Cardiotonics: Harmful or of Beneficial Use in Angina Pectoris, Unstable Angina and Myocardial Infarction?


 Quintiliano H. de Mesquita, M.D.


Since our first experience on unstable angina pectoris (UA) in 1972 and afterwards in the acute myocardial infarction (AMI), we never noticed any harmful effects like arrhythmias and any digitalis intolerances caused by cardiotonics in our patients, due to the correct dosages used.

The first therapeutic trial indicating beneficial effects for the coronary-myocardiopathy was credited by Withering to the digitalis in 1785. Friedrich Ludwig Kreysig from Berlin twenty-nine years later (1814) advocated in his paper "Die Krankheiter des Herzens" the use of digitalis and called the drug a 'God-given Remedy'.

Harmful aspects regarding cardiotonics in stable angina pectoris (AP), and AMI were not experienced also by other authors in the past during the clinical use (James Herrick- 1912; Louis Hamman - 1926; Ernst Edens - 1934; Ferdinand R. Schemm - 1950; John Martin Askey - 1951; Norman H. Boyer - 1955; Malmcrona, R - 1966; Manfred Von Ardenne - 1974; Heinz H. Schoeffler - 1975; Pizzarello, R - 1975; Morrison, J. - 1975; Reikansky, I - 1976; Loeb; H.S. - 1976; O' Rourke, R. A - 1976; Amsterdam, E. A. - 1976; Ferlinz, J - 1978; Vogel, R - 1977; Koeter, V. Schuren - 1978; DeMots, H. - 1976; Kleiman, J.H. - 1978; Rolf Dorhman - 1980).

Besides, many other experimental and clinical studies were made from the last 30 years reinforcing the arguments towards the cardiotonics use in AP, UA and AMI showing ever beneficial, indispensable and insuperable effects.  

These experimental and clinical papers demonstrated the dropping in residual diastolic pressure and volume, decrease in ventricular volume and from the parietal tension of the left ventricle which could prevent or at least to lessen the raise of oxygen demand caused by the contractility improvement. It was not observed abnormal lactates as anaerobiosis neither digitalis consequences in such studies.

The use of cardiotonic increases the ejection fraction, improving the left ventricular function and contractility and reducing the residual diastolic volume without modifying the oxygen consumption due to compensatory mechanisms.

Cardiotonics in general have effects of physical recovery and of metabolic and energetic restoration in unbalance generated through the pathophysiology of UA and AMI, under the Myogenic Theory point of view, represented by: Primary regional myocardial insufficiency and Secondary regional myocardial ischemia, without any harmful effect.

It's a fact that all studies realized until today didnít show any clinical proofs of harmful effects caused by the cardiotonics use in AP, UA and AMI.

So, any concern or even afraid by doctors to give cardiotonics to their patients in these medical conditions, are based only in presumptions.

How to prove? Just use it!