring showed no difference between morning and afternoon Cardioscint LVEF values. Short-lasting fluctuations in LVEFs greater than 10 EF units were observed in the majority of the patients. After 24 hours, the mean reduction in the physical decay-corrected count rate of the blood samples was most pronounced for the two in vitro blood-labeling kits (57% +/- 9% and 41% +/- 3%) and less for the in vivo blood-labeling kit (32% +/- 26%). This "biologic decay" had a marked influence on the Cardioscint monitoring results, demanding frequent background correction. CONCLUSION: A fairly accurate estimate of LVEF can be obtained with the nonimaging Cardioscint system, and continuous bedside LVEF monitoring can proceed for hours with little inconvenience to the patients. Instability of the red blood cell labeling during long-term monitoring necessitates frequent background correction.

Effects of short-term aminophylline administration on cardiac functional reserve in patients with syndrome X.

OBJECTIVES: This study sought to evaluate the effect of adenosine receptor blockade by aminophylline on cardiac functional reserve in patients with syndrome X. BACKGROUND: Aminophylline may have a potentially antiischemic effect through the inhibition of adenosine and, thus, the coronary steal phenomenon in patients with syndrome X. METHODS: A single-blind, placebo-controlled study of an intravenous infusion of aminophylline (6 mg/kg body weight over 15 min) or placebo (20 ml of saline solution over 15 min) was performed during continuous radionuclide monitoring of left ventricular ejection fraction in 12 patients performing supine bicycle ergometric exercise. RESULTS: Aminophylline increased exercise time (aminophylline 400 s vs. placebo 355 s, p < 0.01), decreased degree of ST segment depression (aminophylline 1.6 mm vs. placebo 2.4 mm, p < 0.01) and either abolished (seven patients) or diminished (five patients) chest pain during exercise. Aminophylline also increased left ventricular ejection fraction at rest (aminophylline 66.5% vs. placebo 62.3%, p < 0.05) but did not improve its deterioration at peak exercise (aminophylline 60.1% vs. placebo 56.6%, p = NS) or shorten the abnormally prolonged interval between the end of exercise and the overshoot (aminophylline 115 s vs. placebo 130 s, p = NS). CONCLUSIONS: Aminophylline infusion increases ischemic threshold and prolongs exercise duration in patients with syndrome X. It is hypothesized that aminophylline acts by inhibiting the coronary steal phenomenon through adenosine receptor blockade. It does not improve the deterioration in left ventricular function at peak exercise or the delayed response in ejection fraction in the recovery period, presumably because the beneficial effects of aminophylline that result from the redistribution of coronary blood flow are limited.

Ambulatory monitoring of left ventricular function during cardiopulmonary exercise tests in normal sedentary subjects.

UNLABELLED: Ambulatory monitoring (VEST) of left ventricular (LV) function is a useful and accurate method to measure cardiac function during exercise and rest. The aim of this study was to evaluate LV response to exercise in normal sedentary subjects. METHODS: Ten normal sedentary subjects underwent continuous ambulatory monitoring of LV function by VEST during upright bicycle exercise associated with combined analysis of pulmonary gas exchange. All parameters of LV function were measured in control conditions at rest, at the anaerobic threshold (point of nonlinear increase in ventilation relative to oxygen uptake) and at peak oxygen uptake (peak VO2). RESULTS: Heart rate and cardiac output significantly increased from control conditions to anaerobic threshold (p < 0.001) and from anaerobic threshold to peak VO2 (p < 0.001). Ejection fraction, end diastolic volume and stroke volume significantly increased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2. Finally, end-systolic volume significantly decreased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2. CONCLUSION: VEST is particularly useful in the evaluation of cardiac response to exercise in normal sedentary subjects, providing a better understanding of the spectrum of the normal LVEF response to exercise. Our data demonstrate that ejection fraction response to exercise is variable after anaerobic threshold, and a uniform increase is not necessarily expected in normal sedentary subjects.