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1.
Internist (Berl) ; 60(4): 424-430, 2019 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-30770942

RESUMO

Arterial hypertension represents one of the most frequent chronic diseases that can lead to complications, such as stroke, dementia, heart attack, heart failure and renal failure. By 2025 the number of hypertensive patients will increase to approximately 1.6 billion people worldwide. The new guidelines of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH) on the management of arterial hypertension replace the guidelines of the ESC/ESH from 2013. The 2018 guidelines of the ESC/ESH were adopted by the German Cardiac Society and the German Hypertension League. In these comments national characteristics are worked out and the essential new aspects of the guidelines are critically discussed. These include, for example, the definition of hypertension, the importance of out of office blood pressure measurements, revised blood pressure targets, the modified algorithm for drug treatment and the relevance of device-based hypertension treatments. Important aspects for the management of hypertensive emergencies are also presented.


Assuntos
Cardiologia , Hipertensão , Anti-Hipertensivos , Pressão Sanguínea , Determinação da Pressão Arterial , Humanos
2.
Herz ; 43(6): 490-497, 2018 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-30073398

RESUMO

Increasing complexity and new highly differentiated therapeutic procedures in cardiology result in a need for additional training beyond cardiology board certification. The German Cardiac Society therefore developed a variety of certifications of educational curricula and definition of specialized centers. Standardization and structuring in education and patient treatment, as defined by certifications may be helpful; however, introduction of certification can have serious consequences for hospital structure, the side effects of which may impair quality of treatment for individual patients. The current article discusses these issues against the background of the following questions: how is quality defined? How do certifications interfere with patient care on a nationwide level, how do they influence responsibilities and teamwork? Are there conflicts of interests by designing certifications and how good are the organizational structures? Finally, suggestions are made on what has to be considered when designing certifications. Certifications should acknowledge all cardiologists, irrespective of their position in the level of care. There should be a coherent unified concept synchronizing all certifications and administration needs to be transparent and well structured.


Assuntos
Cardiologia , Certificação , Cardiologia/normas , Humanos
3.
Internist (Berl) ; 59(10): 999-1010, 2018 10.
Artigo em Alemão | MEDLINE | ID: mdl-30105398

RESUMO

Although pacemakers and implantable defibrillators have become the standard treatment of bradycardic and tachycardic arrhythmias, long-term complications caused by the transvenously inserted pacing and defibrillation leads, such as electrode fracture, lead infection and tricuspid valve insufficiency are not uncommonly observed. Therefore, leadless pacemakers and purely subcutaneously implantable cardioverter defibrillators (S-ICDs) have been developed in recent years, which are implanted without transvenous electrodes with the aim to reduce long-term complications with these devices; however, currently available leadless pacemakers are limited to single chamber stimulation and S­ICDs are limited to pure defibrillation without antibradycardic, antitachycardic pacing or cardiac resynchronization capabilities. Thus, these devices cannot yet be used as multichamber pacemakers or defibrillators even though in these circumstances a higher complication rate is to be expected due to the multiple number of transvenous leads. This article summarizes the current state of knowledge on leadless pacemakers and ICDs, discusses the limitations of these devices and provides an outlook into their future development.


Assuntos
Estimulação Cardíaca Artificial , Terapia de Ressincronização Cardíaca/métodos , Desfibriladores Implantáveis , Marca-Passo Artificial , Arritmias Cardíacas/terapia , Desenho de Equipamento , Humanos , Taquicardia
4.
Europace ; 12(1): 71-7, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19864311

RESUMO

AIMS: Little is known about the incidence of paroxysmal atrial tachycardias (PAT) in patients with heart failure (HF). The availability of cardiac resynchronization therapy (CRT) devices with extended diagnostics for AT enables continuous monitoring of PAT episodes. The aim of the study was to assess the incidence over time of PAT in HF patients treated with CRT. METHODS AND RESULTS: Consecutive patients in NYHA functional class III or IV despite optimal drug therapy, QRS duration > or = 130 ms, left ventricular ejection fraction < or = 35%, and left ventricular end-diastolic dimension > or = 55 mm were eligible for enrolment. Patients with permanent or persistent atrial fibrillation (AF) were not included in the study. The first follow-up examination was performed 2 weeks after implantation, to optimize atrial sensing and CRT. Subsequent follow-up examinations were carried out 15 and 28 weeks after implantation, to collect the telemetric data. A total of 173 patients (67 +/- 11 years, M 116) were enrolled. Complete arrhythmia monitoring data were available from 120 patients over a mean follow-up of 183 +/- 23 days. Atrial tachycardia episodes were detected through telemetry in 25 of 120 patients (21%) during at least one follow-up examination. Atrial tachycardia episodes were recorded in 29 and 17% (P = NS) of patients with and without previous history of AF, respectively. CONCLUSION: More than 20% of the overall HF patient population treated with CRT suffer PAT episodes. Paroxysmal atrial tachycardia may interfere with response to CRT. Therefore, telemetric data may be relevant to drive the appropriate therapy in each patient.


Assuntos
Fibrilação Atrial/epidemiologia , Fibrilação Atrial/prevenção & controle , Estimulação Cardíaca Artificial/estatística & dados numéricos , Eletrocardiografia Ambulatorial/estatística & dados numéricos , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/prevenção & controle , Idoso , Fibrilação Atrial/diagnóstico , Comorbidade , Europa (Continente)/epidemiologia , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Incidência , Masculino , Medição de Risco/métodos , Fatores de Risco , Resultado do Tratamento
5.
Clin Res Cardiol ; 109(1): 1-12, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31410547

RESUMO

Indications for TF-TAVI (transfemoral transcatheter aortic valve implantation) are rapidly changing according to increasing evidence from randomized controlled trials. Present trials document the non-inferiority or even superiority of TF-TAVI in intermediate-risk patients (STS-Score 4-8%) as well as in low-risk patients (STS-Score < 4%). However, risk scores exhibit limitations and, as a single criterion, are unable to establish an appropriate indication of TF-TAVI vs transapical TAVI vs SAVR (surgical aortic valve replacement). The ESC (European Society of Cardiology)/EACTS (European Association for Cardio-Thoracic Surgery) guidelines 2017 and the German DGK (Deutsche Gesellschaft für Kardiologie)/DGTHG (Deutsche Gesellschaft für Thorax-, Herz- und Gefäßchirurgie) commentary 2018 offer a framework for the selection of the best therapeutic method, but the individual decision is left to the discretion of the heart teams. An interdisciplinary TAVI consensus group of interventional cardiologists of the ALKK (Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte e.V.) and cardiac surgeons has developed a detailed consensus on the indications for TF-TAVI to provide an up-to-date, evidence-based, comprehensive decision matrix for daily practice. The matrix of indication criteria includes age, risk scores, contraindications against SAVR (e.g., porcelain aorta), cardiovascular criteria pro TAVI, additional criteria pro TAVI (e.g., frailty, comorbidities, organ dysfunction), contraindications against TAVI (e.g., endocarditis) and cardiovascular criteria pro SAVR (e.g., bicuspid valve anatomy). This interdisciplinary consensus may provide orientation to heart teams for individual TAVI-indication decisions. Future adaptations according to evolving medical evidence are to be expected. Interdisciplinary consensus on indications for transfemoral transcatheter aortic valve implantation (TF-TAVI).


Assuntos
Estenose da Valva Aórtica/cirurgia , Substituição da Valva Aórtica Transcateter/métodos , Consenso , Artéria Femoral , Humanos , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Herzschrittmacherther Elektrophysiol ; 17(4): 205-10, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17211751

RESUMO

In the past decade molecular genetic analysis has greatly expanded our knowledge about inherited arrhythmogenic syndromes. The congenital long QT syndrome (LQTS) and the recently described short QT syndrome (SQTS), with the defining characteristic of abnormal prolongation or shortening of the QTc interval on the surface electrocardiogram, are caused by cardiac ion channel dysfunctions. These "channelopathies" show a high degree of genetic heterogeneity of the molecular pathways in terms of the relationships between genetic defects and phenotypic expression. In this brief review we summarize the current understanding of the molecular basis of long and short QT syndrome with focus on the impact of molecular genetics on the clinical management of these diseases.


Assuntos
Canalopatias/genética , Eletrocardiografia , Síndrome do QT Longo/genética , Taquicardia Supraventricular/genética , Mapeamento Cromossômico , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Triagem de Portadores Genéticos , Predisposição Genética para Doença/genética , Testes Genéticos , Genótipo , Humanos , Fenótipo
7.
Circulation ; 104(25): 3026-9, 2001 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-11748094

RESUMO

BACKGROUND: Cardiac resynchronization therapy (CRT) improves systolic function in heart failure patients with ventricular conduction delay by stimulating the left ventricle (LV) or both ventricles (biventricular, BV). Optimal LV site selection is of major clinical interest for CRT device implantation; however, the dependence of hemodynamics on LV stimulation site has not been established. Thus, the objective of this study was to compare the hemodynamic response to CRT for 2 LV coronary vein sites: the free wall and anterior wall. Methods and Results- A total of 30 patients (mean NYHA class, 2.7; mean QRS interval, 152 ms; mean PR interval, 194 ms) enrolled in the PATH-CHF-II trial were studied. CRT was administered with LV and BV stimulation in VDD mode at 4 AV delays. LV stimulation was at the lateral free wall or anterior wall, whereas right ventricular stimulation was fixed near the apex. LV+dP/dt(max) and aortic pulse pressure changes from baseline during CRT were compared for LV sites. Free wall sites with LV and BV stimulation yielded significantly larger LV+dP/dt(max) (14% versus 6%, P<0.001 for LV; 12% versus 5%, P<0.001 for BV) and pulse pressure (8% versus 4%, P<0.001 for LV; 9% versus 5%, P<0.001 for BV) compared with anterior sites. In one third of patients, CRT at free wall sites increased LV+dP/dt(max), whereas it decreased at anterior sites over most AV delays. CONCLUSION: CRT with LV free wall stimulation produced significantly better LV systolic performance compared with anterior stimulation. Further studies are warranted to prove the clinical superiority of the LV free wall as a site for long-term CRT.


Assuntos
Estimulação Cardíaca Artificial/métodos , Insuficiência Cardíaca/terapia , Ventrículos do Coração/fisiopatologia , Idoso , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Sístole , Fatores de Tempo
8.
Circulation ; 104(20): 2430-5, 2001 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-11705820

RESUMO

BACKGROUND: Cardiac parasympathetic nerves run alongside the superior vena cava (SVC) and accumulate particularly epicardially adjacent to the orifice of the coronary sinus (CS). In animals, these nerves can be electrically stimulated inside the SVC or CS, which results in negative chronotropic/dromotropic effects and negative inotropic effects in the atria but not the ventricles. Parasympathetic nerve stimulation (PS) with 20 Hz in the CS, however, also excites the atria, thereby inducing atrial fibrillation. The present study overcomes this limitation by applying high-frequency nerve stimuli within the atrial refractory period. Using this technique, we investigated for the first time whether neurophysiological effects similar to those in animals can be obtained in humans. METHODS AND RESULTS: In 25 patients, parasympathetic nerves were stimulated via a multipolar electrode catheter placed in the SVC (stimulation with 20 Hz; n=14) or CS (pulsed 200-Hz stimuli; n=11). A significant sinus rate decrease and prolongation of the antegrade Wenckebach period was achieved during PS in the SVC. During PS in the CS, a graded-response prolongation of the antegrade Wenckebach interval was observed with increasing PS voltage until third-degree AV block occurred in 8 of 11 patients. The negative chronotropic/dromotropic effects started and terminated immediately after the onset and termination of PS, respectively. Atropine abolished these effects (n=11). CONCLUSIONS: Human parasympathetic efferent nerve stimulation induces reversible negative chronotropic and dromotropic effects. PS may serve as an adjunctive tool for the diagnosis/treatment of supraventricular tachycardias and may be beneficial for ventricular rate slowing during tachycardic atrial fibrillation in patients with congestive heart failure.


Assuntos
Cateterismo Cardíaco/métodos , Coração/inervação , Sistema Nervoso Parassimpático/fisiologia , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/terapia , Nó Atrioventricular/inervação , Estimulação Elétrica , Eletrocardiografia , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Dor/diagnóstico , Radiografia , Veia Cava Superior/diagnóstico por imagem , Veia Cava Superior/inervação
9.
Circulation ; 103(5): 691-8, 2001 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-11156881

RESUMO

BACKGROUND: After cardioversion of atrial fibrillation (AF), the contractile function of the atria is temporarily impaired. Although this has significant clinical implications, the underlying cellular mechanisms are poorly understood. METHODS AND RESULTS: Forty-nine consecutive patients submitted for mitral valve surgery were investigated. Twenty-three were in persistent AF (>/=3 months); the others were in sinus rhythm. Before extracorporal circulation, the right atrial appendage was excised. ss-Adrenoceptors were quantified by radioligand binding, and G proteins were quantified by Western blot analysis. The isometric contractile response to Ca(2+), isoproterenol, Bay K8644, and the postrest potentiation of contractile force were investigated in thin atrial trabeculae, which were also examined histologically. The contractile force of the atrial preparations obtained from AF patients was 75% less than that in preparations from patients in sinus rhythm. Also, the positive inotropic effect of isoproterenol was impaired, and Bay K8644 failed to increase atrial contractile force. In contrast, the response to extracellular Ca(2+) was maintained, and the postrest potentiation was preserved. Beta-adrenoceptor density and G-protein expression were unchanged. Histological examination revealed 14% more myolysis in the atria of AF patients. CONCLUSIONS: After prolonged AF, atrial contractility was reduced by 75%. The impairment of beta-adrenergic modulation of contractile force cannot be explained by downregulation of ss-adrenoceptors or changes in G proteins. Dysfunction of the sarcoplasmic reticulum does not occur after prolonged AF. Failure of Bay K8644 to restore contractility suggests that the L-type Ca(2+) channel is responsible for the contractile dysfunction. The restoration of contractile force by high extracellular Ca(2+) shows that the contractile apparatus itself is nearly completely preserved after prolonged AF.


Assuntos
Fibrilação Atrial/fisiopatologia , Contração Miocárdica , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Fibrilação Atrial/metabolismo , Western Blotting , Agonistas dos Canais de Cálcio/farmacologia , Doença Crônica , Feminino , Humanos , Masculino , Microscopia , Pessoa de Meia-Idade , Contração Miocárdica/efeitos dos fármacos , Receptores Adrenérgicos beta/metabolismo , Transdução de Sinais
10.
Circulation ; 99(23): 2993-3001, 1999 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-10368116

RESUMO

BACKGROUND: Previous studies of pacing therapy for dilated congestive heart failure (CHF) have not established the relative importance of pacing site, AV delay, and patient heterogeneity on outcome. These variables were compared by a novel technique that evaluated immediate changes in hemodynamic function during brief periods of atrial-synchronous ventricular pacing. METHODS AND RESULTS: Twenty-seven CHF patients with severe left ventricular (LV) systolic dysfunction and LV conduction disorder were implanted with endocardial pacing leads in the right atrium and right ventricle (RV) and an epicardial lead on the LV and instrumented with micromanometer catheters in the LV, aorta, and RV. Patients in normal sinus rhythm were stimulated in the RV, LV, or both ventricles simultaneously (BV) at preselected AV delays in a repeating 5-paced/15-nonpaced beat sequence. Maximum LV pressure derivative (LV+dP/dt) and aortic pulse pressure (PP) changed immediately at pacing onset, increasing at a patient-specific optimal AV delay in 20 patients with wide surface QRS (180+/-22 ms) and decreasing at short AV delays in 5 patients with narrower QRS (128+/-12 ms) (P<0.0001). Overall, BV and LV pacing increased LV+dP/dt and PP more than RV pacing (P<0.01), whereas LV pacing increased LV+dP/dt more than BV pacing (P<0.01). CONCLUSIONS: In this population, CHF patients with sufficiently wide surface QRS benefit from atrial-synchronous ventricular pacing, LV stimulation is required for maximum acute benefit, and the maximum benefit at any site occurs with a patient-specific AV delay.


Assuntos
Arritmias Cardíacas/fisiopatologia , Estimulação Cardíaca Artificial , Cardiomiopatia Dilatada/fisiopatologia , Doença das Coronárias/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Hemodinâmica , Sístole , Idoso , Análise de Variância , Arritmias Cardíacas/etiologia , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/terapia , Doença das Coronárias/complicações , Doença das Coronárias/terapia , Estudos Cross-Over , Feminino , Bloqueio Cardíaco/etiologia , Bloqueio Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego
11.
J Am Coll Cardiol ; 38(7): 1957-65, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738300

RESUMO

OBJECTIVES: We sought to investigate the impact of six months of cardiac resynchronization therapy (CRT) on echocardiographic variables of left ventricular (LV) function. BACKGROUND: Cardiac resynchronization therapy has recently been introduced as a new therapeutic modality in patients with advanced heart failure (HF) and conduction abnormalities. However, most studies have only investigated the early hemodynamic effects of CRT. METHODS: Twenty-five patients (12 women and 13 men; 59.8 +/- 5.1 years old) with advanced HF caused by ischemic (n = 7) or idiopathic dilated cardiomyopathy (n = 18) and a prolonged QRS complex were analyzed. All patients underwent early hemodynamic testing with a randomized testing protocol; echocardiographic measurements were compared before implantation and after six months of CRT. RESULTS: Left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD, respectively) were significantly reduced after six months (LVEDD from 71 +/- 10 to 68 +/- 11 mm, p = 0.027; LVESD from 63 +/- 11 to 58 +/- 11 mm, p = 0.007), as were LV end-diastolic and end-systolic volumes (LVEDV from 253 +/- 83 to 227 +/- 112 ml, p = 0.017; LVESV from 202 +/- 79 to 174 +/- 101 ml, p = 0.009). Ejection fraction was significantly increased (from 22 +/- 7% to 26 +/- 9%, p = 0.03). "Nonresponders," with regard to LV volume reduction, had significantly higher baseline LVEDV, compared with "responders" (351 +/- 52 vs. 234 +/- 74 ml, p = 0.018). Overall, there was only mild mitral regurgitation at baseline, with a minor reduction by semiquantitative analysis. The results of early hemodynamic testing did not predict the volume response. CONCLUSIONS: Cardiac resynchronization therapy may lead to a reduction in LV volumes in patients with advanced HF and conduction disturbances. Volume nonresponders have significantly higher baseline LVEDV.


Assuntos
Eletrocardiografia , Insuficiência Cardíaca/terapia , Síndrome do QT Longo/terapia , Isquemia Miocárdica/terapia , Marca-Passo Artificial , Disfunção Ventricular Esquerda/terapia , Idoso , Volume Cardíaco/fisiologia , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Dilatada/terapia , Ecocardiografia , Feminino , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Hemodinâmica/fisiologia , Humanos , Síndrome do QT Longo/diagnóstico por imagem , Síndrome do QT Longo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia
12.
J Am Coll Cardiol ; 38(1): 91-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451302

RESUMO

OBJECTIVES: The objective of this study was to compare electroanatomic mapping for the assessment of myocardial viability with nuclear metabolic imaging using positron emission computed tomography (PET) and with data on functional recovery after successful myocardial revascularization. BACKGROUND: Animal experiments and first clinical studies suggested that electroanatomic endocardial mapping identifies the presence and absence of myocardial viability. METHODS: Forty-six patients with prior (> or =2 weeks) myocardial infarction underwent fluorine-18 fluorodeoxyglucose (FDG) PET and Tc-99m sestamibi single-photon emission computed tomography (SPECT) before mapping and percutaneous coronary revascularization. The left ventricular endocardium was mapped and divided into 12 regions, which were assigned to corresponding nuclear regions. Functional recovery using the centerline method was assessed in 25 patients with a follow-up angiography. RESULTS: Regional unipolar electrogram amplitude was 11.0 mV +/- 3.6 mV in regions with normal perfusion, 9.0 mV +/- 2.8 mV in regions with reduced perfusion and preserved FDG-uptake and 6.5 mV +/- 2.6 mV in scar regions (p < 0.001 for all comparisons). At a threshold amplitude of 7.5 mV, the sensitivity and specificity for detecting viable (by PET/SPECT) myocardium were 77% and 75%, respectively. In infarct areas with electrogram amplitudes >7.5 mV, improvement of regional wall motion (RWM) from -2.4 SD/chord +/- 1.0 SD/chord to -1.5 SD/chord +/- 1.1 SD/chord (p < 0.01) was observed, whereas, in infarct areas with amplitudes <7.5 mV, RWM remained unchanged at follow-up (-2.3 SD/chord +/- 0.7 SD/chord to -2.4 SD/chord +/- 0.7 SD/chord). CONCLUSIONS: These data suggest that the regional unipolar electrogram amplitude is a marker for myocardial viability and that electroanatomic mapping can be used for viability assessment in the catheterization laboratory.


Assuntos
Técnicas Eletrofisiológicas Cardíacas , Endocárdio/fisiologia , Coração/diagnóstico por imagem , Infarto do Miocárdio/patologia , Idoso , Angioplastia Coronária com Balão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/terapia , Miocárdio/metabolismo , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular
13.
Am J Cardiol ; 83(5B): 130D-135D, 1999 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-10089855

RESUMO

In conjunction with pharmacologic therapy, pacing has been proposed as a potential treatment to decrease symptoms in patients with moderate-to-severe congestive heart failure (CHF). Uncontrolled studies of pacing therapy for CHF dealing with different pacing sites, modes of pacing, and atrioventricular delays have reported mixed outcomes. The Pacing Therapies in Congestive Heart Failure (PATH-CHF) study is a single-blind, randomized, crossover, controlled trial designed to evaluate the effects of pacing on acute hemodynamic function and to assess chronic clinical benefit in patients with moderate-to-severe CHF. The effect of pacing on oxygen consumption at peak exercise and at anaerobic threshold during cardiopulmonary exercise tests, and on 6-minute walk distance, have been selected as primary endpoints of the study. Secondary endpoints of the trial were changes in New York Heart Association (NYHA) functional class, quality-of-life as assessed by the Minnesota Living with Heart Failure questionnaire, and hospitalization frequency. Finally, changes in ejection fraction, cardiac output, and filling pattern were assessed by echocardiography. The trial was planned to include 53 patients from 7 centers in Europe over a period of 3 years. The study was divided into 2 parts: acute testing and chronic follow-up. The acute study, performed during the pacemaker implantation, involved extensive testing using a custom-designed computer (FLEXSTIM) and a unique burst pacing protocol (FLEXSTIM protocol) to determine the best ventricular pacing sites and the most appropriate atrioventricular delays. The chronic phase consisted of a crossover study designed to test in each patient the best univentricular pacing site and biventricular pacing as assessed by the acute hemodynamic study. The study started with the first implant in 1995 and has, to date, included 42 patients. The study is expected to be completed by the end of 1998. The results of a first interim analysis showed trends toward improvement in all primary and secondary endpoints during the pacing periods compared with no pacing.


Assuntos
Insuficiência Cardíaca/terapia , Marca-Passo Artificial , Adulto , Idoso , Estudos Cross-Over , Eletrocardiografia Ambulatorial/instrumentação , Teste de Esforço/instrumentação , Feminino , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Processamento de Sinais Assistido por Computador/instrumentação , Volume Sistólico/fisiologia , Resultado do Tratamento
14.
Am J Cardiol ; 86(9A): 133K-137K, 2000 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11084113

RESUMO

Dilated cardiomyopathy is frequently associated with electrical conduction disturbances. Development of left bundle-branch block with discoordinated ventricular contraction pattern further contributes to impaired hemodynamic performance. Biventricular pacing has evolved as a new treatment option for patients with dilated cardiomyopathy and conduction disturbances. The "electrical" approach aims to normalize the disturbed contraction pattern, thereby improving hemodynamic function by simultaneous stimulation at different ventricular sites. Acute hemodynamic improvement with biventricular pacing has been demonstrated in patients with depressed left ventricular function and delayed intraventricular conduction. Due to the variations in optimal pacing site and atrioventricular delay, individual optimization to achieve optimal hemodynamic benefit is necessary. Echocardiography has the potential to provide hemodynamic data by Doppler techniques and combine these with geometric information about ventricular volumes, ejection fraction, and contraction patterns. This article focuses on the use of echocardiographic techniques for noninvasive optimization in cardiac pacing and presents preliminary experience from the initial trials on multisite pacing in heart failure.


Assuntos
Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/terapia , Estimulação Cardíaca Artificial/métodos , Eletrocardiografia , Insuficiência Cardíaca/complicações , Hemodinâmica , Humanos
15.
Am J Cardiol ; 86(9A): 138K-143K, 2000 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11084114

RESUMO

Ventricular resynchronization therapy (VRT) by left or biventricular stimulation is gaining increasing acceptance as a new therapy in addition to drugs in patients with advanced heart failure and intraventricular conduction disturbances. Several studies have demonstrated acute hemodynamic benefit of VRT in these patients, although there are only limited long-term data in small patient cohorts. Many open questions remain: whether to pace both ventricles or the left ventricle alone, the optimal left ventricular pacing site, the criteria used to identify the optimal candidate for VRT (e.g., QRS width), and the importance of an integrated defibrillator function in a VRT device. The Pacing Therapy in Congestive Heart Failure (PATH-CHF) II study is a prospective, randomized, cross-over study currently investigating the potential benefit of VRT in a population with advanced heart failure, with or without an accepted indication for an implantable defibrillator. It focuses on the effects of optimized univentricular pacing in these patients, and both acute hemodynamic and chronic functional effects are assessed. Acute hemodynamic testing mainly investigates the impact of different left ventricular pacing sites, alone or combined with right ventricular sites, on hemodynamic performance. Primary endpoint of the study is an improvement in functional capacity as assessed by cardiopulmonary exercise testing and 6-minute walk distance; secondary endpoints include improvement in quality of life (assessed by Minnesota quality of life score, New York Heart Association (NYHA) functional class, and hospitalization frequency), and improvements in prognostic and hemodynamic parameters. The trial aims to enroll 64 patients with full datum sets (separately in 2 groups with a QRS of < or = 150 or > 150 msec, respectively) in 9 European centers. The enrollment began September 1998, and is expected to conclude in summer 2000 to reach the number of necessary datum sets.


Assuntos
Arritmias Cardíacas/terapia , Estimulação Cardíaca Artificial/métodos , Insuficiência Cardíaca/complicações , Arritmias Cardíacas/etiologia , Estudos Cross-Over , Hemodinâmica , Humanos , Seleção de Pacientes , Estudos Prospectivos , Projetos de Pesquisa
16.
Am J Cardiol ; 86(9A): 144K-151K, 2000 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11084115

RESUMO

Right ventricular pacing at various sites and shortened atrioventricular (AV) delay has failed to demonstrate a convincing short-term and long-term improvement of left ventricular function. Left-ventricular-based stimulation offers a new therapeutic option for patients with symptomatic congestive heart failure and conduction disturbances, especially of left bundle-branch block configuration. Left ventricular mechanical improvement seems mainly dependent on the pacing site, in addition to optimizing the AV delay. Predominantly retrospective data suggest that pacing the posterolateral free wall results in the greatest hemodynamic improvement. Based on the evaluation of different pacing sites in 2 patients, we noted that site is of major importance for maximal improvement of left ventricular function, and pacing at a suboptimal site can even deteriorate left ventricular contractility. Moreover, lead technology has advanced rapidly and different areas of the left ventricle can now be reached transvenously for acute and chronic placement. Therefore, ongoing trials will help to identify the optimal pacing site and might indicate whether invasive testing will be required in the future.


Assuntos
Arritmias Cardíacas/terapia , Estimulação Cardíaca Artificial/métodos , Insuficiência Cardíaca/complicações , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Ventrículos do Coração , Hemodinâmica , Humanos , Estudos Prospectivos , Estudos Retrospectivos
17.
Am J Cardiol ; 83(5B): 136D-142D, 1999 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-10089856

RESUMO

Despite increasing evidence of hemodynamic benefit and long-term improvement in clinical status of congestive heart failure (CHF) patients with left ventricular and biventricular pacing, the risks and technical limitations of placing a permanent left ventricular pacing lead have prevented widespread clinical adoption of this therapy. Results of this and other recent investigations suggest it is necessary to target specific sites on the left ventricle to maximize hemodynamic benefit. However, limitations and variations of coronary vein anatomy, as well as patient safety, lead dislodgement, pacing thresholds, lead handling, and ease-of-use issues, present technical challenges for current transvenous permanent pacing lead designs. However, a new transvenous lead system based on an over-the-wire design appears to solve many of these problems and has proved feasible in acute clinical studies.


Assuntos
Insuficiência Cardíaca/terapia , Disfunção Ventricular Esquerda/terapia , Animais , Vasos Coronários , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/fisiologia , Humanos , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/fisiologia
18.
Am J Cardiol ; 83(5B): 143D-150D, 1999 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-10089857

RESUMO

Treatment of congestive heart failure (CHF) aims for symptomatic relief and reduction of mortality both from sudden death and pump failure. The implantable cardioverter defibrillator (ICD) is highly effective in the prevention of sudden death, but no mortality benefit in advanced CHF has yet been shown. Biventricular pacing may lead to functional improvement in selected patients with CHF. Thus, a biventricular pacemaker with defibrillation capabilities may be ideal for patients with advanced CHF. We retrospectively analyzed the data from 384 patients (age 59 +/- 12 years, 322 male and 62 female) with regard to New York Heart Association (NYHA) CHF class, mean QRS duration, mean PR interval, presence of a QRS > 120 msec and incidence of atrial fibrillation at the time of ICD implantation. Based on eligibility criteria from studies in biventricular pacing, we analyzed how many patients may benefit from biventricular pacing. Patients with CHF were older (NYHA class III: 60.9 +/- 9.7, class II: 61.3 +/- 10 versus class I: 50.8 +/- 13.6 years, p < 0.001 each) and mean QRS duration was longer with advanced CHF (NYHA class III 127.8 +/- 30 msec; class II 119.4 +/- 27.7 msec; class 0-1: 103.9 +/- 17.7 msec, p < 0.001, analysis of variance) as was the mean PR interval (NYHA class III 189.9 +/- 33.5 msec; class II 176.1 +/- 29.3 msec; class 0-1 162.7 +/- 45.9 msec, p < 0.001, analysis of variance). The incidence of atrial fibrillation was higher in class III (25.5%) compared with class 0-1 (16.9%) and class II patients (14.1%, p = 0.043, chi-square test). A total of 28 patients (7.3%) fulfilled eligibility criteria for biventricular pacing if NYHA class III patients were considered candidates and 48 (12.5%) if patients with NYHA II CHF and ejection fraction < or = 30% were included. Thus, biventricular pacing may offer a promising therapeutic approach for a significant proportion of patients with CHF at risk for ventricular tachyarrhythmia.


Assuntos
Desfibriladores Implantáveis , Insuficiência Cardíaca/terapia , Marca-Passo Artificial , Taquicardia Ventricular/terapia , Idoso , Terapia Combinada , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Eletrocardiografia Ambulatorial , Desenho de Equipamento , Feminino , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Volume Sistólico/fisiologia , Taxa de Sobrevida , Taquicardia Ventricular/mortalidade , Taquicardia Ventricular/fisiopatologia
19.
Ann Thorac Surg ; 69(5): 1358-62, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10881805

RESUMO

BACKGROUND: New onset of atrial fibrillation is a frequent complication after coronary artery bypass grafting and is a major cause of postoperative morbidity. Preoperative oral treatment with amiodarone hydrochloride has been shown to be efficacious as prophylaxis. The present study investigated whether intraoperative use of intravenous amiodarone has a preventive effect on the incidence of atrial fibrillation after coronary revascularization. METHODS: In a prospective study, 150 consecutive patients (mean age, 63 +/- 8 years; 132 men and 18 women) undergoing coronary artery bypass grafting were randomly assigned to one of three groups. Two groups received different doses of intravenous amiodarone (group I, 300-mg bolus and 20 mg x kg(-1) x day(-1) for 3 days; group II, 150-mg bolus and 10 mg x kg(-1) x day(-1) for 3 days) after aortic cross-clamping and one group, placebo (group III). Continuous electrocardiographic online monitoring was performed for 10 days. Arrhythmias were analyzed with respect to type, frequency, duration, and clinical relevance. RESULTS: New onset of atrial fibrillation occurred in 24% of patients in group I, 28% in group II, and 34% in group III (p = not significant). Atrial fibrillation with a rapid ventricular response (>120 beats per minute) was significantly more frequent in the control group (group I, 14%; group II, 24%; group III, 32%; p < 0.05, group I versus group III) and appeared significantly earlier (group I, day 4.3 +/- 2.5; group II, day 4.8 +/- 2.9; group III, day 2.6 +/- 1.3; p < 0.05, group III versus groups I and II). Temporary atrial pacing because of bradycardia (<60 beats per minute) was necessary significantly more often in group I (group I, 48%; group II, 40%; group III, 28%; p < 0.05, group I versus group III). Early mortality rate (group I, 4%; group II, 2%; group III, 4%), rate of perioperative complications (group I, 14%; group II, 20%; group III, 14%), and duration of hospital stay (group I, 14.0 days; group II, 14.4 days; group III, 14.7 days) were not different between groups. CONCLUSIONS: Intraoperative prophylactic use of amiodarone does not prevent new onset of atrial fibrillation in patients undergoing coronary artery bypass grafting and had no effect on outcome. Therefore, intraoperative prophylactic treatment with amiodarone at the tested doses does not appear to be justified.


Assuntos
Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/prevenção & controle , Ponte de Artéria Coronária , Cuidados Intraoperatórios , Bradicardia/prevenção & controle , Feminino , Humanos , Injeções Intravenosas , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Resultado do Tratamento
20.
Int J Cardiol ; 70(2): 109-18, 1999 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-10454298

RESUMO

Body surface potential maps (BSPM) from patients with coronary artery disease or no structural heart disease were analyzed with respect to their spatial features and QT/QTc dispersion in order to determine whether BSPM allows identification of patients with ventricular fibrillation. QRST integral maps and QT/QTc dispersion were acquired from simultaneous recordings of 62 ECG leads during sinus rhythm in patients with idiopathic ventricular fibrillation (n=13), ventricular fibrillation and coronary artery disease (n=22), coronary artery disease without ventricular fibrillation (n=21) and healthy controls (n=18). The Karhunen-Loeve transformation was applied to reduce the dimensionality of the data matrix of the QRST map to eight coefficients. Linear discriminant analysis allowed discrimination between idiopathic ventricular fibrillation patients and controls with high sensitivity (85%) and specificity (89%). However, discrimination between coronary artery disease patients with or without ventricular fibrillation was poor (68% and 67%, respectively). QTc dispersion calculated from BSPM was longer in idiopathic ventricular fibrillation patients than in controls (99+/-30 ms vs 70+/-14 ms, P=0.009) in contrast to QTc dispersion taken from 12-lead ECG (53+/-21 ms vs. 47+/-12 ms, P=n.s.). No significant difference was noted for coronary artery disease patients with or without ventricular fibrillation. In conclusion, repolarization disturbances detected by BSPM allow identification of ventricular fibrillation patients without structural heart disease. However, our results do not suggest a major impact of QT/QTc dispersion or QRST integral mapping for identification of ventricular fibrillation patients with coronary artery disease.


Assuntos
Mapeamento Potencial de Superfície Corporal , Doença das Coronárias/diagnóstico , Frequência Cardíaca , Fibrilação Ventricular/diagnóstico , Doença das Coronárias/complicações , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fibrilação Ventricular/complicações , Fibrilação Ventricular/fisiopatologia
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