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1.
Biomed Res Int ; 2017: 1483873, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29270425

RESUMO

Heart failure (HF) is a major and growing public health problem with high morbidity and mortality (Ponikowski et al., 2016). It affects 1-2% of the general population in developed countries, and the average age at diagnosis is 76 years. Because of a better management of acute phase and comorbidities, HF incidence is increasing in elderly patients, with a prevalence rising to 10% among people aged 65 years or older (Mozaffarian et al., 2014). Therefore, a substantial number of elderly patients need to be treated. However, because of clinical trial exclusion criteria or coexisting comorbidities, currently recommended therapies are widely based on younger population with a much lower mean age. In this review, we will focus on available pharmacological, electrical, and mechanical therapies, underlining pros, cons, and practical considerations of their use in this specific patient population.


Assuntos
Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Insuficiência Cardíaca/patologia , Humanos
2.
Minerva Cardioangiol ; 55(3): 325-33, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17534251

RESUMO

Sudden cardiac death (SCD) is one of a major cause of morbidity and mortality in patients with chronic heart failure (CHF). There is a circadian variation of the frequency of SCD. Beta-blocker therapy significantly reduces the incidence of SCD. These clinical observations suggest a close association between ventricular arrhythmia and sympathetic activity. The identification of patients at risk is a major clinical problem not only for the unpredictability of the event, but also for the continuous growth of patients'number. The implantable cardioverter-defibrillator (ICD) is highly effective at terminating life threatening ventricular tachyarrhythmia At present, 1-2% of the population has heart failure and numbers continue to increase, but the ICD remains expensive. The challenge lies in identifying patients with heart failure who are at significant risk of arrhythmia and who would benefit from an ICD in addition to other anti-arrhythmic strategies. Our power of identifying heart failure patients at risk for arrhythmic death is far from being satisfactory. Heart rate variability and baroreflex sensitivity analysis has been largely utilized to obtain information on autonomic modulation of sinus node as well as to identify patients at risk. It is possible that the combination of results of multiple noninvasive tests such as reduction in ejection fraction and positivity for T wave alternans may not only provide general prognostic information but also facilitate the appropriate identification of patients at risk who may benefit from antiarrhythmic therapy.


Assuntos
Arritmias Cardíacas/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Antagonistas Adrenérgicos beta/uso terapêutico , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/terapia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia , Humanos , Prognóstico , Medição de Risco , Fatores de Risco
3.
Int J Cardiol ; 111(3): 377-85, 2006 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-16256222

RESUMO

BACKGROUND: We evaluated whether multidisciplinary disease management programme developed with collaboration of physicians and nurses inside and outside general district hospital settings can affect clinical outcomes in heart failure population over a 12-month period. METHODS: 571 patients hospitalised with CHF were referred to our unit and 509 patients agreed to participation. The intervention team included physicians and nurses from Internal Medicine and Cardiac Dept., and the patient's general practitioners. Contacts were on a pre-specified schedule, included a computerised programme of hospital visits and phone calls; in case of NYHA functional class III and IV patients, home visits were also planned. RESULTS: The median age of patients was 77.7+/-9 years (43.3% women). At baseline the percentage of patients with NYHA class III and IV was 56.0% vs. 26.0% after 12 months (P<0.05). Programme enrolment reduced total hospital admissions (82 vs. 190, -56%, P<0.05), number of patients hospitalised (62 vs. 146, 57%, P<0.05). All NYHA functional class benefited (class I=75%, class IV=67%), with reduction in the costing (-48%, P<0.05). Improvement in symptoms (-9.0+/-3.2) and signs (-5.2+/-3.1) scores was measured (P<0.01). Therapy optimisation was obtained by 20.5% increase in patients taking betablockade and 21.0% increase in those on anti-aldosterone drugs. CONCLUSIONS: Multidisciplinary approach to CHF management can improve clinical management, reducing hospitalisation rate and costing.


Assuntos
Gerenciamento Clínico , Insuficiência Cardíaca/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Equipe de Assistência ao Paciente , Idoso , Aconselhamento , Feminino , Insuficiência Cardíaca/economia , Hospitalização/economia , Hospitais de Distrito/economia , Humanos , Itália , Masculino , Equipe de Assistência ao Paciente/economia , Educação de Pacientes como Assunto , Estudos Prospectivos
4.
Minerva Anestesiol ; 69(5): 353-6, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12768166

RESUMO

Defibrillation as soon as possible is the mainstay of modern emergency system in the treatment of sudden cardiac death. The emergency medical system (EMS) should be integrated with first responders in the community trained to use the semiautomatic external defibrillators (AED). Piacenza Progetto Vita is a European project of early defibrillation through lay first responders integrated within the EMS. After 22 months of the project 1 285 first responders were trained to the use of AED. Survival from sudden cardiac arrest significantly increased (from 3.3% to 10.5%, p<0.01). In particular in the group of patients treated by first responders survival from ventricular fibrillation was 44.1% vs 21.2% of EMS treated group (p < 0.05). A simple training for the use of AED without cardiopulmonary resuscitation training increased survival and created a group of competent AED operator integrated within the EMS.


Assuntos
Morte Súbita Cardíaca/prevenção & controle , Cardioversão Elétrica , Idoso , Cardioversão Elétrica/economia , Cardioversão Elétrica/instrumentação , Serviços Médicos de Emergência , Humanos , Itália , Análise de Sobrevida
5.
Ann Cardiol Angeiol (Paris) ; 52(1): 34-40, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12710293

RESUMO

OBJECTIVES: The cardiac safety of a once-a-day 200 mg controlled-release formulation of flecainide acetate in the prevention of paroxysmal atrial fibrillation (PAF) was assessed in outpatients. MATERIAL AND METHODS: The drug was administered for 24 weeks to 227 patients diagnosed with recurrent Paf episodes. Cardiac safety was assessed primarily by the maximum change from baseline in QRS duration. Changes in left ventricular function at echocardiography, incidence of proarrhythmic effects determined from ECG and Holter recordings and cardiovascular adverse events were also taken into account to assess cardiac safety. Efficacy was documented by actuarial methods. RESULTS: Mean maximum QRS increase from baseline was 11.4% (n = 181); QRS increase was < 15% in 71.8% of the patients and > or = 25% in 18.8%. Only 4 patients had maximum QRS value > 100 ms under treatment. Left ventricular ejection fraction remained within +/- 20% of baseline for 90% of the patients, increased above 20% for 8.6% and decrease below 30% for 1.4% (n = 139). Bradycardia (13.2%; n = 129) and ventricular extrasystoles (10.6%; n = 104) were the most frequently identified proarrhythmic effects. Atrio-ventricular block (4.0%), supra-ventricular tachycardia (2.2%), bundle branch block (1.8%) and atrial fibrillation (1.3%) were the most frequent drug-related cardiac adverse events. Estimated treatment success rate was 74% (95% CI: [68%; 80%]) and the incidence of Paf episodes decreased from baseline 28.6% to 11.0% (P < 0.0001). CONCLUSIONS: We provided evidence for a good cardiac safety profile of the controlled-release formulation of flecainide acetate and confirmed the effectiveness of the drug in the prevention of PAF recurrences.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/prevenção & controle , Flecainida/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antiarrítmicos/farmacologia , Bradicardia/tratamento farmacológico , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Eletrocardiografia , Feminino , Flecainida/farmacologia , Bloqueio Cardíaco/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/estatística & dados numéricos , Volume Sistólico/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Complexos Ventriculares Prematuros/tratamento farmacológico
6.
Eur Heart J ; 23(18): 1471-9, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12208228

RESUMO

BACKGROUND: Atrial fibrillation has a high incidence in patients wearing an implantable cardioverter defibrillator for ventricular tachyarrhythmias and may lead to palpitations, heart failure, angina, stroke and inappropriate defibrillator discharge. The aim of the study was to evaluate the efficacy of a dual chamber defibrillator with atrial antitachycardia functions in treating spontaneous atrial tachyarrhythmias. METHODS: One hundred and twelve patients, 88 male, mean age 64+/-11 years, were enrolled. Seventy-six had ischaemic heart disease, 21 idiopathic dilated cardiomyopathy, nine other heart diseases, six no structural heart disease. The mean left ventricular ejection fraction was 40+/-11%. Sixty-two had prior atrial tachyarrhythmias. RESULTS: Follow-up lasted 11+/-9 months (range 1-42). Among 933 ventricular tachyarrhythmia episodes, 100% of ventricular fibrillation and 92% of ventricular tachycardia were successfully cardioverted. Among 414 detected sustained atrial tachyarrhythmias, 195 were classified as atrial tachycardia (47.1%), 192 as atrial fibrillation (46.4%) and 27 (6.5%) as sinus rhythm. The detection-positive predictive value was 93.5%. Therapy success rates: antitachy pacing on atrial tachycardia = 71.3% (crude estimate); 66.1% (adjusted estimate); 50 Hertz on atrial fibrillation=36.2% (crude estimate); 13.5% (adjusted estimate); atrial shock on atrial fibrillation = 62.5% (mean energy 7.8+/-14.1J). Shock efficacy was 32% when delivered energy was < or = 2 atrial defibrillation threshold at implant and 92% when >2. Duration of successfully treated atrial episodes was significantly lower than that of unsuccessfully treated (6+/-26 min vs 42+/-60). CONCLUSIONS: Atrial antitachy pacing and shock therapies demonstrated very high efficacy in treating atrial tachyarrhythmias in defibrillator patients.


Assuntos
Fibrilação Atrial/terapia , Desfibriladores Implantáveis , Cardioversão Elétrica/métodos , Marca-Passo Artificial , Taquicardia Ventricular/terapia , Fibrilação Ventricular/terapia , Fibrilação Atrial/complicações , Cardioversão Elétrica/instrumentação , Desenho de Equipamento , Segurança de Equipamentos , Feminino , Seguimentos , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Taquicardia Ventricular/complicações , Resultado do Tratamento , Fibrilação Ventricular/complicações
7.
Circulation ; 104(19): 2324-30, 2001 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-11696473

RESUMO

BACKGROUND: In chronic heart failure (CHF), overactivation of ergoreceptors (afferents sensitive to the metabolic effects of muscular work) may be a link between peripheral changes, sympathetic overactivation, and increased hemodynamic and ventilatory responses to exercise. The relationship between ergoreceptors, autonomic changes, and the progression of the syndrome has not yet been studied. METHODS AND RESULTS: Thirty-eight stable CHF patients (age, 57+/-1 years; ejection fraction, 26+/-2%) were compared with 12 age-matched normal control subjects. The ergoreflex contribution to the ventilatory and hemodynamic responses to exercise, together with peripheral and central chemoreceptor sensitivity, arterial baroreflex sensitivity, plasma norepinephrine, epinephrine, and heart rate variability, were measured. Enhanced ergoreflex effects on ventilation (78+/-2% versus 50+/-8%), peripheral chemosensitivity (0.6+/-0.4 versus 0.2+/-0.1 L/min per percent SaO(2)), and central chemosensitivity (2.9+/-0.2 versus 2.0+/-0.2 L. min(-1). mm Hg(-1)) and an impaired baroreflex function (4.1+/-0.6 versus 9.1+/-5.6 ms/mm Hg) were confirmed in CHF compared with control subjects (P<0.01 in all comparisons). Ergoreceptor overactivity was associated with a worse symptomatic state (NYHA class, P<0.05), lower exercise tolerance (peak VO(2), P<0.05), and pronounced exercise hyperventilation (VE/VCO(2), P<0.01). It was also a strong predictor of increased central chemosensitivity (independently of clinical parameters), baroreflex impairment, and sympathetic activation (plasma catecholamines and heart rate variability indexes; all P<0.05). In multivariate analysis, among all reflexes studied, the ventilatory component of the ergoreflex was the only independent predictor of peak VO(2) and VE/VCO(2). CONCLUSIONS: In CHF, overactivation of the ergoreflex is associated with abnormal cardiorespiratory reflex control, independently of clinical severity. Among impaired reflexes, overactivation of the ergoreflex is an important determinant of exercise hyperventilation and reduced exercise tolerance.


Assuntos
Barorreflexo , Células Quimiorreceptoras/fisiopatologia , Metabolismo Energético , Insuficiência Cardíaca/fisiopatologia , Respiração , Sistema Nervoso Autônomo/fisiopatologia , Doença Crônica , Progressão da Doença , Eletrocardiografia , Metabolismo Energético/fisiologia , Epinefrina/sangue , Teste de Esforço , Feminino , Testes de Função Cardíaca , Frequência Cardíaca , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Músculos/metabolismo , Neurônios Aferentes , Norepinefrina/sangue , Estudos Prospectivos , Análise de Regressão , Resistência Vascular
8.
Am Heart J ; 142(6): 1047-55, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11717611

RESUMO

BACKGROUND: New atrial pacing techniques and overdrive pacing algorithms have been introduced to prevent atrial fibrillation. This study was designed to test the hypotheses that (1) interatrial septum pacing (IASP) at the triangle of Koch would be more effective than right atrial appendage pacing (RAAP) in preventing paroxysmal atrial fibrillation (PAF) in patients with sinus bradycardia and (2) an algorithm (CAP) designed to achieve constant atrial capture would increase the efficacy of rate-responsive atrial pacing. METHODS: We studied 46 patients with PAF and sinus bradycardia implanted with a DDD(R) (Medtronic Thera) pacemaker. Twenty-four patients (6.0 +/- 10.1 PAF episodes/month within 3 months before study) were randomized to RAAP and 22 patients (5.4 +/- 7.1, not significant) to IASP. Within each arm 2 randomized crossover periods of CAP-OFF and CAP-ON function were programed. RESULTS: The PAF episodes per month significantly decreased in the RAAP (CAP-OFF: 2.1 +/- 4.2, P <.05; CAP-ON: 1.9 +/- 3.8, P <.05) and in the IASP group (CAP-OFF: 0.2 +/- 0.5, P <.05; CAP-ON: 0.2 +/- 0.5, P <.05). Values were significantly lower in the IASP group than in the RAAP group in both CAP-OFF (0.2 +/- 0.5 vs 2.1 +/- 4.2, P <.05) and CAP-ON (0.2 +/- 0.5 vs 1.9 +/- 3.8, P <.05) conditions. PAF burden was significantly lower in the IASP than in the RAAP group in CAP-OFF (47 +/- 84 min/d vs 140 +/- 217, P <.05) and in CAP-ON (41 +/- 72 vs 193 +/- 266, P <.05) conditions. No differences were observed within each arm in PAF burden between the 2 crossover CAP programing periods. CONCLUSIONS: Rate-adaptive IASP at the triangle of Koch is more effective than RAAP in preventing PAF in patients with sinus bradycardia. In our sample of patients no additional clinical benefit is furnished by the CAP algorithm.


Assuntos
Fibrilação Atrial/prevenção & controle , Bradicardia/complicações , Estimulação Cardíaca Artificial/métodos , Idoso , Fibrilação Atrial/etiologia , Estudos Cross-Over , Feminino , Humanos , Masculino , Marca-Passo Artificial , Próteses e Implantes
11.
Acta Physiol Scand ; 171(3): 295-303, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11412141

RESUMO

Patients with heart failure are limited in their ability to tolerate exercise. Recent research has suggested that this limitation cannot be entirely attributed to cardiac or lung impairment but rather that changes in peripheral muscles may play an important role. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism and function are present in both conditions. Moreover, an exaggerated activity of the receptors sensitive to exercise-derived metabolic signals (muscle ergoreceptors and peripheral and central chemoreceptors) leads to early and profound exercise-induced fatigue and dyspnoea. These muscle afferents contribute to the ventilatory, haemodynamic and autonomic responses to exercise both in physiological and pathological conditions, including chronic heart failure. Against this background, a skeletal muscle origin of symptoms in heart failure has been proposed. The protective effects of physical training have been described in many recent studies: training improves ventilatory control, skeletal muscle metabolism and autonomic nervous system activity. The exercise training appears to induce its beneficial effects on skeletal muscle both directly (on muscle function, histological and biochemical features) and indirectly (by reducing the activation of the muscle afferents). The metabolic mediators of these muscle afferents may become a potential target in the future therapy of heart failure symptoms.


Assuntos
Exercício Físico , Insuficiência Cardíaca/fisiopatologia , Músculo Esquelético/fisiopatologia , Sistema Nervoso Autônomo/fisiologia , Doença Crônica , Insuficiência Cardíaca/metabolismo , Humanos , Músculo Esquelético/metabolismo , Aptidão Física
13.
J Interv Card Electrophysiol ; 5(1): 33-44, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11248773

RESUMO

AIM OF THE STUDY: The Consistent Atrial Pacing (CAP) algorithm has been designed to achieve a high percentage of atrial pacing to suppress paroxysmal atrial fibrillation. The aim of our study was to compare the impact of DDDR+CAP versus DDDR pacing on paroxysmal atrial fibrillation recurrences and triggers in patients with Brady-Tachy Syndrome. METHODS: 61 patients, 23 M and 38 F, mean age 75+/-9 y, affected by Brady-Tachy Syndrome, implanted with a DDDR pacemaker, were randomized to DDDR or DDDR+CAP pacing with cross over of pacing modality after 1 month. RESULTS: 78 % of patients in DDDR pacing and 73 % in DDDR + CAP pacing (p=n.s.) were free from symptomatic paroxysmal atrial fibrillation recurrences. During DDDR+CAP pacing, the atrial pacing percentage increased from 77+/-29 % to 96+/-7 % (p<0.0001). Automatic mode switch episodes/day were 0.73+/-1.09 in DDDR and 0.79+/-1.14 (p=n.s.) in DDDR+CAP. In patients with less than 50 % of atrial pacing during DDDR, automaticmode switch episodes/day decreased during DDDR+CAP from 1.13+/-1.59 to 0.23+/-0.32 (p<0.05) and in patients with less than 90 % from 1.23+/-1.27 to 0.75+/-1.10 (p<0.001). The number of premature atrial complexes per day decreased during DDDR + CAP from 2665+/-4468 to 556+/-704 (p<0.02). CONCLUSION: CAP algorithm allowed continuous overdrive atrial pacing without major side effects. Triggers of paroxysmal atrial fibrillation induction, such as premature atrial complexes, were critically decreased. Paroxysmal atrial fibrillation episodes were reduced in patients with atrial pacing percentage lower than 90 % during DDDR pacing.


Assuntos
Algoritmos , Fibrilação Atrial/prevenção & controle , Estimulação Cardíaca Artificial , Síndrome do Nó Sinusal/terapia , Idoso , Estudos Cross-Over , Eletrocardiografia , Feminino , Humanos , Masculino , Estudos Prospectivos , Prevenção Secundária , Síndrome do Nó Sinusal/complicações
14.
Eur Heart J ; 22(23): 2180-91, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11913480

RESUMO

BACKGROUND: Antiarrhythmic drugs are still used for the treatment of ventricular tachyarrhythmias, in combination with implantable cardioverter-defibrillators or without them. AIM OF THE STUDY: In a double-blind randomized crossover design, the short- and long-term efficacy and safety of oral dofetilide or oral sotalol were compared in 135 patients with ischaemic heart disease and inducible sustained ventricular tachycardia. METHODS: The inducibility of ventricular tachycardia was determined by programmed electrophysiological stimulation at baseline. Patients were then blindly randomized to receive either oral dofetilide 500 microg twice daily or oral sotalol 160 mg twice daily, for 3 to 5 days. Suppression of inducible ventricular tachycardia on the drug was then assessed by programmed electrophysiological stimulation. After a wash-out period of at least 2.5 days, the patients received the alternative treatment for 3 to 5 days. Suppression of inducible ventricular tachycardia on the alternate drug was again determined by programmed electrophysiological stimulation. Selection of long-term treatment was allocated blindly according to programmed electrophysiological stimulation results. RESULTS: During the acute phase, 128 patients received both dofetilide and sotalol. Sixty-seven patients were responders to either drug. Forty-six patients (35.9%) were responders to dofetilide compared with 43 (33.6%) to sotalol (P=ns). Only 23 patients responded to both dofetilide and sotalol. Adverse events, deemed to be treatment related, were seen in 2.3% of patients receiving dofetilide and 8.6% of patients receiving sotalol (P=0.016). Three patients on dofetilide had torsade de pointes. Two patients receiving sotalol died during the acute phase (one was arrhythmic death, and the other was due to heart failure). During the long-term phase, two of 42 patients (4.8%) receiving dofetilide and three of 27 patients (11.1%) receiving sotalol withdrew from treatment due to lack of efficacy. Overall, during the long-term phase, 23.8% of the patients receiving dofetilide and 37.0% of the patients receiving sotalol, withdrew from treatment with a similar pattern of withdrawals for the two drugs. CONCLUSION: Dofetilide was as efficacious as sotalol in preventing the induction of sustained ventricular tachycardia. There was no concordance in the response rate in two-thirds of the patients. Dofetilide was significantly better tolerated during the acute phase than sotalol. Both dofetilide and sotalol were well tolerated during the long term with no statistically significant difference in the adverse events.


Assuntos
Antiarrítmicos/uso terapêutico , Fenetilaminas/uso terapêutico , Sotalol/uso terapêutico , Sulfonamidas/uso terapêutico , Taquicardia Ventricular/tratamento farmacológico , Adulto , Idoso , Antiarrítmicos/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/tratamento farmacológico , Fenetilaminas/efeitos adversos , Sotalol/efeitos adversos , Estatística como Assunto , Sulfonamidas/efeitos adversos , Taquicardia Ventricular/mortalidade
15.
Ital Heart J Suppl ; 2(12): 1296-302, 2001 Dec.
Artigo em Italiano | MEDLINE | ID: mdl-11838351

RESUMO

Supraventricular tachyarrhythmias can be responsible for severe hemodynamic derangement which may contribute to the progression and worsening of heart failure. The resultant effect of these arrhythmias, however, is conditioned by several concomitant factors, such as age of the patients, left ventricular systolic function, and ventricular rate response. If the role of such arrhythmias in functional class, morbidity, and functional capacity is well accepted, controversial data are available on their role on mortality in patients with heart failure.


Assuntos
Fibrilação Atrial/etiologia , Insuficiência Cardíaca/complicações , Taquicardia Supraventricular/etiologia , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/prevenção & controle , Fibrilação Atrial/terapia , Ablação por Cateter , Ensaios Clínicos como Assunto , Eletrofisiologia , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Hemodinâmica , Humanos , Marca-Passo Artificial , Prognóstico , Estudos Prospectivos , Taquicardia Supraventricular/fisiopatologia , Taquicardia Supraventricular/terapia
16.
Vet J ; 160(3): 235-41, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11061960

RESUMO

We studied 205 dogs with cardiac diseases associated with left atrial enlargement (LAE). On the basis of electrocardiogram results, they were divided into: Group A, 50 dogs with atrial fibrillation (AF) and Group B, 155 dogs without AF. Group B was further subdivided in Group BI (123 dogs with sinus rhythm) and Group BII (32 dogs with cardiac arrhythmias other than AF). Bodyweight (BW) and left atrial diameter (LA) of Group A dogs were significantly greater (P< 0.05) than dogs in all other groups. The left atrium/aorta (LA/Ao) ratio of Group A dogs was significantly higher (P< 0.05) than that of dogs of Group B and BI. Using the couple of variables BW and LA, the logistic regression models were able to predict "non-development of AF" (with 92.3% probability) vs. "development of AF" (with 74% probability), and "maintaining sinus rhythm" (with 95.1% probability) vs."development of AF" (with 86% probability).


Assuntos
Fibrilação Atrial/veterinária , Cardiomegalia/veterinária , Doenças do Cão/etiologia , Animais , Fibrilação Atrial/etiologia , Fibrilação Atrial/patologia , Peso Corporal , Cardiomegalia/complicações , Doenças do Cão/patologia , Cães , Eletrocardiografia/veterinária , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Modelos Logísticos , Análise de Regressão , Estudos Retrospectivos , Ultrassonografia
18.
Clin Cardiol ; 23(9): 678-80, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11016018

RESUMO

BACKGROUND: Single-lead VDD pacing systems are an alternative to conventional DDD pacemakers in patients with atrioventricular (AV) block and normal sinus function. HYPOTHESIS: The aim of this study was to assess changes of P-wave amplitude occurring in dynamic conditions in two groups of patients with a single-lead VDD and with a DDD pacing system, respectively. METHODS: Twenty-eight patients with second- or third-degree AV block and normal sinus function were enrolled prospectively into the study. Seventeen patients were implanted with a single-lead VDD pacing system and 11 with a DDD pacemaker. Patients were evaluated at 3 months (all patients) and at 6 months (26 patients) at supine and in dynamic conditions (postural changes, hyperventilation, and during exercise). RESULTS: Mean P-wave values at supine were 1.92 +/- 1.10 mV at 3 months and 1.76 +/- 1.01 mV at 6 months for VDD systems, and 4.63 +/- 2.18 mV at 3 months and 4.58 +/- 2.80 mV at 6 months for DDD pacemakers. In dynamic conditions, P-wave amplitude changes compared with supine condition ranged between -74 and +226% in VDD, and between -53 and +138% in DDD; however P-wave amplitudes showed no significant changes compared with baseline. Moreover, changes in atrial signal amplitudes did not occur randomly, and in both systems P-wave amplitudes remained significantly correlated with supine values. CONCLUSIONS: A wide range of P-wave amplitude variations occurs in different postural conditions or during exercise, both with single-lead VDD and DDD pacing systems. However, with appropriate programming of atrial sensitivity based on supine values, constant atrial tracking can be maintained.


Assuntos
Estimulação Cardíaca Artificial/métodos , Bloqueio Cardíaco/terapia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Eletrodos Implantados , Teste de Esforço , Humanos , Pessoa de Meia-Idade , Postura , Estudos Prospectivos , Respiração
19.
Am Heart J ; 140(3): e12, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10966543

RESUMO

BACKGROUND: Electric conversion of atrial fibrillation is the most widely used and effective treatment for sinus rhythm restoration. However, it has a limited success rate and a high recurrence rate. HYPOTHESIS: Pretreatment with calcium channel blocker may improve the efficacy by reversing the so-called "electric remodeling" phenomenon, also related to overload in cytosolic calcium. METHODS: The efficacy of diltiazem or amiodarone pretreatment (oral, 1 month before and 1 month after conversion) on direct-current conversion of persistent atrial fibrillation was assessed in 120 patients, randomly assigned to 3 matched groups: A (n = 44, diltiazem); B (n = 46, amiodarone), and C (n = 30, digoxin). RESULTS: Before electric conversion, all treatments significantly decreased mean heart rate. Spontaneous conversion to sinus rhythm was achieved in 6% of patients of group A (3 of 46) versus 25% of group B (11 of 44) and 3% (1 of 30) of group C (A/C vs B, P < .005). Current conversion was more successful in group B (91%) compared with group A (76%) and group C (67%) (B vs A/C, P < .05), with no difference in the electric threshold for effective conversion (P = not significant). At the 24-hour time point, early relapse of atrial fibrillation was similar between groups A and B (A, 2%; B, 3%; P = not significant) and lower than group C (12%) (P < .01), whereas at the 1-month time point the recurrence rate was lower in group B (28%) versus groups A (56%) and C (78%) (B vs A/C, P < .01). No significant side effects were reported. CONCLUSIONS: Although diltiazem seems to be as effective as amiodarone in reducing early atrial fibrillation recurrences, diltiazem is less effective in determining spontaneous or electric conversion, with a higher recurrence rate at 2 months. Diltiazem pretreatment could be considered as only a second choice treatment in those patients in whom amiodarone is contraindicated.


Assuntos
Fibrilação Atrial/terapia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Diltiazem/uso terapêutico , Cardioversão Elétrica , Pré-Medicação , Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Método Simples-Cego , Resultado do Tratamento
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