Marcelo Imbroinise Bittencourt

Assessing autonomic function in hypertrophic cardiomyopathy

OBJECTIVE Assess the autonomic function in hypertrophic cardiomyopathy (HCM) through heart rate variability (HRV) and to correlate it to echocardiographic data. METHODS Two groups were studied, and compared for gender, age and HR: A) Ten (10) patients reporting septal HCM (70% non-obstructive); B) Ten (10) healthy volunteers. HRV was analyzed along four successive stages: at rest, under controlled breathing, while bending, and controlled breathing associated to bending. Variables means were compared between groups and intra-groups in the different stages; in Group A, variables means were correlated to echocardiographic measurements (interventricular septum and left atrial diameter). RESULTS No HRV difference was reported among groups in the first 3 stages. In the fourth stage vagal activity was shown to be higher in Group A [quadratic mean log between RR intervals (RMSSD) - 1.35+/-0.14 vs 1.17+/-0.16; p=0.019; high frequency component logarithm (LogHF)- 4.89+/-0.22 vs 4.62+/-0.26; p=0.032]. Along the stages, vagal measurements [rate of pairs of consecutive RR intervals whose difference is > or =50 ms (pNN50) and LogHF] also showed lower reduction in the third stage in Group A, while LogHF showed some increase in last stage (p=0.027), thus indicating marked parasympathetic activity in that group. Group A HRV analysis showed no difference among patients reporting larger hypertrophy or atrial diameter. CONCLUSION 1) Parasympathetic prevalence was shown during autonomic stimulation in HCM patients; 2) No correlation was found between HRV and echocardiographic measurements under analysis.

Angiotensin-converting enzyme genetic polymorphism: its impact on cardiac remodeling

Background The role of angiotensin-converting enzyme genetic polymorphisms as a predictor of echocardiographic outcomes on heart failure is yet to be established. The local profile should be identified so that the impact of those genotypes on the Brazilian population could be identified. This is the first study on exclusively non-ischemic heart failure over a follow-up longer than 5 years. Objective To determine the distribution of angiotensin-converting enzyme genetic polymorphism variants and their relation with echocardiographic outcome of patients with non-ischemic heart failure. Methods Secondary analysis of the medical records of 111 patients and identification of the angiotensin-converting enzyme genetic polymorphism variants, classified as DD (Deletion/Deletion), DI (Deletion/Insertion) or II (Insertion/Insertion). Results The cohort means were as follows: follow-up, 64.9 months; age, 59.5 years; male sex, 60.4%; white skin color, 51.4%; use of beta-blockers, 98.2%; and use of angiotensin-converting-enzyme inhibitors or angiotensin receptor blocker, 89.2%. The angiotensin-converting enzyme genetic polymorphism distribution was as follows: DD, 51.4%; DI, 44.1%; and II, 4.5%. No difference regarding the clinical characteristics or treatment was observed between the groups. The final left ventricular systolic diameter was the only isolated echocardiographic variable that significantly differed between the angiotensin-converting enzyme genetic polymorphisms: 59.2 ± 1.8 for DD versus 52.3 ± 1.9 for DI versus 59.2 ± 5.2 for II (p = 0.029). Considering the evolutionary behavior, all echocardiographic variables (difference between the left ventricular ejection fraction at the last and first consultation; difference between the left ventricular systolic diameter at the last and first consultation; and difference between the left ventricular diastolic diameter at the last and first consultation) differed between the genotypes (p = 0.024; p = 0.002; and p = 0.021, respectively). Conclusion The distribution of the angiotensin-converting enzyme genetic polymorphisms differed from that of other studies with a very small number of II. The DD genotype was independently associated with worse echocardiographic outcome, while the DI genotype, with the best echocardiographic profile (increased left ventricular ejection fraction and decreased left ventricular diameters).

Use of anticoagulation and D-dimer levels in patients with acute heart failure

Decompensated heart failure (DHF) is associated with several coagulation disturbances, including elevation of the circulating D-dimer levels, contributing to pathophysiology and thromboembolic events. The influence of oral anticoagulant on D-dimer levels in patients with HF has not been established.

Diretriz Brasileira de Insuficiência Cardíaca Crônica e Aguda

Parte 1: Diretriz Brasileira de Insuficiencia Cardiaca Cronica […] Diretriz Brasileira de Insuficiencia Cardiaca Cronica e Aguda

Sudden Death in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is an autosomal dominant, genetic heart muscle disease, characterized by ventricular hypertrophy in the absence of any other medical condition causing heart overload. The disease has an estimated prevalence of 1:500 and is a significant cause of sudden death, especially in young individuals, with an annual incidence of approximately 1%. Among the risk markers for the occurrence of malignant ventricular arrhythmias and sudden death in this scenario, we emphasize, in addition to a fatal event that has occurred and was aborted, the family history of sudden death; wall thickness greater or equal to 30 mm; unexplained syncope; presence of non-sustained ventricular tachycardia on Holter; abnormal blood pressure response during exercise testing; and the presence of delayed enhancement on cardiac magnetic resonance. The presence or absence of these markers can define the need or not of an implantable cardioverterdefibrillator to prevent sudden death in these patients. However, there is still much controversy about how these patients should be stratified. It is known that these markers do not have the same weight in predicting who is more likely to suffer a fatal event. This fact becomes particularly important when it is considered that the cardioverter-defibrillator implantation procedure is not free of complications, in addition to the economic impact, in terms of cost, to the health system. The purpose of this article is to carry out a review of the main aspects involved in the sudden death in these patients, from the pathophysiology, risk assessment, prevention and future perspectives.

Prediction of heart failure by C-reactive protein in patients with acute myocardial infarction

Inflammatory markers such as C-reactive protein (CRP) have shown a high prognostic value in the setting of coronary artery disease and heart failure (HF).