Prevalence of Left Ventricular Dyssynchrony in Patients with Congenital Atrioventricular Block and Long-Term Pacing: A Three-Dimensional Echocardiographic Study.

BACKGROUND: Left ventricular (LV) dysfunction is the major reason for poor outcomes in patients with congenital complete atrioventricular block (CCAVB) and pacemaker. Long-term pacing has been associated with LV mechanical dyssynchrony. However, the relationship of dyssynchrony and LV dysfunction is not clear. OBJECTIVE: We sought to evaluate the prevalence of LV dyssynchrony by real time three-dimensional echocardiography (RT3DE) in patients with CCAVB and its association with LV dysfunction. In addition, we evaluated the agreement between RT3DE and tissue Doppler imaging (TDI) for detecting LV dyssynchrony. METHOD: We studied 50 patients [median age 20 years old (5 months to 62 years), 68% women] with CCAVB and pacemaker who underwent complete two-dimensional echocardiography and RT3DE. LV dyssynchrony was considered if the systolic dyssynchrony index (SDI) was ≥ 5%. Intraventricular mechanical delay was defined by TDI when differences in electromechanical activation between LV walls were > 65 msec. RESULTS: LV systolic dysfunction was present in 16 patients (32%) by two-dimensional and in 20 patients (40%) by RT3DE. There was a good correlation between LV ejection fraction by two-dimensional and RT3DE (r = 0.75; P < 0.001). Fourteen (28%) patients had intraventricular dyssynchrony by TDI, while 12 (24%) had intraventricular dyssynchrony by RT3DE. There was a good agreement between LV dyssynchrony by TDI and RT3DE (Kappa = 0.735; P < 0.001). There was a negative correlation between LV ejection fraction and SDI obtained by RT3DE (r = -0.58; P < 0.001) CONCLUSIONS: In patients with CCAVB and long-term pacing, LV dyssynchrony occurred in one-third of patients and was related to LV dysfunction. There was a good correlation between dyssynchrony obtained by RT3DE and TDI.

The impact of preexisting myocardial remodeling on ventricular function early after tetralogy of Fallot repair.

BACKGROUND: Twenty-three patients (median age 23 months) who underwent Fallot's tetralogy repair were investigated prospectively to detect a possible association between histopathologic myocardial remodeling and echocardiographic findings of systolic or diastolic ventricular dysfunction. METHODS: Intraoperatively resected infundibular bands and subendocardial biopsy samples from the right ventricle (RV) and left ventricle were obtained for histopathologic evaluation. Tissue Doppler echocardiographic interrogation of the ventricles was performed before surgery and in the postoperative period. RESULTS: Histopathologic data revealed hypertrophy of the RV cardiomyocytes and increased interstitial collagen in both ventricles. Mean values of RV isovolumic acceleration decreased significantly at the third evaluation compared with the preoperative values (P = .006). RV myocardial fibrosis greater than 8.3% was associated with a probability of altered E' of at least 0.7 (odds ratio = 2.31). CONCLUSION: Preoperative histologic myocardial remodeling influenced the postoperative RV function in this group of patients with late repair. Further studies are necessary to evaluate the myocardium in younger patients and to define its influence in the long-term follow-up.

Avaliação da dissincronia ventricular mecânica pela ecocardiografia tridimensional em pacientes portadores de bloqueio atrioventricular total congênito e marcapasso / Left ventricular dyssynchrony evaluated by three-dimensional echocardiography in patients with congenital complete atrioventricular block and long-term pacing

A disfunção ventricular esquerda (VE) é o principal determinante de mau prognóstico nos pacientes com bloqueio atrioventricular completo congênito (BAVTC) e marcapasso (MP). A dissincronia mecânica do VE pode desempenhar um papel importante no desenvolvimento da disfunção ventricular. Como o uso do MP é um fator de risco para dissincronia, nosso(s) objetivo(s) foram: (1) avaliar a dissincronia do VE pelo ecocardiograma tridimensional (3D) em tempo real e comparar com os parâmetros de dissincronia pelo Doppler tecidual ; (2) verificar a possível correlação entre o local do estímulo e o segmento ativado tardiamente; (3) correlacionar o tempo de marcapasso e a presença de dissincronia e remodelamento ventricular. Avaliamos 50 pacientes com BAVTC e MP através do ecocardiograma bidimensional (2D), Doppler tecidual e ecocardiograma tridimensional. Dados clínicos e anteriores ao implante do MP foram revistos pelos prontuários. Houve 12 (23,5%) pacientes com dissincronia pelo 3D e 14 (28%) pelo Doppler tecidual. Em 16 (32%) e 20 (40%) havia disfunção ventricular esquerda pelos 2D e 3D respectivamente. O remodelamento ventricular ocorreu em 50% dos pacientes. Houve uma excelente correlação entre o Doppler tecidual e o 3D para diagnóstico de dissincronia (kappa = 0,735, p <0,001). A fração de ejeção do VE (FEVE) correlacionou-se negativamente com a dissincronia pelo eco 3D (r= -0,58, p = 0,000001). A duração do ciclo cardíaco medida pelo intervalo RR teve também uma significante correlação negativa com o índice de dissincronia pelo 3D (r=-0,74, p=0,0011). O remodelamento do VE pelo Eco 3D (índices de esfericidade e conicidade) teve uma boa correlação com a disfunção do VE (p = 0,005 e 0,003 respectivamente). O tempo de marcapasso, a idade do implante e o local do eletrodo não se correlacionaram com a dissincronia. Comparando os pacientes com BAVTC e MP menores que 18 anos com um grupo controle de crianças normais, houve uma significante diferença em relação...

The left ventricle (LV) dysfunction is the major reason for poor outcome in patients with congenital complete atrioventricular block (CCAVB) and pacemaker (PM). The LV mechanical dyssynchrony may play a significant role in the development of LV dysfunction in this population. As the long-term pacing is a potential risk factor for dyssynchrony, we sought to: (1) evaluate by real time three-dimensional echocardiography (RT3DE) the LV dyssynchrony and compare with Tissue Doppler (TDI) parameters; (2) verify the potential correlation between the electrode location and the latest segment activated; (3) correlate the time of pacing and LV dyssynchrony and LV remodeling. Two-dimensional (2D), TDI and RT3DE were performed in 50 patients with CCAVB and PM (mean age of 21,4 years DP 13,4). Clinical data were reviewed. Twelve (23,5%) had LV dyssynchrony by RT3DE and 14 (28%) by Tissue Doppler criteria. Sixteen (32%) and 20 (40%) had LV dysfunction by 2D and 3D, respectively. LV remodeling occurred in 50% of patients. There was an excellent correlation between RT3DE and TDI (Kappa = 0,735; p <0,001). The LV ejection fraction (LVEF) had a significant negative correlation with the dyssynchrony index by 3D (r = -0,58, p = 0,000001). The duration of the cardiac cycle measured by RR interval had a significant negative correlation with the LV dyssynchrony index by 3D (r = - 0,74, p = 0,0011). LV remodeling demonstrated by the sphericity and conic indexes had a good correlation with the presence of LV dysfunction (p = 0,005 and 0,003 respectively). The pacing time, the age at pacemaker implantation and the location of the electrode did not correlate with LV dyssynchrony. Patients bellow 18 years of age were significantly different in terms of LV dyssynchrony indexes, LV remodeling and LV volumes when compared with a control group with similar age and body surface area. In conclusion, in a cohort study of patients with CCAVB and long-term pacing, the RT3DE had an excellent...

A novel adjustable pulmonary artery banding system for hypoplastic left heart syndrome.

OBJECTIVE: Hypoplastic left heart syndrome remains a challenge for worldwide surgeons. Initial palliation employing bilateral pulmonary artery banding along with ductal stent implantation and atrial septostomy has been proposed as an alternative approach. However, the surgically placed bands are fixed and may become inadequate after sternum closure or with somatic growth of the patient. We describe the first case in which a neonate with hypoplastic left heart syndrome was initially managed using a mini banding system that allows for fine percutaneous adjustments of pulmonary blood flow. METHOD: Through a mid sternotomy, a 5 day-old neonate underwent bilateral pulmonary artery banding using this new system combined with placement of a main pulmonary artery to innominate artery shunt. RESULTS: The patient had an uneventful postoperative course. Three percutaneous adjustments of the banding system were necessary to keep the arterial oxygen saturation in the 75%-85% range. On the 48th day of life, she was submitted to stent placement (6 mm) within the atrial septum to treat a restrictive atrial septal defect. The Norwood operation and the bidirectional Glenn shunt were carried out on the 106th day of life. The bands were removed with no distortion of the pulmonary arteries. CONCLUSIONS: The clinical use of this innovative pulmonary artery banding system was feasible, safe and effective. It allowed for customization of the pulmonary blood flow according to the underlying clinical needs, resulting in a more precise balance between the pulmonary and systemic circulations.

Gender differences in chronotropic and hemodynamic responses during dobutamine-atropine stress echocardiography.

AIM: The aim of this study was to determine the influence of gender on chronotropic and hemodynamic response during dobutamine stress echocardiography with early injection of atropine (EA-DSE). METHODS: From January 2000 to June 2003, we retrospectively evaluated patients who underwent EA-DSE for known or suspected coronary artery disease. We studied 494 patients, 243 men and 251 women, who were not under beta-blocker or calcium channel-blocker therapy (Group A) and 326 patients, 157 men and 169 women, using these medications (Group B). Differences on chronotropic and hemodynamic responses during EA-DSE were assessed by gender in the two groups. Predictors of need for higher doses of dobutamine were determined by multivariate analysis. RESULTS: In Group A, higher proportion of women achieved test end points at the stage of 20 mcg/kg per minute. Dobutamine and atropine doses were lower in women than in men (29 +/- 5 versus 31 +/- 6 mcg/kg per minute; P = 0.001 and 0.61 +/- 0.32 versus 0.78 +/- 0.43 mg; P = 0.006). Cardiac chronotropism and systolic blood pressure response patterns differed by gender. In Group B, there was no difference in the proportion of patients who achieved test end points at each stage of dobutamine. The independent predictors of the need for higher doses of dobutamine in Group A were gender [Odds Ratio (OR) = 1.99, 95% Confidence Interval (CI) = 1.19-3.32; P = 0.008], age (OR = 0.91,CI = 0.89-0.93; P < 0.001), and baseline heart rate (OR = 0.95,CI = 0.93-0.98; P < 0.001). Independent predictors in the total population were age (OR = 0.92,CI = 0.90-0.94; P < 0.001), baseline heart rate (OR = 0.95,CI = 0.93-0.97; P < 0.001), and beta-blocker therapy (OR = 0.42,CI = 0.18-1.51; P = 0.04). CONCLUSION: Gender has influence on heart rate and blood pressure response to the EA-DSE in patients without use of drugs with negative chronotropic effects.

Evaluation of blood flow reserve in left anterior descending coronary artery territory by quantitative myocardial contrast and Doppler echocardiography.

We sought to compare the feasibility and accuracy of myocardial blood flow reserve (MBFR) measured by quantitative real-time myocardial contrast echocardiography with those of coronary flow velocity reserve (CFVR) obtained by transthoracic Doppler echocardiography for detecting left anterior descending coronary artery (LAD) stenosis. We studied 71 patients who underwent adenosine stress contrast echocardiography, transthoracic Doppler echocardiography, and quantitative coronary angiography within 1 month. An index of myocardial blood flow (A x beta) was determined by quantification of peak plateau acoustic intensity (A) and microbubble replenishment velocity (beta) by contrast echocardiography. Feasibilities of qualitative analysis of myocardial perfusion, and CFVR and MBFR measurements were 98%, 83%, and 94%, respectively. Patients with LAD stenosis had lower CFVR (1.1 +/- 0.4 vs 2.7 +/- 0.8, P < .001), MBFR (1.2 +/- 0.5 vs 2.5 +/- 0.8, P < .001), and beta reserve (1.1 +/- 0.5 vs 2.4 +/- 0.6, P < .001) than those without lesion. Sensitivities, specificities, and accuracies for detecting LAD stenosis were 64%, 93%, and 80% for qualitative analysis of myocardial perfusion; 92%, 94%, and 93% for CFVR; 84%, 87%, and 86% for MBFR; and 80%, 97%, and 89% for beta reserve. In this selected study population, CFVR was the best index for detecting LAD stenosis (odds ratio = 1.78, 95% confidence interval = 1.28-2.47).

Nova bandagem ajustável das artérias pulmonares na Síndrome de Hipoplasia de Câmaras Esquerdas / A novel adjustable pulmonary artery banding system for hypoplastic left heart syndrome

OBJETIVO: A Síndrome de Hipoplasia de Câmaras Esquerdas representa um grande desafio para cirurgiões do mundo inteiro. Atualmente, tem sido proposto procedimento paliativo alternativo, por meio da bandagem bilateral das artérias pulmonares associada à colocação de stent no canal arterial e atrioseptostomia. No entanto, as bandagens utilizadas são fixas, podendo tornar-se inadequadas após o fechamento do esterno ou com o rápido crescimento somático do paciente. Descrevemos a primeira aplicação clínica do novo dispositivo miniaturizado de bandagem ajustável das artérias pulmonares em neonato portador da síndrome de hipoplasia de câmaras esquerdas, o qual permitiu ajustes percutâneos precisos do fluxo sangüíneo pulmonar. MÉTODO: Através de esternotomia mediana, neonato de 5 dias de vida foi submetido à bandagem pulmonar bilateral, usando este novo dispositivo, combinada com interposição de tubo de PTFE entre o tronco pulmonar e o tronco braquiocefálico. RESULTADOS: O paciente apresentou boa evolução pós-operatória. Três ajustes percutâneos das bandagens foram necessários para manter a saturação arterial de oxigênio entre 75-85 por cento. No 48° dia de vida, o paciente foi submetido a atrioseptostomia com colocação de stent (6 mm) para tratamento de comunicação interatrial restritiva. No 106° dia de vida, realizou-se operação de Norwood associada à anastomose cavopulmonar bilateral. As bandagens foram removidas, sem distorção das artérias pulmonares. CONCLUSÕES: O uso clínico deste sistema inovador de bandagem ajustável das artérias pulmonares mostrou-se factível, seguro e eficaz. Permitiu o ajuste fino do fluxo pulmonar de acordo com as necessidades clínicas, proporcionando um equilíbrio preciso entre as circulações pulmonar e sistêmica.

OBJECTIVE: Hypoplastic left heart syndrome remains a challenge for worldwide surgeons. Initial palliation employing bilateral pulmonary artery banding along with ductal stent implantation and atrial septostomy has been proposed as an alternative approach. However, the surgically placed bands are fixed and may become inadequate after sternum closure or with somatic growth of the patient. We describe the first case in which a neonate with hypoplastic left heart syndrome was initially managed using a mini banding system that allows for fine percutaneous adjustments of pulmonary blood flow. METHOD: Through a mid sternotomy, a 5 day-old neonate underwent bilateral pulmonary artery banding using this new system combined with placement of a main pulmonary artery to innominate artery shunt. RESULTS: The patient had an uneventful postoperative course. Three percutaneous adjustments of the banding system were necessary to keep the arterial oxygen saturation in the 75 percent-85 percent range. On the 48th day of life, she was submitted to stent placement (6 mm) within the atrial septum to treat a restrictive atrial septal defect. The Norwood operation and the bidirectional Glenn shunt were carried out on the 106th day of life. The bands were removed with no distortion of the pulmonary arteries. CONCLUSIONS: The clinical use of this innovative pulmonary artery banding system was feasible, safe and effective. It allowed for customization of the pulmonary blood flow according to the underlying clinical needs, resulting in a more precise balance between the pulmonary and systemic circulations.