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2.
Korean Circ J ; 49(10): 960-972, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31074229

RESUMO

BACKGROUND AND OBJECTIVES: Acute myocardial infarction-related heart failure (HF) is associated with poor outcome. This study was designed to investigate the usefulness of global longitudinal strain (GLS), global circumferential strain (GCS) and mean longitudinal strain of left anterior descending artery territory (LSant) measured by 2-dimensional speckle tracking echocardiography (2D STE) in prediction of acute anterior wall ST-segment elevation myocardial infarction (ant-STEMI)-related HF. METHODS: A total of 171 patients with ant-STEMI who underwent successful primary coronary intervention and had available 2D STE data were enrolled. Patients were divided into 3 groups: in-hospital HF, post-discharge HF, and no-HF groups. RESULTS: In-hospital and post-discharge HF developed in 39 (22.8%) and 13 (7.6%) of patients, respectively and 113 patients (69.6%) remained without HF. Multivariate analysis showed that GLS was the only factor significantly associated with the development of in-hospital HF. For post-discharge HF, LSant was the only independent predictor. Other echocardiographic or laboratory parameters did not show independent association with the development of ant-STEMI-related HF. CONCLUSIONS: GLS is a powerful echocardiographic parameter related to development of in-hospital HF and LSant was significantly associated with post-discharge HF in patients with successfully reperfused ant-STEMI.

3.
Korean J Intern Med ; 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30808127

RESUMO

Background/Aims: Pheochromocytoma and paraganglioma (PPGL) are catecholamine-producing tumors that can cause blood pressure (BP) elevation and cardiovascular complications. Clinical presentation of these tumors may be changed through widespread use of imaging studies, which enables detection of PPGLs before onset of symptoms. We investigated clinical profiles of patients with surgically resected PPGLs. Methods: From 2005 to 2017, 111 consecutive patients with surgically resected PPGLs in two tertiary hospitals in Korea were studied. Results: Mean age was 52 ± 16 years, 57 patients (51.4%) were male and 54 (48.6%) were hypertensive. Twenty-nine PPGLs (26.1%) were extra-adrenal paragangliomas. Sixteen (14.4%) and seven patients (6.3%) (Group 1, n = 23) were diagnosed during work-up of hypertension and transient cardiomyopathy respectively, and the remainder (Group 2, n = 88) were incidentalomas detected during routine abdominal imaging. Patients in the Group 1 were younger and more frequently symptomatic, and had higher BPs, heart rates and levels of urinary catecholamines than those in the Group 2. Paragangliomas were less frequent and secretion of epinephrine and metanephrine was more predominant in the Group 1 than in Group 2. After the surgical resections, 18.2% of patients still needed antihypertensive medications. Conclusions: Out of 111 patients with surgically resected PPGLs, 88 (79.3%) were diagnosed as incidentalomas. Seven patients presented with transient cardiomyopathy and 16 with hypertension. Tumor location and secretion of catecholamine may vary depending on the presence of symptoms.

4.
Am J Trop Med Hyg ; 97(5): 1316-1318, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29016300

RESUMO

To investigate the relationship between heart rate and temperature, we examined 493 febrile patients with documented disease. These patients were diagnosed serologically and analyzed retrospectively: 337 (68.4%) responded to fever with increased heart rate < 10 beats/minute/°C (relative bradycardia [RB]), and 156 patients had a heart rate response ≥ 10 beats/minute/°C (general heart rate increase [GHRI]). The RB group had a higher median resting heart rate and lower heart rate at maximum temperature than the GHRI group. Despite differences in heart rate response, no significant differences were seen in clinical outcomes (acute kidney injury, systemic inflammatory response syndrome (SIRS), and death). We concluded that most patients with scrub typhus presented with RB. In scrub typhus infection, RB can be included as one of the clinical features for differential diagnosis from other infectious diseases.


Assuntos
Bradicardia/diagnóstico , Tifo por Ácaros/diagnóstico , Idoso , Temperatura Corporal , Bradicardia/complicações , Diagnóstico Diferencial , Feminino , Febre/diagnóstico , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tifo por Ácaros/complicações
5.
Pacing Clin Electrophysiol ; 40(2): 162-174, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28000227

RESUMO

BACKGROUND: The role of J-waves in the pathogenesis of ventricular fibrillation (VF) occurring in structurally normal hearts is important. METHODS: We evaluated 127 patients who received an implantable cardioverter-defibrillator (ICD) for Brugada syndrome (BS, n = 53), early repolarization syndrome (ERS, n = 24), and patients with unknown or deferred diagnosis (n = 50). Electrocardiography (ECG), clinical characteristics, and ICD data were analyzed. RESULTS: J-waves were found in 27/50 patients with VF of unknown/deferred diagnosis. The J-waves were reminiscent of those seen in BS or ERS, and this subgroup of patients was termed variants of ERS and BS (VEB). In 12 VEB patients, the J/ST/T-wave morphology was coved, although amplitudes were <0.2 mV. In 15 patients, noncoved-type J/ST/T-waves were present in the right precordial leads. In the remaining 23 patients, no J-waves were identified. VEB patients exhibited clinical characteristics similar to those of BS and ERS patients. Phenotypic transition and overlap were observed among patients with BS, ERS, and VEB. Twelve patients with BS had background inferolateral ER, while five ERS patients showed prominent right precordial J-waves. Patients with this transient phenotype overlap showed a significantly lower shock-free survival than the rest of the study patients. CONCLUSIONS: VEB patients demonstrate ECG phenotype similar to but distinct from those of BS and ERS. The spectral nature of J-wave morphology/distribution and phenotypic transition/overlap suggest a common pathophysiologic background in patients with VEB, BS, and ERS. Prognostic implication of these ECG variations requires further investigation.


Assuntos
Síndrome de Brugada/classificação , Síndrome de Brugada/diagnóstico , Eletrocardiografia/métodos , Infarto do Miocárdio com Supradesnível do Segmento ST/classificação , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Heart ; 102(19): 1558-65, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27207979

RESUMO

OBJECTIVE: Hypothermia can induce ECG J waves. Recent studies suggest that J waves may be associated with ventricular fibrillation (VF) in patients with structurally normal hearts. However, little is known about the ECG features, clinical significance or arrhythmogenic potentials of therapeutic hypothermia (TH)-induced J waves. METHODS: We analysed ECGs from 240 patients who underwent TH at six major university hospitals in Korea between August 2010 and December 2013. The prevalence, amplitudes and distributions of the J waves and the development of malignant arrhythmia were analysed. RESULTS: The average patient body temperature was 33.5±1.0°C during TH. J waves were observed in 98 patients (40.8%). They were newly developed in 91 cases, and pre-existing J waves were augmented in seven patients. J waves during TH were primarily observed in leads II, III, aVF and V4-6. The average amplitude of the J waves was 0.239±0.152 mV. There were four VF events during TH. These events occurred in three patients who were finally diagnosed with Brugada syndrome, idiopathic VF or early repolarisation syndrome, respectively, and in one patient with non-cardiac aetiology (asphyxia). CONCLUSIONS: J waves were recorded in about 40% of the patients who received TH. They were most frequently observed in the inferior limb leads or lateral precordial leads. Life-threatening VF occurred only rarely (1.7%) during TH and were mainly observed in patients with primary arrhythmic disorder. Although a causal relationship between TH-induced J waves and VF remains unknown, administering TH to this potentially susceptible, high-risk population may require careful attention.


Assuntos
Regulação da Temperatura Corporal , Síndrome de Brugada/diagnóstico , Eletrocardiografia , Parada Cardíaca/terapia , Sistema de Condução Cardíaco/fisiopatologia , Hipotermia Induzida/efeitos adversos , Ressuscitação/efeitos adversos , Fibrilação Ventricular/diagnóstico , Potenciais de Ação , Adulto , Idoso , Síndrome de Brugada/etiologia , Síndrome de Brugada/fisiopatologia , Feminino , Parada Cardíaca/diagnóstico , Parada Cardíaca/fisiopatologia , Frequência Cardíaca , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , República da Coreia , Ressuscitação/métodos , Fatores de Risco , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/fisiopatologia
7.
Korean Circ J ; 46(2): 147-53, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27014344

RESUMO

BACKGROUND AND OBJECTIVES: Wall shear stress contributes to atherosclerosis progression and plaque rupture. There are limited studies for statin as a major contributing factor on whole blood viscosity (WBV) in patients with acute coronary syndrome (ACS). This study investigates the effect of statin on WBV in ACS patients. SUBJECTS AND METHODS: We prospectively enrolled 189 consecutive patients (mean age, 61.3±10.9 years; 132 males; ST-segment elevation myocardial infarction, n=52; non-ST-segment elevation myocardial infarction, n=84; unstable angina n=53). Patients were divided into two groups (group I: previous use of statins for at least 3 months, n=51; group II: statin-naïve patients, n=138). Blood viscosities at shear rates of 1 s-1 (diastolic blood viscosity; DBV) and 300 s-1 (systolic blood viscosity; SBV) were measured at baseline and one month after statin treatment. Rosuvastatin was administered to patients after enrollment (mean daily dose, 16.2±4.9 mg). RESULTS: Baseline WBV was significantly higher in group II ([SBV: group I vs group II, 40.8±5.9 mP vs. 44.2±7.4 mP, p=0.003], [DBV: 262.2±67.8 mP vs. 296.9±76.0 mP, p=0.002]). WBV in group II was significantly lower one month after statin treatment ([SBV: 42.0±4.7 mP, p=0.012, DBV: 281.4±52.6 mP, p=0.044]). However, low-density lipoprotein cholesterol level was not associated with WBV in both baseline (SBV: R2=0.074, p=0.326; DBV: R2=0.073, p=0.337) and after one month follow up (SBV: R2=0.104, p=0.265; DBV: R2=0.112, p=0.232). CONCLUSION: Previous statin medication is an important determinant in lowering WBV in patients with ACS. However, one month of rosuvastatin decreased WBV in statin-naïve ACS patients.

8.
Korean Circ J ; 45(2): 149-57, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25810737

RESUMO

BACKGROUND AND OBJECTIVES: Recent studies showed that, in addition to parasympathetic nerves, cervical vagal nerves contained significant sympathetic nerves. We hypothesized that cervical vagal nerve stimulation (VNS) may capture the sympathetic nerves within the vagal nerve and activate the stellate ganglion. MATERIALS AND METHODS: We recorded left stellate ganglion nerve activity (SGNA), left thoracic vagal nerve activity (VNA), and subcutaneous electrocardiogram in seven dogs during left cervical VNS with 30 seconds on-time and 30 seconds off time. We then compared the SGNA between VNS on and off times. RESULTS: Cervical VNS at moderate (0.75 mA) output induced large SGNA, elevated heart rate (HR), and reduced HR variability, suggesting sympathetic activation. Further increase of the VNS output to >1.5 mA increased SGNA but did not significantly increase the HR, suggesting simultaneous sympathetic and parasympathetic activation. The differences of integrated SGNA and integrated VNA between VNS on and off times (ΔSGNA) increased progressively from 5.2 mV-s {95% confidence interval (CI): 1.25-9.06, p=0.018, n=7} at 1.0 mA to 13.7 mV-s (CI: 5.97-21.43, p=0.005, n=7) at 1.5 mA. The difference in HR (ΔHR, bpm) between on and off times was 5.8 bpm (CI: 0.28-11.29, p=0.042, n=7) at 1.0 mA and 5.3 bpm (CI 1.92 to 12.61, p=0.122, n=7) at 1.5 mA. CONCLUSION: Intermittent cervical VNS may selectively capture the sympathetic components of the vagal nerve and excite the stellate ganglion at moderate output. Increasing the output may result in simultaneously sympathetic and parasympathetic capture.

9.
Heart Rhythm ; 12(3): 498-505, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25460857

RESUMO

BACKGROUND: Predictors of torsades de pointes (TdP) in bradyarrhythmia-induced acquired long QT syndrome are not well defined. OBJECTIVE: The purpose of this study was to search for electrocardiographic (ECG) TdP predictors in patients with acquired atrioventricular block (AVB) and QT prolongation. METHODS: We analyzed 12-lead ECGs from 20 patients (15 females, age 65.9 ± 15.6 years) with TdP episodes from among 898 AVB patients (2.2%) in 3 tertiary hospitals. The ECG repolarization parameters in TdP patients were compared with those of 80 age- and sex-matched control AVB patients with no TdP episodes. RESULTS: TdP was initiated by premature ventricular complexes with a long-short sequence of activation. The average cycle length of the long sequence was 1289.9 ± 228.9 ms and was 2.3 ± 0.6 times longer than the cycle length of the short sequence. TdP patients had a significantly longer mean QT interval (716.4 ± 98.9 ms vs 523.2 ± 91.3 ms, P = .001), mean T peak to end interval (334.2 ± 59.1 ms vs 144.0 ± 73.7 ms, P = .001) and a higher T peak to end interval/QT ratio (0.49 ± 0.09 vs 0.27 ± 0.11, P = .001) compared with non-TdP controls. TdP patients showed a higher prevalence of notched T waves in which T2 was at least 3 mm taller than T1 (45.0% vs 1.3%, P = .001), triphasic T waves (30.0% vs 1.3%, P = .001), reversed asymmetry (20.0% vs 0%, P = .001), and T-wave alternans (35.0% vs 0%, P = .001). An algorithm combining these morphologic parameters was able to differentiate TdP patients from non-TdP patients with high sensitivity (85.0%) and specificity (97.5%). CONCLUSION: An algorithm combining specific T-wave morphologies was useful for identifying patients with AVB who are at risk for developing TdP.


Assuntos
Algoritmos , Bloqueio Atrioventricular/complicações , Eletrocardiografia/métodos , Síndrome do QT Longo/complicações , Torsades de Pointes/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Bloqueio Atrioventricular/fisiopatologia , Estudos de Casos e Controles , Feminino , Humanos , Síndrome do QT Longo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Torsades de Pointes/etiologia , Torsades de Pointes/fisiopatologia
10.
J Cardiovasc Electrophysiol ; 26(1): 70-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25091691

RESUMO

INTRODUCTION: We tested the hypothesis that subcutaneous nerve activity (SCNA) of the thorax correlates with the stellate ganglion nerve activity (SGNA) and can be used to estimate the sympathetic tone. METHODS AND RESULTS: We implanted radio transmitters in 11 ambulatory dogs to record left SGNA, left thoracic vagal nerve activity (VNA), and left thoracic SCNA, including 3 with simultaneous video monitoring and nerve recording. Two additional dogs were studied under general anesthesia with apamin injected into the right stellate ganglion while the right SGNA and the right SCNA were recorded. There was a significant positive correlation between integrated SGNA (iSGNA) and integrated SCNA (iSCNA) in the first 7 ambulatory dogs, with correlation coefficient of 0.70 (95% confidence interval [CI] 0.61-0.84, P < 0.05 for each dog). Tachycardia episodes (heart rate exceeding 150 bpm for ≥3 seconds) were invariably preceded by SGNA and SCNA. There was circadian variation of both SCNA and SGNA. Crosstalk was ruled out because SGNA, VNA, and SCNA bursts had different timing and activation patterns. In an eighth dog, closely spaced bipolar subcutaneous electrodes also recorded SCNA, but with reduced signal to noise ratio. Video monitoring in additional 3 dogs showed that movement was not a cause of high frequency SCNA. The right SGNA correlated strongly with right SCNA and heart rate in 2 anesthetized dogs after apamin injection into the right stellate ganglion. CONCLUSIONS: SCNA recorded by bipolar subcutaneous electrodes correlates with the SGNA and can be used to estimate the sympathetic tone.


Assuntos
Locomoção , Gânglio Estrelado/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Taquicardia/diagnóstico , Taquicardia/fisiopatologia , Telemetria , Nervos Torácicos/fisiopatologia , Animais , Biomarcadores/análise , Ritmo Circadiano , Modelos Animais de Doenças , Cães , Frequência Cardíaca , Imuno-Histoquímica , Valor Preditivo dos Testes , Processamento de Sinais Assistido por Computador , Sistema Nervoso Simpático/enzimologia , Taquicardia/enzimologia , Telemetria/instrumentação , Nervos Torácicos/enzimologia , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/análise , Nervo Vago/fisiopatologia , Gravação em Vídeo
11.
Heart Rhythm ; 11(2): 307-13, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24275433

RESUMO

BACKGROUND: The relationship between cardiac autonomic nerve activity and blood pressure (BP) changes in ambulatory dogs is unclear. OBJECTIVE: The purpose of this study was to test the hypotheses that simultaneous termination of stellate ganglion nerve activity (SGNA) and vagal nerve activity (VNA) predisposes to spontaneous orthostatic hypotension and that specific ß2-adrenoceptor blockade prevents the hypotensive episodes. METHODS: We used a radiotransmitter to record SGNA, VNA, and BP in eight ambulatory dogs. Video imaging was used to document postural changes. RESULTS: Of these eight dogs, five showed simultaneous sympathovagal discharges in which the minute-by-minute integrated SGNA correlated with integrated VNA in a linear pattern (group 1). In these dogs, abrupt termination of simultaneous SGNA-VNA at the time of postural changes (as documented by video imaging) was followed by abrupt (>20 mm Hg over four beats) drops in BP. Dogs without simultaneous on/off firing (group 2) did not have drastic drops in pressure. ICI-118,551 (ICI, a specific ß2-blocker) infused at 3 µg/kg/h for 7 days significantly increased BP from 126 mm Hg (95% confidence interval 118-133) to 133 mm Hg (95% confidence interval 125-141; P = .0001). The duration of hypotension (mean systolic BP <100 mm Hg) during baseline accounted for 7.1% of the recording. The percentage was reduced by ICI to 1.3% (P = .01). CONCLUSION: Abrupt simultaneous termination of SGNA-VNA was observed at the time of orthostatic hypotension in ambulatory dogs. Selective ß2-adrenoceptor blockade increased BP and reduced the duration of hypotension in this model.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/fisiologia , Coração/inervação , Antagonistas de Receptores Adrenérgicos beta 2/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Cães , Feminino , Hipotensão Ortostática/etiologia , Hipotensão Ortostática/fisiopatologia , Hipotensão Ortostática/prevenção & controle , Masculino , Gânglio Estrelado/fisiologia , Nervo Vago/fisiologia
12.
Heart ; 99(24): 1818-24, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24150663

RESUMO

OBJECTIVE: Electrocardiographic markers identifying malignant forms of early repolarisation (ER) from ER of normal variants are of prime clinical importance. We compared the ECG parameters of ER patterns in patients with early repolarisation syndrome (ERS) proximate to the ventricular fibrillation (VF) episodes, remote from the events and those with normal controls with ER. DESIGN: A retrospective, case-control study. SETTING: University hospital. PATIENTS: This study included 12 patients with ERS and 36 age-matched, gender-matched controls with ER. MAIN OUTCOME MEASURES: Dynamic change of J-wave. RESULTS: The highest amplitude of J-wave, sum of the J-wave amplitudes or the number of leads with ER showed a dramatic change during the perievent period. J-wave amplitudes (2.0±1.3 vs 4.0±1.7, p=0.004) and the number of leads with ER (3.3±1.7 vs 5.3±2.0, p=0.021) were significantly higher around the time of VF. In particular, the characteristic morphology of 'giant' (wide, >80 ms) J-waves were observed during the perievent period in 5/12 patients with ERS. However, there were no significant differences in the electrocardiographic parameters of ER pattern remote from VF events between the patients with ERS and normal control subjects with ER. CONCLUSIONS: Although the extent of and amplitude of J-wave or ST segment elevation (STE) increased significantly around VF episodes, the electrocardiographic parameters of ER remote from VF episodes were not significantly different from those of normal controls. The narrow time window of these ECG changes limits early detection of ER patients at risk of developing VF or sudden cardiac death.


Assuntos
Morte Súbita Cardíaca/etiologia , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Fibrilação Ventricular/fisiopatologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Síndrome , Fibrilação Ventricular/complicações , Fibrilação Ventricular/diagnóstico
13.
J Cardiovasc Electrophysiol ; 24(10): 1144-53, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23718850

RESUMO

INTRODUCTION: The apamin-sensitive small-conductance calcium-activated potassium current (IKAS ) is increased in heart failure. It is unknown if myocardial infarction (MI) is also associated with an increase of IKAS . METHODS AND RESULTS: We performed Langendorff perfusion and optical mapping in 6 normal hearts and 10 hearts with chronic (5 weeks) MI. An additional 6 normal and 10 MI hearts were used for patch clamp studies. The infarct size was 25% (95% confidence interval, 20-31) and the left ventricular ejection fraction was 50 (46-54). The rabbits did not have symptoms of heart failure. The action potential duration measured to 80% repolarization (APD80 ) in the peri-infarct zone (PZ) was 150 (142-159) milliseconds, significantly (P = 0.01) shorter than that in the normal ventricles (167 [158-177] milliseconds. The intracellular Ca transient duration was also shorter in the PZ (148 [139-157] milliseconds) than that in normal ventricles (168 [157-180] milliseconds; P = 0.017). Apamin prolonged the APD80 in PZ by 9.8 (5.5-14.1)%, which is greater than that in normal ventricles (2.8 [1.3-4.3]%, P = 0.006). Significant shortening of APD80 was observed at the cessation of rapid pacing in MI but not in normal ventricles. Apamin prevented postpacing APD80 shortening. Patch clamp studies showed that IKAS was significantly higher in the PZ cells (2.51 [1.55-3.47] pA/pF, N = 17) than in the normal cells (1.08 [0.36-1.80] pA/pF, N = 15, P = 0.019). CONCLUSION: We conclude that IKAS is increased in MI ventricles and contributes significantly to ventricular repolarization especially during tachycardia.


Assuntos
Apamina/farmacologia , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , Canais de Potássio Cálcio-Ativados/metabolismo , Potássio/metabolismo , Potenciais de Ação , Animais , Estimulação Cardíaca Artificial , Doença Crônica , Modelos Animais de Doenças , Eletrocardiografia , Feminino , Frequência Cardíaca , Técnicas In Vitro , Cinética , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Técnicas de Patch-Clamp , Perfusão , Coelhos , Volume Sistólico , Taquicardia/metabolismo , Taquicardia/fisiopatologia , Função Ventricular Esquerda
14.
Clin Hemorheol Microcirc ; 55(1): 85-94, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23445630

RESUMO

OBJECTIVES: As most clinical studies measure whole blood viscosity (WBV) from peripheral samples, potential differences in WBV obtained from the coronary arteries are often ignored. This study investigated differences in WBV measured from coronary artery specimens in patients with and without acute coronary syndrome (ACS). METHODS AND RESULTS: Consecutive patients with chest pain who underwent diagnostic coronary angiography were divided into two groups [non-ACS (n = 16), ACS (n = 22)]. The ACS group consisted of unstable angina (n = 13) and acute myocardial infarction (n = 9) patients. Two blood samples were obtained from each patient at the both coronary artery ostia prior to coronary angiography. Low-shear and high-shear blood viscosities (BVs) were measured at shear rates of 1 and 300 s-1, respectively, by a scanning capillary tube viscometer (Bio-Visco Inc., South Korea). Both low-shear and high-shear BVs obtained from peripheral, left and right coronary arteries were not different in both groups. Mean coronary low-shear WBV values obtained in ACS group were 29.2% higher than those in non-ACS group (295.3 ± 87.2 mP vs. 228.5 ± 69.2 mP, p = 0.016). Mean coronary high-shear WBV values obtained in ACS group were 15.6% higher than those in non-ACS group (42.9 ± 10.0 mP vs. 37.1 ± 4.6 mP, p = 0.036). CONCLUSIONS: Direct measurement of WBV from the coronary artery showed no differences with peripheral samples. Future larger studies are needed to clarify our results.


Assuntos
Síndrome Coronariana Aguda/sangue , Adulto , Idoso , Angina Instável/sangue , Viscosidade Sanguínea/fisiologia , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Adulto Jovem
15.
Heart Rhythm ; 10(4): 585-91, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23246597

RESUMO

BACKGROUND: Cervical vagal nerve (CVN) stimulation may improve left ventricular ejection fraction in patients with heart failure. OBJECTIVES: To test the hypothesis that sympathetic structures are present in the CVN and to describe the location and quantitate these sympathetic components of the CVN. METHODS: We performed immunohistochemical studies of the CVN from 11 normal dogs and simultaneously recorded stellate ganglion nerve activity, left thoracic vagal nerve activity, and subcutaneous electrocardiogram in 2 additional dogs. RESULTS: A total of 28 individual nerve bundles were present in the CVNs of the first 11 dogs, with an average of 1.87±1.06 per dog. All CVNs contain tyrosine hydroxylase-positive (sympathetic) nerves, with a total cross-sectional area of 0.97±0.38 mm(2). The sympathetic nerves were nonmyelinated, typically located at the periphery of the nerve bundles and occupied 0.03%-2.80% of the CVN cross-sectional area. Cholineacetyltransferase-positive nerve fibers occupied 12.90%-42.86% of the CVN cross-sectional areas. Ten of 11 CVNs showed tyrosine hydroxylase and cholineacetyltransferase colocalization. In 2 dogs with nerve recordings, we documented heart rate acceleration during spontaneous vagal nerve activity in the absence of stellate ganglion nerve activity. CONCLUSIONS: Sympathetic nerve fibers are invariably present in the CVNs of normal dogs and occupy in average up to 2.8% of the cross-sectional area. Because sympathetic nerve fibers are present in the periphery of the CVNs, they may be susceptible to activation by electrical stimulation. Spontaneous activation of the sympathetic component of the vagal nerve may accelerate the heart rate.


Assuntos
Fibras Adrenérgicas/patologia , Estimulação Elétrica/métodos , Frequência Cardíaca/fisiologia , Gânglio Estrelado/enzimologia , Nervo Vago/patologia , Fibras Adrenérgicas/enzimologia , Fibras Adrenérgicas/fisiologia , Animais , Biópsia por Agulha , Plexo Cervical/patologia , Plexo Cervical/fisiologia , Colina O-Acetiltransferase/metabolismo , Cães , Imuno-Histoquímica , Modelos Animais , Valores de Referência , Sensibilidade e Especificidade , Gânglio Estrelado/patologia , Sistema Nervoso Simpático/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Tirosina 3-Mono-Oxigenase/metabolismo , Nervo Vago/fisiologia
17.
Int J Mol Med ; 30(4): 974-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22797252

RESUMO

In the present study, we investigated the effect of guggulsterone on melanogenesis in B16 melanoma cells and elucidated its possible mechanism of action. The effects of guggulsterone on melanogenesis were determined by assaying melanin synthesis and cellular tyrosinase activity in B16/F10 mouse melanoma cells. Guggulsterone dose-dependently inhibited isobutylmethylxanthine (IBMX)-induced melanogenesis and cellular tyrosinase activity with no cytotoxicity. Decreased melanin biosynthesis was accompanied by the reduced expression of melanogenesis-related genes, such as tyrosinase, microphthalmia-associated transcription factor, tyrosinase-related protein (TRP)-1 and TRP-2. Guggulsterone also inhibited α-melanocyte stimulating hormone- or forskolin-induced increases in melanogenesis, suggesting an action on the cAMP-dependent melanogenic pathway. Co-incubation with chenodeoxycholic acid, a well-known farnesoid-X receptor agonist, did not affect IBMX-induced melanogenesis. These results suggest that guggulsterone exerts a melanogenic inhibitory effect through the downregulation of tyrosinase expression.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Melaninas/metabolismo , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/genética , Monofenol Mono-Oxigenase/genética , Pregnenodionas/farmacologia , Animais , Linhagem Celular Tumoral , Commiphora/química , AMP Cíclico/metabolismo , Melanoma Experimental/metabolismo , Camundongos , Monofenol Mono-Oxigenase/metabolismo
18.
Tex Heart Inst J ; 39(3): 372-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22719147

RESUMO

Catheter ablation of atrial fibrillation that targets complex fractionated electrogram sites has been widely applied in the management of persistent atrial fibrillation. The clinical outcomes of pulmonary vein isolation alone and pulmonary vein isolation plus the use of complex fractionated electrogram-guided ablation (CFEA) have not been fully compared in patients with paroxysmal atrial fibrillation.This prospective study included 70 patients with symptomatic paroxysmal atrial fibrillation that remained inducible after pulmonary vein isolation. For radio-frequency catheter ablation, patients were nonrandomly assigned to a control group (pulmonary vein isolation alone, Group 1, n=35) or a CFEA group (pulmonary vein isolation plus additional CFEA, Group 2, n=35). The times to first recurrence of atrial tachyarrhythmias were compared between the 2 groups.In Group 2, CFEA rendered atrial fibrillation noninducible in 16 patients (45.7%) and converted inducible atrial fibrillation into inducible atrial flutters in 12 patients (34.3%). Atrial fibrillation remained inducible in 7 patients (20%) after the combined ablation procedures. After a mean follow-up of 23 months, freedom from recurrence of atrial tachyarrhythmias was significantly higher in Group 2 than in Group 1 (P=0.037). In Group 1, all of the recurrent tachyarrhythmias were atrial fibrillation, whereas regular tachycardia was the major mechanism of recurrent arrhythmias in Group 2 (atrial tachycardia or atrial flutter in 5 of 6 patients and atrial fibrillation in 1 patient).We found that CFEA after pulmonary vein isolation significantly reduced recurrent atrial tachyarrhythmia and might modify the pattern of arrhythmia recurrence in patients with paroxysmal atrial fibrillation.


Assuntos
Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Veias Pulmonares/cirurgia , Adulto , Idoso , Fibrilação Atrial/fisiopatologia , Flutter Atrial/diagnóstico , Flutter Atrial/etiologia , Estimulação Cardíaca Artificial , Estudos de Casos e Controles , Ablação por Cateter/efeitos adversos , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Veias Pulmonares/fisiopatologia , Recidiva , República da Coreia , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/etiologia , Fatores de Tempo , Resultado do Tratamento
19.
Heart Rhythm ; 9(7): 1125-32, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22387372

RESUMO

BACKGROUND: Na channel blockers are effective in suppressing delayed afterdepolarizations (DADs) in isolated Purkinje fibers. However, in isolated mouse ventricular myocytes lacking calsequestrin, only those Na channel blockers that also inhibit type 2 ryanodine receptor channels were effective against spontaneous Ca elevation (SCaE) and DADs. OBJECTIVE: To test the hypothesis that combined Na channel and type 2 ryanodine receptor channel blocker ((R)-propafenone) is more effective than a Na channel blocker (lidocaine) in suppressing SCaE and DADs in the intact rabbit ventricles. METHODS: We compared (R)-propafenone (3 µmol/L) with lidocaine (50 µmol/L) on SCaE and DADs by using epicardial optical mapping of intracellular calcium (Ca(i)) and membrane voltage in Langendorff-perfused rabbit hearts. SCaE and DADs were induced by rapid pacing trains and isoproterenol (0.3 µmol/L) infusion. One arbitrary unit is equivalent to the Ca transient amplitude of paced beats. RESULTS: SCaEs were observed at the cessation of rapid pacing in all hearts at baseline. (R)-Propafenone nearly completely inhibited DADs and SCaE (0.04 arbitrary units [95% confidence interval 0.02-0.06] vs 0.23 arbitrary units [95% confidence interval 0.18-0.28] at baseline; n = 6 hearts; P <.001). Lidocaine also significantly reduced the SCaE but was significantly (P <.05) less effective than (R)-propafenone. Both drugs increased the rise time of action potential upstroke and reduced conduction velocity to a similar extent, suggesting a significant inhibition of I(Na). CONCLUSIONS: Both Na channel blockers significantly reduced tachycardia-induced SCaEs in the rabbit ventricles, but (R)-propafenone was significantly more effective than lidocaine. These data suggest that type 2 ryanodine receptor inhibition potentiates the activity of Na channel blockers against SCaE and DADs in the intact hearts.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Cálcio/análise , Canal de Liberação de Cálcio do Receptor de Rianodina/efeitos dos fármacos , Potenciais de Ação , Animais , Antiarrítmicos/farmacologia , Estimulação Cardíaca Artificial , Sinergismo Farmacológico , Ventrículos do Coração , Lidocaína/farmacologia , Coelhos
20.
Circ J ; 76(5): 1091-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22333216

RESUMO

BACKGROUND: In typical atrioventricular nodal reentrant tachycardia, radiofrequency (RF) ablation of the slow pathway (SP) is known to change the effective refractory period of the fast pathway (ERP(FP)) after successful RF ablation of the SP. The purpose of this study was to ascertain the mechanism of the ERP(FP) changes after SP ablation by comparing the results of both cryo- and RF ablation. METHODS AND RESULTS: A total of 112 patients were enrolled prospectively and their electrophysiological properties analyzed before and after successful SP ablation. Patients were grouped into cryoablation (n=54) and RF ablation (n=58) groups and each group was subdivided into complete ablation (CG) and modification (MG) based on the presence of the SP after successful ablation. CG was performed in 64 patients: 30 by cryoablation and 34 by RF ablation. In patients who underwent complete SP ablation, the ERP(FP) was shortened significantly after cryoablation (375 ± 74 vs. 281 ± 39 ms, P<0.01), without significant change in the atrio-His (AH) or sinus cycle length (SCL) interval. Similarly, the ERP(FP) was shortened significantly (358 ± 106 vs. 289 ± 84 ms, P=0.01) also after RF ablation without change in AH or SCL interval. CONCLUSIONS: ERP(FP) shortening was observed after complete SP ablation with both cryo- and RF ablation without significant changes in indices of autonomic activity.


Assuntos
Ablação por Cateter/métodos , Criocirurgia/métodos , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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