RESUMEN
BACKGROUND: Sympathetic neural activation plays a key role in the incidence and maintenance of acute myocardial infarction (AMI) induced ventricular arrhythmia (VA). Furthermore, previous studies showed that AMI might induce microglia and sympathetic activation and that microglial activation might contribute to sympathetic activation. Recently, studies showed that light emitting diode (LED) therapy might attenuate microglial activation. Therefore, we hypothesized that LED therapy might reduce AMI-induced VA by attenuating microglia and sympathetic activation. METHODS: Thirty anesthetized rats were randomly divided into three groups: the Control group (n = 6), AMI group (n = 12), and AMI + LED group (n = 12). Electrocardiogram (ECG) and left stellate ganglion (LSG) neural activity were continuously recorded. The incidence of VAs was recorded during the first hour after AMI. Furthermore, we sampled the brain and myocardium tissue of the different groups to examine the microglial activation and expression of nerve growth factor (NGF), interleukin-18 (IL-18), and IL-1ß, respectively. RESULTS: Compared to the AMI group, LED therapy significantly reduced the incidence of AMI-induced VAs (ventricular premature beats [VPB] number: 85.08 ± 13.91 vs 27.5 ± 9.168, P < .01; nonsustained ventricular tachycardia (nSVT) duration: 34.39 ± 8.562 vs 9.005 ± 3.442, P < .05; nSVT number: 18.92 ± 4.52 vs 7.583 ± 3.019, P < .05; incidence rate of SVT/VF: 58.33% vs. 8.33%, P < .05) and reduced the LSG neural activity (P < .01) in the AMI + LED group. Furthermore, LED significantly attenuated microglial activation and reduced IL-18, IL-1ß, and NGF expression in the peri-infarct myocardium. CONCLUSION: LED therapy may protect against AMI-induced VAs by suppressing sympathetic neural activity and the inflammatory response.
Asunto(s)
Corazón/inervación , Láseres de Semiconductores , Terapia por Luz de Baja Intensidad/instrumentación , Infarto del Miocardio/radioterapia , Neuroinmunomodulación , Núcleo Hipotalámico Paraventricular/fisiopatología , Ganglio Estrellado/fisiopatología , Taquicardia Supraventricular/prevención & control , Taquicardia Ventricular/prevención & control , Complejos Prematuros Ventriculares/prevención & control , Potenciales de Acción , Animales , Modelos Animales de Enfermedad , Frecuencia Cardíaca , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Masculino , Microglía/metabolismo , Infarto del Miocardio/complicaciones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/fisiopatología , Miocardio/metabolismo , Factor de Crecimiento Nervioso/metabolismo , Núcleo Hipotalámico Paraventricular/metabolismo , Ratas Sprague-Dawley , Taquicardia Supraventricular/etiología , Taquicardia Supraventricular/metabolismo , Taquicardia Supraventricular/fisiopatología , Taquicardia Ventricular/etiología , Taquicardia Ventricular/metabolismo , Taquicardia Ventricular/fisiopatología , Factores de Tiempo , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/metabolismo , Complejos Prematuros Ventriculares/fisiopatologíaRESUMEN
AIM: Median nerve stimulation (MNS) is a novel neuromodulation approach for treatment of ventricular arrhythmia, but little is known about its chronic effects. The aim of this study was to investigate the effects of chronic MNS on ventricular arrhythmia and ventricular dysfunction postmyocardial infarction (MI). METHOD: Two weeks after MI, 12 rabbits were randomly divided into control and MNS groups, and chronic MNS was performed in MNS group for 2 weeks. Ventricular function and arrhythmias; sympathetic innervation and activity; and interleukin-1 ß (IL-1 ß) and norepinephrine (NE) levels were analyzed. RESULTS: Both the total number of premature ventricular complex and episodes of ventricular tachycardia were lower in MNS group than in control group (20 560 ± 10 314 beats vs 70 079 ± 37 184 beats, P = .021, and 115 ± 63 episodes vs 307 ± 164 episodes, P = .034, respectively). Compared with control group, MNS decreased the cardiac sympathetic nerve density and level of circulating NE in MNS group (1798.42 ± 644.07 µm2 /mm2 vs 1003.79 ± 453.00 µm2 /mm2, P = .041, and 20.86 ± 4.54 pg/mL vs 11.07 ± 1.43 pg/mL, P = .002, respectively). MNS also improved the left ventricular ejection fraction (59.07 ± 1.91% vs 49.77 ± 3.47%, P = .003) and inhibited the level of IL-1 ß in serum (69.19 ± 4.71 pg/mL vs 85.93 ± 12.80 pg/mL, P = .013). CONCLUSION: Chronic MNS appears to protect against ventricular arrhythmia and improves ventricular function post-MI, which may be mediated by suppressing cardiac sympathetic activity and anti-inflammatory effects.
Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Corazón/inervación , Nervio Mediano , Infarto del Miocardio/terapia , Volumen Sistólico , Taquicardia Ventricular/prevención & control , Función Ventricular Izquierda , Complejos Prematuros Ventriculares/prevención & control , Animales , Modelos Animales de Enfermedad , Interleucina-1beta/sangre , Infarto del Miocardio/sangre , Infarto del Miocardio/complicaciones , Infarto del Miocardio/fisiopatología , Norepinefrina/sangre , Conejos , Taquicardia Ventricular/sangre , Taquicardia Ventricular/etiología , Taquicardia Ventricular/fisiopatología , Factores de Tiempo , Complejos Prematuros Ventriculares/sangre , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/fisiopatologíaRESUMEN
BACKGROUND: Whether Brugada syndrome (BrS) depends on functional epicardial substrates, which may be definitively eliminated by radiofrequency ablation, remains unknown. METHODS AND RESULTS: Patients with BrS underwent epicardial mapping to identify areas of abnormal electrograms as target for radiofrequency ablation. Substrate identification consisted in mapping right ventricle epicardial surface before and after flecainide (2 mg/kg per 10 minutes). After radiofrequency ablation, flecainide and remap confirmed elimination of abnormal substrate, BrS ECG pattern, and ventricular tachycardia/ventricular fibrillation inducibility. Flecainide testing was performed at each follow-up visits ≤6 months. Fourteen patients with BrS, median age 39 years (30.3-42.3) with implantable cardioverter-defibrillator were enrolled. Low-voltage areas (<1.5 mV) were commonly identified on the anterior right free wall and right ventricular outflow tract, which increased after flecainide from 17.6 cm(2) (12.1-24.2) to 28.5 cm(2) (21.6-30.2; P=0.001). Similarly, areas with abnormal electrograms increased after flecainide from 19.0 (17.5-23.6) to 27.3 cm(2) (24.0-31.2; P=0.001). After 23.8 minutes (18.1-28.5) of radiofrequency ablation, abnormal electrograms disappeared, whereas low-voltage areas were replaced by scar areas (<0.5 mV) of 25.9 cm(2) (19.6-31.0). Substrate elimination resulted in BrS ECG pattern disappearance and no ventricular tachycardia/ventricular fibrillation inducibility without complications. After a median follow-up of 5 months (3.8-5.3), ECG remained normal despite flecainide. CONCLUSIONS: In patients with BrS, there is a relationship between abnormal ECG pattern, the extent of abnormal epicardial substrate, and ventricular tachycardia/ventricular fibrillation inducibility. Ablation of the substrate identified in the presence of flecainide can eliminate the BrS phenotype and warrants further study.
Asunto(s)
Síndrome de Brugada/cirugía , Ablación por Catéter/métodos , Pericardio/cirugía , Potenciales de Acción , Adulto , Antiarrítmicos/administración & dosificación , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/fisiopatología , Ablación por Catéter/efectos adversos , Muerte Súbita Cardíaca/prevención & control , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Flecainida/administración & dosificación , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Pericardio/fisiopatología , Fenotipo , Valor Predictivo de las Pruebas , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/prevención & control , Factores de Tiempo , Resultado del Tratamiento , Fibrilación Ventricular/fisiopatología , Fibrilación Ventricular/prevención & control , Complejos Prematuros Ventriculares/fisiopatología , Complejos Prematuros Ventriculares/prevención & control , Adulto JovenRESUMEN
: Electrical carotid baroreceptor stimulation (CBS) has shown therapeutic potential for resistant hypertension and heart failure by resetting autonomic nervous system, but the impacts on arrhythmias remains unclear. This study evaluated the effects of CBS on ventricular electrophysiological properties in normal dog heart and arrhythmias after acute myocardial infarction (AMI). In the acute protocol, anesthetized open chest dogs were exposed to 1 hour left anterior descending coronary occlusion as AMI model. Dogs were received either sham treatment (Control group, n = 8) or CBS (CBS group, n = 8), started 1 hour before AMI. CBS resulted in pronounced prolongation of ventricular effective refractory period and reduction of the maximum action potential duration restitution slope (from 0.85 ± 0.15 in the baseline state to 0.67 ± 0.09 at the end of 1 hour, P < 0.05) before AMI. Number of premature ventricular contractions (277 ± 168 in the Control group vs. 103 ± 84 in the CBS group, P < 0.05) and episodes of ventricular tachycardia/ventricular fibrillation (7 ± 3 in the Control group vs. 3 ± 2 in the CBS group, P < 0.05) was decreased compared with the control group during AMI. CBS buffered low-frequency/high-frequency ratio raise during AMI. Ischemic size was not affected by CBS. CBS may have a beneficial impact on ventricular arrhythmias induced by AMI through modulation of autonomic tone.
Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Infarto del Miocardio/terapia , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/prevención & control , Potenciales de Acción/fisiología , Animales , Sistema Nervioso Autónomo/metabolismo , Modelos Animales de Enfermedad , Perros , Masculino , Infarto del Miocardio/complicaciones , Infarto del Miocardio/fisiopatología , Presorreceptores/metabolismo , Taquicardia Ventricular/etiología , Fibrilación Ventricular/etiología , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
OBJECTIVES: To investigate the effects and mechanisms of Nardostachys chinensis (NC) on spontaneous ventricular arrhythmias in rats with hyper-acute myocardial infarction (AMI). METHODS: Seventy-two rats were randomly divided into the control group (n = 24), metoprolol group (n = 24), and the NC group (n = 24). Premature ventricular contractions (PVCs), ventricular tachycardias (VTs), ventricular fibrillations (VFs), and blood pressure were monitored for 4 hours after coronary artery ligation. The connexin 43 (Cx43) expression in ventricular myocardium was measured by immunohistochemistry, Western blot, and real-time RT-PCR. RESULTS: Compared with the control, metoprolol and NC decreased the VF incidence (50% vs. 4.2%, P < 0.001, and 50% vs. 12.5%, P = 0.005, respectively). There was a steady decrease in the cumulative number of PVCs and VTs within 4 hours from ligating in 3 groups. Compared with the control, metoprolol and NC reduced the cumulative number of VTs and PVCs. Compared with control, metoprolol and NC decreased the infarct size of the left ventricular tissue (55.98% ± 6.20% vs. 39.13% ± 4.53%, P < 0.001, and 55.98% ± 6.20% vs. 42.39% ± 3.44%, P < 0.001, respectively). The results from immunohistochemistry, Western blot, and real-time RT-PCR showed that the protein expression of Cx43 in the control group was significantly lower than that in the metoprolol and NC groups in the infarcted zone. CONCLUSIONS: NC decreased the incidence of spontaneous ventricular arrhythmias (especially VF), reduced Cx43 degradation, and improved Cx43 redistribution in myocardial infarcted zone in rats with hyper-AMI. The data of the present study indicated that NC may be a promising drug in the future to prevent patients with AMI from lethal ventricular arrhythmias in prehospital setting.
Asunto(s)
Antiarrítmicos/uso terapéutico , Medicamentos Herbarios Chinos/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Nardostachys/química , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/prevención & control , Complejos Prematuros Ventriculares/prevención & control , Animales , Antiarrítmicos/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Western Blotting , Conexina 43/metabolismo , Medicamentos Herbarios Chinos/administración & dosificación , Electrocardiografía , Femenino , Inmunohistoquímica , Masculino , Metoprolol/administración & dosificación , Metoprolol/uso terapéutico , Infarto del Miocardio/complicaciones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Rizoma/química , Taquicardia Ventricular/etiología , Taquicardia Ventricular/metabolismo , Taquicardia Ventricular/patología , Fibrilación Ventricular/etiología , Fibrilación Ventricular/metabolismo , Fibrilación Ventricular/patología , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/metabolismo , Complejos Prematuros Ventriculares/patologíaRESUMEN
FUNDAMENTO: As extrassístoles ventriculares e supraventriculares (EV e ESSV) são frequentes e muitas vezes sintomáticas. O íon magnésio (Mg) desempenha um papel importante na fisiologia do potencial de ação transmembrana celular e do ritmo cardíaco. OBJETIVO: Avaliar se a administração do pidolato de magnésio (PMg) em pacientes com EV e ESSV tem desempenho superior ao uso do placebo (P) na melhora dos sintomas e densidade das extrassístoles (DES). MÉTODOS: Estudo duplo-cego, randomizado, com 60 pacientes sintomáticos consecutivos, com mais de 240/EV ou ESSV ao Holter de 24 horas e selecionados para receber P ou PMg. Para avaliar a melhora da sintomatologia, foi feito um questionário categórico e específico de sintomas relacionados às extrassístoles. Após o tratamento, foi considerada significante uma redução de mais de 70% na DES por hora. A dose do PMg foi de 3,0 g/dia por 30 dias, equivalente a 260 mg do elemento Mg. Nenhum paciente tinha cardiopatia estrutural ou insuficiência renal. RESULTADOS: Dos 60 pacientes estudados, 33 eram do sexo feminino (55%). A faixa etária variou de 16 a 70 anos. No grupo PMg, 76,6% dos pacientes tiveram redução maior que 70%, 10% deles maior que 50% e somente 13,4% tiveram redução menor que 50% na DES. No grupo P, 40% dos pacientes tiveram melhora de apenas 30% na frequência de extrassístoles (p < 0,001). A melhora dos sintomas foi alcançada em 93,3% dos pacientes do grupo PMg, comparada com somente 16,7% do grupo P (p < 0,001). CONCLUSÃO: A suplementação de Mg via oral reduziu a DES, resultando em melhora dos sintomas.
BACKGROUND: Premature ventricular and supraventricular complexes (PVC and PsVC) are frequent and often symptomatic. The magnesium (Mg) ion plays a role in the physiology of cell membranes and cardiac rhythm. OBJECTIVE:We evaluated whether the administration of Mg Pidolate (MgP) in patients with PVC and PsVC is superior to placebo (P) in improving symptoms and arrhythmia frequency. METHODS: Randomized double-blind study with 60 consecutive symptomatic patients with more than 240 PVC or PsVC on 24-hour Holter monitoring who were selected to receive placebo or MgP. To evaluate symptom improvement, a categorical and a specific questionnaire for symptoms related to PVC and PsVC was made. Improvement in premature complex density (PCD) per hour was considered significant if percentage reduction was >70% after treatment. The dose of MgP was 3.0 g/day for 30 days, equivalent to 260mg of Mg element. None of the patients had structural heart disease or renal failure. RESULTS: Of the 60 patients, 33 were female (55%). Ages ranged from 16 to 70 years old. In the MgP group, 76.6% of patients had a PCD reduction >70%, 10% of them >50% and only 13.4% <50%. In the P group, 40% showed slight improvement, <30%, in the premature complexes frequency (p < 0.001). Symptom improvement was achieved in 93.3% of patients in the MgP group, compared with only 16.7% in the P group (p < 0.001). CONCLUSION: Oral Mg supplementation decreases PCD, resulting in symptom improvement.
Asunto(s)
Adolescente , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven , Complejos Atriales Prematuros/tratamiento farmacológico , Ácido Pirrolidona Carboxílico/administración & dosificación , Complejos Prematuros Ventriculares/tratamiento farmacológico , Complejos Atriales Prematuros/prevención & control , Método Doble Ciego , Efecto Placebo , Estadísticas no Paramétricas , Factores de Tiempo , Resultado del Tratamiento , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
BACKGROUND: Premature ventricular and supraventricular complexes (PVC and PsVC) are frequent and often symptomatic. The magnesium (Mg) ion plays a role in the physiology of cell membranes and cardiac rhythm. OBJECTIVE: We evaluated whether the administration of Mg Pidolate (MgP) in patients with PVC and PsVC is superior to placebo (P) in improving symptoms and arrhythmia frequency. METHODS: Randomized double-blind study with 60 consecutive symptomatic patients with more than 240 PVC or PsVC on 24-hour Holter monitoring who were selected to receive placebo (P) or MgP. To evaluate symptom improvement, a categorical and a specific questionnaire for symptoms related to PVC and PsVC was made. Improvement in premature complex density (PCD) per hour was considered significant if percentage reduction was >70% after treatment. The dose of MgP was 3.0 g/day for 30 days, equivalent to 260 mg of Mg element. Any patient had structural heart disease or renal failure. RESULTS: Of the 60 patients, 33 were female (55%). Ages ranged from 16 to 70 years old. In the MgP group, 76.6% of patients had a PCD reduction >70%, 10% of them >50% and only 13.4% <50%. In the P group, 40% showed slight improvement, <30%, in the PC frequency (p < 0.001). Symptom improvement was achieved in 93.3% of patients in the MgP group, compared with only 16.7% in the P group (p < 0.001). CONCLUSION: Oral Mg supplementation decreases PCD, resulting in symptom improvement.
Asunto(s)
Complejos Atriales Prematuros/tratamiento farmacológico , Ácido Pirrolidona Carboxílico/administración & dosificación , Complejos Prematuros Ventriculares/tratamiento farmacológico , Adolescente , Adulto , Anciano , Complejos Atriales Prematuros/prevención & control , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Efecto Placebo , Estadísticas no Paramétricas , Factores de Tiempo , Resultado del Tratamiento , Complejos Prematuros Ventriculares/prevención & control , Adulto JovenRESUMEN
RATIONALE: ß-Adrenergic receptor stimulation produces sarcoplasmic reticulum Ca(2+) overload and delayed afterdepolarizations in isolated ventricular myocytes. How delayed afterdepolarizations are synchronized to overcome the source-sink mismatch and produce focal arrhythmia in the intact heart remains unknown. OBJECTIVE: To determine whether local ß-adrenergic receptor stimulation produces spatiotemporal synchronization of delayed afterdepolarizations and to examine the effects of tissue geometry and cell-cell coupling on the induction of focal arrhythmia. METHODS AND RESULTS: Simultaneous optical mapping of transmembrane potential and Ca(2+) transients was performed in normal rabbit hearts during subepicardial injections (50 µL) of norepinephrine (NE) or control (normal Tyrode's solution). Local NE produced premature ventricular complexes (PVCs) from the injection site that were dose-dependent (low-dose [30-60 µmol/L], 0.45±0.62 PVCs per injection; high-dose [125-250 µmol/L], 1.33±1.46 PVCs per injection; P<0.0001) and were inhibited by propranolol. NE-induced PVCs exhibited abnormal voltage-Ca(2+) delay at the initiation site and were inhibited by either sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase inhibition or reduced perfusate [Ca(2+)], which indicates a Ca(2+)-mediated mechanism. NE-induced PVCs were more common at right ventricular than at left ventricular sites (1.48±1.50 versus 0.55±0.89, P<0.01), and this was unchanged after chemical ablation of endocardial Purkinje fibers, which suggests that source-sink interactions may contribute to the greater propensity to right ventricular PVCs. Partial gap junction uncoupling with carbenoxolone (25 µmol/L) increased focal activity (2.18±1.43 versus 1.33±1.46 PVCs per injection, P<0.05), which further supports source-sink balance as a critical mediator of Ca(2+)-induced PVCs. CONCLUSIONS: These data provide the first experimental demonstration that localized ß-adrenergic receptor stimulation produces spatiotemporal synchronization of sarcoplasmic reticulum Ca(2+) overload and release in the intact heart and highlight the critical nature of source-sink balance in initiating focal arrhythmias.
Asunto(s)
Agonistas Adrenérgicos beta , Comunicación Celular , Miocitos Cardíacos/metabolismo , Norepinefrina , Receptores Adrenérgicos beta/metabolismo , Complejos Prematuros Ventriculares/inducido químicamente , Potenciales de Acción , Agonistas Adrenérgicos beta/administración & dosificación , Antagonistas Adrenérgicos beta/administración & dosificación , Animales , Señalización del Calcio , Ablación por Catéter , Comunicación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Uniones Comunicantes/metabolismo , Inyecciones , Masculino , Miocitos Cardíacos/efectos de los fármacos , Norepinefrina/administración & dosificación , Perfusión , Propranolol/administración & dosificación , Ramos Subendocárdicos/metabolismo , Ramos Subendocárdicos/cirugía , Conejos , Receptores Adrenérgicos beta/efectos de los fármacos , Retículo Sarcoplasmático/metabolismo , Factores de Tiempo , Complejos Prematuros Ventriculares/metabolismo , Complejos Prematuros Ventriculares/fisiopatología , Complejos Prematuros Ventriculares/prevención & control , Imagen de Colorante Sensible al VoltajeRESUMEN
The root extract of Hemidesmus indicus (Linn.) R. Br. (Asclepiadaceae) (HI) was studied for its cardioprotective effect in Langendorff-perfused rat hearts. HI was perfused for 15 min at a concentration of 0.09 g/L prior to 30 min global ischemia/120 min reperfusion (I/R). Recovery of functional parameters, reperfusion arrhythmias, and infarct size (TTC staining) served as the end-points. After 15 min of perfusion with HI, the left ventricular developed pressure (LVdevP) and HR (heart rate) were not altered significantly (p>0.05), as compared with the pre-drug values. During R, HI showed a significantly higher (p<0.05) recovery of LVdevP at nearly all time points. The recovery of maximal rate of pressure development (+dP/dtmax) and left ventricular end-diastolic pressure (LVEDP) at 40 min of R were significantly better than in non-treated controls. There was also a significant reduction in the total number of ventricular premature beats (VPB) and duration of ventricular tachycardia (VT). HI can protect ischemic myocardium against contractile dysfunction and reperfusion-induced arrhythmias and reduce the extent of irreversible tissue damage following I/R in rat hearts.
Asunto(s)
Cardiotónicos/farmacología , Hemidesmus/química , Daño por Reperfusión Miocárdica/complicaciones , Extractos Vegetales/farmacología , Animales , Cardiotónicos/aislamiento & purificación , Frecuencia Cardíaca/efectos de los fármacos , Masculino , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/etiología , Infarto del Miocardio/prevención & control , Raíces de Plantas , Ratas , Ratas Wistar , Taquicardia Ventricular/etiología , Taquicardia Ventricular/prevención & control , Factores de Tiempo , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
BACKGROUND: n-3 (omega-3) Fatty acids are associated with a reduced risk of cardiovascular disease; however, the relation between dietary intake of n-3 fatty acids and ventricular arrhythmias has not been investigated among acute post-myocardial infarction (AMI) patients-a group at elevated risk of malignant arrhythmias. OBJECTIVE: The objective was to examine the association between n-3 fatty acid consumption and ventricular ectopy among AMI patients. DESIGN: In 260 AMI patients, dietary intake of n-3 fatty acids was assessed by using the Harvard food-frequency questionnaire, and ventricular ectopy was estimated from 24-h electrocardiograph recordings. RESULTS: A greater intake of n-3 fatty acids (eicosapentaenoic acid + docosahexaenoic acid + docosapentaenoic acid + alpha-linolenic acid) was associated with lower ventricular ectopy (beta = -0.35, P = 0.011), and this effect remained after cardiovascular comorbidities were controlled for (beta = -0.47, P = 0.003). Higher concentrations of both marine-based (eicosapentaenoic acid + docosahexaenoic acid) (beta = -0.21, P = 0.060) and plant-based (alpha-linolenic acid) (beta = -0.33, P = 0.024) fatty acids remained associated with lower ventricular ectopy after cardiovascular comorbidities were controlled for. CONCLUSION: These findings extend existing evidence linking n-3 fatty acid consumption to a reduced risk of ventricular arrhythmias by showing that a greater intake of n-3 fatty acids may be associated with low ventricular ectopy among AMI patients.
Asunto(s)
Grasas de la Dieta , Ácidos Grasos Omega-3/metabolismo , Infarto del Miocardio/fisiopatología , Complejos Prematuros Ventriculares/prevención & control , Adulto , Arritmias Cardíacas/epidemiología , Índice de Masa Corporal , Enfermedades Cardiovasculares/prevención & control , Puente de Arteria Coronaria , Estenosis Coronaria/epidemiología , Electrocardiografía , Conducta Alimentaria , Frecuencia Cardíaca/fisiología , Humanos , Persona de Mediana Edad , Infarto del Miocardio/cirugía , Reproducibilidad de los Resultados , Factores de Riesgo , Encuestas y Cuestionarios , Función Ventricular Izquierda , Complejos Prematuros Ventriculares/epidemiologíaRESUMEN
OBJECTIVE: To evaluate the quality of life (QoL), health-care resource utilization, and cost for the patients with premature ventricular contractions (PVCs) by radiofrequency catheter ablation (RFCA). METHODS: RFCA was performed in 58 patients with symptomatic PVCs that were refractory/easy to medication. A 24-hour ambulatory electrocardiographic monitoring, QoL, health-care resources utilization, and cost were assessed at a screening visit and 3 and 12 months after RFCA. RESULTS: RFCA was successfully performed in 56 patients (96.6%). This resulted in a significant improvement in the QoL at 3 and 12 months after the procedure. There were no major complications related to the procedure. Nine patients (15.5%) had residual arrhythmia. Seven of them underwent repeated ablation with successful results. It also improved the QoL and reduced health-care resource utilization and cost. CONCLUSIONS: RFCA is a safe and effective treatment for PVCs, and it is a viable alternative to drugs in the presence of disabling symptoms.
Asunto(s)
Ablación por Catéter/economía , Ablación por Catéter/estadística & datos numéricos , Costos de la Atención en Salud/estadística & datos numéricos , Calidad de Vida , Medición de Riesgo/métodos , Complejos Prematuros Ventriculares/economía , Complejos Prematuros Ventriculares/prevención & control , Adulto , Ablación por Catéter/psicología , China/epidemiología , Análisis Costo-Beneficio , Femenino , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/economía , Complicaciones Posoperatorias/epidemiología , Factores de Riesgo , Resultado del Tratamiento , Complejos Prematuros Ventriculares/epidemiología , Complejos Prematuros Ventriculares/psicologíaRESUMEN
n-3 Fatty acids may protect against heart disease mortality by preventing fatal arrhythmias. Underlying effects on cardiac electrophysiology may be demonstrable in the standard electrocardiogram (ECG) and provide insight into the mechanism. Therefore, we investigated the effect of dietary n-3 fatty acids on heart-rate-corrected QT interval, T-loop width, spatial QRS-T angle and spatial U-wave amplitude in patients with frequent premature ventricular complexes. Seventy-four patients received either capsules providing 1.5 g n-3 fatty acids daily or placebo for approximately 14 weeks. ECG were recorded before and after intervention. None of the ECG characteristics was significantly affected by treatment. The present results do not provide additional support for the hypothesis that n-3 fatty acids prevent cardiac arrhythmia through generic electrophysiologic effects on heart cell membranes. However, we cannot exclude effects of n-3 fatty acids on clinical relevant endpoints that are not easily detected by prior changes in the ECG.
Asunto(s)
Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Aceites de Pescado/administración & dosificación , Complejos Prematuros Ventriculares/prevención & control , Anciano , Dieta , Método Doble Ciego , Electrocardiografía/métodos , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , RecurrenciaRESUMEN
BACKGROUND: A large body of evidence suggests that n-3 fatty acids from fish prevent fatal heart disease. They may be an effective and safe alternative to drug treatment for reducing the risk of arrhythmia and sudden cardiac death. OBJECTIVE: We investigated the effect of n-3 fatty acids on heart rate and premature ventricular complexes (PVCs), a common form of arrhythmia that may trigger arrhythmias that are more life-threatening. DESIGN: Patients (n=84) with >or=1440 PVCs/24 h in a previous Holter recording were randomly assigned to receive 1.5 g/d of either n-3 fatty acids or placebo. Two 24-h Holter recordings were made at baseline, and 2 were made after an intervention of approximately 14 wk. RESULTS: Treatment did not significantly affect the number of PVCs. The number decreased in the fish-oil group by 867/24 h more than it decreased in placebo group (95% CI: -3187, 1453). However, the mean 24-h heart rate was significantly affected, decreasing in the fish-oil group by a mean of 2.1 beats/min more than it decreased in the placebo group (95% CI: -3.9, -0.3). CONCLUSIONS: Supplementation with 1.5 g n-3 fatty acids/d from fish does not substantially suppress the number of PVCs in a patient population with frequent PVCs. However, n-3 fatty acids decreased heart rate by 2.1 beats/min, a significant decrease that predicts a lower risk of sudden death.
Asunto(s)
Ácidos Grasos Omega-3/uso terapéutico , Frecuencia Cardíaca/efectos de los fármacos , Complejos Prematuros Ventriculares/tratamiento farmacológico , Anciano , Animales , Antiarrítmicos/administración & dosificación , Antiarrítmicos/uso terapéutico , Muerte Súbita Cardíaca/prevención & control , Suplementos Dietéticos , Ácidos Docosahexaenoicos/administración & dosificación , Ácidos Docosahexaenoicos/uso terapéutico , Método Doble Ciego , Ácido Eicosapentaenoico/administración & dosificación , Ácido Eicosapentaenoico/uso terapéutico , Electrocardiografía Ambulatoria , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Aceites de Pescado/administración & dosificación , Aceites de Pescado/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Complejos Prematuros Ventriculares/epidemiología , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
BACKGROUND: The aim of the present study was to determine whether repeated 60 degrees C sauna treatment improves cardiac arrhythmias in chronic heart failure (CHF) patients, because ventricular arrhythmias are an important therapeutic target in CHF. METHODS AND RESULTS: Thirty patients (59+/-3 years) with New York Heart Association functional class II or III CHF and at least 200 premature ventricular contractions (PVCs)/24 h assessed by 24-h Holter recordings were studied. They were randomized into sauna-treated (n=20) or non-treated (n=10) groups. The sauna-treated group underwent a 2-week program of a daily 60 degrees C far infrared-ray dry sauna for 15 min, followed by 30 min bed rest with blankets, for 5 days per week. Patients in the non-treated group had bed rest in a temperature-controlled room (24 degrees C) for 45 min. The total numbers of PVCs/24 h in the sauna-treated group decreased compared with the non-treated group [848+/-415 vs 3,097+/-1,033/24 h, p<0.01]. Heart rate variability (SDNN, standard deviation of normal-to-normal beat interval) increased [142+/-10 (n=16) vs 112+/-11 ms (n=8), p<0.05] and plasma brain natriuretic peptide concentrations decreased [229+/-54 vs 419+/-110 pg/ml, p<0.05] in the sauna-treated group compared with the non-treated group. CONCLUSION: Repeated sauna treatment improves ventricular arrhythmias in patients with CHF.
Asunto(s)
Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/terapia , Gasto Cardíaco Bajo/complicaciones , Baño de Vapor , Disfunción Ventricular/fisiopatología , Disfunción Ventricular/terapia , Adulto , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiología , Enfermedad Crónica , Ecocardiografía , Electrocardiografía Ambulatoria , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Neurotransmisores/sangre , Radiografía Torácica , Retratamiento , Factores de Tiempo , Disfunción Ventricular/diagnóstico , Disfunción Ventricular/etiología , Complejos Prematuros Ventriculares/diagnóstico , Complejos Prematuros Ventriculares/prevención & controlAsunto(s)
Arritmias Cardíacas/prevención & control , Suplementos Dietéticos , Ácidos Grasos Omega-3/farmacología , Corazón/efectos de los fármacos , Animales , Arritmias Cardíacas/mortalidad , Arritmias Cardíacas/fisiopatología , Técnicas de Cultivo de Célula , Modelos Animales de Enfermedad , Perros , Aceites de Pescado/farmacología , Cobayas , Haplorrinos , Frecuencia Cardíaca , Canales Iónicos , Bombas Iónicas , Metaanálisis como Asunto , Contracción Miocárdica , Oportunidad Relativa , Técnicas de Cultivo de Órganos , Conejos , Ratas , Medición de Riesgo , Porcinos , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/fisiopatología , Fibrilación Ventricular/prevención & control , Complejos Prematuros Ventriculares/fisiopatología , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
The aim of this study was to assess the cardiovascular effects of a selective phosphodiesterase 5 inhibitor ER-118585, 4-[(3-chloro-4-methoxybenzyl)amino]-1-(2-hydroxy-7-azaspiro[3.5]non-7-yl)-6-phthalazinecarbonitrile monohydrochloride. The present results indicated that 1) ER-118585 significantly inhibited the human ether-a-go-go related gene (HERG) tail current at 10 nM and above with an IC(50) value of 40.7 nM in human embryonic kidney 293 cells transfected with HERG cDNA; 2) ER-118585 at 100 and 1000 nM significantly increased the action potential duration (APD) at 50% and 90% repolarization in isolated papillary muscles of guinea pig; and 3) intravenous infusion of ER-118585 at 10 microg/kg/min significantly prolonged the QT interval by 10.5+/-1.6% from 281+/-2 ms to 311+/-6 ms in six anesthetized dogs subjected to atrial pacing. In consideration of both the plasma concentration of ER-118585 (984+/-78 nM, n=3) and its protein binding fraction (99.0+/-0.1%, n=5), the free plasma concentration was estimated at 9.8+/-0.8 nM, which is consistent with the minimum concentration of HERG current inhibition. In conclusion, these evaluation methods demonstrated that ER-118585 could prolong the QT interval via APD prolongation, attributable to the inhibition of the HERG potassium current.
Asunto(s)
Evaluación Preclínica de Medicamentos , Inhibidores de Fosfodiesterasa/farmacología , Hidrolasas Diéster Fosfóricas/efectos de los fármacos , Ftalazinas/farmacología , Compuestos de Espiro/farmacología , 3',5'-GMP Cíclico Fosfodiesterasas , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Estimulación Cardíaca Artificial , Enfermedades Cardiovasculares/tratamiento farmacológico , Línea Celular , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5 , Perros , Relación Dosis-Respuesta a Droga , Electrocardiografía , Electrofisiología , Cobayas , Humanos , Infusiones Intravenosas , Riñón/citología , Síndrome de QT Prolongado/inducido químicamente , Síndrome de QT Prolongado/genética , Síndrome de QT Prolongado/prevención & control , Masculino , Músculos Papilares/efectos de los fármacos , Músculos Papilares/fisiología , Técnicas de Placa-Clamp , Inhibidores de Fosfodiesterasa/efectos adversos , Inhibidores de Fosfodiesterasa/sangre , Hidrolasas Diéster Fosfóricas/metabolismo , Piperidinas/farmacología , Canales de Potasio con Entrada de Voltaje/antagonistas & inhibidores , Canales de Potasio con Entrada de Voltaje/efectos de los fármacos , Canales de Potasio con Entrada de Voltaje/genética , Unión Proteica , Piridinas/farmacología , Transfección/métodos , Función Ventricular/efectos de los fármacos , Función Ventricular/genética , Función Ventricular/fisiología , Complejos Prematuros Ventriculares/tratamiento farmacológico , Complejos Prematuros Ventriculares/genética , Complejos Prematuros Ventriculares/prevención & controlRESUMEN
This study was designed to assess the efficacy and safety of berberine for chronic congestive heart failure (CHF). One hundred fifty-six patients with CHF and >90 ventricular premature complexes (VPCs) and/or nonsustained ventricular tachycardia (VT) on 24-hour Holter monitoring were randomly divided into 2 groups. All patients were given conventional therapy for CHF, consisting of angiotensin-converting enzyme inhibitors, digoxin, diuretics, and nitrates. Patients in the treatment group (n = 79) were also given berberine 1.2 to 2.0 g/day. The remaining 77 patients were given placebo. Symptoms, a 6-minute walk test, left ventricular (LV) ejection fraction (EF), frequency and complexity of VPCs, and quality of life were assessed after 8 weeks of treatment and during a mean 24-month follow-up. After treatment with berberine, there was a significantly greater increase in LVEF, exercise capacity, improvement of the dyspnea-fatigue index, and a decrease of frequency and complexity of VPCs compared with the control group. There was a significant decrease in mortality in the berberine-treated patients during long-term follow-up (7 patients receiving treatment died vs 13 on placebo, p <0.02). Proarrhythmia was not observed, and there were no apparent side effects. Thus, berberine improved quality of life and decreased VPCs and mortality in patients with CHF.