Ecoestresse físico na cardiomiopatia hipertrófica: como, quando e por quê? / Exercise stress echocardiography in hypertrophic cardiomyopathy: how, when and why?

Resumo Historicamente, o papel do ecocardiograma de estresse físico no manejo da cardiomiopatia hipertrófica tem sido negligenciado na prática clínica, de acordo com a análise das diretrizes do American College of Cardiology/ American Heart Association de 2002, que recomendavam cautela no uso dessa metodologia, em portadores de cardiomiopatia hipertrófica, devido ao risco de possível ocorrência tanto de arritmia cardíaca, como de colapso hemodinâmico no esforço. Atualmente, o estresse físico na cardiomiopatia hipertrófica integra a avaliação rotineira de pacientes sintomáticos com ou sem gradiente da via de saída do ventrículo esquerdo < 50 mmHg, em repouso. Para este grupo, é um método seguro e confiável para medir o gradiente da via de saída do ventrículo esquerdo durante o esforço e sólido diferenciador de pacientes com cardiomiopatia hipertrófica não obstrutivos (gradiente ausente, tanto em repouso quanto no esforço) daqueles com gradientes lábeis (gradiente ausente no repouso e presente no esforço). Portanto, na avaliação da cardiomiopatia hipertrófica, o estresse físico é igualmente útil na quantificação do grau de regurgitação mitral, nas alterações da contratilidade segmentar do ventrículo esquerdo e na avaliação da função diastólica do ventrículo esquerdo, diante do esforço, sendo capaz de predizer o futuro desenvolvimento de sintomas de insuficiência cardíaca. O método é também importante na determinação das diferentes estratégias de tratamento para cada paciente, desde a miomectomia cirúrgica ou a ablação septal alcoólica, para aqueles com gradiente lábil, com sintomas limitantes e refratários ao tratamento medicamentoso versus transplante cardíaco para aqueles sem gradiente.(AU)

Long-term follow-up of neonatal coarctation and left-sided cardiac hypoplasia.

Neonatal coarctation of the aorta (CoA) is often associated with hypoplastic left-sided cardiac structures. Limited data are available regarding the long-term clinical outcomes. Our purposes were to assess the following in neonates with CoA and left-sided cardiac hypoplasia: (1) left-sided cardiac structure growth over time, (2) echocardiographic parameters predicting reintervention, and (3) long-term outcomes and reintervention rates. Data were collected for all patients born with isolated CoA, along with a mitral or aortic Z-score of <-2, who underwent repair before 2 months of age from January 1993 to April 1997. Recent follow-up data were available for 51 of 63 patients (81%) aged 15.4 ± 1.5 years (range 11 to 18). Of the 51 patients, 46 (90%) had a recent echocardiogram, all with normal left ventricular systolic function. The mitral and aortic valve annulus Z-scores increased significantly from the initial measurements: -3.29 ± 1.54 to -0.94 ± 0.58 (p <0.0001) and -3.25 ± 1.98 to 0.08 ± 1.81 (p <0.0001). No significant change was seen from intermediate (6.1 ± 1.6 years) to the latest follow-up examination. Of the 51 patients, 12 (24%) required reintervention at 3 ± 4.5 years; 9 for repeat CoA, 4 for subaortic stenosis, and 2 for aortic stenosis (some in combination). The initial echocardiographic parameters were not associated with reintervention. The overall freedom from reintervention was 76% at 15 years of follow-up. In conclusion, the long-term outcomes after isolated CoA repair with associated left-sided cardiac hypoplasia were excellent. Both aortic and mitral valve sizes had increased substantially by intermediate follow-up but tended to normalize afterward. Although 24% of the patients required reintervention, significant left ventricular inflow or outflow tract obstruction was uncommon.

Cardiomyopathy in offspring of diabetic rats is associated with activation of the MAPK and apoptotic pathways.

BACKGROUND: Maternal diabetes affects the developing fetal cardiovascular system. Newborn offspring of diabetic mothers can have a transient cardiomyopathy. We hypothesized that cardiomyopathic remodeling is associated with activation of the mitogen activated protein kinase (MAPK) signaling and apoptotic pathways. METHODS: To evaluate the effects of moderate and severe maternal hyperglycemia, pregnant rats were made diabetic with an injection of 50 mg/kg of streptozotocin. Moderately well controlled maternal diabetes was achieved with twice daily glucose checks and insulin injections. No insulin was given to severely diabetic dams. Offspring of moderate and severe diabetic mothers (OMDM and MSDM, respectively) were studied on postnatal days 1 (NB1) and 21 (NB21). Echocardiograms were performed to evaluate left ventricular (LV) dimensions and function. Myocardial MAPK and apoptotic protein levels were measured by Western blot. RESULTS: OMDM had increased cardiac mass at NB1 compared to controls that normalized at NB21. OSDM demonstrated microsomia with relative sparing of cardiac mass and a dilated cardiomyopathy at NB1. In both models, there was a persistent increase in the HW:BW and significant activation of MAPK and apoptotic pathways at NB21. CONCLUSION: The degree of maternal hyperglycemia determines the type of cardiomyopathy seen in the offspring, while resolution of both the hypertrophic and dilated cardiomyopathies is associated with activation of MAPK signaling and apoptotic pathways.

Cardiac structures track during the first 2 years of life and are associated with fetal growth and hemodynamics: the Generation R Study.

BACKGROUND: The aim of this study is to examine whether cardiac size and function track in early childhood and are associated with fetal and early postnatal growth and blood flow characteristics. METHODS: This study was embedded in a population-based prospective cohort study from fetal life onward. Fetal growth and fetal and placental blood flow parameters in second and third trimester of pregnancy were measured by ultrasound and Doppler. Left cardiac structures and shortening fraction were measured postnatally at the ages of 1.5, 6, and 24 months. Analyses were based on 1,001 children. RESULTS: Left ventricular mass tended to remain in the lowest and highest quartiles from the age of 1.5 to 24 months (odds ratio 1.70, 95% confidence interval [CI] 1.10-2.63) and 2.15 (95% CI 1.41-3.30), respectively. Similar results were found for aortic root diameter and left atrial diameter. Birth weight was positively associated with aortic root diameter (0.08 mm, 95% CI 0.01-0.17; per SD increase) and left ventricular mass (0.65 g, 95% CI 0.09-1.21; per SD increase). Resistance indices of the umbilical and uterine arteries showed weak tendencies toward inverse associations with left cardiac structures. Fetal cardiac output was positively associated with both left atrial diameter (increase of 1.96 mm, 95% CI 1.28-2.64; per mL/min increase) and left ventricular mass (increase of 1.79 g, 95% CI 0.35-3.22; per mL/min increase). CONCLUSIONS: This study suggest moderate tracking of left cardiac structures during the first 2 years and that small size and hemodynamic variations in fetal life have consequences for postnatal cardiac size and function.

Diastolic function study with conventional and pulsed tissue Doppler echocardiography imaging in acromegalic patients.

UNLABELLED: Acromegaly is associated with myocardial hypertrophy and it can progress to diastolic and systolic dysfunction. PURPOSE: To evaluate diastolic function in acromegalic patients through conventional echocardiography (CD) and tissue Doppler imaging (TDI). METHODS: Seventeen acromegalic patients were submitted to CD and TDI, and early (E) and atriogenic (A) transmitral flow were evaluated in mitral, septal, and tricuspid regions. RESULTS: In comparison with controls the means of conventional (1.06), septal (1.01), and tricuspid (0.98) E/A ratio were significantly lower in acromegalic patients. E/A ratio <1.0 was demonstrated in 41% and 49% of acromegalics by DC and TDI, respectively, with no statistical difference among the two methods. An inverse linear correlation was shown between mitral E/A ratio and acromegalic age (r =-0.7). CONCLUSION: In this study, DC and TDI were equally effective in demonstrating diastolic dysfunction, a common finding in acromegalic patients.

Isolated left ventricular noncompaction in association with rheumatic mitral stenosis.

Fifty year old man with a known case of chronic rheumatic heart disease with atrial fibrillation was presented with severe mitral stenosis. He was incidentally detected to have noncompaction of left ventricle on echocardiography and Doppler examination. He underwent successful percutaneous trans-luminal mitral commissurotomy (PTMC) for severe mitral stenosis. This is the first reported case of isolated ventricular noncompaction (IVNC) associated with acquired chronic rheumatic mitral stenosis.

[Non-compact left ventricular myocardium: current state of the problem].

Non-compaction of the left ventricle or spongy myocardium is a rare congenital cardiomyopathy which is characterized by impaired endomyocardial morphogenesis, hypertrophy of left ventricular myocardium with prominent trabeculation, and deep inter-trabecular recesses. According to WHO classification (1995) this disease belongs to unclassified cardiomyopathies. Main clinical signs of ventricular non-compaction are heart failure, ventricular arrhythmias, systemic and pulmonary embolism. Echocardiography which is a basic method of diagnosis can reveal double layer structure of thickened left ventricular wall and multiple prominent trabeculation with wide inter-trabecular spaces. Predominant localizations of pathological process are region of cardiac apex, inferior and lateral left ventricular walls. Treatment of patients with ventricular non-compaction concentrates on elimination of its main clinical symptoms.

Isolated left ventricular noncompaction of the myocardium as a cause of embolic superior mesenteric artery occlusion.

Isolated noncompaction of the left ventricular (LV) myocardium is a rare congenital disorder resulting from an arrest of the compaction process of the myocardial trabeculae during normal embryogenesis. It is characterized by the presence of prominent LV myocardial trabeculations and deep intertrabecular recesses that are in continuity with the LV cavity. The most common clinical presentation includes progressive LV dysfunction, life-threatening tachyarrhythmias, and the risk for severe cardioembolic events. We describe a case where isolated noncompaction of the LV myocardium was diagnosed after an embolic occlusion of the superior mesenteric artery in a 40-year-old Caucasian woman.

Accessory mitral valve tissue causing severe left ventricular outflow tract obstruction in an adult.

Accessory mitral valve (AMV) is a rare cause of left ventricular outflow tract (LVOT) obstruction and is extremely rare in adults. We report a case of an older adult with an AMV that caused severe LVOT obstruction. A parachute-like piece of tissue (the AMV) protruding into the LVOT during systole was first detected in a 45-year-old woman by echocardiography. Because the pressure gradient and dyspnea gradually progressed, she finally underwent a successful operation for removal when she was 48 years old.

Noncompaction of the ventricular myocardium associated with mitral regurgitation and preserved ventricular systolic function.

Noncompaction of the ventricular myocardium is an embryonic cardiomyopathy that is increasingly being recognized. Mitral regurgitation, when present, is usually a result of the associated left ventricular systolic dysfunction. We report 4 patients with noncompaction of the ventricular myocardium in whom ventricular systolic function was preserved. Mitral regurgitation was associated with changes in the mitral valve leaflets and an abnormal coaptation pattern. This association of noncompaction of the ventricular myocardium with mitral regurgitation has not, to our knowledge, been reported.