RESUMEN
PURPOSE: We aimed to correlate left atrial appendage (LAA) morphology with thrombus formation in patients with severe aortic valve stenosis and atrial fibrillation. METHODS: We analyzed LAA morphology and the prevalence of a thrombus in 231 patients with atrial fibrillation and severe aortic valve stenosis that were referred for pre-interventional CT scan before trans-catheter aortic valve implantation (TAVI) between 2016 and 2018. In addition, we documented neuro-embolic events depending on the presence of LAA thrombus within a follow-up of 18 months. RESULTS: The overall distribution of different LAA morphologies was chicken-wing 25.5%, windsock 51.5%, cactus 15.6% and cauliflower 7.4%. Compared to chicken-wing morphology, patients with non-chicken-wing morphology showed a significantly higher thrombus rate (OR: 2.48, 95%; CI 1.05 to 5.86, p = 0.043). Within the 50 patients with a LAA thrombus, we observed chicken-wing (14.0%), windsock (62.0%), cactus (16.0%) and cauliflower (8.0%) configuration. In patients with LAA thrombus those with chicken-wing configuration have a higher risk (42.9%) to develop neuro-embolic events compared to non-chicken-wing configuration (20.9%). CONCLUSION: We found a lower LAA thrombus rate in patients with chicken-wing morphology compared to patients with non-chicken-wing configuration. However, in the presence of thrombus, those patients with chicken-wing morphology showed a doubled risk for neuro-embolic events compared to patients with non-chicken-wing morphology. These results must be confirmed in larger trials but underline the importance of LAA evaluation in thoracic CT scans and could have an impact on the anticoagulation management.
Asunto(s)
Estenosis de la Válvula Aórtica , Apéndice Atrial , Fibrilación Atrial , Trombosis , Humanos , Apéndice Atrial/diagnóstico por imagen , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Trombosis/diagnóstico por imagen , Trombosis/epidemiología , Trombosis/etiología , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugíaRESUMEN
BACKGROUND: The presence of left bundle branch block (LBBB) represents a particular challenge in properly measuring the QT interval. Here we demonstrate the applicability of the "Bogossian formula" in pacemaker patients with LBBB due to apical or nonapical right ventricular (RV) pacing and preserved left ventricular function. METHODS: A total of 163 patients with a cardiac one- or two-chamber pacemaker were included in this prospective, multicentre observational study. Twelve-lead ECG recordings were obtained during both intrinsic rhythm and RV pacing with induced LBBB. The QT interval measured during LBBB was corrected using the Bogossian formula to obtain the "modified QT" (QTm). The QTmc interval was calculated with the Bazett formula, and this was compared with the QTc interval during intrinsic rhythm. RESULTS: Eighty-three patients (78 ± 9 years; male n = 83) with apical and eighty patients (71 ± 13 years; male n = 80) with non-apical RV pacing were included in this study. In the apical group the QTmc was determined to be 444 ± 39 ms in paced rhythm and the QTc interval 413 ± 36 ms in intrinsic rhythm. In the non-apical group these values were 430 ± 34 ms in paced and 416 ± 32 ms in intrinsic rhythm. CONCLUSION: The Bogossian formula is a reliable tool for QTc interval evaluation in pacemaker patients with LBBB due to apical or non-apical RV pacing. However, an overestimation of 30 ms should be included in the calculation.
Asunto(s)
Bloqueo de Rama/diagnóstico , Estimulación Cardíaca Artificial/métodos , Diagnóstico por Computador/métodos , Electrocardiografía , Ventrículos Cardíacos/fisiopatología , Función Ventricular Izquierda/fisiología , Anciano , Bloqueo de Rama/fisiopatología , Bloqueo de Rama/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
INTRODUCTION: Acute tension pneumopericardium due to gastric perforation is a rare and often lethal condition. Only a few case reports have been described in the literature. Diagnosis based on clinical evaluation is difficult and it is usually made incidentally upon computed tomography (CT) or plain radiography of the chest. Since cardiac tamponade caused by pneumopericardium is life-threatening, immediate diagnosis and emergent therapy is vital. CASE REPORT: We report a 75-year-old male with peptic ulcer disease associated with perforation of the pericardium and acute shock. It is the first reported case with a series of two computed tomograms performed during the 72 h preceding the acute onset of tension pneumopericardium. No radiographic evidence of ulcer perforation was present in the three days prior to the acute event. DISCUSSIONS: Gastric ulcer perforation into the pericardium is rare and could not be detected by CT scan prior the deletorious event. Pneumopericardium seems to be fateful and could not be foreseen by clinical or radiological findings.
RESUMEN
Microvascular obstruction (MO) and coronary flow have been independently described to have a high prognostic impact after acute myocardial infarction (AMI). Their interdependence has not been precisely elucidated, so far. Aim of this study was to investigate the impact of coronary flow on the occurrence of MO in patients with AMI. 336 patients with revascularized AMI were examined by cardiac magnetic resonance imaging. Patients were categorised into two groups based on the presence of MO. Procedural characteristics and marker of infarct size were analyzed. MO was present in 110 (33 %) and absent in 226 (67 %) patients. Both groups differed significantly regarding pre- and post-interventional thrombolysis in myocardial infarction (TIMI) flow. After multivariable regression analysis pre-interventional TIMI-flow 0, proximal culprit lesion, post-interventional TIMI-flow Asunto(s)
Enfermedad de la Arteria Coronaria/terapia
, Circulación Coronaria
, Oclusión Coronaria/terapia
, Vasos Coronarios/fisiopatología
, Microcirculación
, Infarto del Miocardio/terapia
, Intervención Coronaria Percutánea/efectos adversos
, Anciano
, Estudios de Casos y Controles
, Angiografía Coronaria
, Enfermedad de la Arteria Coronaria/diagnóstico por imagen
, Enfermedad de la Arteria Coronaria/fisiopatología
, Oclusión Coronaria/diagnóstico por imagen
, Oclusión Coronaria/fisiopatología
, Vasos Coronarios/diagnóstico por imagen
, Alemania
, Humanos
, Modelos Logísticos
, Imagen por Resonancia Magnética
, Masculino
, Persona de Mediana Edad
, Análisis Multivariante
, Infarto del Miocardio/diagnóstico por imagen
, Infarto del Miocardio/fisiopatología
, Imagen de Perfusión Miocárdica/métodos
, Oportunidad Relativa
, Valor Predictivo de las Pruebas
, Factores de Riesgo
, Resultado del Tratamiento
RESUMEN
Particularly among over 30 years old ambitious hobby- and competitive athletes arrhythmias and even sudden cardiac deaths occur again and again. The spectacular sudden deaths during marathon, football and, just recently, in the trend discipline triathlon seem to support that view. Reports about the "athlete`s heart" and complications in the elderly causes uncertainty among athletes, fitness fans and sports physicians. The question arises, how to avoid complications caused by ambitious sporting activity in the elderly and how to screen hobby- and ambitious athletes between the age of 35 and 75 years. For athletes >â 35 years old besides medical history and physical examination basic examinations including resting ECG, echocardiography and exercise ECG/stress echocardiography are mandatory. Further examinations, if clinically necessary, should be spiroergometry, Holter ECG or magnetic resonance tomography and Carotis-Duplex or Cardio-CT for the purpose of arteriosclerosis screening. In suspicious inflammation a further extended laboratory testing may become necessary (incl. viral/bacterial antibodies) or even a multidisciplinary approach (immunological, neurological, dental or orthodontic examination).
Asunto(s)
Rendimiento Atlético , Cardiomegalia Inducida por el Ejercicio , Conducta Competitiva , Muerte Súbita Cardíaca/prevención & control , Actividades Recreativas , Tamizaje Masivo , Recreación , Deportes , Adulto , Anciano , Rendimiento Atlético/fisiología , Cardiomegalia Inducida por el Ejercicio/fisiología , Conducta Competitiva/fisiología , Ecocardiografía , Electrocardiografía Ambulatoria , Prueba de Esfuerzo , Femenino , Alemania , Humanos , Masculino , Anamnesis , Persona de Mediana Edad , Examen Físico , Recreación/fisiología , Factores de Riesgo , Deportes/fisiologíaRESUMEN
OBJECTIVES: To compare the assessment of global and regional left ventricular (LV) function using 64-slice multislice computed tomography (MSCT), 2D echocardiography (2DE) and cardiac magnetic resonance (CMR). METHODS: Thirty-two consecutive patients (mean age, 56.5+/-9.7 years) referred for evaluation of coronary artery using 64-slice MSCT also underwent 2DE and CMR within 48h. The global left ventricular function which include left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (LVdV) and left ventricular end systolic volume (LVsV) were determine using the three modalities. Regional wall motion (RWM) was assessed visually in all three modalities. The CMR served as the gold standard for the comparison between 64-slice MSCT with CMR and 2DE with CMR. Statistical analysis included Pearson correlation coefficient, Bland-Altman plots and kappa-statistics. RESULTS: The 64-slice MSCT agreed well with CMR for assessment of LVEF (r=0.92; p<0.0001), LVdV (r=0.98; p<0.0001) and LVsV (r=0.98; p<0.0001). In comparison with 64-slice MSCT, 2DE showed moderate correlation with CMR for the assessment of LVEF (r=0.84; p<0.0001), LVdV (r=0.83; p<0.0001) and LVsV (r=0.80; p<0.0001). However in RWM analysis, 2DE showed better accuracy than 64-slice MSCT (94.3% versus 82.4%) and closer agreement (kappa=0.89 versus 0.63) with CMR. CONCLUSION: 64-Slice MSCT correlates strongly with CMR in global LV function however in regional LV function 2DE showed better agreement with CMR than 64-slice MSCT.
Asunto(s)
Ecocardiografía/métodos , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Disfunción Ventricular Izquierda/diagnóstico , Distribución de Chi-Cuadrado , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Variaciones Dependientes del ObservadorRESUMEN
BACKGROUND: The new 64-row multidetector computed tomography (CT)-assisted angiography can now detect coronary artery disease with shorter breath-hold time and at faster heart rates for symptomatic patients. We aim to determine if the 64-row scanner can also overcome limitations due to mild to moderate calcification. METHODS: Scheduled for conventional coronary angiography, 134 symptomatic patients underwent multidetector CT-assisted angiography within 3 months. Patients were divided into those with low or high calcium score (median score 142) by modified Agatston formula: group A calcium score <142 Agatston score (68 patients, mean age 53 years, heart rate 62 beat/min) and group B calcium score > or = 142 Agatston score (66 patients, mean age 57 years, heart rate 62 beat/min). Eleven major coronary segments were evaluated. RESULTS: In group A, 93.6% of segments were evaluable with 97.3% correlation. Segment-by-segment analyses for sensitivity, specificity, and positive and negative predictive values were 85.4%, 98.1%, 76.7%, and 99.2%, respectively. For group B, 86.9% of segments were evaluable with 90.5% correlation. Sensitivity, specificity, and positive and negative predictive values were 79.9%, 92.8%, 78.8%, and 93.5%, respectively. CONCLUSIONS: The 64-slice multidetector CT coronary angiography can reliably detect the presence of significant coronary stenosis in symptomatic patients with mild calcification, but remains limited by moderate to heavy calcification.
Asunto(s)
Calcinosis/diagnóstico por imagen , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad Coronaria/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Calcinosis/complicaciones , Enfermedad Coronaria/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X/métodosRESUMEN
AIM: The extent of urinary iodine excretion (UIE) provides information about iodine supply and release. In the present study we investigated correlations between UIE and radioiodine uptake (RIU) as well as effects of radioiodine therapy on UIE in patients with autonomous goitre. PATIENTS, METHODS: In 197 consecutive patients with thyroid autonomy, UIE was measured twice during radioiodine test (RITe) and correlated with RIU. In 98 of these patients, thyroglobulin and thyroid volume (V) were determined prior to therapy. Individual changes in urinary iodine excretion (DeltaUIE) and TG (DeltaTG) could be investigated four weeks (4W) and six months (6M) after radioiodine therapy. Additionally, DeltaV was determined 6M after therapy. DeltaUIE, DeltaTG and DeltaV were correlated with target dose and target volume. RESULTS: Patients with higher iodine excretion exhibited significantly lower thyroidal radioiodine uptake values. Twofold increased UIE prior to therapy decreased radioiodine uptake by 25%. Compared with pretherapeutic values, UIE and TG were significantly increased four weeks after radioiodine therapy (p < 0.001). Median values of both parameters were found to be doubled. The product of target dose and target volume was not only correlated with a decrease of thyroid volume 6M after therapy, but also with an increase of UIE and TG in the early phase after therapy. CONCLUSIONS: It was confirmed that UIE during RITe is a measure for iodine intake and can be used to investigate the competition between stable iodine and radioiodine. The increase of UIE and TG four weeks after therapeutic administration of radioiodine can be explained by disintegrated thyroid follicles. The therapy-induced iodine release may be one important cause for the development of hyperthyroidism in some patients during the first weeks after radioiodine therapy. It may contribute to the known decrease of radioiodine uptake after preapplications of 131I in various thyroid diseases.
Asunto(s)
Radioisótopos de Yodo/farmacocinética , Yodo/orina , Glándula Tiroides/metabolismo , Humanos , Tiroglobulina/metabolismo , Glándula Tiroides/efectos de los fármacos , Tiroxina/farmacologíaRESUMEN
The accuracy of multi-detector computed tomographic (MDCI) coronary angiography (CTA) is dependant on image quality as well as the experience of the operator. Established centers have reported negative predictive values of over 95%. The aim of our study was to investigate the accuracy and feasibility of CTA for the assessment of haemodynamically significant coronary stenosis in a center with very early experience (<6 months) utilizing the improved spatial and temporal resolutions of the latest generation 64-row MDCI scanner. One hundred and twenty eight patients (93 male, 35 female; mean age 56.2 +/- 9.5 years) with suspected or known coronary artery disease underwent both CIA and conventional coronary angiographv (CCA). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for stenoses > or =50% by CIA compared to CCA were 70%, 97%, 70% and 97% respectively. Evaluation of main and proximal segments in patients with good quality images (78% of patients) produced values of 94%, 95%, 74% and 99% respectively. The improved spatial and temporal resolutions of 64-row MJ) CT provided a high negative predictive value in assessing significant coronary artery stenosis even in a centre with very early experience. However, new centers embarking on CTA might not be able to reproduce the results reported by more experienced centers.
Asunto(s)
Estenosis Coronaria/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Anciano , Competencia Clínica , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Tomógrafos Computarizados por Rayos XRESUMEN
Within the course of an acute posterior wall myocardial infarction there may be involvement of the right ventricle leading to right ventricular infarction. The long-term prognosis of patients with right ventricular infarction is not meaningfully compromised provided that the left ventricular function is preserved. However, in the acute phase, there may be a threefold increase in mortality if the right ventricular infarction leads to substantial right ventricular dysfunction. Consequently, right ventricular involvement should be detected as early as possible. In addition to the clinical presentation, the ECG and echocardiogram can provide decisive information. In addition to reperfusion, specific measures are employed to address the hemodynamic derangement of right ventricular dysfunction. These include administration of fluids for volume expansion to increase filling pressure and avoidance of vasodilators and diuretics.
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Infarto del Miocardio/diagnóstico , Infarto del Miocardio/terapia , Medición de Riesgo/métodos , Disfunción Ventricular Derecha/diagnóstico , Disfunción Ventricular Derecha/terapia , Comorbilidad , Humanos , Infarto del Miocardio/epidemiología , Infarto del Miocardio/mortalidad , Pautas de la Práctica en Medicina , Pronóstico , Factores de Riesgo , Resultado del Tratamiento , Disfunción Ventricular Derecha/epidemiología , Disfunción Ventricular Derecha/mortalidadRESUMEN
Cardiac myocyte apoptosis has been demonstrated in end-stage failing human hearts. The therapeutic utility of blocking apoptosis in congestive heart failure (CHF) has not been elucidated. This study investigated the role of caspase activation in cardiac contractility and sarcomere organization in the development of CHF. In a rabbit model of heart failure obtained by rapid ventricular pacing, we demonstrate, using in vivo transcoronary adenovirus-mediated gene delivery of the potent caspase inhibitor p35, that caspase activation is associated with a reduction in contractile force of failing myocytes by destroying sarcomeric structure. In this animal model gene transfer of p35 prevented the rise in caspase 3 activity and DNA-histone formation. Genetically manipulated hearts expressing p35 had a significant improvement in left ventricular pressure rise (+dp/dt), decreased end-diastolic chamber pressure (LVEDP), and the development of heart failure was delayed. To better understand this benefit, we examined the effects of caspase 3 on cardiomyocyte dysfunction in vitro. Microinjection of activated caspase 3 into the cytoplasm of intact myocytes induced sarcomeric disorganization and reduced contractility of the cells. These results demonstrate a direct impact of caspases on cardiac function and may lead to novel therapeutic strategies via antiapoptotic regimens.
Asunto(s)
Apoptosis , Inhibidores de Caspasas , Insuficiencia Cardíaca/enzimología , Insuficiencia Cardíaca/patología , Contracción Miocárdica , Miocardio/enzimología , Miocardio/patología , Adenoviridae/genética , Animales , Peso Corporal , Caspasa 3 , Caspasas/administración & dosificación , Caspasas/metabolismo , Caspasas/farmacología , Células Cultivadas , Inhibidores de Cisteína Proteinasa/uso terapéutico , Fragmentación del ADN , Expresión Génica , Terapia Genética/métodos , Vectores Genéticos/genética , Proteínas Fluorescentes Verdes , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/terapia , Ventrículos Cardíacos/enzimología , Ventrículos Cardíacos/fisiopatología , Proteínas Luminiscentes , Masculino , Miocardio/metabolismo , Tamaño de los Órganos , Marcapaso Artificial , Conejos , Ratas , Sarcómeros/enzimología , Sarcómeros/metabolismo , Sarcómeros/patología , Taquicardia/fisiopatología , Factores de Tiempo , Transgenes/genéticaRESUMEN
BACKGROUND: Reactivated cytomegalovirus may promote neointima formation after percutaneous coronary interventions by facilitating cell cycle progression through inhibition of the eukariotic tumor suppressor protein p53. This prospective study sought to investigate the effect of previous cytomegalovirus infection on restenosis after coronary stenting. METHODS AND RESULTS: In 551 consecutive patients with successful stent placement, we determined cytomegalovirus IgG titers. Primary and secondary end points were the rate of angiographic restenosis at 6 months and the rate of target vessel reintervention at 1 year, respectively. Three hundred forty patients (62%) had a positive cytomegalovirus IgG titer. We obtained angiographic follow-up in 82% of all patients. Angiographic restenosis rate was 28.7% in patients with positive cytomegalovirus titers and 34.6% in patients with negative titers (P=0.18). Between the groups with and without positive cytomegalovirus titers, there were no significant differences in late lumen loss (1.16+/-0.90 mm and 1.23+/-0.86 mm, respectively, P=0.44). Target vessel reintervention was performed in 16.8% of the patients with positive cytomegalovirus titers and in 17.5% of those without (P=0.82). Even after correction for potential confounding variables by multivariate analysis, positive cytomegalovirus titers did not manifest as a predictor of angiographic restenosis (adjusted odds ratio [95% confidence interval], 0.78 [0.52 to 1.19]). CONCLUSIONS: Previous cytomegalovirus infection does not carry an increased risk of restenosis after stenting.
Asunto(s)
Enfermedad Coronaria/sangre , Infecciones por Citomegalovirus/complicaciones , Stents , Anciano , Anticuerpos Antivirales/sangre , Estudios de Cohortes , Angiografía Coronaria , Enfermedad Coronaria/etiología , Enfermedad Coronaria/terapia , Vasos Coronarios/patología , Vasos Coronarios/fisiopatología , Citomegalovirus/genética , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/virología , ADN Viral/sangre , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Recurrencia , Factores de RiesgoRESUMEN
Cardiac surgery with cardiopulmonary bypass (CPB) leads to a systemic inflammatory response with secretion of cytokines (e.g. IL-6, TNF-alpha, IL-1 beta and sIL-2R). The objective of the following study was to investigate in vitro and in vivo cytokine responses and white blood cell counts (WBC) of patients with high versus low cytokine secretion after a coronary artery bypass grafting (CABG) procedure. Twenty male patients undergoing elective CABG surgery with CPB under general anaesthesia were enrolled in the study. On the day of surgery (postoperatively), serum levels of TNF-alpha and IL-1 beta were significantly higher in patients of the high IL-6 level group compared to the respective values in the patient group with low IL-6 levels. The inter-individual differences in IL-6 release in patients undergoing CABG surgery with CPB were accompanied by differences in the release of other cytokines, such as TNF-alpha, IL-1 beta and sIL-2R. To understand whether genetic background plays a role in influencing cytokine plasma levels under surgical stress, we examined the distribution of polymorphic elements within the promoter regions of the TNF-alpha and IL-6 genes, and determined their genotype regarding the BAT2 gene and TNF-beta intron polymorphisms. Our preliminary data suggests that regulatory polymorphisms in or near the TNF locus, more precisely the allele set 140/150 of the BAT2 microsatellite marker combined with the G allele at -308 of the TNF-alpha gene, could be one of the genetic constructions providing for a less sensitive response to various stimuli. Our results suggest: (1) close relationships between cytokine release in the postoperative period, and (2) inter-individually varying patterns of cytokine release in patients undergoing CABG surgery with CPB.
Asunto(s)
Puente Cardiopulmonar , Interleucina-1/sangre , Interleucina-6/sangre , Receptores de Interleucina-2/sangre , Cirugía Torácica , Factor de Necrosis Tumoral alfa/metabolismo , Humanos , Interleucina-6/genética , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
BACKGROUND: Increased thrombogenicity and smooth muscle cell proliferative response induced by the metal struts compromise the advantages of coronary stenting. The objective of this randomized, multicenter study was to assess whether a reduced strut thickness of coronary stents is associated with improved follow-up angiographic and clinical results. METHODS AND RESULTS: A total of 651 patients with coronary lesions situated in native vessels >2.8 mm in diameter were randomly assigned to receive 1 of 2 commercially available stents of comparable design but different thickness: 326 patients to the thin-strut stent (strut thickness of 50 microm) and 325 patients to the thick-strut stent (strut thickness of 140 microm). The primary end point was the angiographic restenosis (>/=50% diameter stenosis at follow-up angiography). Secondary end points were the incidence of reinterventions due to restenosis-induced ischemia and the combined rate of death and myocardial infarctions at 1 year. The incidence of angiographic restenosis was 15.0% in the thin-strut group and 25.8% in the thick-strut group (relative risk, 0.58; 95% CI, 0.39 to 0.87; P=0.003). Clinical restenosis was also significantly reduced, with a reintervention rate of 8.6% among thin-strut patients and 13.8% among thick-strut patients (relative risk, 0.62; 95% CI, 0.39 to 0.99; P=0.03). No difference was observed in the combined 1-year rate of death and myocardial infarction. CONCLUSIONS: The use of a thinner-strut device is associated with a significant reduction of angiographic and clinical restenosis after coronary artery stenting. These findings may have relevant implications for the currently most widely used percutaneous coronary intervention.
Asunto(s)
Implantación de Prótesis Vascular/efectos adversos , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/cirugía , Oclusión de Injerto Vascular/etiología , Stents/efectos adversos , Anciano , Angiografía Coronaria , Vasos Coronarios/patología , Vasos Coronarios/cirugía , Femenino , Estudios de Seguimiento , Oclusión de Injerto Vascular/diagnóstico , Oclusión de Injerto Vascular/prevención & control , Hemodinámica , Humanos , Incidencia , Modelos Logísticos , Masculino , Riesgo , Medición de Riesgo , Stents/normas , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
OBJECTIVE: Numerous studies support the concept of impaired postischemic sympathetic neurotransmission in the heart. We hypothesized that postischemic neuronal dysfunction (neuronal stunning) is caused by a transient suppression of exocytotic norepinephrine (NE) release from sympathetic nerve terminals. Furthermore, we assessed the role of presynaptic adenosine-receptors and alpha2-adrenoceptors in neuronal stunning. METHODS AND RESULTS: Exocytotic NE release was induced by two electrical field stimulations (S(1) and S(2)) in isolated perfused rat hearts. S(1) was performed under baseline conditions and S(2) either during or following intervention. Results are expressed as mean S(2)/S(1) ratios+/-S.E.M. Stepwise increase of global ischemic periods (10, 20, and 30 min) induced a progressive suppression of NE release in the postischemic hearts, which was reversible during reperfusion. Both the degree and duration of NE suppression was dependent on the extent of the preceding ischemic period. Following 10-min ischemia complete recovery of NE release was achieved after 5-min reperfusion (1.07+/-0.12), whereas 5-min reperfusion did not restore NE release after 30 min (0.36+/-0.07) of ischemia. The adenosine-receptor antagonists 8-phenyltheophylline (8-PT; non-selective) and 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; adenosine A1-receptor subtype selective) significantly increased NE release after 30-min ischemia and 5-min reperfusion (0.78+/-0.06 and 0.64+/-0.07), while in the same experimental protocol blockade of alpha2-adrenoceptors by yohimbine failed to restore the postischemic release (0.24+/-0.06). In non-ischemic hearts the adenosine analogue R(-)N(6)-(2-phenylisopropyl)adenosine (R-PIA) resulted in a marked suppression of NE release (0.61+/-0.07). The inhibitory effect of R-PIA and 2-chloro-N(6)-cyclopentyladenosine (CCPA; adenosine A1-receptor subtype selective agonist) persisted 5 min after cessation of R-PIA (0.62+/-0.05) and CCPA (0.58+/-0.04). Activation of alpha2-adrenoceptors by 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (UK 14,304) also caused a reduction of NE release (0.50+/-0.02), but the release increased to control levels 5 min after cessation of UK 14,304 (0.90+/-0.06). CONCLUSIONS: The results establish the phenomenon of neuronal stunning in terms of a postischemic suppression of exocytotic NE release and provide evidence that neuronal stunning is mediated by endogenous adenosine through activation of presynaptic adenosine A1-receptors.
Asunto(s)
Adenosina/análogos & derivados , Adenosina/fisiología , Aturdimiento Miocárdico/fisiopatología , Miocardio/metabolismo , Norepinefrina/metabolismo , Receptores Purinérgicos P1/metabolismo , Sistema Nervioso Simpático/fisiopatología , Teofilina/análogos & derivados , Adenosina/farmacología , Análisis de Varianza , Animales , Tartrato de Brimonidina , Estimulación Eléctrica , Inhibidores Enzimáticos/farmacología , Masculino , Aturdimiento Miocárdico/metabolismo , Perfusión , Fenetilaminas/farmacología , Fenilisopropiladenosina/farmacología , Antagonistas Purinérgicos , Antagonistas de Receptores Purinérgicos P1 , Quinoxalinas/farmacología , Ratas , Ratas Wistar , Receptores Purinérgicos P2/efectos de los fármacos , Teofilina/farmacología , Factores de Tiempo , Xantinas/farmacologíaRESUMEN
Clopidogrel in combination with aspirin administered as a loading dose of 450 mg reveals an accelerated antiplatelet effect in the early hours after first administration in patients undergoing coronary stent placement.
Asunto(s)
Enfermedad Coronaria/terapia , Inhibidores de Agregación Plaquetaria/administración & dosificación , Pruebas de Función Plaquetaria , Stents , Ticlopidina/análogos & derivados , Ticlopidina/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón , Clopidogrel , Enfermedad Coronaria/sangre , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/efectos adversos , Estudios Prospectivos , Recurrencia , Ticlopidina/efectos adversosRESUMEN
Coronary stent implantation is being performed in an increasing number of patients with a wide spectrum of clinical and lesion characteristics. A variety of stent designs are now available and continuous efforts are being made to improve the stent placement procedure. The objective of this study was to perform a comprehensive analysis of the relation between clinical, lesion, and procedural factors, and restenosis after intracoronary stenting in a large and unselected population of patients. A consecutive series of 4,510 patients with coronary stent placement was analyzed. Exclusion criteria were only a failed procedure and an adverse outcome within the first month after the intervention. Follow-up angiography was performed in 80% of patients at 6 months. Clinical, lesion, and procedural data from all 3,370 patients (4,229 stented lesions) with follow-up angiography were analyzed in a logistic regression model for restenosis (> or =50% diameter stenosis). Clinical factors contributed to the predictive power of the model much less than lesion and procedural factors. The strongest risk factor for restenosis was a small vessel size, with a 79% increase in the risk for a vessel of 2.7 mm versus a vessel of 3.4 mm in diameter. Stent design was the second strongest factor; the incidence of restenosis ranged from 20.0% to 50.3% depending on the stent type implanted. In conclusion, this study demonstrates the predominant role of lesion and procedural factors in determining the occurrence of restenosis after coronary stent placement. Among these factors, stent design appears to play a particularly important role in the hyperplastic response of the vessel wall.
Asunto(s)
Enfermedad Coronaria/cirugía , Stents , Análisis de Varianza , Angiografía Coronaria , Enfermedad Coronaria/patología , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Recurrencia , Factores de RiesgoAsunto(s)
Enfermedad Coronaria/terapia , Activación Plaquetaria/efectos de los fármacos , Stents , Ticlopidina/análogos & derivados , Ticlopidina/administración & dosificación , Aspirina/administración & dosificación , Clopidogrel , Trombosis Coronaria/etiología , Trombosis Coronaria/prevención & control , Esquema de Medicación , Quimioterapia Combinada , Humanos , Agregación Plaquetaria/efectos de los fármacos , Stents/efectos adversosRESUMEN
An experimental model was developed to study the kinetics of electrolytes under different physiological and/or pathological conditions. The model was applied to investigate in vivo the effect of a pharmacological dose of melatonin on the concentrations of Ca2+, K+, Na+, and pH in the anticoagulated blood of anaesthetized male Wistar rats (250-350 g). After the application of 0.25 mg melatonin/kg body weight, injected intraperitoneally into each of 8 rats, the electrolytes were measured by a flow-through system with highly sensitive ion-selective electrodes. The results were compared to a control group (n=8) which was treated with diluent (saline). The electrolytes were monitored continuously via an extracorporeal circulation, on-going for at least 60 min. Melatonin induced a significant increase of blood Ca2+ (p<0.02) by an average of 9.9% after 60 min. However, total calcium concentration did not increase significantly. The extracorporeal circulation provoked an elevation of K+ by hemolysis. This K+ increase was slightly diminished by melatonin (p<0.06). No melatonin effects were seen on Na+, pH and magnesium in blood and plasma, respectively. Also, the urine concentrations of the electrolytes were not altered by melatonin. The mechanism by which melatonin influences the blood concentrations of ionized calcium and potassium is not yet understood.