Emre Yalcinkaya1, Murat Celik2, Baris Bugan3. 1. Departamento de Cardiologia, Hospital Militar Aksaz, Mugla, Turquia. 2. Departamento de Cardiologia, Faculdade Militar de Medicina Gulhane, Ancara, Turquia. 3. Departamento de Cardiologia, Hospital Militar Malatya, Malatya, Turquia.
To the Editor,We read with great interest the article by El Aouar et al.[1], entitled "Relationship between left atrial volume and
diastolic dysfunction in 500 Brazilian patients", which was published in the previous
issue of Arquivos Brasileiros de Cardiologia. The authors[1] aimed to evaluate the relationship between left atrial
volume index and different grades of diastolic dysfunction in Brazilian patients
submitted to echocardiogram. Although we commend the authors for the detailed and
valuable information that they have provided, some comments may be beneficial.Diastolic dysfunction is associated with adverse outcomes and its prevalence among
hypertensive, hyperlipidemic and diabetic adults is very high[2]. It has been shown that lowering blood pressure and
heart rate, management of impaired lipid profile and blood glucose could improve
diastolic dysfunction[2]. Also, thyroid
dysfunction has been associated with the development of diastolic dysfunction even in
patients without underlying heart disease[3].Diuretics, ACE inhibitors and angiotension-II receptor antagonists, nitrates and their
derivatives, calcium channel blockers, alpha-blockers, nicardipine and phosphodiesterase
inhibitors reduce left ventricular filling pressures[2,3].Statins could ameliorate diastolic dysfunction by attenuating myocardial interstitial
fibrosis and angiogenesis independently of their lipid lowering effects[4].Thyroid hormonotherapies increase cardiac output by affecting stroke volume and heart
rate, and reduce systemic vascular resistance by activating the
renin-angiotensin-aldosterone system; resulting in an improvement in diastolic
dysfunction[3].It has been demonstrated in diabetic cardiomyopathy that eplerenone, the
mineralocorticoid receptor blocker, has anti-fibrotic effects which could attenuate
cardiac steatosis, apoptosis and remodelling as well as diastolic dysfunction[5].In conclusion, if the medication details which can be associated with diastolic
dysfunction had been given, the study would have been more valuable.We appreciate your comments in relation to our article. Left ventricular diastolic
function depends on a number of intrinsic and extrinsic factors to the heart. Among
intrinsic factors, the most important is the amount and arrangement of collagen
deposited in the myocardium. Both the synthesis of the different isoforms of
collagen, and the form of deposition of these fibers in myocardial interstice and
around the coronary vessels, have an important influence on myocardial relaxation
rate which leads, from the hemodynamic point of view, by the fall rate of
ventricular pressure during relaxation isovolumetric by transmitral flow rate or by
the rate of myocardium movement on mitral annullus. The echocardiogram has been a
valuable tool in the assessment of diastolic function and, to the extent that the
methods of image become more accessible and improved, and the interest of clinical
cardiologists is growing in the accurate measurement of myocardial lusitropism. It
is important to note that different types of treatments for heart disease (ACE
inhibitors, inhibitors of aldosterone receptors, BRA, etc) or associated clinical
conditions, such as hypertension, mellitus diabetes, hypothyroidism, among others,
are associated with different degrees of diastolic dysfunction. In this respect the
available literature is extensive. However, the goal of our work was not to explore
the pathogenesis of diastolic dysfunction, but rather to focus on two aspects: 1)
evaluate the relationship between the volume of VAEi (left atrium indexed by body
surface area) and the different degrees of diastolic dysfunction in a number of
patients on outpatients treatment with preserved or little reduced systolic function
and that were submitted to the transthoracic echocardiography examination in a
cardiology diagnostic department; 2) identify clinical and echocardiographic
variables independently associated to VAEi increase.To achieve these goals, the origin and the stage of evolution of diastolic
dysfunction are not parameters relevant to the proposed study. However, we consider
your comments relevant and they may certainly be used in future substudies within
the sample included in our article.We appreciate the comments made and the interest in our work.Best regards,