RESUMO
BACKGROUND: The PainFree Smart Shock Technology (SST) study showed a low implantable cardioverter-defibrillator (ICD) inappropriate shock rate. However, the majority of patients were from Western countries with patient characteristics different from those in Japan. ICD shock rates using the novel SST algorithms in Japanese patients are still unknown. METHODS: All 2,770 patients in the PainFree SST study (Japan [JPN]: N = 181, other geographies [OJPN]: N = 2,589) were included in this analysis. RESULTS: Japanese patients had higher average left ventricular ejection fraction (P < 0.0001), higher prevalence of secondary prevention indications (P < 0.0001), nonischemic cardiomyopathy (P < 0.0001), and permanent atrial fibrillation (P < 0.0001). The appropriate shock rate at 12 months was not different between JPN and OJPN: 6.4% and 6.3%, respectively (P = 0.95). The inappropriate shock rate at 12 months was significantly higher in Japanese patients (2.9% vs 1.7%, P = 0.017). However, after propensity score matching to adjust for the difference in baseline characteristics, the difference in inappropriate shock rate was not statistically significant (P = 0.51). CONCLUSIONS: There was no difference in the appropriate shock rate between Japan and other geographies. The inappropriate shock rate in Japan was low, although it was slightly higher compared to other geographies due to baseline characteristics, including a higher prevalence of permanent AF. There was not a statistically significant difference after adjusting for baseline characteristics.
Assuntos
Morte Súbita Cardíaca/prevenção & controle , Cardioversão Elétrica , Idoso , Algoritmos , Desfibriladores Implantáveis , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Medição da Dor , Pontuação de Propensão , Estudos ProspectivosRESUMO
AIMS: Single-chamber (VR-ICD) and subcutaneous (S-ICD) implantable cardioverter-defibrillators are effective to protect patients against sudden death but expose them to higher risk of inappropriate shock (IS). We sought to quantify the annual rate and influencing factors of ISs in VR- and S-ICDs from the literature. METHODS AND RESULTS: PubMed, Embase, and Cochrane Library were searched for full text articles with IS rates. Poisson distribution estimated proportion of patients with ISs; rates were annualized based on follow-up duration. Random effects meta-analysis accounted for study-to-study variation. Out of 3264 articles, 16 qualified for the meta-analysis. Across studies, 6.4% [95% confidence interval (CI) 5.1-7.9%] of patients received an IS per year. Meta-regression analyses demonstrated that IS rates were lower in more recent studies [rate ratio (RR) per year: 0.93, 95% CI: 0.87-0.98; P = 0.01] and trended lower in studies with longer follow-up (RR per year: 0.78, 95% CI: 0.60-1.01; P = 0.06). Use of S-ICDs (RR: 1.81, 95% CI: 0.86-3.81; P = 0.12) and ventricular tachycardia zone programmed on (RR: 1.13, 95% CI: 0.65-1.97; P = 0.66) were not associated with a significantly increased change in risk. The IS rate observed in one of the more recent studies was significantly lower than predicted after accounting for covariates (RR: 0.29, 95% CI: 0.14-0.60; P < 0.001). CONCLUSIONS: A comprehensive review of the literature shows that 6.4% of patients with ICDs experienced their first IS annually. One of the 16 studies was better than predicted with the lowest reported rate (1.9%) and could not be explained by timing of the study or other covariates.
Assuntos
Arritmias Cardíacas/terapia , Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis/efeitos adversos , Cardioversão Elétrica/efeitos adversos , Cardioversão Elétrica/instrumentação , Falha de Prótese , Arritmias Cardíacas/complicações , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/mortalidade , Morte Súbita Cardíaca/etiologia , Cardioversão Elétrica/mortalidade , Estimulação Elétrica , Humanos , Razão de Chances , Desenho de Prótese , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
INTRODUCTION: Implantable cardioverter defibrillator (ICD) shock therapy improves survival of patients at risk for sudden cardiac death. The high sensitivity of ICDs to detect tachycardia events is accompanied by reduced specificity resulting in inappropriate and unnecessary shocks. Up to 30% of ICD patients may experience inappropriate shocks, which are most commonly caused by lead noise, oversensing of T-waves, and supraventricular tachycardias. The new Protecta ICD and cardiac resynchronization therapy devices have been designed to minimize inappropriate and unnecessary shocks through novel SmartShock(TM) technology algorithms targeting these causes. METHODS: The PainFree SST study is a prospective, multicentre clinical trial, which will be conducted in two consecutive phases. Phase I will assess safety and any delay that may arise in ventricular fibrillation (VF) arrhythmia detection time using new algorithms. Phase II will evaluate reduction of inappropriate and unnecessary shocks at 1 year of follow-up. Additional objectives will include Quality of Life, healthcare utilization, safety of extending the ventricular tachyarrhythmia/VF interval detection duration (18 out of 24 vs. 30 out of 40 intervals), and reasons for inappropriate shock. Up to 2000 subjects in 150 centres worldwide will be enrolled with a follow-up of at least 1 year. Subjects enrolled in Phase I will continue in Phase II of the study and data from all enrolled subjects will contribute to the analysis of Phase II objectives. CONCLUSION: Inappropriate and unnecessary shock delivery remains a significant clinical issue for patients receiving device therapies, which has considerable consequences for patients and the healthcare system. The PainFree SST study will investigate the ability of new algorithms to reduce inappropriate shocks. Results from this study are expected in mid-2013.
Assuntos
Algoritmos , Dispositivos de Terapia de Ressincronização Cardíaca/efeitos adversos , Desfibriladores Implantáveis/efeitos adversos , Taquicardia Ventricular/terapia , Fibrilação Ventricular/terapia , Segurança de Equipamentos , Humanos , Cooperação Internacional , Estudos Prospectivos , Projetos de Pesquisa , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
INTRODUCTION: Three-dimensional (3D) navigation systems are widely used for pulmonary vein antrum isolation (PVAI). To circumvent left atrial (LA) mapping, 3D CT reconstructions of the LA can be superimposed directly (CT overlay) on the fluoroscopy image to guide ablation catheters and to mark ablation sites. METHODS AND RESULTS: Sixty-eight patients (pts) with symptomatic AF refractory to medical therapy were randomly assigned to CT overlay (group 1, n = 38) or CartoMerge (group 2, n = 30). In group 1 registration of the CT image was performed with contrast injections in 2 orthogonal projections. In group 2, visualization of all pulmonary vein (PV) ostia was done by PV angiography, followed by merging of the CT image and the Carto shell. We compared procedural success, procedure time, fluoroscopy time and radiation burden, measured as dose area product (DAP). Baseline characteristics were comparable in both groups. Procedural success, defined as disappearance of PV potentials in all PVs, was achieved in 37/38 (97%) of group 1 patients and 27/30 (90%) patients in group 2 (P = NS). Total procedure time was significantly shorter in group 1 compared to group 2 (129 +/- 34 vs 181 +/- 30 min, P < 0.0001). Although fluoroscopy time tended to be longer in the CT overlay group (47 +/- 16 vs 40 +/- 13 min, P = 0.06), proper use of diaphragmation resulted in comparable radiation values for both groups (DAP 53 +/- 27 vs 56 +/- 35 Gy cm(2), P = 0.76). CONCLUSIONS: CT overlay for PV isolation is feasible and may, in comparison to conventional LA navigation systems, shorten procedural time without increases in radiation burden.
Assuntos
Ablação por Cateter/métodos , Processamento de Imagem Assistida por Computador/métodos , Veias Pulmonares/diagnóstico por imagem , Idoso , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Determinação de Ponto Final , Estudos de Viabilidade , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Veias Pulmonares/cirurgia , Doses de Radiação , Tomografia Computadorizada por Raios XRESUMO
STUDY OBJECTIVE: To examine the relationship between timing of the left ventricular (LV) electrogram (EGM) and its acute hemodynamic effect on instantaneous change in LV pressure (LVdP/dt(MAX)). PATIENTS AND METHODS: In 30 patients (mean = age 67 +/- 7.9 years) who underwent implant of cardiac resynchronization therapy systems, the right ventricular (RV) lead was implanted at the RV apex (n = 23) or RV septum (n = 7). The LV lead was placed in a posterior (n = 14) or posterolateral (n = 16) coronary sinus tributary. QRS duration, interval from Q wave to intrinsic deflection of the LV EGM (Q-LV), and interval between intrinsic deflection of RV EGM and LV EGM (RV-LV interval) were measured. The measurements were correlated with the hemodynamic effects of optimized biventricular (BiV) stimulation, using the Pearson correlation coefficient. RESULTS: The mean LVdP/dt(MAX) at baseline was 734 +/- 180 mmHg/s, and increased to 905 +/- 165 mmHg/s during simultaneous BiV pacing, and to 933 +/- 172 mmHg/s after V-V interval optimization. The Pearson correlation coefficient R between QRS duration, the Q-LV interval, and the RV-LV interval at the respective LVdP/dt(MAX) was 0.291 (P = 0.66), 0.348 (P = 0.030), and 0.340 (P = 0.033). CONCLUSIONS: Similar significant correlations were observed between the acute hemodynamic effect of optimized BiV stimulation and the Q-LV and the RV-LV intervals. However, individual measurements showed an 80-ms cut-off for the Q-LV interval, beyond which the increase in LVdP/dt(MAX) was <10%.
Assuntos
Pressão Sanguínea , Estimulação Cardíaca Artificial/métodos , Cardiomiopatias/prevenção & controle , Cardiomiopatias/fisiopatologia , Frequência Cardíaca , Disfunção Ventricular Esquerda/prevenção & controle , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Cardiomiopatias/diagnóstico , Eletrocardiografia/métodos , Feminino , Humanos , Masculino , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnósticoRESUMO
A 74-year-old man with a dual-chamber implantable cardioverter defibrillator implanted 3 years before experienced multiple ventricular tachycardias (VTs). All episodes were initiated by pacemaker-mediated tachycardia (PMT) that was either stopped by atrial undersensing or the tachycardia termination algorithm of the device. After the termination of PMT, two rapid ventricular paced beats, the first initiated by artificial triggering and the second due to retrograde conduction of the first one, initiated VT that was successfully terminated by antitachycardia pacing or a direct current shock of the device. All episodes revealed this pattern of initiation with a short-long-short ventricular sequence inducing VT.
Assuntos
Desfibriladores Implantáveis/efeitos adversos , Marca-Passo Artificial/efeitos adversos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/prevenção & controle , Idoso , Falha de Equipamento , Humanos , MasculinoRESUMO
BACKGROUND: Atrial fibrillation (AF) is a major cause of morbidity and mortality, especially in patients with congestive heart failure. OBJECTIVES: The purposes of this international, prospective multicenter study were to evaluate the efficacy of atrial shock therapy in patients with a cardiac resynchronization therapy defibrillator (CRT-D) and to evaluate the safety of the new CRT-D. The effectiveness of a new wireless telemetry system was also evaluated. METHODS: A total of 282 patients, without permanent AF, who had indications for a CRT-D were included. Atrial shock therapy was tested on both spontaneous and induced AF episodes. The effectiveness of the Medtronic wireless telemetry system (Conexus; Medtronic Inc., Minneapolis, MN, USA) was also tested. Secondary endpoints included the heart failure Clinical Composite Response, system performance evaluation, and adverse event summary. RESULTS: Atrial shock therapy was successful in 168 of 171 episodes (98.2%). Of these, 138 episodes were induced and 33 were spontaneous. Successful cardioversion occurred in 137 of the 138 induced-AF episodes (86.1% with 12 joule (J), 13.1% with 24 J, and 0.7% with 35 J). During the first 3 months of implant, there were 43 system-related complications in 37 subjects out of 278 subjects. There were 1,999 Conexus telemetry uses recorded during this study. This includes 282 uses during the implant procedure. There were no cases of complete loss of telemetry or any adverse events reported using this system. CONCLUSION: We achieved an atrial shock efficacy of 98.2% in patients who met standard CRT-D indications. The wireless telemetry performed well with no reported unanticipated adverse device effects.
Assuntos
Fibrilação Atrial/mortalidade , Fibrilação Atrial/prevenção & controle , Estimulação Cardíaca Artificial/mortalidade , Desfibriladores Implantáveis/estatística & dados numéricos , Telemetria/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estimulação Cardíaca Artificial/estatística & dados numéricos , Feminino , Humanos , Incidência , Internacionalidade , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
INTRODUCTION: We compared the calculated optimal V-V interval derived from intracardiac electrograms (IEGM) with the optimized V-V interval determined by invasive measurement of LVdP/dt(MAX). METHODS AND RESULTS: Thirty-two patients with heart failure (six females, ages 68 +/- 7.8 years) had a CRT device implanted. After implantation of the atrial, right and a left ventricular lead, the optimal V-V interval was calculated using the QuickOpt formula (St. Jude Medical, Sylmar, CA, USA) applied to the respective IEGM recordings (V-V(IEGM)), and also determined by invasive measurement of LVdP/dt(MAX) (V-V(dP/dt)). The optimal V-V(IEGM) and V-V(dP/dt) intervals were 52.7 +/- 18 ms and 24.0 +/- 33 ms, respectively (P = 0.017), without correlation between the two. The baseline LVdP/dt(MAX) was 748 +/- 191 mmHg/s. The mean value of LVdP/dt(MAX) at invasive optimization was 947 +/- 198 mmHg/s, and at the calculated optimal V-V(IEGM) interval 920 +/- 191 mmHg/s (P < 0.0001). In spite of this significant difference, there was a good correlation between both methods (R = 0.991, P < 0.0001). However, a similarly good correlation existed between the maximum value of LVdP/dt(MAX) and LVdP/dt(MAX) at a fixed V-V interval of 0 ms (R = 0.993, P < 0.0001), or LVdP/dt(MAX) at a randomly selected V-V interval between 0 and +80 ms (R = 0.991, P < 0.0001). CONCLUSION: Optimizing the V-V interval with the IEGM method does not yield better hemodynamic results than simultaneous BiV pacing. Although a good correlation between LVdP/dt(MAX) determined with V-V(IEGM) and V-V(dP/dt) can be constructed, there is no correlation with the optimal settings of V-V interval in the individual patient.
Assuntos
Mapeamento Potencial de Superfície Corporal/métodos , Estimulação Cardíaca Artificial/métodos , Eletrocardiografia/métodos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/prevenção & controle , Terapia Assistida por Computador/métodos , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/terapia , Idoso , Algoritmos , Diagnóstico por Computador/métodos , Feminino , Humanos , Masculino , Controle de Qualidade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A 68-year-old male with heart failure and a suitable candidate for resynchronization therapy was referred to our hospital because of a failed coronary sinus (CS) lead implant. Catheterization of the CS initially also failed in our department but a left coronary angiogram revealed atresia of the CS and drainage of the coronary venous system via a persistent left superior vena cava (PLSVC). Implantation of a CS lead through the PLSVC could be accomplished after a selective angiogram, even in spite of the presence of a large thrombus at the junction of PLSVC and CS.
Assuntos
Estimulação Cardíaca Artificial/métodos , Seio Coronário/anormalidades , Ventrículos do Coração/fisiopatologia , Marca-Passo Artificial , Trombose/complicações , Veia Cava Superior/anormalidades , Idoso , Cardiomiopatias/terapia , Angiografia Coronária , Eletrocardiografia , Humanos , Masculino , Volume Sistólico , Trombose/diagnóstico , Resultado do TratamentoRESUMO
BACKGROUND: Optimization of cardiac resynchronization therapy (CRT) with respect to the interventricular (V-V) interval is mainly limited to pacing at a resting heart rate. We studied the effect of higher stimulation rates with univentricular and biventricular (BiV) pacing modes including the effect of the V-V interval optimization. METHODS: In 36 patients with heart failure and chronic atrial fibrillation (AF), the effects of right ventricular (RV), left ventricular (LV), simultaneous BiV, and optimized sequential BiV (BiVopt) pacing were measured. The effect of the pacing mode and the optimal V-V interval was determined at stimulation rates of 70, 90, and 110 ppm using invasive measurement of the maximum rate of left ventricular pressure rise (LV dP/dt(max)). RESULTS: The average LV dP/dt (max) for all pacing modalities at stimulation rates of 70, 90, and 110 ppm was 781 +/- 176, 833 +/- 197, and 884 +/- 223 mmHg/s for RV pacing; 893 +/- 178, 942 +/- 186, and 981 +/- 194 mmHg/s for LV pacing; 904 +/- 179, 973 +/- 187, and 1052 +/- 206 mmHg/s for simultaneous BiV pacing; and 941 +/- 186, 1010 +/- 198, and 1081 +/- 206 mmHg/s for BiVopt pacing, respectively. In BiVopt pacing, the corresponding optimal V-V interval decreased from 34 +/- 29, 28 +/- 28, and21 +/- 27ms at stimulation rates of 70, 90, and 110 ppm, respectively. In two individuals, LV dP/dt(max) decreased when the pacing rate was increased from 90 to 110 ppm. CONCLUSION: In patients with AF and heart failure, LV dP/dt(max) increases for all pacing modalities at increasing stimulation rates in most, but not all, patients. The rise in LV dP/dt(max) with increasing stimulation rates is higher in biventricular (BiV and BiVopt) than in univentricular (LV and RV) pacing. The optimal V-V interval at sequential biventricular pacing decreases with increasing stimulation rates.
Assuntos
Estimulação Cardíaca Artificial/métodos , Eletrocardiografia/métodos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/prevenção & controle , Garantia da Qualidade dos Cuidados de Saúde/métodos , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/prevenção & controle , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Resultado do TratamentoRESUMO
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an uncommon heritable disease presenting with syncope or sudden cardiac death. Two genes involved in calcium homeostasis, the ryanodine receptor gene and the calsequestrin 2 (CASQ2) gene, have been implicated in this disease. We describe a young man presenting with exercise-induced syncope, clinically diagnosed as CPVT. Genetic analysis revealed two mutations, p.Y55C (c.164A>G) and p.P308L (c.923C>T), in the CASQ2 gene. Subsequent familial analysis indicates a compound heterozygous form of inheritance.
Assuntos
Calsequestrina/genética , Polimorfismo de Nucleotídeo Único/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Adulto , Análise Mutacional de DNA , Predisposição Genética para Doença/genética , Humanos , Masculino , MutaçãoRESUMO
AIM: The influence of location and extent of transmural scar and its relation with dyssynchrony in cardiac resynchronization therapy (CRT) was investigated as posterolateral scar tissue has been invoked as a cause of non-response to CRT. METHODS AND RESULTS: Fifty-seven patients eligible for CRT were assessed for transmural scar with gadolinium-enhanced MRI and for left ventricular (LV) dyssynchrony with tissue Doppler. After implant, both atrioventricular and interventricular pacing intervals were optimized. LV reverse remodeling was defined as >/=10% decrease in LV end-systolic volume after 3 months. Sixteen patients had transmural scar in the posterolateral (PL) area (LV lead location), 14 at a remote site (non-PL) and 27 patients had no scar. LV reverse remodeling was observed in respectively 25%, 64% and 89% (P = 0.0001). Univariate analyses showed a relation with LV dyssynchrony (P = 0.004) and with absence of PL scar (P = 0.04) but not with QRS duration and the extent of LV scar tissue. In multivariate analysis, only LV dyssynchrony (OR: 19.62; 95% CI: 2.5-151.9; P = 0.004) independently predicted LV reverse remodeling. CONCLUSION: In this study LV dyssynchrony remains the most important determinant of response to CRT, even in the presence of posterolateral scar provided atrioventricular and interventricular pacing intervals are optimized.
Assuntos
Estimulação Cardíaca Artificial , Infarto do Miocárdio/terapia , Disfunção Ventricular Esquerda/terapia , Remodelação Ventricular , Idoso , Cicatriz , Ecocardiografia Doppler , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/etiologiaRESUMO
BACKGROUND: The effect of implantable cardioverter-defibrillator (ICD) shock on device-measured activity and patient-reported outcomes is unknown. OBJECTIVE: The purpose of this study was to analyze the acute and long-term effects of ICD shock on objective behavioral data (ie, device-based physical activity) and subjective patient-reported outcomes (eg, quality of life and shock anxiety). METHODS: The PainFree Smart Shock Technology (SST) clinical trial included 2770 patients with a single- or dual-chamber ICD or cardiac resynchronization therapy - defibrillator device who were followed for 22 ± 9 months. Participants completed measures of quality of life (EuroQol-5D [EQ-5D] questionnaire) and shock anxiety (Florida Shock Anxiety Scale) at baseline, biannual visits, and monthly for 6 months after an ICD shock. Daily physical activity data were obtained from a built-in device accelerometer. RESULTS: The average daily activity was 185.3 ± 119.4 min/d. Activity was significantly reduced after an ICD shock (P < .0001) and recovered to a normal level after â¼90 days. An ICD shock was also associated with decreased quality of life (EQ5-D health score) and increased EQ-5D anxiety scores, but it did not affect mobility, self-care, activity, or pain. Similarly, shock anxiety (Florida Shock Anxiety Scale) increased in shocked patients and remained significantly elevated at 24 months, regardless of appropriate or inappropriate shock delivery. CONCLUSION: ICD shocks have a long-lasting adverse effect on both objective, device-measured physical activity and subjective patient-reported outcomes of quality of life and shock anxiety. Successful management of patients with an ICD requires attention to clinically relevant behavioral and psychological outcomes to expedite recovery and return to activities of daily living.
Assuntos
Ansiedade/etiologia , Arritmias Cardíacas/terapia , Desfibriladores Implantáveis/efeitos adversos , Exercício Físico/fisiologia , Dor/etiologia , Qualidade de Vida , Acelerometria , Idoso , Ansiedade/psicologia , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/psicologia , Eletrocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dor/psicologia , Estudos Prospectivos , Inquéritos e Questionários , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Variable results of cardiac resynchronization therapy (CRT) on diastolic function have been described. We investigated 3 and 12 months' effect of CRT on diastolic function and left ventricular (LV) filling pressures and their relation to LV reverse remodeling. METHODS: Fifty-two patients' (36 male, 69 +/- 8 years, QRS duration 170 +/- 29 milliseconds) echo-Doppler was performed before and 3 and 12 months after CRT. Tissue Doppler early diastolic annular (Em) and color M-mode-derived flow propagation (Vp) velocities were used to estimate LV filling pressures by E/Em and E/Vp ratios. RESULTS: After 12 months, LV reverse remodeling (end-systolic volume decrease >15%) was observed in 58%. Despite a significantly more compromised baseline diastolic function of patients without LV reverse remodeling, multivariate analysis revealed that only LV dyssynchrony could predict LV reverse remodeling. Grades 2 and 3 diastolic function improved only in LV reverse remodeling patients (from 34% to 13% to 10%), whereas a nonsignificant increase from 59% to 67% to 72% was observed in patients without reverse remodeling. Irrespective of LV volume response, short-term symptomatic benefit was related to decreased filling pressure. However, after 12 months, E/Em and E/Vp only significantly decreased in patients with LV reverse remodeling (from 16.0 +/- 6 to 10.4 +/- 4 and 2.2 +/- 0.6 to 1.5 +/- 0.4, respectively). CONCLUSIONS: Left ventricular reverse remodeling induced by CRT is accompanied by improvement in diastolic function and estimated LV filling pressure. Short-term symptomatic benefit was related to decreased filling pressure. However, for longer-term symptomatic improvement and decreased filling pressures, LV reverse remodeling appeared mandatory.
Assuntos
Estimulação Cardíaca Artificial , Cardiomiopatias/fisiopatologia , Cardiomiopatias/terapia , Diástole , Pressão Ventricular , Idoso , Cardiomiopatias/complicações , Cardiomiopatias/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Resultado do Tratamento , Ultrassonografia , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/terapia , Remodelação VentricularRESUMO
Isovolumic times (IVTs) comprise a determinant of exercise capacity in cardiomyopathy. We postulated that an increase in exercise capacity after cardiac resynchronization therapy (CRT) might be related to a more efficient cardiac cycle due to decreasing IVTs and increased filling times. According to standard selection criteria, a CRT device was implanted in 52 patients (37 men; 69 +/- 8 years) with a QRS duration of 174 +/- 30 ms. The etiology was ischemic in 22 and idiopathic in 30 patients. A 6-minute walking test (MWT) and echocardiographic Doppler were performed before and 3 and 6 months after CRT. Timing cycles were obtained with echocardiographic Doppler. An improvement in MWT by >15% (responders) after 6 months of CRT was observed in 46% of patients. The MWT was moderately correlated with baseline time intervals (IVT r = -0.44, filling time r = 0.52), but not to baseline left ventricular ejection fraction (r = -0.06). However, change in the MWT after 3 and 6 months was best related to changes in IVT (r = -0.66 and -0.68, respectively). Receiver-operating characteristic curve analysis of baseline IVT showed that an IVT >29% predicted exercise response with a positive predictive value of 89% and a negative predictive value of 77%. In conclusion, improvement in exercise tolerance after CRT is associated with a decrease in prolonged IVT. Baseline IVT might be used as an adjunctive parameter for selecting symptomatic responders to CRT.
Assuntos
Estimulação Cardíaca Artificial , Cardiomiopatias/terapia , Tolerância ao Exercício , Volume Sistólico , Idoso , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/fisiopatologia , Ecocardiografia Doppler , Eletrocardiografia , Sistema de Condução Cardíaco , Humanos , Masculino , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e EspecificidadeRESUMO
A multiphasic septal motion and typical septal-to-lateral apical shuffle of the left ventricle can be observed echocardiographically in some patients with left branch bundle block. The relation of both with left ventricular (LV) dyssynchrony according to tissue Doppler and LV reverse remodeling after cardiac resynchronization therapy was investigated. Fifty-three patients (37 men; age 68+/-8 years) with ischemic (n=26) or idiopathic (n=27) cardiomyopathy, baseline QRS duration 171+/-30 ms, LV ejection fraction 21+/-7%, and LV end-diastolic volume 257+/-91 ml were studied. LV dyssynchrony using tissue Doppler was considered present if the SD of the interval between QRS and onset of systolic velocity of 6 basal LV segments was >20 ms. Shuffle was evaluated visually independently by 5 cardiologists and considered present if observed in>or=1 view. LV reverse remodeling, defined as LV end-systolic volume decrease>or=10%, was observed in 37 patients (70%) after 3 months of CRT. Sensitivity and specificity of either shuffle or multiphasic septal motion for all 5 observers (range 90% to 97% and 67% to 83%, respectively) were found to predict LV dyssynchrony. To predict LV reverse remodeling, sensitivity and specificity from 87% to 92% and 69% to 81% were observed, respectively. In conclusion, the qualitative observation of a typical shuffle or multiphasic septal motion predicts LV dyssynchrony and LV reverse remodeling adequately.
Assuntos
Estimulação Cardíaca Artificial , Septos Cardíacos/fisiopatologia , Remodelação Ventricular , Idoso , Bloqueio de Ramo/fisiopatologia , Bloqueio de Ramo/terapia , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Dilatada/terapia , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologia , Isquemia Miocárdica/terapia , Variações Dependentes do Observador , Marca-Passo Artificial , Projetos de Pesquisa , Sensibilidade e Especificidade , Volume Sistólico , Resultado do TratamentoRESUMO
BACKGROUND: Coronary sinus (CS) lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a failure rate at implant and short-term follow-up between 10% and 15%. OBJECTIVE: The purpose of this study was to assess the feasibility of transseptal endocardial LV pacing in patients in whom transvenous CS lead placement had failed. METHODS: An atrial transseptal LV lead placement was attempted in 10 patients (six females, age 69.4 +/- 9.6 years), in whom CS lead placement for CRT had failed. After transseptal puncture and septal dilatation from the femoral route, the left atrium was cannulated with a combination of catheters and guide wires from the left or right subclavian vein. After advancement of this guide catheter into the LV, a standard bipolar screw-in lead could be implanted in the posterolateral wall. All patients were maintained on anticoagulant therapy with warfarin after implant. RESULTS: An LV lead could be successfully implanted in nine of the 10 patients. The stimulation threshold was 0.78 +/- 0.24 V, and the R-wave amplitude was 14.2 +/- 9.7 mV. At 2 months' follow-up, the stimulation threshold was 1.48 +/- 0.35 V with a 0.064 +/- 0.027 ms pulse width. There was no phrenic nerve stimulation observed in any of the patients. There were no thromboembolic complications at follow-up. CONCLUSIONS: LV transseptal endocardial lead implantation from the pectoral area is a feasible approach in patients with a failed CS approach and in whom epicardial surgical lead placement is not an option. Longer follow-up is warranted to determine the risk of thromboembolic complications.
Assuntos
Estimulação Cardíaca Artificial/métodos , Vasos Coronários/cirurgia , Endocárdio/cirurgia , Septos Cardíacos/cirurgia , Idoso , Idoso de 80 Anos ou mais , Cardiomiopatia Dilatada/terapia , Cateterismo/instrumentação , Desfibriladores Implantáveis , Estimulação Elétrica , Estudos de Viabilidade , Feminino , Seguimentos , Ventrículos do Coração/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/terapia , Marca-Passo Artificial , Nervo Frênico , Resultado do TratamentoRESUMO
This study investigated the optimal echocardiographic indexes to determine the most hemodynamically appropriate atrioventricular (AV) delay in cardiac resynchronization therapy (CRT) for heart failure. Doppler echocardiographic optimization of AV delay in CRT has not been correlated with invasive hemodynamic indexes. In 30 patients who underwent CRT, invasive left ventricular (LV) pressure measurements with a sensor-tipped pressure guidewire and Doppler echocardiographic examination were performed <24 hours after pacemaker implantation. Invasively, the optimal sensed AV delay was determined by LV dP/dt(max). The Doppler echocardiographic methods evaluated were the velocity-time integral (VTI) of the transmitral flow (EA VTI), diastolic filling time (EA duration), the VTI of the LV outflow tract or aorta (LV VTI), and Ritter's formula. Biventricular pacing with optimized interventricular and AV delay increased LV dP/dt(max) from 777 +/- 149 to 1,010 +/- 163 dynes/s (p<0.0001). The optimal AV delay with the EA VTI method was concordant with LV dP/dt(max) in 29 of 30 patients (r = 0.96), with EA duration in 20 of 30 patients (r= 0.83), with LV VTI in 13 patients (r = 0.54), and with Ritter's formula in none of the patients (r = 0.35). In conclusion, to obtain the optimal acute hemodynamic benefit of CRT, Doppler echocardiography is a reliable tool to optimize the AV delay compared with the invasive LV dP/dt(max). The measurement of the maximal VTI of mitral inflow is the most accurate method.
Assuntos
Nó Atrioventricular/fisiopatologia , Cardiomiopatia Dilatada/complicações , Ecocardiografia Doppler/métodos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/terapia , Hemodinâmica , Marca-Passo Artificial , Idoso , Feminino , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , MasculinoRESUMO
Atrial tachy-arrhythmias may give rise to mode switching or noise rate reversion in dual-chamber pacemakers. In case of high amplitude of the atrial electrogram during tachycardia, a paradoxical behavior of atrial sensitivity programming can be observed. Two patients with implanted dual-chamber pacemakers showed intermittent and complete loss of atrial sensing during atrial tachycardia during device programming to a higher atrial sensitivity setting. This phenomenon is caused by amplifier ringing and can be considered as a state of amplifier saturation, which disables atrial sensing in spite of the high amplitude of the atrial signal. In patients with high amplitude of the atrial electrogram during atrial tachycardia, a paradoxical behavior of sensitivity programming resulting in atrial undersensing can be observed.