Mortality risk score for patients with Chagas cardiomyopathy and pacemaker.

BACKGROUND: Prognosis of Chronic Chagasic Cardiomyopathy (CCC) patients depends on functional and clinical factors. Bradyarrhythmia requiring pacemaker is a common complication. Prognosis of these patients is poorly studied, and mortality risk factors are unknown. We aimed to identify predictors of death and to define a risk score for mortality in a large cohort of CCC patients with pacemaker. METHODS: It was an observational, unicentric and prospective study. The endpoint was all-cause mortality. Cox regression was used to identify predictors of death and to define a risk score. Bootstrapping method was used to internal score validation. RESULTS: We included 555 patients and after a mean follow-up of 3.7±1.5 years, 100 (18%) deaths occurred. Predictors of death were: right ventricular dysfunction (HR [hazard ratio] 2.24; 95%CI 1.41-3.53; P = 0.001); heart failure class III or IV (HR 2.16; 95% confidence interval [95%CI] 1.16-4.00; P = 0.014); renal disease (HR 2.14; 95%CI 1.24-3.68; P = 0.006); left ventricular end-systolic diameter > 44mm (HR 1.97; 95%CI 1.26-3.05; P = 0.003); atrial fibrillation (HR 1.94; 95%CI 1.25-2.99; P = 0.003) and cardiomegaly on X-ray (HR 1.87; 95%CI 1.10-3.17; P = 0.020). The score identified patients with: low (0-20 points), intermediate (21-30 points) and high risk (>31points). The optimism-corrected C-statistic of the predictive model was 0.751 (95% CI 0.696-0.806). Internal validation with bootstrapping revealed a calibration slope of 0.946 (95% CI 0.920-0.961), reflecting a small degree of over-optimism and C-statistic of 0.746 (95% CI 0.692-0.785). CONCLUSIONS: This study identified predictors of mortality in CCC patients with pacemaker defining a simple, validated and specific risk score.

Síndrome de Kearns Sayre - relato de caso / Kearns Sayre Syndrome - case report

A Síndrome de Kearns Sayre (SKS) é uma miopatia de origem mitocondrial rara. Caracterizase pela tríade de oftalmoplegia externa, retinose pigmentar e acometimento do sistema de condução cardíaco, descrita em 1958. O objetivo deste relato de caso é descrever um caso de SKS e discutir achados clínicos com ênfase no acometimento cardíaco. Paciente J.A., masculino, 35 anos, com sintomas iniciais de diplopia, estrabismo e ptose. Evoluiu com alteração da motricidade ocular extrínseca, retinopatia pigmentosa e fraqueza muscular difusa o que levou à hipótese de SKS. O diagnóstico definitivo foi feito através de biópsia do bíceps que revelou padrão miopático mitocondrial. Em seguida, encaminhado para investigação de distúrbio de condução. Em primeira consulta evidenciado eletrocardiograma com ritmo sinusal, BAV 1° grau, bloqueio de ramo esquerdo, pausa sinusal e ritmo juncional de 40 bpm. Ecocardiograma com FE 62% e contratilidade preservada. Indicado implante de marcapasso (MP) atrioventricular. Atualmente, com necessidade de 100% de pacing ventricular sem escape ventricular e fibrilação atrial paroxística em anticoagulação. Desde então, segue em acompanhamento ambulatorial. A SKS é uma doença genética relacionada a mutação do DNA mitocondrial. As mitocôndrias são responsáveis pela produção de ATP e fornecimento de energia para diversas funções metabólicas. Por isso, tecidos com alto gasto energético, são os mais acometidos em tais anomalias genéticas. As manifestações cardiológicas ocorrem em 57% dos casos. As alterações eletrocardiográficas mais comuns são bloqueio divisional anterossuperior e bloqueio de ramo direito. Tipicamente ocorre progressão para bloqueio atrioventricular avançado. Morte súbita está associada em até 20% dos casos. A Sociedade Europeia, em sua diretriz de estimulação cardíaca artificial 2021, orienta implante de MP diante do achado de prolongamento de intervalo PR e evidência de bloqueio atrioventricular de qualquer grau, bloqueio de ramo ou bloqueio fascicular. A SKS é uma doença incomum e com repercussão clínica importante. Se negligenciada, o acometimento cardíaco é potencialmente fatal. Assim, cabe ao cardiologista estar atento ao momento ideal de indicação de MP.

Effect of chronic kidney disease in ischemic cardiomyopathy: Long-term follow-up - REVISION-DM2 trial.

A strong association exists between chronic kidney disease (CKD) and coronary artery disease (CAD). The role of CKD in the long-term prognosis of CAD patients with versus those without CKD is unknown. This study investigated whether CKD affects ventricular function.From January 2009 to January 2010, 918 consecutive patients were selected from an outpatient database. Patients had undergone percutaneous, surgical, or clinical treatment and were followed until May 2015.In patients with preserved renal function (n = 405), 73 events (18%) occurred, but 108 events (21.1%) occurred among those with CKD (n = 513) (P < .001). Regarding left ventricular ejection fraction (LVEF) <50%, we found 84 events (21.5%) in CKD patients and 12 (11.8%) in those with preserved renal function (P < .001). The presence of LVEF <50% brought about a modification effect. Death occurred in 22 (5.4%) patients with preserved renal function and in 73 (14.2%) with CKD (P < .001). In subjects with LVEF <50%, 66 deaths (16.9%) occurred in CKD patients and 7 (6.9%) in those with preserved renal function (P = .001). No differences were found in CKD strata regarding events or overall death among those with preserved LVEF. In a multivariate model, creatinine clearance remained an independent predictor of death (P < .001).We found no deleterious effects of CKD in patients with CAD when ventricular function was preserved. However, there was a worse prognosis in patients with CKD and ventricular dysfunction.Resgistry number is ISRCTN17786790 at https://doi.org/10.1186/ISRCTN17786790.

A cohort study of cardiac resynchronization therapy in patients with chronic Chagas cardiomyopathy.

Aims: Cardiac resynchronization therapy (CRT) is an established procedure for patients with heart failure. However, trials evaluating its efficacy did not include patients with chronic Chagas cardiomyopathy (CCC). We aimed to assess the role of CRT in a cohort of patients with CCC. Methods and results: This retrospective study compared the outcomes of CCC patients who underwent CRT with those of dilated (DCM) and ischaemic cardiomyopathies (ICM). The primary endpoint was all-cause mortality and the secondary endpoints were the rate of non-advanced New York Heart Association (NYHA) class 12 months after CRT and echocardiographic changes evaluated at least 6 months after CRT. There were 115 patients in the CCC group, 177 with DCM, and 134 with ICM. The annual mortality rates were 25.4%, 10.4%, and 11.3%, respectively (P < 0.001). Multivariate analysis adjusted for potential confounders showed that the CCC group had a two-fold [hazard ratio 2.34 (1.47-3.71), P < 0.001] higher risk of death compared to the DCM group. The rate of non-advanced NYHA class 12 months after CRT was significantly higher in non-CCC groups than in the CCC group (DCM 74.0% vs. ICM 73.9% vs. 56.5%, P < 0.001). Chronic Chagas cardiomyopathy and ICM patients had no improvement in the echocardiographic evaluation, but patients in the DCM group had an increase in left ventricular ejection fraction and a decrease in left ventricular end-diastolic diameter. Conclusion: This study showed that CCC patients submitted to CRT have worse prognosis compared to patients with DCM and ICM who undergo CRT. Studies comparing CCC patients with and without CRT are warranted.

Evidence for cardiac safety and antiarrhythmic potential of chloroquine in systemic lupus erythematosus.

AIMS: To perform a comprehensive evaluation of heart rhythm disorders and the influence of disease/therapy factors in a large systemic lupus erythematosus (SLE) cohort. METHODS AND RESULTS: Three hundred and seventeen consecutive patients of an ongoing electronic database protocol were evaluated by resting electrocardiogram and 142 were randomly selected for 24 h Holter monitoring for arrhythmia and conduction disturbances. The mean age was 40.2 ± 12.1 years and disease duration was 11.4 ± 8.1 years. Chloroquine (CQ) therapy was identified in 69.7% with a mean use of 8.5 ± 6.7 years. Electrocardiogram abnormalities were detected in 66 patients (20.8%): prolonged QTc/QTd (14.2%); bundle-branch block (2.5%); and atrioventricular block (AVB) (1.6%). Age was associated with AVB (P = 0.029) and prolonged QTc/QTd (P = 0.039) whereas anti-Ro/SS-A and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores were not (P > 0.05). Chloroquine was negatively associated with AVB (P = 0.01) as was its longer use (6.1 ± 6.9 vs. 1.0 ± 2.5 years, P = 0.018). Time of CQ use was related with the absence of AVB [odds ratio (OR) = 0.103; 95% confidence interval (CI) = 0.011-0.934, P = 0.043] in multiple logistic regression. Holter monitoring revealed abnormalities in 121 patients (85.2%): supraventricular ectopies (63.4%) and tachyarrhythmia (18.3%); ventricular ectopies (45.8%). Atrial tachycardia/fibrillation (AT/AF) were associated with shorter CQ duration (7.05 ± 7.99 vs. 3.63 ± 5.02 years, P = 0.043) with a trend to less CQ use (P = 0.054), and older age (P < 0.001). Predictors of AT/AF in multiple logistic regression were age (OR = 1.115; 95% CI = 1.059-1.174, P < 0.001) and anti-Ro/SS-A (OR = 0.172; 95% CI = 0.047-0.629, P = 0.008). CONCLUSIONS: Chloroquine seems to play a protective role in the unexpected high rate of cardiac arrhythmias and conduction disturbances observed in SLE. Further studies are necessary to determine if this antiarrhythmic effect is due to the disease control or a direct effect of the drug.

Effects of cardiac resynchronization therapy on muscle sympathetic nerve activity.

INTRODUCTION: Muscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable. OBJECTIVES: In this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF. METHODS: We assessed 11 HF patients (51 ± 3.4 years; New York Heart Association class III-IV; left ventricular ejection fraction 27.8 ± 2.2%; optimal medical therapy) submitted to CRT. Evaluations were made prior to and 3 months after CRT. MSNA was performed at rest and during moderate static exercise (handgrip). Peak oxygen consumption (VO2 ) was evaluated by means of cardiopulmonary exercise test. HF patients with advanced NYHA class without CRT and healthy individuals were also studied. RESULTS: CRT reduced MSNA at rest (48.9 ± 11.1 bursts/min vs 33.7 ± 15.3 bursts/min, P < 0.05) and during handgrip exercise (MSNA 62.3 ± 13.1 bursts/min vs 46.9 ± 14.3 bursts/min, P < 0.05). Among HF patients submitted to CRT, the peak VO2 increased (12.9 ± 2.8 mL/kg/min vs 16.5 ± 3.9 mL/kg/min, P < 0.05) and an inverse correlation between peak VO2 and resting MSNA (r = -0.74, P = 0.01) was observed. CONCLUSIONS: In patients with advanced HF and severe systolic dysfunction: (1) a significant reduction of MSNA (at rest and during handgrip) occurred after CRT, and this behavior was significantly superior to HF patients receiving only medical therapy; (2) MSNA reduction after CRT had an inverse correlation with O2 consumption outcomes.

Terapia de ressincronização cardíaca na cardiomiopatia chagásicacrônica: boa resposta clínica e pior prognóstico / Cardiac resynchronization therapy in chronic chagasic cardiomyopathy: a good clinical response and the worst prognosis

Os efeitos da terapia de ressincronização cardíaca (TRC) em pacientes com cardiomiopatiaisquêmica (CMI) e dilatada (CMD) são bem conhecidos. Entretanto, faltam evidências científicas da TRC nacardiomiopatia chagásica crônica (CCC). Objetivo: avaliar o comportamento clínico de pacientes submetidos àTRC, considerando a importância da CCC. Método: no período de janeiro de 2005 a dezembro de 2007 foramincluídos 343 pacientes em seguimento clínico na Unidade de Estimulação Cardíaca do Instituto do Coração,submetidos a intervenção cirúrgica relacionada à TRC. A análise estatística de previsores de mortalidade foirealizada por regressão logística com seleção stepwise, incluindo variáveis com p<0,1 na análise univariada. Asvariáveis estudadas foram: idade, gênero, classe funcional (CF) da New York Heart Association, cardiopatia, tipode bloqueio de ramo, parâmetros ecocardiográficos, medicações em uso e óbito. Resultados: foram selecionados343 pacientes, 65% do sexo masculino, com idade média de 59,7 ± 12,3 anos e seguimento médio de 4,2 ± 2,7anos após a TRC. A CF pré-implante foi II em 18,3%, III em 64,5% e IV em 17,3%. A fração de ejeção média doventrículo esquerdo foi de 27,66 ± 8,99. A cardiopatia de base distribuiu-se em: CMD em 35%; CMI em 29,4%;CCC em 22,4% e outras etiologias em 13,1%. A taxa de melhora da classe funcional após a TRC foi semelhante,independente da cardiopatia, mas a CCC mostrou pior prognóstico (odds ratio=3,03; IC 95%, 1,15-7,97, p<0,001).Conclusão: pacientes com CCC submetidos à TRC apresentam melhora sintomática, porém o risco de óbito é trêsvezes maior em comparação com as outras cardiopatias.

The effects of cardiac resynchronization therapy (CRT) in patients with ischemic (ICM) and dilated(DCM) cardiomyopathy are known. In chronic chagasic cardiomyopathy (CCC), scientific evidence is lacking.Objective: To evaluate the clinical response of patients undergoing CRT, considering the importance of theCCC. Methods: From January 2005 to December 2007, we included 343 patients in clinical follow-up in CardiacPacing Unit of Heart Institute, who underwent surgery related to CRT. Statistical analysis of mortality predictorswas performed using logistic regression with stepwise selection, including variables with P<0.1 in the univariateanalysis. The variables studied were age, gender, functional class of New York Heart Association, etiology of heartdisease, type of bundle branch block, echocardiographic parameters, medications and death. Results: The studyenrolled 343 patients, 65% male, mean age 59.7 ± 12.3 years, with a mean follow-up after CRT of 4.2 ± 2.7 years. The functional class before implant was II, III and IV in 18.3%, 64.5% and 17.3%, respectively. The mean ejectionfraction of the left ventricle was 27.66 ± 8.99. The underlying heart disease was DMC, ICM, CCC and othercauses in 35%, 29.4%, 22.4% and 13.1%, respectively. The rate of improvement in functional class after CRT wassimilar, independent of heart disease etiology, but the CCC showed the worst prognosis (Odds ratio=3.03; 95%CI 1.15-7.97, P<0.001). Conclusion: Patients with CCC undergoing CRT show symptomatic improvement, butthe risk of death is three times higher, compared with other heart diseases.

Los efectos de la terapia de resincronización cardiaca (TRC) en pacientes con miocardiopatía isquémica(MCI) y dilatada (MCD) son conocidos. En la miocardiopatía chagásica crónica (MCC), sin embargo, faltanevidencias científicas. Objetivo: Evaluar el comportamiento clínico de pacientes sometidos a la TRC, considerándosela importancia de la MCC. Métodos: En el período de enero de 2005 a diciembre de 2007, fueron incluidos 343pacientes en seguimiento clínico en la Unidad de Estimulación Cardiaca del Instituto del Corazón, sometidos ala intervención quirúrgica relacionada a la TRC. El análisis estadístico de predictores de mortalidad fue llevado acabo por regresión logística con selección stepwise, incluyéndose variables con p<0,1 en el análisis univariado. Lasvariables estudiadas fueron: edad, género, clase funcional (CF) de la New York Heart Association, cardiopatía, tipode bloqueo de rama, parámetros ecocardiográficos, fármacos en uso y defunción. Resultados: Fueron seleccionados343 pacientes, el 65% del sexo masculino, edad media de 59,7 ± 12,3 años, con seguimiento medio tras la TRC de4,2 ± 2,7 años. La CF pre implante fue II en el 18,3%, III en el 64,5% y IV en el 17,3%. La fracción de eyección deventrículo izquierdo media fue de 27,66 ± 8,99. La cardiopatía de base se distribuyó en: MCD en el 35%; MCI enel 29,4%; MCC en el 22,4% y otras etiologías en el 13,1%. El índice de mejora de clase funcional tras la TRC fuesemejante, independientemente de la cardiopatía, pero la MCC mostró peor pronóstico (Odds Ratio=3,03 IC95%1,15-7,97, p<0,001). Conclusión: Pacientes con MCC sometidos a la TRC presentan mejora sintomática, sin embargo,riesgo de fallecimiento tres veces mayor, en comparación con las otras cardiopatías.

Global and regional ventricular repolarization study by body surface potential mapping in patients with left bundle-branch block and heart failure undergoing cardiac resynchronization therapy.

BACKGROUND: The controversial effects promoted by cardiac resynchronization therapy (CRT) on the ventricular repolarization (VR) have motivated VR evaluation by body surface potential mapping (BSPM) in CRT patients. METHODS: Fifty-two CRT patients, mean age 58.8 ± 12.3 years, 31 male, LVEF 27.5 ± 9.2, NYHA III-IV heart failure with QRS181.5 ± 14.2 ms, underwent 87-lead BSPM in sinus rhythm (BASELINE) and biventricular pacing (BIV). Measurements of mean and corrected QT intervals and dispersion, mean and corrected T peak end intervals and their dispersion, and JT intervals characterized global and regional (RV, Intermediate, and LV regions) ventricular repolarization response. RESULTS: Global QTm (P < 0.001) and QTc(m) (P < 0.05) were decreased in BIV; QTm was similar across regions in both modes (P = ns); QTc(m) values were lower in RV/LV than in Intermediate region in BASELINE and BIV (P < 0.001); only RV/Septum showed a significant difference (P < 0.01) in the BIV mode. QTD values both of BASELINE (P < 0.01) and BIV (P < 0.001) were greater in the Intermediate than in the LV region. CRT effect significantly reduced global/regional QTm and QTc(m) values. QTD was globally decreased in RV/LV (Intermediate: P = ns). BIV mode significantly reduced global T peak end mean and corrected intervals and their dispersion. JT values were not significant. CONCLUSIONS: Ventricular repolarization parameters QTm, QTc(m), and QTD global/regional values, as assessed by BSPM, were reduced in patients under CRT with severe HF and LBBB. Greater recovery impairment in the Intermediate region was detected by the smaller variation of its dispersion.

Papel da medicina nuclear na terapia de ressincronização cardíaca: [revisão] / Role of nuclear medicine in the cardiac resinchronization therapy: [review]

A terapia de ressincronização cardíaca (TRC) surgiu como a mais promissora abordagem no tratamento da dissincronia cardíaca, em pacientes com insuficiência cardíaca refratária ao tratamento medicamentoso. Embora seus resultados clínicos e funcionais sejam de fato promissores, as análises das respostas individuais revelam que uma significativa parcela dos pacientes não responde ao tratamento. Nesta revisão, foi discutido o papel da medicina nuclear e imagem molecular na seleção de candidatos à TRC, por meio do estudo da dissincronia cardíaca, avaliação de viabilidade, perfusão e fluxo sanguíneo miocárdicos e atividade simpática cardíaca. O potencial uso dessa técnica, no aprimoramento da compreensão dos efeitos deletérios da dissincronia, sobre a função cardíaca e na avaliação e monitorização de resposta à TRC, foram também abordados. Outros alvos moleculares que caracterizam metabolismo glicolítico e de ácido graxo, apoptose, atividade da enzima conversora da angiotensina e angiogênese, que podem seravaliados e medidos por essa técnica, foram descritos.

Cardiac resynchronization therapy (CRT) emerged as one of the most promising approaches in the treatment of cardiac dyssynchrony in heart failure patients’ refractory to medical treatment. However, despite very promising clinical and functional results, individual response analyses show that a significant number of patients do not respond to treatment. The role of nuclear medicine and molecular imaging in the selection of CRT candidates by the assessment of cardiac dyssynchrony, myocardial viability, myocardial perfusion and blood flow and sympathetic cardiac activity has been discussed in this review. The potential utilization of this tool to improve the comprehension of detrimental effects of dyssynchrony on cardiac function and the evaluation and monitoring of the response to CRT were also considered. Other molecular targets that characterize glucose and fatty acid metabolism, apoptosis, angiotensin converting enzyme activity and angiogenesis that can be evaluated with this technique were described.

"Hyper-response" evaluated by 3D echocardiography after cardiac resynchronization therapy.

Cardiac resynchronization therapy consists of a promising treatment for patients with severe heart failure, but about 30% of patients do not exhibit clinical improvement with this procedure. However, approximately 10% of patients undergoing this therapy may have hyperresponsiveness, and three-dimensional echocardiography can provide an interesting option for the selection and evaluation of such patients.

"Hiper-resposta" avaliada pelo eco 3D após terapia de ressincronização cardíaca / "Hyper-response" evaluated by 3D echocardiography after cardiac resynchronization therapy / "Hiperrespuesta" evaluada por el eco 3D después de la terapia de resincronización cardíaca

A terapia de ressincronização cardíaca consiste em tratamento promissor para pacientes com insuficiência cardíaca grave, porém cerca de 30 por cento dos pacientes não apresentam melhora clínica com este tratamento. Por outro lado, aproximadamente 10 por cento dos pacientes submetidos a essa terapia podem apresentar hiper resposta, e a ecocardiografia tridimensional pode oferecer uma opção interessante para a seleção e avaliação de tratamento desses pacientes.

Cardiac resynchronization therapy consists of a promising treatment for patients with severe heart failure, but about 30 percent of patients do not exhibit clinical improvement with this procedure. However, approximately 10 percent of patients undergoing this therapy may have hyperresponsiveness, and three-dimensional echocardiography can provide an interesting option for the selection and evaluation of such patients.

La terapia de resincronización cardíaca consiste en un tratamiento promisorio para pacientes con insuficiencia cardíaca grave, sin embargo cerca de un 30 por ciento de los pacientes, no presentan una mejoría clínica con ese tratamiento. Por otro lado, aproximadamente un 10 por ciento de los pacientes sometidos a esa terapia pueden presentar hiperrespuesta, y la ecocardiografía tridimensional puede ser una opción interesante para la selección y la evaluación del tratamiento de esos pacientes.

Efficacy of antibiotic prophylaxis before the implantation of pacemakers and cardioverter-defibrillators: results of a large, prospective, randomized, double-blinded, placebo-controlled trial.

BACKGROUND: Although routinely administered, definitive evidence for the benefits of prophylactic antibiotics before the implantation of permanent pacemakers and implantable cardioverter-defibrillators from a large double-blinded placebo-controlled trial is lacking. The purpose of this study was to determine whether prophylactic antibiotic administration reduces the incidence of infection related to device implantation. METHODS AND RESULTS: This double blinded study included 1000 consecutive patients who presented for primary device (Pacemaker and implantable cardioverter-defibrillators) implantation or generator replacement randomized in a 1:1 fashion to prophylactic antibiotics or placebo. Intravenous administration of 1 g of cefazolin (group I) or placebo (group 2) was done immediately before the procedure. Follow-up was performed 10 days, 1, 3, and 6 months after discharge. The primary end point was any evidence of infection at the surgical incision (pulse generator pocket), or systemic infection related to be procedure. The safety committee interrupted the trial after 649 patients were enrolled due to a significant difference in favor of the antibiotic arm (group I: 2 of 314 infected patients-0.63%; group II: 11 of 335 to 3.28%; RR=0.19; P=0.016). The following risk factors were positively correlated with infection by univariate analysis: nonuse of preventive antibiotic (P=0.016); implant procedures (versus generator replacement: P=0.02); presence of postoperative hematoma (P=0.03) and procedure duration (P=0.009). Multivariable analysis identified nonuse of antibiotic (P=0.037) and postoperative hematoma (P=0.023) as independent predictors of infection. CONCLUSIONS: Antibiotic prophylaxis significantly reduces infectious complications in patients undergoing implantation of pacemakers or cardioverter-defibrillators.

Efetividade do CDI na taquicardia ventricular sincopal e na parada cardíaca / ICD therapy efficacy is similar in cardiac arrest survivors and in patients with syncope due to ventricular tachycardia

Objetivo: Comparar o comportamento clínico-evolutivo de portadores de CDI por taquicardia ventricular (TV) sincopal ou parada cardíaca (PC) por TV/FV. Método: 585 pacientes foram submetidos a implante de CDI entre jan/2000 e jul/2005 para prevenção secundária de morte súbita cardíaca (MSC). Foram selecionados 415 pacientes de um banco de dados prospectivo, distribuídos em dois grupos: G1, com TV sincopal (n=318) e G2, com PC por TV/FV (n=97). As variáveis analisadas foram: idade, sexo, fração de ejeção do ventrículo esquerdo(FEVE), classe funcional de insuficiência cardíaca (CF IC), medicamentos, terapias de choque apropriadas (TCA) pelo CDI e óbitos. Para análise estatística...

Cardiac resynchronization therapy evaluated by myocardial scintigraphy with 99mTc-MIBI: changes in left ventricular uptake, dyssynchrony, and function.

PURPOSE: (99m)Tc-MIBI gated myocardial scintigraphy (GMS) evaluates myocyte integrity and perfusion, left ventricular (LV) dyssynchrony and function. Cardiac resynchronization therapy (CRT) may improve the clinical symptoms of heart failure (HF), but its benefits for LV function are less pronounced. We assessed whether changes in myocardial (99m)Tc-MIBI uptake after CRT are related to improvement in clinical symptoms, LV synchrony and performance, and whether GMS adds information for patient selection for CRT. METHODS: A group of 30 patients with severe HF were prospectively studied before and 3 months after CRT. Variables analysed were HF functional class, QRS duration, LV ejection fraction (LVEF) by echocardiography, myocardial (99m)Tc-MIBI uptake, LV end-diastolic volume (EDV) and end-systolic volume (ESV), phase analysis LV dyssynchrony indices, and regional motion by GMS. After CRT, patients were divided into two groups according to improvement in LVEF: group 1 (12 patients) with increase in LVEF of 5 or more points, and group 2 (18 patients) without a significant increase. RESULTS: After CRT, both groups showed a significant improvement in HF functional class, reduced QRS width and increased septal wall (99m)Tc-MIBI uptake. Only group 1 showed favourable changes in EDV, ESV, LV dyssynchrony indices, and regional motion. Before CRT, EDV, and ESV were lower in group 1 than in group 2. Anterior and inferior wall (99m)Tc-MIBI uptakes were higher in group 1 than in group 2 (p<0.05). EDV was the only independent predictor of an increase in LVEF (p=0.01). The optimal EDV cut-off point was 315 ml (sensitivity 89%, specificity 94%). CONCLUSION: The evaluation of EDV by GMS added information on patient selection for CRT. After CRT, LVEF increase occurred in hearts less dilated and with more normal (99m)Tc-MIBI uptake.

Cardiac resynchronization therapy improves the uptake of MIBI-99mTc and cardiac function.

This case shows the improvement promoted by cardiac resynchronization therapy (CRT) on myocardial perfusion and left ventricular (LV) performance assessed by gated myocardial perfusion scintigraphy. The patient had idiopathic dilated cardiomyopathy, left bundle branch block and severe heart failure despite optimized medical treatment. After CRT, clinical improvement, QRS reduction and improvement of previously hypoperfused anterior and septal walls were observed. There was also decrease in LV end-diastolic and systolic volumes and increase in LV ejection fraction.