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1.
J Hum Hypertens ; 22(3): 191-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18046434

RESUMO

Diabetes mellitus (DM) may cause an increase in the inflammatory status and oxidative stress as well as sympathetic nervous system overactivity, even in the absence of any other organic heart disease. We investigated the effect of perindopril, an angiotensin-converting enzyme inhibitor (ACE-i), on indexes of systemic inflammation and oxidative stress in normotensive patients with type 2 DM. We also examined the effect of the drug on the disturbances of left ventricular myocardial adrenergic innervation that may be seen in these patients. We studied 62 normotensive patients with type 2 DM, who were randomized to receive perindopril (n=32) or placebo (n=30). At the start of the study and after 6 months' therapy blood samples were taken to evaluate total peroxides (TP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha), and the patients underwent a (123)I-metaiodobenzylguanidine myocardial scintigraphy study. ACE-i caused a significant reduction in levels of cytokines and TP (P<0.001 for IL-6 and TNF-alpha, P=0.001 for TP). There was also a reduction in total defect score (P<0.001) and the heart to mediastinum ratio at 10 min and 4 h was improved (P<0.001 for both). No significant alterations were observed in the placebo group. Our data indicate that the addition of ACE-i to the medication of normotensive diabetic type 2 patients may improve the disturbed myocardial adrenergic innervation, the systemic inflammatory status and oxidative stress. Our findings indicate the cardioprotective action of ACE-i and suggest that earlier treatment might be appropriate in those patients.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Diabetes Mellitus Tipo 2/complicações , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/inervação , Perindopril/farmacologia , Sistema Nervoso Simpático/efeitos dos fármacos , Distribuição de Qui-Quadrado , Feminino , Humanos , Inflamação/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Estatísticas não Paramétricas
3.
J Am Coll Cardiol ; 33(4): 966-71, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10091823

RESUMO

OBJECTIVES: The purpose of this study was to investigate the efficacy and safety of amiodarone and propafenone in the conversion of chronic atrial fibrillation in a prospective, randomized, placebo-controlled study. BACKGROUND: The effectiveness of amiodarone and propafenone in the treatment of patients with chronic atrial fibrillation has not been adequately studied. METHODS: One hundred one patients (48 men, mean age 64 +/- 9 years) with atrial fibrillation lasting >3 weeks participated in the study. Thirty-four patients received amiodarone (300 mg intravenously over 1 h, followed by 20 mg/kg over the next 24 h plus 600 mg orally, in three doses, for 1 week, then 400 mg/day orally, for three weeks), 32 received propafenone (2 mg/kg intravenously over 15 min, followed by 10 mg/kg over 24 h and then 450 mg/day orally, for one month) and the remaining 35 served as control subjects. All patients received digoxin and anticoagulant treatment as indicated (International Normalized Ratio 2 to 3). RESULTS: Conversion to sinus rhythm was achieved in 16 (47.05%) patients who received amiodarone, in 13 (40.62%) who received propafenone and in none of the control subjects (p < 0.001 for both groups vs. control subjects). Those who converted had smaller atria than those who did not and atrial fibrillation of shorter duration in both the amiodarone and propafenone groups. Treatment was discontinued in one patient of the propafenone group because of significant QRS widening. CONCLUSIONS: Amiodarone and propafenone appear to be safe and equally effective in the termination of chronic atrial fibrillation. Left atrial diameter and arrhythmia duration are independent predictors of conversion.


Assuntos
Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Propafenona/uso terapêutico , Idoso , Amiodarona/efeitos adversos , Antiarrítmicos/efeitos adversos , Doença Crônica , Eletrocardiografia/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propafenona/efeitos adversos , Resultado do Tratamento
4.
J Am Coll Cardiol ; 33(5): 1338-46, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10193736

RESUMO

OBJECTIVES: The purpose of this study was to determine whether scintigraphic myocardial perfusion defects in patients with left bundle branch block (LBBB) and normal coronary arteries are related to abnormalities in coronary flow velocity pattern and/or coronary flow reserve. BACKGROUND: Septal or anteroseptal defects on exercise myocardial perfusion scintigraphy are common in patients with LBBB and normal coronary arteries. METHODS: Thirteen patients (7 men, age 61+/-8 years) with LBBB and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In all patients and in 11 control subjects coronary blood flow parameters were calculated from Doppler measurements of flow velocity in the left anterior descending coronary artery (LAD) before and after adenosine administration. RESULTS: The time to maximum peak diastolic flow velocity was significantly longer both for the seven patients with (134+/-19 ms) and for the six without (136+/-7 ms) exercise perfusion defects than for controls (105+/-12 ms, p < 0.05), whereas the acceleration was slower (170+/-54, 186+/-42 and 279+/-96 cm/s2, respectively, p < 0.05). Coronary flow reserve in the patients with exercise perfusion defects (2.7+/-0.3) was significantly lower than in those without (3.7+/-0.5, p < 0.05) or in the control group (3.4+/-0.5, p < 0.05). CONCLUSIONS: Patients with LBBB have an impairment of early diastolic blood flow in the LAD due to an increase in early diastolic compressive resistance resulting from delayed ventricular relaxation. Furthermore, exercise scintigraphic perfusion defects in these patients are associated with a reduced coronary flow reserve, indicating abnormalities of microvascular function in the same vascular territory.


Assuntos
Bloqueio de Ramo/fisiopatologia , Circulação Coronária , Vasos Coronários , Adenosina , Idoso , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Bloqueio de Ramo/diagnóstico por imagem , Angiografia Coronária , Circulação Coronária/efeitos dos fármacos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/efeitos dos fármacos , Diástole/efeitos dos fármacos , Dipiridamol , Ecocardiografia Doppler , Eletrocardiografia , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão de Fóton Único , Resistência Vascular/efeitos dos fármacos , Vasodilatadores
5.
J Am Coll Cardiol ; 37(1): 124-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11153726

RESUMO

OBJECTIVES: The purposes of this study were to test the specificity of dipyridamole myocardial perfusion scintigraphy in patients with permanent ventricular pacing (PVP) and to evaluate coronary blood flow and reserve in these patients. BACKGROUND: Permanent ventricular pacing is associated with exercise perfusion defects on myocardial scintigraphy in the absence of coronary artery disease (CAD). On the basis of studies in patients with left bundle brunch block, coronary vasodilation with dipyridamole has been proposed as an alternative to exercise testing for detecting CAD in paced patients, but this approach has never been tested. METHODS: Fourteen patients with a PVP and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In these patients and in eight control subjects, coronary flow velocities were measured in the left anterior descending coronary artery (LAD) and in the dominant coronary artery before and after adenosine administration. RESULTS: In the paced patients, coronary flow velocities in the LAD and in the dominant coronary artery were significantly lower than those in the control subjects. In addition, seven patients showed perfusion defects on dipyridamole thallium-201 single-photon emission computed tomography, with a specificity of 50% for this test. The defect-related artery in these patients had lower coronary flow reserve (2.6 +/- 0.5) as compared with those without perfusion defects (3.9 +/- 1.0, p < 0.05) or the control group (3.5 +/- 0.5, p < 0.05). CONCLUSIONS: Permanent ventricular pacing is associated with alterations in regional myocardial perfusion. Furthermore, abnormalities of microvascular flow, as indicated by reduced coronary flow reserve in the defect-related artery, are at least partially responsible for the uncertain specificity of dipyridamole myocardial perfusion scintigraphy.


Assuntos
Circulação Coronária/fisiologia , Isquemia Miocárdica/diagnóstico por imagem , Marca-Passo Artificial , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Bloqueio de Ramo/diagnóstico por imagem , Bloqueio de Ramo/fisiopatologia , Bloqueio de Ramo/terapia , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/fisiopatologia , Diagnóstico Diferencial , Dipiridamol , Teste de Esforço , Feminino , Humanos , Masculino , Microcirculação/fisiopatologia , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologia , Radioisótopos de Tálio
6.
Am J Cardiol ; 79(2): 160-5, 1997 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9193016

RESUMO

The aim of this study was to examine whether the indexes of heart rate variability (HRV) are stable from day-to-day in patients with vasovagal syncope and whether the stability of the HRV indexes is linked with that of the clinical results of the tilt test. Nineteen patients with a history of syncopal episodes and a positive tilt test underwent a second test 1 week later. Of these, 11 (group P-P) also had a positive second test, whereas 8 (group P-N) had a negative second test. Fifteen healthy volunteers served as a control group. Five time domain indexes were derived: the mean of all coupling intervals between normal beats (mean NN), the SD about the mean of all coupling intervals between normal beats (SDNN), the mean of all 5-minute standard deviations of NNs (SD), the proportion of adjacent normal RR intervals differing by >50 ms (pNN50), the root-mean-square of the difference between successive RRs (rMSSD) and the standard deviations of 5-minute mean NN intervals (SDANN). The control group showed good reproducibility of all HRV indexes (slope 0.86 to 0.97). The syncopal patients taken as a whole had significantly less reproducibility than the controls in the pNN50 parameter. This difference was due entirely to the patients in the P-N group, who had a remarkable lack of reproducibility in both the pNN50 and rMSSD measures (slope pNN50, 0.52; rMSSD, 0.78), whereas the P-P group had a reproducibility of all HRV indexes, which was no different from that in controls (slope 0.83 to 1.04). In patients with vasovagal syncope, certain HRV measures that express parasympathetic tone did not show the high reproducibility found in normal subjects. Syncopal patients who lack reproducibility in these HRV parameters also show a lack of reproducibility in the clinical result of tilt testing.


Assuntos
Frequência Cardíaca/fisiologia , Síncope Vasovagal/fisiopatologia , Análise de Variância , Ritmo Circadiano , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Sistema Nervoso Parassimpático/fisiopatologia , Reprodutibilidade dos Testes , Teste da Mesa Inclinada , Fatores de Tempo
7.
Am J Cardiol ; 83(1): 58-61, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-10073786

RESUMO

The efficacy and safety of amiodarone in the conversion of persistent atrial fibrillation (AF) were investigated in a prospective, randomized, controlled study. Of 67 consecutive patients (32 men, mean age 64+/-9 years) with AF lasting >48 hours, 33 received amiodarone and 34 received placebo. Baseline clinical characteristics were similar in the 2 groups. Patients randomized to amiodarone received 300 mg intravenously for 1 hour and then 20 mg/kg for 24 hours. They were also given 600 mg/day orally, divided into 3 doses, for 1 week and thereafter 400 mg/day for 3 weeks. Patients randomized to placebo received an identical amount of saline IV over 24 hours and then oral placebo for 1 month. Conversion to sinus rhythm was achieved in 16 of the 33 patients (48.5%) who received amiodarone and in none of the 34 patients in the placebo group (p <0.001). None of the patients converted to sinus rhythm within the first 3 days. Those who converted had smaller atria than those who did not (diameter 41.9+/-7.2 vs 50.4+/-5.7 mm, p <0.001). Sex, age, baseline heart rate, left ventricular ejection fraction, and the duration of AF did not differ significantly between patients who converted and those who did not. No side effects requiring discontinuation of treatment were observed in either group. Amiodarone, administered both intravenously and orally, appears to be safe and effective in the termination of persistent AF. Left atrial diameter is the sole independent predictor of conversion.


Assuntos
Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Frequência Cardíaca/efeitos dos fármacos , Idoso , Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/fisiopatologia , Fatores de Confusão Epidemiológicos , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Método Simples-Cego , Resultado do Tratamento
8.
Am J Cardiol ; 81(8): 995-8, 1998 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9576159

RESUMO

To compare the safety and efficacy of amiodarone and sotalol in the treatment of patients with recurrent symptomatic atrial fibrillation (AF), 70 patients were entered into a randomized, double-blind study. Of these, 35 received amiodarone and 35 sotalol. There were no significant differences in baseline clinical characteristics between groups. Patients with ejection fraction < 40% or clinically significant heart disease were excluded. Patients randomized to amiodarone began with 800 to 1,600 mg/day for 7 to 14 days orally. After the initial loading phase, the drug dose was tapered to maintenance levels over 7 to 12 days; thereafter, therapy was generally maintained at a dosage of 200 mg/day. The sotalol dosage was 80 to 360 mg twice daily, as tolerated. Follow-up clinical evaluations were conducted at 1, 2, 4, 6, 9, and 12 months. The proportion of patients remaining in sinus rhythm on each agent was calculated for the 2 groups using the Kaplan-Meier method. Ten of the 35 patients who were taking amiodarone developed AF during the 12-month observation period, compared with 21 of the 35 who were taking sotalol (p = 0.008). No significant effect of sex, age, left atrial size, or type of AF could be detected that increased the risk of development of AF. We conclude that both amiodarone and sotalol can be used for the maintenance of normal sinus rhythm in patients with recurrent symptomatic AF but that amiodarone is the more effective of the 2 drugs for this purpose.


Assuntos
Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Sotalol/administração & dosagem , Amiodarona/efeitos adversos , Amiodarona/uso terapêutico , Antiarrítmicos/efeitos adversos , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Método Duplo-Cego , Feminino , Seguimentos , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Segurança , Sotalol/efeitos adversos , Sotalol/uso terapêutico , Volume Sistólico , Resultado do Tratamento
9.
Chest ; 117(6): 1538-45, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10858380

RESUMO

STUDY OBJECTIVES: To investigate the efficacy and safety of amiodarone administered as the drug of first choice in the conversion of atrial fibrillation, regardless of its duration. DESIGN: : Prospective, randomized, controlled clinical study. SETTING: : Tertiary cardiac referral center. PATIENTS: Two-hundred eight consecutive patients (102 men; mean [+/- SD] age, 65 +/- 10 years) with atrial fibrillation. INTERVENTIONS: One-hundred eight patients received amiodarone, and 100 patients received placebo treatment. Patients randomized to amiodarone received 300 mg IV for 1 h, and then 20 mg/kg for 24 h. They were also given 600 mg/d orally, divided into three doses, for 1 week, and thereafter 400 mg/d for 3 weeks. Patients randomized to placebo treatment received an identical amount of saline solution IV over 24 h, and oral placebo treatment for 1 month. MEASUREMENTS AND RESULTS: Baseline clinical characteristics were similar in the two groups. Conversion to sinus rhythm was achieved in 87 of 108 patients (80.05%) who received amiodarone, and in 40 of 100 patients (40%) in the placebo group (p < 0.0001). Statistical analysis showed that the duration of the arrhythmia and the size of the left atrium affected both the likelihood of conversion to sinus rhythm and the time to conversion in both groups. No side effects requiring discontinuation of treatment were observed in either group. CONCLUSIONS: Amiodarone appears to be safe and effective in the termination of atrial fibrillation. However, extreme cases with a large left atrium and long-lasting arrhythmia need long-term therapy.


Assuntos
Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Administração Oral , Adulto , Idoso , Amiodarona/efeitos adversos , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/diagnóstico , Relação Dose-Resposta a Droga , Esquema de Medicação , Eletrocardiografia/efeitos dos fármacos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
10.
Chest ; 117(3): 910-2, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10713029

RESUMO

A 52-year-old patient underwent percutaneous balloon pericardiotomy because of rapid fluid accumulation. During the procedure, we calculated the amount of blood flow to the nondiseased left anterior descending coronary artery while pericardial pressure was gradually increased by the infusion of warmed normal saline solution. Coronary vasodilator reserve was assessed by intracoronary adenosine. With increasing pericardial pressure, there was a continuous decline in coronary blood flow, due to an increase in coronary vascular resistance, and an unaffected hyperemic response throughout. The maximal hyperemic flow was far less under increased pericardial pressure than at normal pressure, which implies an augmented susceptibility to myocardial ischemia.


Assuntos
Tamponamento Cardíaco/fisiopatologia , Circulação Coronária/fisiologia , Resistência Vascular/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Tamponamento Cardíaco/cirurgia , Ecocardiografia Doppler , Humanos , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Pericardiectomia , Pericardiocentese , Reoperação
11.
Chest ; 120(1): 233-9, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451844

RESUMO

OBJECTIVE: The fluorescence of tissue when stimulated by a laser beam is a well-known phenomenon. The resulting emission spectra depend on the biochemical and structural composition of the tissue. In this study, we examined the spectra of laser-induced fluorescence emitted by myocardial tissue. METHODS: We used an argon-ion laser to stimulate the myocardium of 20 intact sheep hearts. For each spectral emission, we calculated the intensity in specific regions in order to characterize the spectra and to reveal intercavitary and intracavitary morphologic differences. RESULTS: The statistical analysis showed significant differences in the emission spectra intensity between atria and ventricles. The intensity was higher in the atria than in the ventricles (p < 0.001). The atrial emission spectra were morphologically different from those of the ventricles. There was no difference in the intensity or morphology of emission spectra within each chamber. All measurements showed good reproducibility after a short period of time. CONCLUSIONS: Laser-induced fluorescence of myocardial tissue seems to have the characteristics necessary for tissue recognition. This might prove useful in identifying cardiomyopathies and transplant rejection, as well as for myocardial mapping, assisting electrophysiologists in discovering fibrotic arrhythmogenic foci.


Assuntos
Coração/anatomia & histologia , Lasers , Espectrometria de Fluorescência , Animais , Átrios do Coração/anatomia & histologia , Ventrículos do Coração/anatomia & histologia , Técnicas In Vitro , Miocárdio/citologia , Reprodutibilidade dos Testes , Ovinos , Processamento de Sinais Assistido por Computador
12.
Coron Artery Dis ; 10(7): 471-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10562915

RESUMO

OBJECTIVES: To investigate the contribution of Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole-stress to the diagnosis of coronary artery disease (CAD). DESIGN: This was a clinical study. METHODS: Echocardiographic studies under baseline and peak dipyridamole stresses were performed on 15 normal subjects and 32 patients with angiographically confirmed CAD. Peak Doppler velocity, acceleration, and acceleration time of the ascending aorta, as well as segmental left ventricular wall motion, were analyzed. RESULTS: The sensitivity, specificity and overall accuracy of wall-motion abnormalities induced by dipyridamole for the detection of CAD were 62.5, 100, and 74.5%, respectively. When wall-motion abnormalities were combined with the percentage changes in peak aortic velocity and acceleration, the overall sensitivities were 84.38 and 78.15%, respectively, the specificities were 66.7 and 80.00%, respectively, and the accuracy was 78.72% for both models. When all three parameters were combined, the sensitivity, specificity and overall accuracy of the method were 87.5, 86.7, and 87.2%, respectively. CONCLUSIONS: Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole stress could be a useful adjunct to two-dimensional echocardiography by improving its sensitivity in the diagnosis of CAD.


Assuntos
Doença das Coronárias/fisiopatologia , Dipiridamol , Ecocardiografia Doppler , Função Ventricular Esquerda/fisiologia , Ecocardiografia Doppler/efeitos adversos , Ecocardiografia Doppler/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico/fisiologia
13.
Dig Liver Dis ; 34(11): 775-80, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12546512

RESUMO

BACKGROUND: Autonomic function in inflammatory bowel disease has not yet been studied by means of analysis of 24-hour heart rate variability. AIM: To measure heart rate variability in inflammatory bowel disease patients in remission. PATIENTS AND METHODS: Study population comprised 27 patients with inflammatory bowel disease in remission and 28 healthy, sex- and age-matched controls. Two frequency ranges were analysed: low frequency (0.06-0.15 Hz) and high frequency (0.15-0.40 Hz). RESULTS: Mean values of low frequency and low frequency/high frequency ratio were lower in patients than in controls (p < 0.001). High frequency in patients tended to be higher than in controls (p = 0.09). The only factor that had a marginal effect on heart rate variability indexes was age. In high frequency, there was a significant time effect (p = 0.001) for both groups. There was also a significant time effect in low frequency/high frequency ratio in both groups (p < 0.001). During daytime, the mean values in low frequency/high frequency ratio were lower in patients than in controls (p < 0.001). CONCLUSIONS: There is a shift in the autonomic balance in patients with inflammatory bowel disease in remission towards a condition of relative parasympathetic predominance, which, in the first place, reflects a sympathetic pullback. This imbalance has a circadian rhythm and it is more pronounced during the day.


Assuntos
Doenças do Sistema Nervoso Autônomo/complicações , Doenças do Sistema Nervoso Autônomo/diagnóstico , Transtornos Cronobiológicos/complicações , Doenças Inflamatórias Intestinais/complicações , Anti-Inflamatórios não Esteroides/uso terapêutico , Transtornos Cronobiológicos/diagnóstico , Eletrocardiografia Ambulatorial/métodos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Mesalamina/uso terapêutico , Pessoa de Meia-Idade , Indução de Remissão
14.
Int J Cardiol ; 52(3): 235-9, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8789182

RESUMO

The aim of the study was to investigate whether the optimisation of atrioventricular (AV) delay in patients with complete AV block, with or without heart failure, paced under VDD mode, has an effect on heart rate variability and consequently on the autonomic nervous system in these patients. We studied 10 patients (Group I: 7 men, aged 68 +/- 9 years) with normal left ventricular function and 9 patients (Group II: 6 men, aged 70 +/- 6 years) with systolic left ventricular dysfunction (NYHA heart failure Class II or III). Each patient was paced for 24 h with the optimal and 24 h with the worst AV delay in random order and ambulatory electrocardiograms (ECGs) (Marquette) were recorded. Spectral heart rate variability was analysed for each 24-h period on a Holter analysis system (Marquette Series 8000). The optimal and worst AV delay were determined by echo-Doppler as those which produced the greatest and least cardiac output, respectively. For the patients in Group I, there was no difference between the two AV delays as regards indices of heart rate variability. In contrast, for Group II the total frequency (TF) was significantly higher and the low frequency (LF) and LF/high frequency (HF) ratio were significantly lower when the patients were paced with optimum AV delay. Furthermore, this AV delay resulted in significantly higher mean NN and SD. In conclusion, in patients with normal left ventricular function, changes in AV delay do not appear to affect the activity of the autonomic nervous system in the heart. In patients with mild to moderate heart failure, optimisation of the AV delay causes a significant drop in sympathetic nervous tone.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Débito Cardíaco , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/inervação , Humanos , Masculino , Marca-Passo Artificial , Distribuição Aleatória , Disfunção Ventricular Esquerda/diagnóstico por imagem
15.
Int J Cardiol ; 57(1): 61-7, 1996 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8960945

RESUMO

This study investigated the relationship between silent myocardial ischaemia during daily life and ventricular ectopic activity in patients with angiographically confirmed coronary artery disease and preserved left ventricular function. We studied 45 patients (37 men, 8 women, aged 42-70 years) who satisfied the above criteria. All underwent 72-h continuous electrocardiographic monitoring for the detection of silent ischaemic episodes and ventricular arrhythmias. A total of 225 ischaemic episodes were recorded, of which 198 (88%) were silent. Fourteen of the silent episodes (7.1%) were associated with ventricular arrhythmias. There was no statistically significant relationship between the association of silent ischaemia with arrhythmias and the patients' exercise test or angiography findings. However, the ventricular arrhythmias tended to be associated with ischaemic episodes of longer duration and with greater maximum ST-segment depression. Silent myocardial ischaemia during everyday activity is accompanied by ventricular ectopic activity in only a small percentage of cases. The association between ischaemia and ventricular arrhythmias seems to have more to do with the duration of the ischaemic episode and the degree of ST segment depression than with the severity of the underlying coronary artery disease.


Assuntos
Arritmias Cardíacas/complicações , Doença das Coronárias/complicações , Adulto , Idoso , Angiografia Coronária , Eletrocardiografia Ambulatorial , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
16.
Int J Cardiol ; 46(3): 267-73, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7814180

RESUMO

INTRODUCTION: Transtelephonic electrocardiographic transmission is a diagnostic technique which has been systematically applied in recent years, mainly for the detection of arrhythmias or pacemaker malfunction. The purpose of this study was to assess the efficacy of this method in the recording and transmission of ST segment and T wave changes. METHOD: A Bruce protocol exercise stress test was carried out in 47 consecutive patients (39 males, eight females, age 53.1 +/- 11.5 years) with suspected coronary artery disease (CAD). At the same time, a transtelephonic ECG system, with a 2-min memory and the capability for 16.5 days continuous recording, was used to transmit the ECG (modified leads II and V5). RESULTS: A positive ST segment shift was observed in 19 patients (40.4%) during the exercise test. The transtelephonic system recorded this change in 18 of these patients but missed the anteroseptal ST segment depression (V2-V4) in one patient (sensitivity 94.7%). All of the 23 patients with no ST segment changes during the exercise test had a negative transtelephonic ECG transmission (specificity 100%). The width of the ST depression recorded from modified lead II on the transtelephonic recording was not significantly different from that of the 12-lead ECG. The same was true for modified lead V5. CONCLUSION: Transtelephonic ECG transmission in patients with suspected CAD can significantly contribute to the investigation of this problem, since the method has high sensitivity and specificity. The capacity for continuous recording and the memory of the device make possible the monitoring of high risk patients for a good length of time.


Assuntos
Doença das Coronárias/diagnóstico , Eletrocardiografia/métodos , Telemetria , Telefone , Eletrocardiografia/normas , Estudos de Avaliação como Assunto , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Int J Cardiol ; 52(2): 157-62, 1995 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-8749876

RESUMO

In this study the tilt test, in combination with isoproterenol administration, was used to investigate 44 patients with unexplained syncope. The reproducibility of the method was studied in a group of 32 patients who underwent a second test. The administration of isoproterenol during the test increased the sensitivity of the method from 52 to 70% and the reproducibility of a positive result from 61% to 83%, at the expense of a small decrease in specificity (from 100% to 93%). Isoproterenol should thus be considered an essential part of the method, although the low reproducibility of specific types of haemodynamic response limits its value in the choice and the follow up of treatment in individual cases.


Assuntos
Cardiotônicos , Isoproterenol , Síncope/diagnóstico , Teste da Mesa Inclinada/métodos , Pressão Sanguínea , Cardiotônicos/administração & dosagem , Feminino , Frequência Cardíaca , Humanos , Infusões Intravenosas , Isoproterenol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Síncope/etiologia , Sistema Vasomotor/fisiopatologia
18.
Int J Cardiol ; 64(2): 185-94, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9688438

RESUMO

Spectral analysis of heart rate variability was used to assess changes in autonomic function in 44 patients with vasovagal syndrome and 20 normal controls before and during postural tilt and to attempt to relate such changes to specific types of haemodynamic response to tilt. Frequency domain measurements of the high (HF) and low (LF) frequency bands and the ratio LF/HF were derived from Holter recordings, computed by Fast Fourier Analysis for 4 min intervals immediately before tilt testing, immediately after tilting and just before the end of the test. In the syncopal patients the mean values of LF and HF decreased significantly in response to tilting, while the LF/HF ratio remained constant. All parameters showed a statistically significant increase just before the onset of syncope. In the control group there was an increase in the LF and LF/HF ratio and a decrease in the HF immediately after tilting. The three subgroups of patients had similar patterns of changes in autonomic activity. The results of this study show that syncopal patients have a different pattern of response to the tilting test. The pathological mechanism leading to vasovagal syncope appears to be independent of the specific type of haemodynamic response to tilt testing.


Assuntos
Frequência Cardíaca/fisiologia , Síncope Vasovagal/fisiopatologia , Teste da Mesa Inclinada , Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/fisiologia , Estudos de Casos e Controles , Eletrocardiografia Ambulatorial/métodos , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Processamento de Sinais Assistido por Computador , Nervo Vago/fisiologia
19.
Clin Cardiol ; 23(10): 734-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11061051

RESUMO

BACKGROUND: The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population. HYPOTHESIS: We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients. METHODS: In all, 127 patients (67 men, 60 women, aged 68 +/- 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque. RESULTS: Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients > or = 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged > or = 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD. CONCLUSIONS: The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.


Assuntos
Doenças da Aorta/diagnóstico por imagem , Arteriosclerose/diagnóstico por imagem , Doença das Coronárias/diagnóstico por imagem , Ecocardiografia Transesofagiana , Idoso , Idoso de 80 Anos ou mais , Aorta Torácica/diagnóstico por imagem , Angiografia Coronária , Ecocardiografia Transesofagiana/instrumentação , Ecocardiografia Transesofagiana/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco
20.
Int Angiol ; 20(4): 295-300, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11782695

RESUMO

BACKGROUND: Atherosclerosis may affect the entire cardiovascular system despite absence of symptoms. Early changes in the wall of the carotid artery have been related to a higher morbidity and mortality from coronary artery disease (CAD). This study was conducted to investigate the relationship between the presence of occult aorto-iliac disease (OAID) and certain risk factors with the severity of CAD. METHODS: Two hundred and eighty-four consecutive patients subjected to coronary angiography (CA) were studied. Additional images of the aorto-iliac arterial segment were taken. Patients with negative CA or symptomatic lower limb arterial disease (LLAD) were excluded from further analysis. In the remaining patients, the risk factors (age, smoking, diabetes mellitus, hypertension, hyperlipidemia and positive family history for atherosclerosis) and the severity of coronary artery disease (CAD) were analyzed in relation to the presence or absence of OAID. RESULTS: Twelve patients with impaired renal function were excluded from the study. Negative CA was found in 12% (32/272) and symptomatic LLAD was present in 14% (37/272). Eligible for further analysis were 203 patients with positive CA and no LLAD. A hundred and ten of them had a positive CA and the presence of OAID whereas the remaining 93 patients had only a positive CA. The patients with OAID had more severe CAD on CA (p=0.003). There was no difference between the two groups concerning age and gender. The most common risk factors in both groups were hypercholesterolemia and a positive family history but with a significantly higher prevalence in the patients with OAID (p=0.008 and p<0.001, respectively). CONCLUSIONS: The presence of OAID in coronary patients was associated with more severe CAD and with a significantly higher prevalence of hypercholesterolemia and positive family history for atherosclerosis. This subset of patients may represent those with more aggressive atherosclerosis.


Assuntos
Doenças da Aorta/complicações , Arteriosclerose/complicações , Doença das Coronárias/etiologia , Artéria Ilíaca , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Índice de Gravidade de Doença
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