RESUMEN
OBJECTIVES: This study sought to define the impact of paclitaxel-coated balloon angioplasty for treatment of drug-eluting stent restenosis compared with uncoated balloon angioplasty alone. BACKGROUND: Drug-coated balloon angioplasty is associated with favorable results for treatment of bare-metal stent restenosis. METHODS: In this prospective, single-blind, multicenter, randomized trial, the authors randomly assigned 110 patients with drug-eluting stent restenoses located in a native coronary artery to paclitaxel-coated balloon angioplasty or uncoated balloon angioplasty. Dual antiplatelet therapy was prescribed for 6 months. Angiographic follow-up was scheduled at 6 months. The primary endpoint was late lumen loss. The secondary clinical endpoint was a composite of cardiac death, myocardial infarction attributed to the target vessel, or target lesion revascularization. RESULTS: There was no difference in patient baseline characteristics or procedural results. Angiographic follow-up rate was 91%. Treatment with paclitaxel-coated balloon was superior to balloon angioplasty alone with a late loss of 0.43 ± 0.61 mm versus 1.03 ± 0.77 mm (p < 0.001), respectively. Restenosis rate was significantly reduced from 58.1% to 17.2% (p < 0.001), and the composite clinical endpoint was significantly reduced from 50.0% to 16.7% (p < 0.001), respectively. CONCLUSIONS: Paclitaxel-coated balloon angioplasty is superior to balloon angioplasty alone for treatment of drug-eluting stent restenosis. (PEPCAD DES-Treatment of DES-In-Stent Restenosis With SeQuent® Please Paclitaxel Eluting PTCA Catheter [PEPCAD-DES]; NCT00998439).
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Angioplastia Coronaria con Balón/métodos , Reestenosis Coronaria/cirugía , Stents Liberadores de Fármacos , Paclitaxel/farmacología , Anciano , Antineoplásicos Fitogénicos/farmacología , Angiografía Coronaria , Reestenosis Coronaria/diagnóstico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Diseño de Prótesis , Falla de Prótesis , Método Simple Ciego , Resultado del TratamientoRESUMEN
AIMS: In pacemaker patients with preserved atrio-ventricular (AV) conduction, atrial fibrillation (AF) can lead to symptomatic ventricular rate irregularity and loss of ventricular stimulation. We tested if dynamic ventricular overdrive (DVO) as a potentially pacemaker-integrated algorithm could improve both aspects. METHODS AND RESULTS: Different settings of DVO and ventricular-ventricular-inhibited-pacing (VVI) with different base rates were tested in two consecutive phases during electrophysiological studies for standard indications. Mean heart rate (HR), HR irregularity and percentage of ventricular pacing were evaluated. A fusion index (FI) indicative of the proportion of fusion beats was calculated for each stimulation protocol. Dynamic ventricular overdrive from the right ventricular apex was acutely applied in 38 patients (11 females, mean age 62.1 ± 11.5 years) with sustained AF and preserved AV conduction. Dynamic ventricular overdrive at LOW/MEDIUM setting increased the amount of ventricular pacing compared with VVI pacing at 60, 70, and 80 beats per minute (bpm; to 81/85% from 11, 25, and 47%, respectively; P < 0.05). It also resulted in a maximum decrease in interval differences (to 48 ± 18 ms from 149 ± 28, 117 ± 38, and 95 ± 46 ms, respectively; P < 0.05) and fusion (to 0.13 from 0.41, 0.42, and 0.36, respectively; P < 0.05) compared with VVI pacing at 60, 70, and 80 bpm. However, the application of DVO resulted in a significant increase in HR compared with intrinsic rhythm and VVI pacing at 80 bpm (to 97 bpm from 89 and 94 bpm, respectively; P < 0.05). CONCLUSION: Dynamic ventricular overdrive decreases HR irregularity and increases ventricular pacing rate compared with VVI pacing at fixed elevated base rates and spontaneous rhythm. Fusion index might help to refine information on pacing percentages provided by device counters.
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Algoritmos , Fibrilación Atrial/fisiopatología , Terapia de Resincronización Cardíaca/métodos , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/fisiopatología , Anciano , Fibrilación Atrial/terapia , Nodo Atrioventricular/fisiopatología , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Marcapaso Artificial/clasificación , Posición SupinaRESUMEN
AIMS: Image integration of three-dimensional (3D) reconstructions of left atrial (LA) and pulmonary vein (PV) anatomy into electroanatomical mapping (EAM) plays a major role in atrial fibrillation (AF) ablation. Point-by-point EAM is commonly used for registration of imported LA and PV anatomy. We aimed to assess the accuracy of intraprocedural rotational angiography-based LA imaging registered by spatial reconstruction of intracardiac echocardiography (ICE) in patients undergoing AF ablation. METHODS AND RESULTS: Twenty-two patients (11 males, 66 ± 12 years) were studied. Reconstructions of LA and PVs based on rotational angiography were registered by a second 3D reconstruction based on ICE. In a second step, EAM points were added to ICE 3D reconstructions. A 3D image of the LA and PVs was reconstructed in all patients by both imaging modalities. Rotational angiography and ICE-based LA 3D reconstructions took 11.5 ± 5.2 and 20.4 ± 11.2 min, respectively. A total of 17 ± 6 two-dimensional ICE fans were used for spatial reconstruction of ICE. The deviation between the two 3D shells was 2.6 ± 0.5 mm. Integration of 78 ± 58 EAM points into ICE 3D reconstruction did not significantly reduce the deviation to rotational angiography-based reconstructions (2.7 ± 0.6 mm). All PVs were isolated successfully. CONCLUSIONS: Intraprocedural 3D reconstruction of LA and PVs for ablation of AF is feasible based on both rotational angiography and ICE. LA reconstructions based on rotational angiography can accurately be registered using 3D ICE shells. Additional EAM does not enhance accuracy. Therefore, registration of rotational angiography-based 3D reconstructions by 3D reconstructions from ICE seems to be an alternative technique to support AF ablation.
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Angiografía/métodos , Fibrilación Atrial/cirugía , Técnicas de Imagen Cardíaca/métodos , Ablación por Catéter , Ecocardiografía/métodos , Atrios Cardíacos/diagnóstico por imagen , Anciano , Estudios de Factibilidad , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio/métodos , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugíaRESUMEN
INTRODUCTION: Exact visualization of complex left atrial (LA) anatomy is crucial for safety and success rates when performing catheter ablation of atrial fibrillation (AF). The aim of our study was to validate the accuracy of integrating rotational angiography-based 3-dimensional (3D) reconstructions of LA and pulmonary vein (PV) anatomy into an electroanatomical mapping (EAM) system. METHODS AND RESULTS: In 38 patients (62 +/- 8 years, 25 females) undergoing catheter ablation of paroxysmal (n = 19) or persistent (n = 19) AF, intraprocedural rotational angiography of LA and PVs was performed. The subsequent 3D reconstruction and segmentation of LA and PVs was transferred to the EAM system and registered to the EAM. The distances of all EAM points to corresponding points on the LA syngo DynaCT Cardiac surface were calculated. Segmentation of LA with clear visualization of adjacent structures was possible in all patients. Also, the integrated segmentation of the LA was used to guide the encirclement of ipsilateral veins, which resulted in PV isolation in all patients. Integration into the 3D mapping system was achieved with a distance error of 2.2 +/- 0.4 mm when compared with the EAM surface. Subgroups with paroxysmal and persistent AF showed distance errors of 2.3 +/- 0.3 mm and 2.1 +/- 0.4 mm, respectively (P = n.s.). CONCLUSION: Intraprocedural registration of LA and PV anatomy by contrast enhanced rotational angiography was feasible and accurate. There were no differences between patients with paroxysmal or persistent AF. Therefore, integration of rotational angiography-based reconstructions into 3D EAM systems might be helpful to guide catheter ablation for AF.
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Angiografía/métodos , Aortografía/métodos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Mapeo del Potencial de Superficie Corporal/métodos , Venas Pulmonares/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Técnica de Sustracción , Integración de Sistemas , Resultado del TratamientoRESUMEN
PURPOSE: To evaluate if computed tomography (CT) coronary calcium scoring is needed after detection of coronary calcifications on conventional chest radiographs. MATERIALS AND METHODS: One hundred and five patients (67 men; 57.2+/-12.8 years) with suspected coronary artery disease underwent conventional chest radiography and non-enhanced, retrospectively ECG-gated multislice spiral CT (MSCT) of the heart (4 mm x 2.5 mm, 120 kV, 133 mAs(eff.)). Chest radiographs were assessed independently by two radiologists. Detection of coronary calcifications was compared between both methods. Sensitivity, specificity, negative and positive predictive values, median, 25% and 75% percentiles for the detection of coronary calcifications were calculated. Receiver operating characteristics (ROC) analyses were computed. RESULTS: In 90 patients, MSCT revealed coronary calcifications. The mean coronary calcium score was 526.2 (0-4784.5). On chest radiographs, coronary calcifications were correctly detected in 46 (61) patients by observer 1 (observer 2). The corresponding sensitivity was 51.1% in observer 1 and 67.8% in observer 2. Median of detected coronary calcifications was 361.9 (426.4) for observer 1 (observer 2). Corresponding 25% und 75% percentiles were 109.6 (109.6) and 798.5 (898.5). The area under the ROC curve was 0.636 for observer 1 and 0.715 for observer 2. There was no correlation between image quality and the detection of coronary calcifications on plain film radiographs. CONCLUSION: As coronary calcifications of various extents are inconsistently detected on plain chest radiographs, CT calcium scoring may not be omitted even if coronary artery calcifications were detected on conventional chest radiographs.
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Calcinosis/diagnóstico por imagen , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Radiografía Torácica/métodos , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Cardiac resynchronization therapy (CRT) using left- (LV) or biventricular pacing is widely applied in selected heart failure patients. However, transvenous LV-lead placement into coronary sinus (CS) branches can be challenging. A 77-year-old female patient with New York Heart Association class III symptoms due to dilated cardiomyopathy [LV ejection fraction (LVEF): 10%, QRS-duration: 150 ms], despite optimal medical treatment presented for CRT. Coronary sinus angiograms were performed after transvenous CS cannulation. Within a large posterolateral vein, low phrenic nerve stimulation thresholds were found. The only alternative smaller tortuous lateral branch showed a significant narrowing, making LV-lead advancement impossible. Angioplasty was performed, using a venoplasty balloon. This caused complete branch occlusion. After recanalization of the vessel by implantation of a bare metal stent, the lead could be advanced through the stent. Optimal pacing parameters without phrenic nerve stimulation were established. Angioplasty of CS branches during CRT implantation procedures bears the risk of complete branch occlusion, but recanalization can acutely be achieved by stent implantation. This is the first report on rescue-stenting of a CS branch after angioplasty-related occlusion. Transthoracic lead implantation, accompanied risks, and slower recovery could thus be avoided.
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Disección Aórtica/complicaciones , Disección Aórtica/etiología , Prótesis Vascular , Seno Coronario/lesiones , Seno Coronario/cirugía , Estenosis Coronaria/etiología , Estenosis Coronaria/cirugía , Electrodos Implantados/efectos adversos , Marcapaso Artificial/efectos adversos , Stents , Anciano , Femenino , Humanos , Resultado del TratamientoRESUMEN
INTRODUCTION: Coronary artery disease is often accompanied with deterioration in left ventricular function. Left ventricular pacing has been shown to improve cardiac function in chronic heart failure. However, data are limited about left ventricular pacing during acute ischemia. Therefore, we studied the effects of acute myocardial ischemia on myocardial function during left ventricular pacing. METHODS: In 8 anesthetized dogs, the left ventricle was rapidly paced (180 bpm) from a basolateral and apicoseptal site during normal perfusion and mild and severe ischemia of the left anterior descending coronary artery. Effects on myocardial function were measured at each level of ischemia before and during pacing. RESULTS: Significant differences (p < 0.05) between basolateral and apicoseptal pacing were found for segmental shortening (12.1+/-1.6 vs. 10.8+/-1.6%), and QRS duration (77.3+/-4.1 vs. 85.7+/-3.8 ms) at normal coronary perfusion. During mild ischemia, significant differences (p < 0.05) were seen for myocardial contractility dP/dt(max) (1277+/-197 vs. 1158+/-156 mm Hg/s), segmental shortening (10.3+/-1.9 vs. 8.1+/-1.7%), left ventricular end-systolic pressure (76.9+/-7.5 vs. 69.6+/-7.9 mm Hg), and QRS duration, and for myocardial contractility dP/dt(max) (1033+/-209 vs. 917+/-207 mm Hg/s) and left ventricular end-systolic pressure (69.2+/-13.5 vs. 62.2+/-15.0 mm Hg) during severe ischemia. There were no significant differences in coronary blood flow during pacing from both sites. CONCLUSIONS: During acute myocardial ischemia, depression of left ventricular function was lowest, when pacing from a left ventricular basolateral site. The effects of rapid left ventricular pacing were amplified by reduced coronary perfusion pressures. The choice of pacing site did not relevantly influence coronary blood flow.
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Estimulación Cardíaca Artificial , Corazón/fisiopatología , Isquemia Miocárdica/fisiopatología , Animales , Perros , Femenino , Masculino , Función Ventricular IzquierdaRESUMEN
Implantable cardioverter defibrillators and pacemakers detect an increasing number of silent episodes of AF. In a porcine model, the study evaluated the contractility of the left atrial appendage (LAA) during AF paroxysms as they may occur in patients. Peak outflow velocity of the LA and mean outflow velocity of the LAA (LAA-V(outmean)) (n = 17) were measured before, during, and after induction of self-terminating AF. LAA-V(outmean) was also measured during incremental pacing from different atrial sites using epicardial Doppler probes (n = 6) and during continuous recordings (n = 5) of 40 minutes of pacing maintained AF. Compared to baseline sinus rhythm, LAA-V(outmean) increased during short AF episodes (41 +/- 3 vs 35 +/- 2 cm/s, P < 0.05). After termination of the AF episodes, LAA-V(outmean) further increased (69 +/- 15 cm/s, P < 0.001 vs baseline). This "postfibrillatory enhancement" maintained after repeated induction of short AF paroxysms. During prolonged AF episodes lasting 40 minutes, an initial hypercontractility (44 +/- 2 vs 38 +/- cm/s, P < 0.01) was followed by a hypocontractility after 20 minutes (29 +/- 12 P < 0.05 vs SR) and a postfibrillatory enhancement after cessation of AF (56 +/- 12 vs 27 +/- 9 cm/s at 40 minutes AF, P < 0.001). L-type Ca channel blockade abolished the initial hypercontractility during AF and the postfibrillatory enhancement. Repetitive AF paroxysms up to 2 minutes did not decrease left atrial contractility. During maintained AF up to 40 minutes an initial hypercontractility and a consecutive hypocontractility, which is overcompensated by a postfibrillatory enhancement of atrial inotropy after cessation of AF, are present. The observed phenomenon seems to be related to an increased Ca(2+) influx through the L-type Ca(2+) channel.
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Apéndice Atrial/fisiopatología , Fibrilación Atrial/fisiopatología , Función del Atrio Izquierdo/fisiología , Estimulación Cardíaca Artificial , Contracción Miocárdica/fisiología , Análisis de Varianza , Animales , Fibrilación Atrial/diagnóstico por imagen , Velocidad del Flujo Sanguíneo/fisiología , Canales de Calcio Tipo L/fisiología , Ecocardiografía , Femenino , PorcinosRESUMEN
UNLABELLED: Heterogeneous perfusion in left bundle branch block (LBBB) has been demonstrated by (99m)Tc-methoxyisobutylisonitrile (MIBI) SPECT. Locally different contraction is also associated with LBBB. Quantitative analysis of myocardial SPECT is influenced by partial-volume effects depending on systolic wall thickening. Therefore, partial-volume effects may mimic perfusion heterogeneity in LBBB. METHODS: Fifteen patients with nonischemic dilated cardiomyopathy and LBBB underwent resting (15)O-water PET, (99m)Tc-MIBI SPECT, and gated (18)F-FDG PET for analysis of wall thickening. Myocardial blood flow corrected for rate-pressure product (corrMBF), (99m)Tc-MIBI uptake, and wall thickening were determined in 4 left ventricular wall areas. In 14 patients, M-mode echocardiographic recordings were available for comparison. RESULTS: Homogeneous distribution was found for corrMBF (1.09 +/- 0.41 to 1.19 +/- 0.31 mL x g(-1) x min(-1)). (99m)Tc-MIBI uptake and wall thickening were heterogeneous (P < 0.0001), with the lowest values septal ((99m)Tc-MIBI, 65% +/- 10%; wall thickening, 16% +/- 14%) and the highest lateral ((99m)Tc-MIBI, 84% +/- 5%; wall thickening, 55% +/- 17%). Similar relationships in systolic wall thickening were observed by M-mode echocardiography (anteroseptal, 20% +/- 11%; posterolateral, 37% +/- 18%; P < 0.001). CONCLUSION: Heterogeneity of (99m)Tc-MIBI uptake in LBBB corresponds to differences in wall thickening and does not reflect distribution of corrMBF. Supplementary analysis of wall thickening is recommended when assessing (99m)Tc-MIBI SPECT in LBBB.
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Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/fisiopatología , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/fisiopatología , Circulación Coronaria , Vasos Coronarios/diagnóstico por imagen , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Adulto , Anciano , Arterias , Velocidad del Flujo Sanguíneo , Bloqueo de Rama/complicaciones , Cardiomiopatía Dilatada/complicaciones , Femenino , Fluorodesoxiglucosa F18 , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Radioisótopos de Oxígeno , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único/métodos , Ultrasonografía , Disfunción Ventricular Izquierda/complicaciones , AguaRESUMEN
Regional and global myocardial blood flow and coronary vascular resistance were determined in patients with idiopathic-dilated cardiomyopathy and left bundle branch block before and during cardiac resynchronization therapy (CRT) using oxygen-15 water positron emission tomography. The investigated parameters did not exhibit regional heterogeneity and were not influenced by CRT. This implies that the beneficial effects of CRT do not require additional oxygen demand or regional reallocation of oxidative metabolism.
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Bloqueo de Rama/diagnóstico por imagen , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada/diagnóstico por imagen , Circulación Coronaria/fisiología , Velocidad del Flujo Sanguíneo , Análisis Factorial , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Radioisótopos de Oxígeno , Flujo Sanguíneo Regional , Estadísticas no Paramétricas , Tomografía Computarizada de EmisiónRESUMEN
OBJECTIVES: We studied the effects of cardiac resynchronization therapy (CRT) on regional myocardial strain distribution, as determined by echocardiographic strain rate (SR) imaging. BACKGROUND: Dilated hearts with left bundle branch block (LBBB) have an abnormal redistribution of myocardial fiber strain. The effects of CRT on such abnormal strain patterns are unknown. METHODS: We studied 18 patients (12 males and 6 females; mean age 65 +/- 11 years [range 33 to 76 years]) with symptomatic systolic heart failure and LBBB. Doppler myocardial imaging studies were performed to acquire regional longitudinal systolic velocity (cm/s), systolic SR (s(-1)), and systolic strain (%) data from the basal and mid-segments of the septum and lateral wall before and after CRT. By convention, negative SR and strain values indicate longitudinal shortening. RESULTS: Before CRT, mid-septal peak SR and peak strain were lower than in the mid-lateral wall (peak SR: -0.79 +/- 0.5 [septum] vs. -1.35 +/- 0.8 [lateral wall], p < 0.05; peak strain: -7 +/- 5 [septum] vs. -11 +/- 5 [lateral wall], p < 0.05). This relationship was reversed during CRT (peak SR: -1.35 +/- 0.8 [septum] vs. -0.93 +/- 0.6 [lateral wall], p < 0.05; peak strain: -11 +/- 6 [septum] vs. -7 +/- 6 [lateral wall], p < 0.05). Cardiac resynchronization therapy reversed the septal-lateral difference in mid-segmental peak strain from -46 +/- 94 ms (LBBB) to 17 +/- 92 ms (CRT; p < 0.05). CONCLUSIONS: Left bundle branch block can lead to a significant redistribution of abnormal myocardial fiber strains. These abnormal changes in the extent and timing of septal-lateral strain relationships can be reversed by CRT. The noninvasive identification of specific abnormal but reversible strain patterns should help to improve patient selection for CRT.
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Bloqueo de Rama/complicaciones , Estimulación Cardíaca Artificial/métodos , Insuficiencia Cardíaca/complicaciones , Disfunción Ventricular Izquierda/terapia , Adulto , Anciano , Ecocardiografía Doppler , Femenino , Humanos , Masculino , Persona de Mediana Edad , Contracción Miocárdica/fisiología , Resultado del Tratamiento , Disfunción Ventricular Izquierda/etiología , Remodelación Ventricular/fisiologíaRESUMEN
BACKGROUND: Multislice spiral computed tomography (MSCT) has evolved as a new promising method for non-invasive visualization of the coronary arteries and detection of native coronary artery stenosis. We determined the value of MSCT to non-invasively detect significant in-stent restenosis after coronary artery stenting. METHODS: Twenty patients (age 56.3+/-8.6 years) were investigated by MSCT (4x1 mm cross-sections, 500 ms tube rotation, table feed 1.5 mm/rotation, intravenous contrast agent, retrospectively ECG-gated image reconstruction) at a mean interval of 9.6+/-4.2 months after coronary stent implantation. Results were compared with conventional quantitative coronary angiography (QCA). A total number of 32 stents were studied, four different stent types were evaluated. RESULTS: QCA showed in-stent restenosis >50% diameter stenosis in five (16%) stents. Using MSCT it was impossible in all stents, irrespective of stent type or diameter, to directly visualize the stent lumen due to partial volume effects and beam hardening. MSCT allowed the visualization of the coronary vessel proximal and distal to the stent. This allowed confirmation of stent patency in 18/18 cases and correct identification of total stent occlusion in two patients. CONCLUSIONS: MSCT allows no direct visualization of coronary in-stent restenosis, but it correctly differentiates between stent patency and stent occlusion. The reasons are mainly partial volume effects and beam hardening, which are induced by the stent material.
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Angiografía Coronaria/métodos , Reestenosis Coronaria/diagnóstico por imagen , Revascularización Miocárdica/efectos adversos , Stents/efectos adversos , Tomografía Computarizada Espiral/instrumentación , Reestenosis Coronaria/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Grado de Desobstrucción VascularRESUMEN
OBJECTIVES: We investigated whether cardiac resynchronization therapy (CRT) affects myocardial glucose metabolism and perfusion in dilated cardiomyopathy (DCM) and left bundle branch block (LBBB). BACKGROUND: Patients with DCM and LBBB present with asynchronous left ventricular (LV) activation, leading to reduced septal glucose metabolism. Cardiac resynchronization therapy recoordinates LV activation, but its effects on myocardial glucose metabolism and perfusion remain unknown. METHODS: In 15 patients (10 females; 61 +/- 13 years) with DCM and LBBB (QRS width 165 +/- 15 ms), gated (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and technetium-99m ((99m)Tc)-sestamibi single-photon emission computed tomography were performed before and after two weeks of CRT. Uptake of FDG and (99m)Tc-sestamibi was determined in four LV wall areas. Ejection fraction and volumes were calculated from gated PET. RESULTS: Baseline FDG uptake was heterogeneous (p < 0.0001), with lowest uptake in the septal region (56 +/- 12%) and highest uptake in the lateral region (89 +/- 6%). During CRT, septal and anterior increases (p < 0.01) and lateral decreases (p < 0.01) resulted in homogeneously distributed glucose metabolism. Baseline heterogeneity (p < 0.0001) in (99m)Tc-sestamibi uptake was modest (lowest septal 65 +/- 10%; maximum lateral 84 +/- 5%) and also reduced with CRT, although some heterogeneity (p < 0.05) remained. The septal-to-lateral ratio increased with CRT for FDG (0.62 +/- 0.12 to 0.91 +/- 0.26, p < 0.001) and (99m)Tc-sestamibi uptake (0.77 +/- 0.13 to 0.85 +/- 0.16, p < 0.01). The LV end-diastolic and end-systolic volumes decreased from 293 +/- 160 to 272 +/- 158 ml (p < 0.05) and from 244 +/- 164 to 220 +/- 160 ml (p < 0.01), respectively. Ejection fraction increased from 22 +/- 12% to 25 +/- 13% (p < 0.01). CONCLUSIONS: Glucose metabolism is reduced more than perfusion in the septal compared with LV lateral wall in patients with DCM and LBBB. Cardiac resynchronization therapy restores homogeneous myocardial glucose metabolism with less influence on perfusion.
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Bloqueo de Rama/metabolismo , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada/metabolismo , Cardiomiopatía Dilatada/terapia , Circulación Coronaria/fisiología , Glucosa/metabolismo , Miocardio/metabolismo , Anciano , Bloqueo de Rama/diagnóstico por imagen , Cardiomiopatía Dilatada/diagnóstico por imagen , Femenino , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/metabolismo , Atrios Cardíacos/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/fisiopatología , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada de Emisión , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
OBJECTIVES: We studied the acute effects of cardiac resynchronization therapy (CRT) on functional mitral regurgitation in heart failure (HF) patients with left bundle branch block (LBBB). BACKGROUND: Both an decrease [corrected] in left ventricular (LV) closing force and mitral valve tethering have been implicated as mechanisms for functional mitral regurgitation (FMR) in dilated hearts. We hypothesized that an increase in LV closing force achieved by CRT could act to reduce FMR. METHODS: Twenty-four HF patients with LBBB and FMR were studied after implantation of a biventricular CRT system. Acute changes in FMR severity between intrinsic conduction (OFF) and CRT were quantified according to the proximal isovelocity surface area method by measuring the effective regurgitant orifice area (EROA). Results were compared with the changes in estimated maximal rate of left ventricular systolic pressure rise (LV+dP/dt(max)) and transmitral pressure gradients (TMP), both measured by Doppler echocardiography. RESULTS: Cardiac resynchronization therapy was associated with a significant reduction in FMR severity. Effective regurgitant orifice area decreased from 25 +/- 19 mm(2) (OFF) to 13 +/- 8 mm(2) (CRT). The change in EROA was directly related to the increase in LV+dP/dt(max) (r = -0.83, p < 0.0001). Compared with OFF, TMP increased more rapidly during CRT, and a higher maximal TMP was observed (OFF 73 +/- 24 mm Hg vs. CRT 85 +/- 26 mm Hg, p < 0.01). CONCLUSIONS: Functional mitral regurgitation is reduced by CRT in patients with HF and LBBB. This effect is directly related to the increased closing force (LV+dP/dt(max)). The results support the hypothesis that an increase in TMP, mediated by a rise in LV+dP/dt(max) due to more coordinated LV contraction, may facilitate effective mitral valve closure.
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Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/terapia , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/terapia , Anciano , Bloqueo de Rama/complicaciones , Cardiomiopatía Dilatada/complicaciones , Estudios de Cohortes , Ecocardiografía , Ecocardiografía Doppler , Femenino , Estudios de Seguimiento , Pruebas de Función Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/complicaciones , Variaciones Dependientes del Observador , Probabilidad , Estudios Prospectivos , Medición de Riesgo , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Volumen Sistólico , Resultado del TratamientoRESUMEN
RATIONALE AND OBJECTIVES: To evaluate the reconstruction interval dependent bandwidth of the coronary calcium score, considering different methods of image reconstruction and quantification of coronary calcifications. MATERIALS AND METHODS: Seventy-five patients underwent coronary calcium scoring by use of retrospectively ECG-gated multislice spiral CT. In all patients overlapping and nonoverlapping image reconstruction was performed every 10% of the RR-interval. Coronary calcium score was calculated for every reconstructed image series using the Agatston score and a volumetric scoring method. In 25 patients the analysis was performed twice to determine the reconstruction interval dependent intraobserver variability. RESULTS: For nonoverlapping image reconstruction the median of the calcium score determined by the Agatston method ranged from 125.8 to 216.2 and from 166.9 to 211.7 for the volumetric scoring method. For overlapping image reconstruction the corresponding values ranged from 91.6 to 160.5 for the Agatston score and 128.3 to 175.3 for the volumetric calcium score. Reconstruction interval dependent median (mean) variation of the coronary calcium score ranged from 24.1 (45.5)% for nonoverlapping image reconstruction using the Agatston score to 17.5 (25.2)% utilizing a volumetric calcium score with overlapping image reconstruction. There was no statistical significant (P< 0.05) difference between the different methods. Intraobserver variability for the different image reconstruction intervals ranged from 0.78% to 21.51%. The least intraobserver variability was found for overlapping image reconstruction during the diastole using the volumetric scoring method. CONCLUSIONS: Diastolic image reconstruction at 50% or 60% of the RR-interval is recommendable for retrospectively ECG-gated multislice spiral CT. Volumetric calcium scoring and overlapping image reconstruction are beneficial to reduce the variation of the coronary calcium score.
Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Corazón/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Electrocardiografía , Femenino , Frecuencia Cardíaca , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVES: We sought to determine whether radial left ventricular (LV) asynchrony in patients with heart failure predicts systolic function improvement with cardiac resynchronization therapy (CRT). BACKGROUND: We quantified LV wall motion by echocardiography to correlate the effects of CRT on LV systolic function with wall motion synchrony. METHODS: Thirty-four patients underwent echocardiographic phase analysis of LV septal and lateral wall motion and hemodynamic testing before CRT. Phase relationships were measured by the difference between the lateral (Phi(L)) and septal (Phi(S)) wall motion phase angles: Phi(LS) = Phi(L) - Phi(S). The absolute value of Phi(LS) was used as an order-independent measure of synchrony: the absolute value Phi(LS) = the absolute value of Phi(L) - Phi(S). RESULTS: Three phase relationships were identified (mean +/- SD): type 1 (n = 4; peak positive LV pressure [dP/dt(max)] 692 +/- 310 mm Hg/s; Phi(LS) = 5 +/- 6 degrees, synchronous wall motion); type 2 (n = 17; dP/dt(max) 532 +/- 148 mm Hg/s; Phi(LS) = 77 +/- 33 degrees, delayed lateral wall motion); and type 3 (n = 13; dP/dt(max) 558 +/- 154 mm Hg/s; Phi(LS) = -115 +/- 33 degrees, delayed septal wall motion, triphasic). A large absolute value of Phi(LS) predicted a larger increase in dP/dt(max) with CRT (r = 0.74, p < 0.001). Sixteen patients were studied during right ventricular (RV), LV and biventricular (BV) pacing. Cardiac resynchronization therapy acutely reduced the absolute value of Phi(LS) from 104 +/- 41 degrees (OFF) to 86 +/- 45 degrees (RV; p = 0.14 vs. OFF), 71 +/- 50 degrees (LV; p = 0.001 vs. OFF) and 66 +/- 42 degrees (BV; p = 0.001 vs. OFF). A reduction in the absolute value of Phi(LS) predicted an improvement in dP/dt(max) in type 2 patients for LV (r = 0.87, p = 0.005) and BV CRT (r = 0.73, p = 0.04). CONCLUSIONS: Echocardiographic quantification of LV asynchrony identifies patients likely to have improved systolic function with CRT. Improved synchrony is directly related to improved hemodynamic systolic function in type 2 patients.