Heart failure. Pathogenesis of heart failure and diagnosis of the incipient stage of heart failure
Widimsky, J.
Cor et Vasa 17(4): 302-314
1975
ISSN/ISBN: 0010-8650 PMID: 1212876 Document Number: 3219
Heart failure may be classified according to the type of the primary load as follows: I. Increased heart-load 1. a) pressure load (load of the contractile myocardial function) - e.g. aortic stenosis, pulmonary stenosis, pulmonary hypertension, systemic hypertension; b) primary myocardial lesion (load of the contractile myocardial function) - e.g. myocardial ischaemia, myocardial infarction, cardiomyopathy; 2. Volume load (load of myocardial distensibility) - for instance in valvular insufficiency, α-v shunt, anaemia. II. Obstruction of blood flow to the heart. Increased load of the vascular bed. Example: pericardial tamponade, constrictive pericarditis, tricuspid or mitre' stenosis without affection of the myocardium. Definition of incipient heart failure is not a simple matter. Incipient means rather the beginning of a certain process which develops than a pathophysiologically expressed balanced state or clinical syndrome. It is therefore difficult to obtain an accurate definition of incipient heart failure. It may be, however, stated that the factors retaining their value in clinical examination include signs of fatigue, especially dyspnoea; data on its progression and degree, on nycturia, are probably the most valuable clinical anamnestic data. Highly effective acute compensatory mechanisms designed to maintain blood supply to tissue capillaries are cardiac dilatation, tachycardia and elevation of myocardial contractility. However, these compensatory mechanisms gradually deteriorate and their compensatory power weakens. The correlation between pathophysiologic signs and clinical symptoms such as fatigue, dyspnoea and nycturia is in haemodynamic studies, concerning the situation at rest, usually poor. The sensitivity of haemodynamic studies is usually raised by the fact that we are testing the haemodynamic situation at load. Indications of incipient heart failure, either at rest or only at load, are: 1) increased cardiac dimensions, 2) tachycardia, 3) increased end-diastolic pressure, 4) reduced velocity of the shortening of the contractile elements in relation to the myocardial wall tension, 5) an increased share of lost and effective mechanical work. A cardinal role in considerations concerning heart failure is naturally held by the cardiac output which, however, we must consider in the whole context not only of the heart as a pump but of the whole circulation. The Congress showed the present state of the pathogenesis of heart failure and certain possibilities as well as obstacles for early diagnosis of heart failure, especially from the point of view of the application of auxiliary examination methods, both invasive and non-invasive. It is quite logical that the application of auxiliary examination methods does not mean neglect of the classic clinical approach which even in this difficult problem of diagnosis of incipient heart failure retains its important role.
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