Association of angiotensin-converting enzyme activity and polymorphism with echocardiographic measures in familial and nonfamilial hypertrophic cardiomyopathy

Angiotensin-converting enzyme (ACE) activity and polymorphism contribute significantly to the prognosis of patients with cardiomyopathy. The aim of this study was to determine the activity and type of ACE polymorphism in patients with familial and nonfamilial hypertrophic cardiomyopathy (HCM) and to correlate these with echocardiographic measurements (echo-Doppler). We studied 136 patients (76 males) with HCM (69 familial and 67 nonfamilial cases). Mean age was 41 ¡À 17 years. DNA was extracted from blood samples for the polymerase chain reaction and the determination of plasma ACE levels. Left ventricular mass, interventricular septum, and wall thickness were measured. Mean left ventricular mass index, interventricular septum and wall thickness in familial and nonfamilial forms were 154 ¡À 63 and 174 ¡À 57 g/m2 (P = 0.008), 19 ¡À 5 and 21 ¡À 5 mm (P = 0.02), and 10 ¡À 2 and 12 ¡À 3 mm (P = 0.0001), respectively. ACE genotype frequencies were DD = 35%, ID = 52%, and II = 13%. A positive association was observed between serum ACE activity and left ventricular mass index (P = 0.04). Logistic regression showed that ACE activity was twice as high in patients with familial HCM and left ventricular mass index ¡Ý190 g/m2 compared with the nonfamilial form (P = 0.02). No other correlation was observed between ACE polymorphisms and the degree of myocardial hypertrophy. In conclusion, ACE activity, but not ACE polymorphisms, was associated with the degree of myocardialhypertrophy in the patients with HCM.

N-terminal prohormone brain natriuretic peptide (NT-proBNP) as a noninvasive marker for restrictive syndromes

Constrictive pericarditis (CP) and restrictive cardiomyopathy share many similarities in both their clinical and hemodynamic characteristics and N-terminal prohormone brain natriuretic peptide (NT-proBNP) is a sensitive marker of cardiac diastolic dysfunction. The objectives of the present study were to determine whether serum NT-proBNP was high in patients with endomyocardial fibrosis (EMF) and CP, and to investigate how this relates to diastolic dysfunction. Thirty-three patients were divided into two groups: CP (16 patients) and EMF (17 patients). The control group consisted of 30 healthy individuals. Patients were evaluated by bidimensional echocardiography, with restriction syndrome evaluated by pulsed Doppler of the mitral flow and serum NT-proBNP measured by immunoassay and detected by electrochemiluminescence. Spearman correlation coefficient was used to analyze the association between log NT-proBNP and echocardiographic parameters. Log NT-proBNP was significantly higher (P < 0.05) in CP patients (log mean: 2.67 pg/mL; 95 percentCI: 2.43-2.92 log pg/mL) and in EMF patients (log mean: 2.91 pg/mL; 95 percentCI: 2.70-3.12 log pg/mL) compared with the control group (log mean: 1.45; 95 percentCI: 1.32-1.60 log pg/mL). There were no statistical differences between EMF and CP patients (P = 0.689) in terms of NT-proBNP. The NT-proBNP log tended to correlate with peak velocity of the E wave (r = 0.439; P = 0.060, but not with A wave (r = -0.399; P = 0.112). Serum NT-proBNP concentration can be used as a marker to detect the presence of diastolic dysfunction in patients with restrictive syndrome; however, serum NT-proBNP levels cannot be used to differentiate restrictive cardiomyopathy from CP.

Leptin levels in different forms of Chagas' disease

Leptin is produced primarily by adipocytes. Although originally associated with the central regulation of satiety and energy metabolism, increasing evidence indicates that leptin may be an important mediator in cardiovascular pathophysiology. The aim of the present study was to investigate plasma leptin levels in patient with Chagas' heart disease and their relation to different forms of the disease. We studied 52 chagasic patients and 30 controls matched for age and body mass index. All subjects underwent anthropometric, leptin and N-terminal pro-brain natriuretic peptide (NT-proBNP) measurements and were evaluated by echocardiography, 12-lead electrocardiogram (ECG), and chest X-ray. All patients had fasting blood samples taken between 8:00 and 9:00 am. Chagasic patients were divided into 3 groups: group I (indeterminate form, IF group) consisted of 24 subjects with 2 positive serologic reactions for Chagas' disease and no cardiac involvement as evaluated by chest X-rays, ECG and two-dimensional echocardiography; group II (showing ECG abnormalities and normal left ventricular systolic function, ECG group) consisted of 14 patients; group III consisted of 14 patients with congestive heart failure (CHF group) and left ventricular dysfunction. Serum leptin levels were significantly lower (P < 0.001) in the CHF group (1.4 ± 0.8 ng/mL) when compared to the IF group (5.3 ± 5.3 ng/mL), ECG group (9.7 ± 10.7 ng/mL), and control group (8.1 ± 7.8 ng/mL). NT-proBNP levels were significantly higher (P < 0.001) in the CHF group (831.8 ± 800.1 pg/mL) when compared to the IF group (53.2 ± 33.3 pg/mL), ECG group (83.3 ± 57.4 pg/mL), and control group (32 ± 22.7 pg/mL). Patients with Chagas' disease and an advanced stage of CHF have high levels of NT-ProBNP andlow plasma levels of leptin. One or more leptin-suppressing mechanisms may operate in chagasic patients.

Doenças cardiovasculares observadas durante o seguimento de um grupo de pacientes na forma indeterminada da doença de Chagas / Cardiovascular diseases observed during follow-up of a group of patients in undetermined form of Chagas'Disease

OBJETIVO - Observar, num grupo de pacientes na forma indeterminada da doença de Chagas, o aparecimento de doenças cardiovasculares e sua possível relação com a doença de base. MÉTODOS - Foram seguidos, prospectivamente, 160 pacientes por até 177 meses com avaliaçöes clínicas trimestrais. RESULTADOS - Tornaram-se hipertensos 23 (14,4 'por cento') pacients, sendo 21 (13,2 'por cento') com pressão arterial diastólica <110mmHg. Duas pacientes (1,2 'por cento') hipertensas tiveram acidente vascular cerebral isquêmico (AVCI). Uma (0,6 'por cento') paciente teve hemorragia meníngea por ruptura de aneurisma cerebral. Quatro (2,4 'por cento') pacientes apresentaram arritmia clinicamente, dois (1,2 'por cento') extra-sístoles ventriculares, um (0,6 'por cento') extra-sístoles supra-ventriculares e um (0,6 'por cento') fibrilação atrial aguda. Dois (1,2 'por cento') pacientes desenvolveram coronariopatias comprovada angiograficamente, um (0,6 'por cento') com infarto agudo do miocárdio, outro com angina estável. Um (0,6 'por cento') paciente desenvolveu sinais e sintomas de insuficiência cardíaca, juntamente com o aparecimento de hipertensão arterial sistêmica (HAS). CONCLUSÄO - A doença cardiovascular mais freqüente foi a HAS. Duas hipertensas apresentaram AVCI. As arritmias observadas não foram mais freqüentes que na população normal e a coronariopatia também ocorreu raramente, confirmando um bom prognóstico clínico a longo prazo desse grupo de pacientes.

Capacidade funcional máxima e função diastólica em portadores de cardiomiopatia chagásica sem insuficiência cardíaca congestiva / Maximal functinsl capacity and diastolic function in patients with cardiomyopathy due to Chagas'disease without congestive heart failure

OBJETIVO - Identificar disfunçöes cardíacas precoces em pacientes assintomáticos com cardiomiopatia chagásica. MÉTODOS - Foram estudados 38 indivíduos masculinos, sendo o grupo controle constituído de 20 indivíduos sedentários normais e o grupo Chagas de 18 pacientes assintomáticos, portadores da doença de Chagas, com eletrocardiograma alterado e fração de encurtamento (DD) normal ao ecocardiograma. Ambos os grupos foram submetidos à avaliação da capacidade funcional máxima, com medidas do máximo de oxigênio (PO2max), ventilação máxima (VEmax), freqüência cardíaca máxima (FCmax), e limiar anaeróbico do VO2max (LA-VO2). A função diastólica do ventrículo esquerdo foi avaliada pelo ecocardiograma convencional (ondas E e A além da relação E/A). RESULTADOS - Não ocorreram diferenças significativas entre os dois grupos em relação ao DD (p=0,212) e a idade média (p=0,060). Houve diferença significativa (p<0,001) em relação aos parâmetros VO2max, PO2max, VEmax, FCmax, LA-VO2, onda E e relação E/A. Não houve significância (p=0,520) em relação a onda A. CONCLUSÄO - O comprometimento na função ventricular pode contribuir para as diferenças acima mencionadas, como conseqüência de disfunção sistólica e diastólica.

Valor do indice cardiotoracico na avaliacao do comprometimento miocardico. Correlacao com avaliacao ecocardiografica. / Value of cardiothoracic index on the evaluation of myocardial involvement. Correlation with echocardiographic evaluation

Foram estudados 22 portadores de doenca de Chagas, divididos em dois grupos: Grupo A, constituido de 11 pacientes sem cardiomegalia e Grupo B, constituido de 11 pacientes com cardiomegalia. Analisou-se as variaveis diametro transverso do coracao (dt) e o indice cardiotoracico (ICT) obtidos atraves do estudo radiologico do coracao e dos diametros sistolico (Ds) e diastolico (Dd) e a variacao do encurtamento sistico do ventriculo esquerdo (delta D%) obtidos no estudo ecocardiografico, comparando-se os valores de cada grupo entre si Em seguida, realizou-se estudo do relacionamento entre estas variaveis, obtendo-se os coeficientes de explicacao e as equacoes de regressao. Observou-se nitida correlacao entre as medidas ecocardiograficas e medidas obtidas no estudo radiologico, de forma que o aumento do diametro transverso do coracao corresponde aumento dos diametros sistolico e diastolico ecocardiografico do ventriculo esquerdo e o aumento do ICT corresponde diminuicao do delta D%, sendo significantes os coeficientes de explicacao e as equacoes de regressao. Observou-se nitida correlacao entre as medidas obtidas no estudo radiologico, de forma que o aumento do diametro transverso do coracao corresponde aumento dos diametros sistolico e diastolico ecocardiografico do ventriculo esquerdo e o aumento do ICT corresponde diminuicao do delta D%, sendo significantes os coeficientes de explicacao desta correlacao