RESUMO
BACKGROUND AND AIMS: The independent role of serum uric acid (SUA) as a marker of cardio-renal risk is debated. The aim of this study was to assess the relationship between SUA, metabolic syndrome (MS), and other cardiovascular (CV) risk factors in an Italian population of hypertensive patients with a high prevalence of diabetes. METHODS AND RESULTS: A total of 2429 patients (mean age 62 ± 11 years) among those enrolled in the I-DEMAND study were stratified on the basis of SUA gender specific quartiles. MS was defined according to the NCEP-ATP III criteria, chronic kidney disease (CKD) as an estimated GFR (CKD-Epi) <60 ml/min/1.73 m(2) or as the presence of microalbuminuria (albumin-to-creatinine ratio ≥2.5 mg/mmol in men and ≥3.5 mg/mmol in women). The prevalence of MS, CKD, and positive history for CV events was 72%, 43%, and 20%, respectively. SUA levels correlated with the presence of MS, its components, signs of renal damage and worse CV risk profile. Multivariate logistic regression analysis revealed that SUA was associated with a positive history of CV events and high Framingham risk score even after adjusting for MS and its components (OR 1.10, 95% CI 1.03-1.18; P = 0.0060; OR 1.28, 95% CI 1.15-1.42; P < 0.0001). These associations were stronger in patients without diabetes and with normal renal function. CONCLUSIONS: Mild hyperuricemia is a strong, independent marker of MS and high cardio-renal risk profile in hypertensive patients under specialist care. Intervention trials are needed to investigate whether the reduction of SUA levels favorably impacts outcome in patients at high CV risk.
Assuntos
Doenças Cardiovasculares/epidemiologia , Hipertensão/epidemiologia , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Ácido Úrico/sangue , Idoso , Albuminúria/sangue , Albuminúria/epidemiologia , Biomarcadores/sangue , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Estudos de Coortes , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Humanos , Hipertensão/sangue , Hiperuricemia/sangue , Hiperuricemia/epidemiologia , Itália , Modelos Logísticos , Masculino , Síndrome Metabólica/sangue , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/epidemiologia , Fatores de RiscoRESUMO
OBJECTIVES: We sought to investigate the effect of angiotensin-converting enzyme (ACE) inhibition <9 h after myocardial infarction (MI) on left ventricular (LV) dilation in patients receiving thrombolysis. BACKGROUND: The ACE inhibitors reduce mortality after MI. Attenuation of LV dilation has been suggested as an important mechanism. METHODS: The data of 845 patients with three-month echocardiographic follow-up after MI were combined from three randomized, double-blind, placebo-controlled studies. The criteria for these studies included: 1) thrombolytic therapy; 2) ACE inhibition within 6 to 9 h; and 3) evaluation of LV dilation as the primary objective. RESULTS: The ACE inhibitor was started 3.2+/-1.7 h after the patients' first (mainly, 85%) anterior MI. After three months, LV dilation was not significantly attenuated by very early treatment with an ACE inhibitor. The diastolic volume index was attenuated by 0.5 ml/m2 (95% confidence interval [CI] -1.5 to 2.5, p = 0.61), and the systolic volume index by 0.5 ml/m2 (95% CI -1.0 to 1.9, p = 0.50). Subgroup analysis demonstrated that LV dilation was significantly attenuated by ACE inhibitor treatment for patients in whom reperfusion failed. In contrast, LV dilation was almost unaffected by ACE inhibitor treatment in successfully reperfused patients. CONCLUSIONS: We could not demonstrate attenuation of LV dilation in patients receiving thrombolysis by ACE inhibitor treatment within 6 to 9 h after MI. We speculate that very early treatment with an ACE inhibitor has a beneficial effect on LV remodeling only in patients in whom reperfusion failed. Other mechanisms may be responsible for the beneficial effects of ACE inhibitors in successfully reperfused patients after MI.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Terapia Trombolítica , Disfunção Ventricular Esquerda/tratamento farmacológico , Dilatação Patológica , Ventrículos do Coração/patologia , Humanos , Infarto do Miocárdio/complicações , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologiaRESUMO
To propose a test to evaluate endothelial function, based on VO(2) on-transition kinetics in sub-anaerobic threshold (AT) constant load exercise, we tested healthy subjects and patients with ischemic-hypertensive cardiopathy by two cardiopulmonary tests on a cycle ergometer endowed with an electric motor to overcome initial inertia: a pre-test and, after at least 24 h, one 6 min constant load exercise at 90 % AT. We measured net phase 3 VO(2)-on kinetics and, by phase 2 time constant (tau), valued endothelial dysfunction. We found shorter tau in repeated tests, shorter time between first and second test, by persisting endothelium-dependent arteriolar vasodilatation and/or several other mechanisms. Reducing load to 80 % and 90 % AT did not produce significant changes in tau of healthy volunteers, while in heart patients an AT load of 70 %, compared to 80 % AT, shortened tau (delta=4.38+/-1.65 s, p=0.013). In heart patients, no correlation was found between NYHA class, ejection fraction (EF), and the two variables derived from incremental cycle cardio-pulmonary exercise, as well as between EF and tau; while NYHA class groups were well correlated with tau duration (r=0.92, p=0.0001). Doxazosin and tadalafil also significantly reduced tau. In conclusion, the O(2) consumption kinetics during the on-transition of constant load exercise below the anaerobic threshold are highly sensitive to endothelial function in muscular microcirculation, and constitute a marker for the evaluation of endothelial dysfunction.
Assuntos
Limiar Anaeróbio , Endotélio Vascular/fisiopatologia , Hipertensão/fisiopatologia , Microcirculação , Isquemia Miocárdica/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Exercício Físico/fisiologia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos/irrigação sanguíneaRESUMO
The effects of a moderate dietary salt restriction on intralymphocytic sodium content and pressor response to stress (mental arithmetic, handgrip, and bicycle exercise) were tested in 25 young subjects with borderline hypertension. The study was performed by a randomized, cross-over, within-patient, experimental design. Diet did not significantly reduce blood pressure at rest but did so significantly in both systolic and diastolic blood pressure during stress and exercise. Variations in diastolic blood pressure induced by stimulation correlated significantly with intralymphocytic sodium content both before and during low-salt diet whereas no correlation was found in the case of systolic blood pressure and heart rate variations. These findings suggest that in young subjects with borderline hypertension, sodium homeostasis and blood pressure regulation are somehow interrelated, and that a moderate dietary salt restriction reduces both intralymphocytic sodium content and pressor response to adrenergic stimulation. This could be useful in preventing the development of sustained hypertension.
Assuntos
Hipertensão/dietoterapia , Linfócitos/análise , Sódio/sangue , Estresse Psicológico/complicações , Adolescente , Adulto , Dieta Hipossódica , Feminino , Humanos , Hipertensão/etiologia , Masculino , Esforço FísicoRESUMO
In 27 hypertensive patients already receiving antihypertensive treatment and with serum total cholesterol levels between 260 and 350 mg/dl, captopril in a dosage of 50 mg twice a day was substituted for one of the drugs they were taking. Patients taking a diuretic continued the same diuretic at the same dosage. After six months of therapy that included captopril, patients resumed their former therapy. Diet and physical activity remained unchanged during the study. Biochemical and blood pressure determinations were performed before captopril was begun, after three and six months of captopril therapy, and three months after the former therapy was resumed. During the regimens that included captopril, the triglyceride value was reduced from 249 to 184 mg/dl (p less than 0.05), the total cholesterol level decreased from 287 to 237 mg/dl (p less than 0.005), and the high-density lipoprotein cholesterol value rose from 40 to 51 mg/dl (p less than 0.005). The reduction in cholesterol was unrelated to blood pressure changes or to changes in serum triglyceride, glucose, or potassium levels. Treatment regimens that included captopril also induced a greater diastolic blood pressure reduction than regimens that did not include captopril. The antihypertensive efficacy of a therapeutic regimen that includes captopril, along with its favorable effect on lipid profile, could be useful in preventing cardiovascular complications in hypertensive patients.
Assuntos
Captopril/uso terapêutico , Hipertensão/sangue , Lipídeos/sangue , Colesterol/sangue , HDL-Colesterol/sangue , Feminino , Humanos , Hipertensão/tratamento farmacológico , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Triglicerídeos/sangueRESUMO
The aim of this 3-month, double-blind, double-dummy, parallel group study was to compare the antihypertensive efficacy and acceptability of perindopril (4-8 mg/day) in 54 patients (30 males, 24 females, 25-68 years of age) and captopril (50-100 mg/day) in 54 patients (39 males, 15 females, 29-66 years of age) in the treatment of essential hypertension. In a subgroup of 38 patients a complete echocardiographic study was performed. The two groups had similar (ANOVA) blood pressure (BP), heart rate (HR), body mass index, and duration of hypertension. Supine and standing BP was significantly reduced by both drugs, without differences between them. Owing to poor control of BP, hydrochlorothiazide (25 mg/day) was added to 27% of patients on perindopril and to 41% of patients on captopril (p less than 0.05). Normalization of supine diastolic BP (less than or equal to 90 mm Hg) was obtained in 67% of patients on perindopril and in 47% of patients on captopril (p less than 0.01). No change in HR was detected. Only mild untoward effects were recorded. Left ventricular mass was significantly reduced by either drug, with no change in systolic function. In conclusion, perindopril and captopril, at these doses, were both well tolerated and on average reduced BP to a similar extent; however, treatment with perindopril showed that fewer patients needed the addition of a thiazide and BP became normal in a larger number of patients.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Captopril/uso terapêutico , Hipertensão/tratamento farmacológico , Indóis/uso terapêutico , Adulto , Idoso , Benzotiadiazinas , Pressão Sanguínea/efeitos dos fármacos , Diuréticos , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Perindopril , Inibidores de Simportadores de Cloreto de Sódio/uso terapêutico , UltrassonografiaRESUMO
OBJECTIVE: To collect statistically significant information on patterns of antihypertensive therapy in medical practice, with particular attention to the drugs used in the pharmacological management of hypertensive patients and the reasons for the limited achievement of therapeutic goals during treatment DESIGN: A survey conducted among general practitioners, specialists, and hypertensive patients. METHODS: A total of 28,000 physicians were contacted by letter and 3,394 declared their willingness to participate and received a questionnaire. Subsequently, 1,255 questionnaires suitable for analysis (corresponding to 37.0% of adhering physicians) were received. In addition, 4,612 questionnaires completed by patients were pooled and evaluated. The prevalence of hypertension was calculated from a base of 254,192 patients, seen by general practitioners. RESULTS: The prevalence of hypertension, defined as systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or current treatment, was 19.7%. The average number of hypertensive patients in each general practitioner's file, covering the previous 12 months, was approximately 230. Physicians reported a 66% rate of discontinuation of treatment or switching to another drug. Physicians and patients both considered inadequate blood pressure control and side effects to be the two main reasons for switching antihypertensive therapy, but in opposite order. Furthermore, physicians indicated a prevalence of drug side effects between 10 and 20%, according to class of drug used, whereas 69% of patients reported to have experienced side effects. In the doctors' opinions, there were many reasons for poor patient adherence: complexity of the drug regimen, appearance of side effects, forgetfulness, reduced patient understanding of the need for long-term continuation of treatment, and refusal to accept a chronic pathological condition. CONCLUSIONS: The survey showed awareness of the disease among physicians and provides a representation of the experiences of both general practitioners and specialists, in addition to that of their patients. During antihypertensive therapy, a disconcerting degree of discontinuation and switching of drugs occurred. Insufficient blood pressure control and side effects accounted for most of the observed treatment changes. This survey revealed the existence of a gap between the physicians' perception of tolerability and the real experience of patients, a clear need for greater tolerability of treatments, and a need for an enhancement of patient-physician communication.
Assuntos
Anti-Hipertensivos/administração & dosagem , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Padrões de Prática Médica , Anti-Hipertensivos/efeitos adversos , Coleta de Dados , Humanos , Itália , Cooperação do Paciente , Médicos , PrevalênciaRESUMO
OBJECTIVES: To compare the effect of the angiotensin converting enzyme (ACE) inhibitor ramipril with that of the beta-blocker atenolol on reversal of left ventricular hypertrophy, on blood pressure and on other echocardiographic parameters. DESIGN: The study was conducted in accord with the PROBE (prospective randomized open blinded endpoint) design. Randomized treatment either with ramipril or with atenolol was continued for 6 months, and echocardiograms were recorded before and after 3 and 6 months of treatment. The echo tracings were blindly evaluated in a single reading centre. METHODS: M-mode, two-dimensional guided echocardiography was used to measure left ventricular wall thicknesses and dimensions, from which left ventricular mass was calculated, according to the Penn convention. RESULTS: Of 193 patients at 16 centres, 111 had echocardiograms that could be quantitatively evaluated. The primary analysis of the study was performed using data from those patients. In addition, echocardiograms of 88 patients were analysed on an 'according to protocol' basis (patients with preset values of left ventricular mass). Systolic and diastolic blood pressures were significantly reduced both by ramipril and by atenolol without any significant difference between the two drug treatments. The heart rate was significantly reduced by atenolol only. Both the 'primary' and the 'according to protocol' analyses showed that the left ventricular mass was significantly reduced by ramipril only. Comparison between treatments according to a multivariate analysis demonstrated a significantly greater reduction in left ventricular mass during ramipril than during atenolol treatment. CONCLUSIONS: The present study is the first of suitably large size in which a direct comparison of the effects of an ACE inhibitor and a beta-blocker on echocardiographic left ventricular mass has been performed. It has demonstrated that ramipril is more effective than atenolol in reversing left ventricular hypertrophy in essential hypertensive patients.
Assuntos
Atenolol/uso terapêutico , Ecocardiografia , Coração/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Ramipril/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Atenolol/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ramipril/efeitos adversos , Sístole , Função Ventricular EsquerdaRESUMO
OBJECTIVES: To identify factors predisposing subjects to the development of stable hypertension and to estimate their relative importance in 70 young patients with borderline hypertension monitored for 10 years. DESIGN: Longitudinal evaluation of the incidence of stable hypertension [diastolic blood pressure (DBP) > 95 mmHg]. METHODS: Patients were examined at baseline by determination of resting blood pressure, intracellular sodium level and individual pressor response to mental arithmetic and to intravenous saline loading. They were re-examined after 10 years to assess the prevalence of established hypertension and the importance of some prognostic variables identified prospectively (age, sex, intracellular sodium level, baseline blood pressure, pressor response to stress and acute salt-sensitivity). RESULTS: The prevalence of sustained hypertension (DBP > 95 mmHg) was 35.8% after 10 years of follow-up study. Subjects developing hypertension were older (26.9 +/- 1.3 versus 21.0 +/- 1.8 years) and showed a higher percentage of family history of hypertension (92 versus 64%) and of acute salt-sensitivity (72 versus 53%). The pressor response to mental arithmetic was greater in patients who developed hypertension (systolic blood pressure 26.9 +/- 1 versus 22.7 +/- 0.9 mmHg, P = 0.005 DBP = 16.6 +/- 0.8 versus 13.1 +/- 0.7 mmHg, P = 0.005), who also showed higher levels of intracellular sodium (30.7 +/- 0.6 versus 27.3 +/- 0.5 mmol/kg, P = 0.001). The same variables were found to be related to the development of hypertension in a multivariate analysis and the concomitant presence of 4-5 risk factors was associated with a reasonable predictive power for the identification of patients at high risk (sensitivity 72%, specificity 67%, predictive accuracy 76%). CONCLUSIONS: The present study demonstrates that borderline hypertensives at high risk of stable hypertension can be identified by the concomitant evaluation of some clinical and cellular characteristics directly related to long-term development of high blood pressure.
Assuntos
Hipertensão/etiologia , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Fatores de RiscoRESUMO
OBJECTIVE: In accordance with international recommendations on the need to decrease doses of antihypertensive drugs, a low-dose (1.5 mg) sustained-release (SR) formulation of indapamide was developed to optimize the drug's efficacy : safety ratio. The aim of this work was to evaluate the benefit of a low-dose diuretic by consolidating the efficacy and safety results of two clinical trials with a similar design. PATIENTS AND METHODS: Clinical data were obtained in two European randomized double-blind studies with 690 mild to moderate hypertensive patients (95 mmHg < or = supine diastolic blood pressure < or = 114 mmHg using a mercury sphygmomanometer) treated respectively for 2 and 3 months, with a mean age of 53 and 57 years, 44 and 57% males, mean supine diastolic blood pressure of 100.6 and 102.5 mmHg and mean supine systolic blood pressure of 161.0 and 164.5 mmHg. RESULTS: The first study, a dose-finding study with indapamide SR at 1.5, 2 and 2.5 mg versus placebo and the immediate-release (IR) formulation of indapamide, showed that the 1.5 mg dosage of the new indapamide formulation had an improved antihypertensive efficacy : safety ratio. The second study confirmed the equivalence of blood pressure reductions with 1.5 mg indapamide SR and 2.5 mg indapamide IR, and better acceptability with 1.5 mg indapamide SR, particularly in the number of patients with serum potassium levels < 3.4 mmol/l, which was reduced by more than 50%. The long-term efficacy of 1.5 mg indapamide SR was observed through a 9-month open-treatment follow-up to the second study. CONCLUSION: The 1.5 mg SR formulation of indapamide has an improved antihypertensive efficacy : safety ratio, which is in accordance with international recommendations for the use of low-dose antihypertensive drugs and diuretics in first-line therapy of hypertension.
Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Indapamida/uso terapêutico , Adulto , Idoso , Angina Pectoris/induzido quimicamente , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Transtornos Cerebrovasculares/induzido quimicamente , Preparações de Ação Retardada , Tontura/induzido quimicamente , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Cefaleia/induzido quimicamente , Humanos , Indapamida/administração & dosagem , Indapamida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pacientes Desistentes do Tratamento , Potássio/sangue , Decúbito Dorsal , Fatores de Tempo , Resultado do TratamentoRESUMO
The use of angiotensin-converting enzyme (ACE) inhibitors in acute myocardial infarction (AMI) is based on their capacity to limit ventricular enlargement and dysfunction. To date, the safety profile of administration of ACE inhibitors early in the course of AMI has not been established. In-hospital and long-term consequences of treatment with the ACE inhibitor zofenopril initiated within 24 hours of the onset of symptoms were compared with those of standard treatment in an open-label trial involving 204 patients with AMI who were not undergoing thrombolytic treatment. Zofenopril promptly blocked ACE activation. Blockade was almost complete (91 +/- 6%) after 72 hours and paralleled decreases in systolic blood pressure. Systemic blood pressure was acutely reduced by zofenopril, and severe but reversible hypotension occurred in 15% of hospitalized patients and in 3% of those treated over the long term. No adverse clinical or biochemical events were reported during the course of zofenopril therapy. Overall cardiovascular mortality was not significantly reduced by early zofenopril compared with placebo therapy (7.8% vs 10.7% [difference not significant]). The inhospital incidence of acute left ventricular failure and ventricular arrhythmias decreased by 63% and 39%, respectively, among zofenopril-treated patients, who also reported fewer anginal episodes both acutely (68% reduction) and over the long term (56% reduction) and did not require as much drug treatment (i.e., diuretics, digoxin, and/or anti-ischemic agents) during the follow-up phase. Left ventricular size decreased and ejection fraction (EF) increased in patients who received zofenopril, and the improvement was greater among patients with poorer ventricular function (EF less than 40%). Early administration of ACE inhibitors may therefore constitute a safe form of therapy for patients with AMI, particularly when the event is complicated by clinical signs or evidence of ventricular dysfunction.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Captopril/análogos & derivados , Infarto do Miocárdio/tratamento farmacológico , Administração Oral , Angina Pectoris/prevenção & controle , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Captopril/administração & dosagem , Captopril/efeitos adversos , Captopril/uso terapêutico , Débito Cardíaco/efeitos dos fármacos , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Projetos Piloto , Placebos , Pressão Propulsora Pulmonar/efeitos dos fármacos , Renina/sangue , Sistema Renina-Angiotensina/efeitos dos fármacos , Segurança , Volume Sistólico/efeitos dos fármacos , Resultado do Tratamento , Resistência Vascular/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
Chronic congestive heart failure (CHF) is a common disease responsible for a high mortality and morbidity whose clinical course can be improved by angiotensin-converting-enzyme (ACE) inhibition. However, limited data are available on the effects of ACE inhibitors on the onset and progression of CHF in patients with acute myocardial infarction (AMI). The present study was performed as a substudy of the Survival of Myocardial Infarction Long-term Evaluation trial and involved 1,146 patients with anterior wall AMI not undergoing thrombolysis with the exclusion of patients with prior history or clinical signs of CHF on admission. Patients were randomly allocated to treatment with zofenopril (7.5 to 30 mg twice daily) or placebo for a cumulative period of 6 weeks. The prevalence of CHF, either mild to moderate or severe, has been the main objective and has been evaluated 6 weeks and 1 year after AMI. The overall prevalence of CHF was not reduced by zofenopril after both 6 weeks and 12 months. Conversely the prevalence of severe CHF (1.6% vs 2.6%: risk reduction 55.5%; 95% confidence interval 9 to 63; p = 0.0325) and the combined occurrence of death or severe CHF (4.8% vs 8.2%: risk reduction 59%; 95% confidence interval 11 to 71; p = 0.024) were reduced after 6 weeks of treatment with zofenopril. Moreover, the percentage of patients experiencing a deterioration to severe CHF after 1 year was significantly reduced with zofenopril (11.0% vs 24.3%; p = 0.001). In conclusion, the early administration of zofenopril to patients with AMI attenuates the progression of the clinical symptoms of CHF and its clinical consequences, suggesting that ACE inhibitors should be regarded as a suitable strategy for the prevention and treatment of CHF in patients with AMI.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Captopril/análogos & derivados , Insuficiência Cardíaca/prevenção & controle , Infarto do Miocárdio/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Captopril/uso terapêutico , Progressão da Doença , Método Duplo-Cego , Feminino , Seguimentos , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/etiologia , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Prevalência , Estudos Prospectivos , Fatores de TempoRESUMO
An increased venous tone responsible for changes in systemic hemodynamics has been described in borderline hypertensive patients along with the release, in response to intravenous sodium chloride, of an endogenous sodium ion/potassium ion adenosine triphosphatase (Na+/K+ ATPase) inhibitor with vasoconstrictive properties. The hemodynamic and humoral effects of a 2-hour intravenous saline infusion were studied in 25 borderline hypertensives characterized on the basis of their forearm venous distensibility (VV30) in normal (n = 15) and low (n = 10) VV30. VV30 was slightly reduced by saline in the entire hypertensive group (1.47 vs 1.36 ml/100 ml; p less than 0.05), whereas blood pressure and plasma Na+/K+ ATPase inhibitor were unchanged. Normal VV30 showed a sudden increase in plasma Na+/K+ ATPase inhibitor in response to saline associated with an increase in blood pressure, a forearm arterial and venous constriction, and a sluggish suppression in plasma renin activity, whereas low VV30 exhibited a completely opposite pattern. The changes in plasma Na+/K+ ATPase inhibitor inversely correlated to VV30 decreases in borderline hypertensives with normal VV30 (r = -0.49; p less than 0.05), whereas they did not in all hypertensive patients. Atrial natriuretic peptide response to saline infusion was delayed in normal VV30 and inversely related to the changes in Na/K+ ATPase inhibitory activity (r = -42; p less than 0.05) attained after 2 hours of infusion in the entire hypertensive population. Results of this study suggest the ability of acute volume expansion to reduce peripheral venous distensibility in borderline hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hipertensão/fisiopatologia , Volume Plasmático , Pressão Venosa , Adolescente , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/metabolismo , Feminino , Antebraço , Hemodinâmica/fisiologia , Humanos , Masculino , Volume Plasmático/efeitos dos fármacos , Proteínas/metabolismo , ATPases Translocadoras de Prótons/antagonistas & inibidores , Renina/sangue , Cloreto de Sódio/administração & dosagem , Urina/análise , Vasodilatação/fisiologia , Proteína Inibidora de ATPaseRESUMO
Studies in animals and humans have shown that angiotensin-converting enzyme (ACE) inhibitors can prevent or at least attenuate ventricular dilation and remodeling following acute myocardial infarction (MI) and can improve subsequent left ventricular dysfunction, a strong predictor of survival. The question as to which patients will benefit most from ACE inhibitor therapy and the optimal timing of administration of such intervention after the onset of symptoms is still matter of debate, even if it is hypothesized that a greater benefit in terms of remodeling prevention may occur after early administration. However, while it is currently accepted that patients with asymptomatic postinfarctual left ventricular dysfunction can benefit from long-term administration of an ACE inhibitor when therapy is started late, the usefulness of an early administration is still to be clarified. In this setting, the question of early versus late ACE inhibitor treatment has to be related to the different evolving pattern of myocardial infarction with regard to the different degrees of postinfarction ventricular dysfunction and neurohormonal activation, whose extent could influence the effect of ACE inhibition. For example, not all patients with acute MI show progressive ventricular dilation. Early dilation is frequent in patients with anterior localization of necrosis, whereas it is usually not relevant in patients with acute inferior MI. Thus, different postinfarction patterns may differently influence the clinical success of therapeutic interventions, which can be instituted at various stages following acute MI.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Animais , Ensaios Clínicos como Assunto , Humanos , Fatores de TempoRESUMO
The efficacy of propafenone, a new antiarrhythmic drug, was studied in 21 patients with ventricular arrhythmias refractory to previous antiarrhythmic medications. Group A included 10 patients with chronic ventricular premature complexes (VPCs), 6 of whom had nonsustained ventricular tachycardia (VT) and 4 of whom had recurrent, sustained VT; all received propafenone, 900 mg/day. Group B included 11 patients, all with chronic VPCs, 9 of whom had nonsustained VT and 5 of whom had sustained VT; all received propafenone, 450 mg/day. Drug efficacy was evaluated as a 70% or greater reduction in VPC frequency with complex VPC abolition in ambulatory monitoring and suppression of nonsustained VT and sustained VT during a follow-up period up to 154 +/- 58 days in group A and 96 +/- 42 days in group B. Drug plasma levels were measured during chronic therapy in pharmacologic steady state. In group A, propafenone reduced the frequency of chronic VPCs in 9 patients and abolished nonsustained VT in 4 of 6 and sustained VT in 3 of 4; in group B, propafenone reduced the frequency of chronic VPCs in 6 patients and abolished nonsustained VT in 6 of 9 and sustained VT in 3 of 5. Two patients with recurrences of sustained VT in this group were later successfully treated with propafenone, 900 mg/day; overall, 8 of 9 patients with recurrences of sustained VT were successfully treated with 900 mg/day.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Antiarrítmicos/uso terapêutico , Propiofenonas/uso terapêutico , Taquicardia/tratamento farmacológico , Adulto , Idoso , Antiarrítmicos/efeitos adversos , Antiarrítmicos/sangue , Cromatografia Líquida de Alta Pressão , Tontura/induzido quimicamente , Feminino , Humanos , Hipotensão/induzido quimicamente , Cinética , Masculino , Pessoa de Meia-Idade , Propafenona , Propiofenonas/efeitos adversos , Propiofenonas/sangue , RecidivaRESUMO
The clinical usefulness of calcium entry-blockers for the treatment of high blood pressure is related to their capacity to act upon the primary hemodynamic derangement in hypertension: the increased peripheral vascular resistance. They can be used alone or in combination with other antihypertensive agents for the treatment of various forms of hypertensive disease. The calcium entry-blockers appear to be the most useful agents for the treatment of hypertension in the elderly and for the treatment of hypertension associated with ischemic heart disease, pulmonary obstructive disease, peripheral vascular disease, and supraventricular arrhythmias. They are effective in reducing blood pressure in pregnancy-associated hypertension and must be considered as first-line therapy for the treatment of hypertensive crisis.
Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Hipertensão/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/farmacocinética , Bloqueadores dos Canais de Cálcio/farmacologia , HumanosRESUMO
The potential of angiotensin-converting enzyme (ACE) inhibitors to protect the heart is a topic that has emerged recently as matter of scientific discussion. Experimental and clinical studies have shown the beneficial effects of ACE inhibitors on the metabolism, function, and structure of healthy and damaged hearts and these studies support the concept of both primary and secondary "cardioprotection" with these drugs. More recently, the prevention of atherosclerotic lesions has been demonstrated in animal models, extending the concept to a more general definition of "cardiovascular" protection with ACE inhibitors involving both the heart and the vessels. The potential role of ACE inhibitors on the primary prevention of atherosclerotic disease in humans is currently evaluated in PHYLLIS (Plaque HYpertension Lipid Lowering Italian Study), a multicenter clinical trial in which fosinopril sodium, a new ACE inhibitor, is administered to hypertensive patients with at least one uncomplicated carotid artery lesion. The primary aim of the study is to evaluate the effect of the drug on the long-term (3 years) progression of carotid artery atherosclerosis, noninvasively detected by B-mode ultrasound imaging. In addition to studies on primary prevention, some large clinical trials have been conducted to establish the role of ACE inhibitors on secondary prevention, in particular in patients with acute myocardial infarction (MI). The beneficial effect of these drugs is well established when administered in the subacute phase of acute MI.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Captopril/análogos & derivados , Doenças das Artérias Carótidas/tratamento farmacológico , Fosinopril/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Arteriosclerose/prevenção & controle , Captopril/uso terapêutico , Ensaios Clínicos como Assunto , HumanosRESUMO
To evaluate the existence of a relationship between atrial natriuretic factor (ANF) and plasma Na+/K+ATPase inhibitory activity in humans, we examined the hemodynamic and humoral response to volume expansion in 41 borderline hypertensive patients (BHT) with either normal (n = 33) or low plasma renin activity (n = 8). The study was carried out by measuring blood pressure, forearm circulation, plasma renin activity (PRA), ANF, and plasma levels of an endogenous Na+/K+ATPase inhibitor before and after 2 h of acute intravenous NaCl infusion (0.22 mL/min/kg bodyweight). The early (45 min) changes of ANF and those of Na+/K+ATPase inhibitory activity attained at the end of saline infusion were inversely related in BHT with normal PRA and directly related in the low-PRA population (r = 0.64). The time-course of ANF response to sodium loading was significantly delayed in BHT characterized by normal venous distensibility. They also showed a greater increase in plasma Na+/K+ATPase inhibitory activity occurring with an hypertensive, vasoconstrictive, and sodium retaining response as well. We conclude that in normal PRA borderline hypertensives, ANF may modulate the release of a plasma Na+/K+ATPase inhibitor in a setting where extracellular volume is acutely expanded. Our findings also suggest that dissimilarities in peripheral venous distensibility are able to influence the time-course of ANF response. The blunted ANF increase observed in response to NaCl loading in a subset of BHT could represent an early marker of the attitude of such patients to develop high blood pressure leading to the release of a Na(+)-pump inhibitor and influencing individual salt-sensitivity.
Assuntos
Fator Natriurético Atrial/farmacologia , Inibidores Enzimáticos/sangue , Hipertensão/sangue , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Adulto , Humanos , Hipertensão/enzimologiaRESUMO
The effect of serum K+ of the alarm reaction induced by the participation to an experimental noninvasive study was evaluated in 35 subjects with borderline hypertension and in 18 essential hypertensives. A group of 44 inpatients undergoing routine blood sampling served as a control. Serum K+, blood pressure and heart rate were measured before (casual) and after (baseline) 20 min of rest in the recumbent position. Baseline serum K+ values were significantly higher than casual values in patients participating to the experimental protocol while no change was observed in inpatients undergoing routine blood sampling. The increase in serum K+ induced by relaxation was significantly related to heart rate decrease (r = 0.73). After relaxation 75% of patients had an increase in serum K+ with a change greater than 10% in about 35% of patients. In a subgroup of patients who repeated the same test three times, the alarm reaction was still evident and not reproducible within each patient. These data suggest that when potassium levels are measured in outpatients undergoing diagnostic or experimental procedures falsely reduced levels can be found in a large proportion of subjects.
Assuntos
Hipertensão/sangue , Potássio/sangue , Relaxamento/fisiologia , Estresse Psicológico/sangue , Adulto , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Hipertensão/fisiopatologia , Masculino , Fatores de TempoRESUMO
The nature of the cardiovascular response to isometric exercise is still debated. An adequate blood supply to exercising muscles at the onset of contraction seems to be an important factor controlling the extent of pressor response to isometric contraction. In comparison to normotensive subjects without familiar hypertensive history (F-), normotensive subjects with family history of hypertension (F+) have a reduced peripheral vasodilator capacity which impairs the possibility to adjust the muscular blood flow during exercise. An enhanced pressor response to handgrip test was observed in F+ and this hyperresponsivity was inversely related to the extent of forearm vasodilation capacity and largely prevented by the pretest increase of blood flow in exercising muscles. Our results suggest the importance of local vasodilating capacity as a determinant of reflex pressor response to isometric exercise.