RESUMEN
Background Chronic Kidney disease is a major health problem in the world. Native arteriovenous Fistula (AVF) is well established as the best vascular access for haemodialysis. Little is known about the outcome of AVF in sub-Saharan Africa. We aim to analyze the outcome of patients undergoing AVF creation during the pilot program established at the Douala general hospital (DGH). Method This was hospital-based, longitudinal study with a retrospective phase (April 2010-January 2014) and a prospective phase (January 2014-April 2014). All consecutive patients operated for AVF creation were included in this study. Socio-demographics data, functionality, and complications were analyzed. Results Eighty-one patients including 52 men were enrolled in this study (49 prospectively and 32 retrospectively). The mean age was 52, 3 years (range 18-81 years). Hypertension (66, 7%), diabetes (17, 3%), and HIV (8, 6%) were the most observed co-morbidities. About 96.3% of AVF were native and 3.7% were prosthetic graft. Radiocephalic AVF was performed at a rate of 77.8%. The primary function rate was 97.7% and the mean follow-up period 43.4 weeks. The overall rate of complications was 44.4% of whom 30.5% were early, 30.5% secondary, and 39% lasted. The treatment of these complications was conservative in 48.7% of cases. Conclusions The results of the pilot program of AVF creation at the DGH are encouraging. However, the sustainability of this project requires human capacity building.
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Catéteres de Permanencia , Fallo Renal Crónico/terapia , Diálisis Peritoneal/métodos , Diálisis Renal/métodos , Dispositivos de Acceso Vascular , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Camerún , Países en Desarrollo , Femenino , Estudios de Seguimiento , Hospitales Generales , Humanos , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/mortalidad , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Evaluación de Resultado en la Atención de Salud , Diálisis Peritoneal/estadística & datos numéricos , Proyectos Piloto , Diálisis Renal/estadística & datos numéricos , Estudios Retrospectivos , Medición de Riesgo , Adulto JovenRESUMEN
BACKGROUND AND AIM OF THE STUDY: Estimation of stroke volume in the left ventricular outflow tract (LVOT) is a main limitation to aortic valve area (AVA) calculation by echocardiography when using the continuity equation. In this study, the hypothesis was tested that a hybrid method using thermodilution-derived cardiac output measurement and simultaneous Doppler estimation of the systolic ejection period and transvalvular aortic velocities could be used to accurately assess AVA in patients with low-gradient severe aortic stenosis (AS). METHODS: Eighteen patients with low mean gradient (< 40 mmHg) and nine patients with conventionally defined (> or = 40 mmHg) severe AS (< 1 cm2), as assessed by the echocardiographic continuity equation (baseline echocardiography), underwent catheterization and simultaneous Doppler recording of trans-aortic velocities. RESULTS: The mean pressure gradient was slightly lower by Doppler in the catheterization laboratory (35.8 +/-15.7 mmHg) compared to baseline echocardiography (37.4 +/- 15.2 mmHg) and invasive (38.5 +/- 16.6 mmHg) measurements (both p < 0.05). The AVA values were 0.72 +/- 0.12 cm2 during baseline echocardiography, 0.74 +/- 0.14 cm2 by catheterization, and 0.71 +/- 0.14 cm2 by the hybrid method (bias -0.01 +/- 0.11 cm2 and -0.02 +/- 0.08 cm2, versus echocardiography and catheterization, respectively; both p = NS). CONCLUSION: The hybrid method is reasonably accurate in assessing AVA in patients with low-gradient severe AS. Although the continuity equation should be used in routine clinical practice in most patients, this method could serve as an alternative when the LVOT diameter and/or velocities seem questionable.
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Estenosis de la Válvula Aórtica/patología , Válvula Aórtica/patología , Ecocardiografía Doppler/métodos , Termodilución/métodos , Anciano , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Presión Sanguínea , Cateterismo Cardíaco , Gasto Cardíaco , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Volumen SistólicoRESUMEN
We present a case of acute anterior myocardial infarction in a breastfeeding woman, 10 days after delivery. The presumed cause was proximal left anterior artery vasospasm, induced by a combination of smoking a first cigarette in the early morning and salbutamol inhalation, in the particular context of peripartum. We discuss briefly the epidemiology, pathophysiology, risk factors, diagnosis, treatment and prognosis of myocardial infarction related to pregnancy and the postpartum period.
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Infarto de la Pared Anterior del Miocardio/etiología , Complicaciones Cardiovasculares del Embarazo/etiología , Trastornos Puerperales/etiología , Agonistas de Receptores Adrenérgicos beta 2/efectos adversos , Adulto , Albuterol/efectos adversos , Infarto de la Pared Anterior del Miocardio/fisiopatología , Lactancia Materna , Vasoespasmo Coronario/complicaciones , Vasoespasmo Coronario/fisiopatología , Femenino , Humanos , Embarazo , Complicaciones Cardiovasculares del Embarazo/fisiopatología , Trastornos Puerperales/fisiopatología , Fumar/efectos adversosRESUMEN
OBJECTIVE: An abnormal circadian blood pressure (BP) profile is associated with adverse cardiovascular and all-cause outcomes. It is highly prevalent after heart, liver and kidney transplantation. We aimed to assess the prevalence of an abnormal ambulatory BP pattern in lung transplant recipients (LTx). METHODS: Ambulatory BP monitoring (ABPM) was performed in 53 LTx and compared to those of 42 control subjects matched for age, gender and daytime BP. In 19 patients in whom at least two recordings were performed, we compared the first and the last one. RESULTS: The non-dipping pattern (a less than 10% reduction in nocturnal BP) was more prevalent in LTx than in control subjects (89 versus 64%, P < 0.01). Nighttime BP was higher in LTx than in control subjects (P < 0.01 and < 0.001 for systolic BP (SBP) and diastolic BP (DBP), respectively). The nocturnal reduction of BP was lower in LTx than in control subjects (3 versus 8% for SBP and 6 versus 13% for DBP, both P < 0.001). These results remained significant after adjustment for the presence of diabetes mellitus and creatinine clearance. In the 19 patients in whom ABPM was performed twice (mean interval between the two recordings was 22 months), ambulatory BP values remained unchanged between the two recordings, although the number of antihypertensive agents was significantly higher. CONCLUSION: An abnormal circadian BP profile is highly prevalent after lung transplantation. It is observed consistently over prolonged periods of time.
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Monitoreo Ambulatorio de la Presión Arterial , Ritmo Circadiano/fisiología , Hipertensión/epidemiología , Hipertensión/fisiopatología , Trasplante de Pulmón , Adulto , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Humanos , Modelos Lineales , Estudios Longitudinales , Masculino , Persona de Mediana Edad , PrevalenciaRESUMEN
1. Recently, we have demonstrated that cigarette smoke exposure proportionally increases plasma nicotine levels and arterial wave reflection to the aorta. However, the exact contribution of nicotine to the smoke-induced enhancement of wave reflection and the potential underlying mechanisms have not been fully investigated. 2. The present study was a prospective study in 15 healthy male non-smokers. All received a placebo and a 2 mg nicotine tablet, according to a randomized double-blind cross-over study design. Each subject underwent repeated measurements at baseline and for 1 h after nicotine or placebo intake, using carotid-femoral pulse wave velocity (PWV) to assess arterial compliance. Concurrently, aortic pressures and the augmentation index were evaluated using applanation tonometry. 3. Plasma nicotine concentrations achieved 1 h after intake of the nicotine tablet reached comparable levels to those achieved after 1 h exposure to passive smoke (3.6 +/- 0.4 vs 3.2 +/- 0.4 ng/mL, respectively; P = 0.4). 4. Nicotine enhanced arterial wave reflection to the aorta, as assessed by the augmentation index corrected for heart rate (4.2 +/- 1.3 vs-0.7 +/- 0.8% with placebo; P = 0.001). In addition, a progressive increase in carotid-femoral PWV was noted after nicotine administration (0.3 +/- 0.1 vs-0.02 +/- 0.1 m/s with placebo; P = 0.04). This remained significant even after adjustment for changes in mean blood pressure and heart rate (P = 0.01). 5. Plasma nicotine concentrations comparable to those achieved after exposure to passive smoke enhance arterial wave reflection to the aorta. This is accompanied by an increase in carotid-femoral PWV, denoting a deterioration of arterial compliance by nicotine.
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Aorta/efectos de los fármacos , Arterias Carótidas/efectos de los fármacos , Arteria Femoral/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Nicotina/efectos adversos , Animales , Aorta/fisiopatología , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Arterias Carótidas/fisiopatología , Estudios Cruzados , Método Doble Ciego , Elasticidad , Arteria Femoral/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Hemodinámica/fisiología , Humanos , Masculino , Nicotina/sangre , Estudios Prospectivos , Contaminación por Humo de Tabaco/efectos adversos , Adulto JovenRESUMEN
OBJECTIVE: To assess the prevalence and determinants of high blood pressure (BP) and awareness, treatment, and control rates in the Far North Region of Cameroon, where these variables have not been explored so far. METHODS: In total, 889 individuals (41.5% women) aged at least 18 years participated in a cross-sectional survey conducted in Maroua (urban area) and Tokombere (rural area) from November 2014 to May 2015, using a multistage cluster sampling frame. Anthropometric variables, BP, and fasting capillary glucose were assessed in all participants. Hypertension was defined as BP at least 140/90âmmHg or antihypertensive therapy and BP control as BP less than 140/90âmmHg. Prevalence estimates were age standardized to the Cameroon population. RESULTS: The prevalence of hypertension was 37.8% (rural: 34%; urban: 41.2%; men: 38.8%; women: 37.9%). Hypertension was associated with urban environment (odds ratio: 1.42; 95%; confidence interval 1.06-1.89), age at least 70 years (4.06; 2.02-6.14), male sex (4.06; 2.02-6.14), abdominal obesity (2.36; 1.54-3.61), and high blood sugar (2.01; 1.31-3.08). Among individuals with hypertension, 18.6% (rural: 17.9%; urban: 19.5%) were aware of having high BP. Among those aware, 29.3% (rural: 17.3%; urban: 36.3%) reported receiving treatment, of whom 16.3% (rural: 22.6%; urban: 4.2%) had BP controlled. Awareness, treatment, and BP control levels were higher in women than men. CONCLUSION: Hypertension is highly prevalent in Far North Cameroon and awareness, treatment, and control rates are low. Efforts to improve detection, treatment, and control of hypertension in Cameroon are needed.
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Conocimientos, Actitudes y Práctica en Salud , Hipertensión/epidemiología , Adulto , Concienciación , Presión Sanguínea , Camerún/epidemiología , Estudios Transversales , Femenino , Humanos , Hipertensión/psicología , Hipertensión/terapia , Masculino , Persona de Mediana Edad , Prevalencia , Población Rural/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Adulto JovenRESUMEN
Coronary hypersensitivity to serotonin promotes platelet aggregation, entailing the progression of the atherosclerotic process. This abnormality is a common finding in cardiac transplant recipients and may be triggered by reactive oxygen species, which plays a main role in the inflammatory process. Hence, this study aimed to determine the influence of intimal hyperplasia on this abnormality and its reversibility after acute supplementation with the superoxide anion scavenger vitamin C. Therefore, intracoronary injections of serotonin (3 microg), bradykinin (600 ng), and nitroglycerin (isosorbide dinitrate 200 microg) were administered to 21 cardiac transplant recipients (1 year after transplantation) with normal coronary angiographic results; the serotonin injections were repeated after intracoronary vitamin C supplementation (40 mg/min for 14 minutes). In the segments in which serotonin effects were the most pronounced, the diameter changes were measured by quantitative angiography, and vessel wall morphology was studied by intravascular ultrasound (IVUS). The IVUS examination revealed moderate to severe intimal thickening (total area - luminal area/total area) in 9 patients (group 1) of 25 +/- 2%, compatible with the early stage of graft vasculopathy. In this group, hypersensitivity to serotonin remained unchanged after intracoronary vitamin C supplementation, from -21 +/- 3% (percentage from baseline) to -25 +/- 3%, whereas in the other 12 patients with mild intimal thickening (9 +/- 1%; group 2), hypersensitivity to serotonin was attenuated from -20 +/- 5% to -4 +/- 6% (p <0.01). In contrast, the responses to bradykinin and isosorbide dinitrate were similar in the 2 groups. In group 1, plasma levels of high-sensitivity C-reactive protein and proinflammatory cytokines (interleukin-6 and -8) were significantly enhanced. For all the patients studied, the effect of vitamin C on the response to serotonin was significantly correlated with the intimal thickening. In conclusion, at 1 year after transplantation, morphologic changes compatible with the early stage of the graft vasculopathy are accompanied by hypersensitivity to serotonin unresponsive to vitamin C, despite a relatively preserved endothelial function (unaltered response to bradykinin).
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Ácido Ascórbico/farmacología , Vasos Coronarios/efectos de los fármacos , Suplementos Dietéticos , Trasplante de Corazón , Serotonina/farmacología , Adulto , Bradiquinina/farmacología , Vasos Coronarios/patología , Humanos , Hiperplasia , Dinitrato de Isosorbide/farmacología , Persona de Mediana Edad , Nitroglicerina/farmacología , Estrés Oxidativo/efectos de los fármacos , Serotonina/administración & dosificación , Factores de Tiempo , Túnica Íntima/patología , Ultrasonografía IntervencionalRESUMEN
BACKGROUND: Cardiac resynchronization therapy (CRT) by pacing the left and right ventricles is an emerging option for treatment of severe heart failure with ventricular conduction disturbances. Stimulation through a coronary vein is currently the technique of choice to achieve left ventricular (LV) pacing. Unfortunately, this approach carries significant limitations and drawbacks. Therefore we explored robotic-enhanced thoracoscopic implantation of an epicardial lead as an alternative technique to stimulate the LV in cardiac resynchronization therapy. METHODS: A total of 15 patients were included in this study. Right (atrial and ventricular) leads were implanted classically through the left subclavian vein. Robotic-enhanced thoracoscopy was then performed to implant the LV epicardial lead. RESULTS: Of the 15 patients, 13 underwent successful endoscopic robotic cardiac resynchronization therapy. Two patients underwent conversion to a small thoracotomy. No perioperative complication occurred in the patients who did not undergo conversion. Acute and chronic LV lead thresholds were satisfactory in all patients, improving over time. All were subjectively and objectively improved at 4 months. As compared with conventional methods, the procedural cost was not significantly affected. CONCLUSIONS: Based on this feasibility study, we believe that robotic LV epicardial lead implantation is a valuable option to achieve biventricular resynchronization therapy. It allows for more reproducible acute thresholds for LV pacing and sensing than does the percutaneous approach; enables fine tuning of the LV lead position, thus potentially providing optimal hemodynamic benefit; and avoids the pitfalls and limitations of the endovenous approach. Therefore it deserves further prospective studies to assess its place in the therapeutic armamentarium against heart failure.
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Desfibriladores Implantables , Insuficiencia Cardíaca/cirugía , Robótica , Toracoscopía/métodos , Disfunción Ventricular Izquierda/cirugía , Anciano , Bélgica , Estimulación Cardíaca Artificial , Enfermedad Crónica , Electrocardiografía , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Pruebas de Función Cardíaca , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Probabilidad , Medición de Riesgo , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Disfunción Ventricular Izquierda/diagnósticoRESUMEN
BACKGROUND: Pulmonary vein isolation (PVI) has been shown to be effective treatment of patients with symptomatic paroxysmal atrial fibrillation (PAF). The percutaneous approach is currently the technique of choice. Unfortunately, this procedure has limitations and complications that lead to fluctuating success rates. We explored an alternative technique of robotic-enhanced, closed-chest PVI with an endoscopic microwave-based catheter. METHODS: Seven symptomatic PAF patients were included in the study. The pulmonary veins were isolated through right (only) robotic-enhanced thoracoscopy on the beating heart. RESULTS: Six patients underwent successful endoscopic PVI. In 1 patient the operation was converted into small right thoracotomy. Operative assessment of the ablation line showed a successful electric block in every patient. Three months after the procedure, the first 5 patients were in permanent sinus rhythm. The 2 other patients had AF but had less frequent and less symptomatic episodes compared with the preoperative situation. CONCLUSIONS: On the basis of this preliminary experience, we believe that in the near future endoscopic right-chest robotic-enhanced PVI on the beating heart may become a valid option in the treatment of symptomatic PAF patients. This procedure allows for more-reproducible ablation lines and may avoid many of the pitfalls and drawbacks of the percutaneous approach. Therefore this technique deserves larger prospective evaluation in the treatment of AF.
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Fibrilación Atrial/cirugía , Endoscopía/métodos , Sistema de Conducción Cardíaco/cirugía , Venas Pulmonares/cirugía , Robótica/métodos , Cirugía Asistida por Computador/métodos , Procedimientos Quirúrgicos Torácicos/métodos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization.
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Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico , Vasos Coronarios , Imagenología Tridimensional , Imagen Multimodal/métodos , Interpretación de Imagen Radiográfica Asistida por Computador , Tomografía de Coherencia Óptica , Ultrasonografía Intervencional , Puntos Anatómicos de Referencia , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/patología , Estudios de Factibilidad , Humanos , Valor Predictivo de las Pruebas , Pronóstico , Índice de Severidad de la Enfermedad , Programas Informáticos , Flujo de TrabajoRESUMEN
Myocardial bridging (MB) is a frequent condition usually considered benign but it may be associated with myocardial ischemia. When bridging is symptomatic, therapeutic options are numerous and in the absence of guidelines all options are conceivable. This is a case of a 27-year-old man who benefited from a new surgical approach: myotomy for MB of the left anterior descending coronary artery with the help of left robotic thoracoscopy.
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Procedimientos Quirúrgicos Cardíacos , Puente Miocárdico/cirugía , Robótica , Cirugía Asistida por Computador , Toracoscopía , Adulto , Angiografía Coronaria , Humanos , Masculino , Puente Miocárdico/diagnóstico por imagen , Resultado del TratamientoRESUMEN
Nicotine has been recognized for years as being pharmacologically responsible for the sympathoexcitatory effects of smoking. The effects of nicotine supplementation on myocardial blood flow as assessed by positron emission tomography are, however, unknown. We tested the hypothesis that nicotine substitution could interfere with myocardial blood flow autoregulation at rest in habitual smokers at risk of coronary artery disease. The short-term effect of a 4-mg nicotine tablet on myocardial blood flow was quantified with 13N ammonia positron emission tomography in 12 smokers with high cardiovascular risk (10 males and 2 females; mean age = 58+/-8 years; SCORE risk >5%). Nicotine increased systolic blood pressure from 129+/-7 to 134+/-7 mmHg (p = .03) and heart rate from 67+/-2 to 69+/-2 bpm (p = .04). As a result, nicotine raised the rate-pressure product from 8618+/-622 to 9285+/-627 bpm mmHg (p = .02). Nicotine tended to increase myocardial blood flow in the circumflex artery territory, but this effect failed to reach the level of statistical significance (from 0.56+/-0.06 to 0.63+/-0.03 ml/min/g; p>.15). This trend disappeared when myocardial blood flow was normalized for the rise in the rate-pressure product. Global myocardial perfusion, normalized for the changes in rate-pressure product, remained unchanged from 0.70+/-0.06 at baseline to 0.71+/-0.03 (ml/min/g)/(bpm mmHg) after nicotine. Nicotine supplementation in habitual smokers with high cardiovascular risk increased myocardial work without compromising resting myocardial blood flow autoregulation.
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Circulación Coronaria/efectos de los fármacos , Homeostasis/efectos de los fármacos , Nicotina/administración & dosificación , Agonistas Nicotínicos/administración & dosificación , Tabaquismo/tratamiento farmacológico , Administración Oral , Enfermedad Coronaria/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Agonistas Nicotínicos/efectos adversos , Cese del Hábito de Fumar/métodos , Prevención del Hábito de Fumar , Comprimidos , Tabaquismo/complicacionesRESUMEN
Left ventricular outflow tract obstruction may be dynamic, most commonly associated with hypertrophic cardiomyopathy, and, uncommonly, by congenital anomalies such as discrete subaortic stenosis. We describe a patient with Behçet's disease, presenting with a systolic murmur, fever, and syncope, in whom a diagnosis of subaortic obstruction caused by a pseudo-aneurysm dissecting the interventricular septum and associated with a complete atrioventricular block was made.
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Síndrome de Behçet/complicaciones , Estenosis Subaórtica Fija/complicaciones , Ecocardiografía Transesofágica , Bloqueo Cardíaco/etiología , Obstrucción del Flujo Ventricular Externo/etiología , Adulto , Estenosis Subaórtica Fija/diagnóstico por imagen , Estenosis Subaórtica Fija/cirugía , Electrocardiografía , Femenino , Bloqueo Cardíaco/diagnóstico por imagen , Bloqueo Cardíaco/cirugía , Humanos , Obstrucción del Flujo Ventricular Externo/diagnóstico por imagen , Obstrucción del Flujo Ventricular Externo/cirugíaRESUMEN
Granulocyte--colony-stimulating factor administered for autologous hematopoietic stem cell isolation from blood may favor restenosis in patients implanted after acute myocardial infarction (AMI). We therefore tested the isolation of peripheral-blood CD34+ cells without mobilization in six patients with AMI. After large-volume cytapheresis and positive CD34+ cell selection, 3.6 to 27.6 million CD34+ cells were obtained. We performed intra-coronary implantation of these cells and recorded no restenosis or arrhythmia. We used positron emission tomography (PET) to assess myocardial-labeled CD34+ cell homing, which accounted for 5.5% of injected cells 1 hour after implantation. In conclusion, large amounts of CD34+ cells, in the range reported in previous studies, can be obtained from nonmobilized peripheral blood. PET with [18F]-fluorodeoxyglucose cell labeling is an efficient imaging method for homing assessment.
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Antígenos CD34/metabolismo , Movimiento Celular , Trasplante de Células Madre Hematopoyéticas/métodos , Células Madre Hematopoyéticas/fisiología , Infarto del Miocardio/terapia , Miocardio/ultraestructura , Adulto , Anciano , Reestenosis Coronaria , Vasos Coronarios/fisiología , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Movilización de Célula Madre Hematopoyética/métodos , Humanos , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones/métodos , Cintigrafía/métodosRESUMEN
Cardiac resynchronization therapy (CRT) decreases muscle sympathetic nerve activity (MSNA) in patients with severe congestive heart failure (CHF) and cardiac asynchrony. Whether this affects equally patients who clinically respond or not to CRT is unknown. We tested the hypothesis that the favorable effects of CRT on MSNA disappear on CRT interruption only in those who respond to CRT. Twenty-three consecutive CHF patients participated in the study, among whom 16 presented a symptomatic improvement by one or more New York Heart Association (NYHA) functional classes 15 +/- 5 mo after CRT (responders), and seven had not improved after 12 +/- 4 mo of CRT (nonresponders). MSNA and echocardiographic recordings were obtained in random order during atrio-right ventricular pacing (ARV), without stimulation in patients who were not pacemaker dependent (OFF, n = 17), and during atrio-biventricular pacing (BIV). Responders had a longer 6-min walking distance, a lower NYHA class and brain natriuretic peptide levels, and a better quality of life than did nonresponders (all P < 0.05). MSNA increased by 25 +/- 7% in the responders, whereas it remained unchanged in the nonresponders, when shifting from the BIV mode to a nonsynchronous condition (ARV and OFF modes) (P < 0.01). Cardiac output decreased by 0.7 +/- 0.2 l/min in the responders but did not change when shifting from the BIV mode to the nonsynchronous pacing mode in the nonresponders (P < 0.01). In conclusion, reversible sympathoinhibition is a marker of the clinical response to CRT.
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Bloqueo de Rama/fisiopatología , Gasto Cardíaco Bajo/terapia , Estimulación Cardíaca Artificial , Sistema de Conducción Cardíaco/fisiopatología , Receptores Adrenérgicos/fisiología , Sistema Nervioso Simpático/fisiología , Anciano , Gasto Cardíaco , Gasto Cardíaco Bajo/fisiopatología , Electrocardiografía , Femenino , Ventrículos Cardíacos/inervación , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Contracción Miocárdica/fisiología , Estudios Retrospectivos , Resultado del Tratamiento , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
AIMS: Permanent right ventricular apical pacing (RVP) is associated with a wide range of myocardial abnormalities. The purpose of this study was to determine the changes over time of RVP on myocardial blood flow (MBF) and glucose metabolism as assessed by positron emission tomography (PET). METHODS: In eight candidates for permanent pacemaker implantation PET imaging was performed with 13N-ammonia and 18F-Fluorodeoxyglucose (FDG) to assess MBF and glucose metabolism before (PET1) and repeated after 3 months of RVP (PET2). For the analysis, the left ventricle was divided into three parts (apex, mid-ventricular and base) and subdivided into six segments (inferior, posterior, lateral, anterior, antero-septal and infero-septal). RESULTS: After RVP, defects of FDG uptake were found in the left ventricle near the stimulation site, without corresponding changes in MBF. Changes over time in the mean FDG uptake were statistically significant between PET1 and PET2 in the apical inferior, apical-posterior, apical-anterior, apical antero-septal, apical infero-septal, mid-inferior and mid-infero-septal segments. CONCLUSIONS: This study shows that RVP induces major changes in the distribution of FDG uptake in the left ventricular myocardium. FDG uptake significantly decreases in the regions surrounding the pacing site.
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Estimulación Cardíaca Artificial , Técnicas Electrofisiológicas Cardíacas , Glucosa/metabolismo , Miocardio/metabolismo , Tomografía de Emisión de Positrones , Anciano , Anciano de 80 o más Años , Amoníaco , Presión Sanguínea , Circulación Coronaria , Femenino , Fluorodesoxiglucosa F18 , Frecuencia Cardíaca , Ventrículos Cardíacos , Humanos , Masculino , Persona de Mediana Edad , Radioisótopos de Nitrógeno , Radiofármacos , Función Ventricular IzquierdaRESUMEN
BACKGROUND: Sympathetic benefits of thoracoscopic cardiac resynchronization therapy (TCRT) in congestive heart failure (CHF) are unknown. We determined cardiac hemodynamics, functional status, and muscle sympathetic nerve activity (MSNA) in a group of TCRT patients. We aimed to compare these patients with CHF patients with cardiac asynchrony (ASY) to substantiate the beneficial effects of TCRT. METHODS AND RESULTS: Eleven patients resynchronized by TCRT 6 +/- 1 months before study inclusion (SYN) and 10 matched ASY patients underwent blood pressure, heart rate, and MSNA recordings. All underwent functional status, cardiac index, and left ventricular ejection fraction (LVEF) assessments. SYN patients had shorter QRS duration and interventricular mechanical delays, longer 6 minute walking distance and lower New York Heart Association class (all P < .05) than ASY patients. MSNA of 56 +/- 2 bursts/min in ASY patients was higher than in SYN patients (48 +/- 3 bursts/min, P < .05). Cardiac index was higher in SYN patients than in ASY patients (2.8 +/- 0.2 versus 1.9 +/- 0.2 L.min.m2, P < .05, respectively). MSNA was highest in the patients with the lowest LVEF (r = -0.49, P < .05), cardiac index (r = -0.48, P < .05) and 6-minute walking distance (r = -0.50, P < .05). CONCLUSION: Lower sympathetic nerve activities in TCRT patients are related to more favorable cardiac indexes and six minute walking distances suggesting a sympathetic, hemodynamic, and functional improvement by TCRT.
Asunto(s)
Insuficiencia Cardíaca/terapia , Marcapaso Artificial , Sistema Nervioso Simpático/fisiopatología , Anciano , Presión Sanguínea/fisiología , Ecocardiografía , Electrocardiografía , Tolerancia al Ejercicio/fisiología , Femenino , Sistema de Conducción Cardíaco/diagnóstico por imagen , Sistema de Conducción Cardíaco/fisiopatología , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico/fisiología , Sistema Nervioso Simpático/diagnóstico por imagen , Toracoscopía , Resultado del Tratamiento , Caminata/fisiologíaRESUMEN
Angiotensin II, via AT1 receptors plays a key role in endothelial dysfunction and therefore, in atherogenesis. In order to assess whether long-term blockade of these receptors improve peripheral and coronary endothelial function, 13 patients were treated by candesartan cilexetil (AT2B, 16 mg/d in 10 patients and 8 mg in 3). Flow-mediated dilation (FMD, measured with ultra-sound technique) in the brachial artery and cold pressor testing (CPT)-induced changes in myocardial blood flow (MBF, measured with positron emission tomography) were assessed before and after a 6 month treatment period. AT2B did not alter FMD: 5.0 +/- 1.2% vs. 6.4 +/- 0.9% after treatment. MBF increased significantly during CPT before and after AT2B. Although AT2B did not significantly modify heart rate and blood pressure, MBF normalized to the rate pressure product (MBF/RPP x 10000) was significantly higher and this change remained significant during CPT: it increased from 0.94 +/- 0.05 ml/g/min to 1.14 +/- 0.09 ml/g/min after AT2B (P < .05) and did not decrease during CPT (1.12 +/- 0.08 ml/g/min). Moreover, these AT2B-induced changes in normalized MBF were significantly correlated with the changes in FMD (r = 0.66, P < 0.05). Thus, long-term AT2B improves coronary vasomotion. Although no significant alteration in peripheral conduit endothelial function has been observed, treatment-induced FMD changes seem to be a predictor of coronary circulation improvement.