ASPECTS OF REPOLARIZATION AFTER ACUTE PHASE
IN THE EVOLUTION OF MYOCARDIAL INFARCTION
 WITH DISAPPEARANCE OF NECROSIS Q WAVE

Radu GRIGORE¹, Cristina SUTESCU², Carmen GINGHINA^3
1Department of cardiology County Hospital Galati, ROMANIA
²M.I. Polyclinic, Bucharest, ROMANIA
³Department of cardiology Hospital FUNDENI, Bucharest, ROMANIA

Abstract: The disappearance of the necrosis Q wave is possible in evolution of myocardial infarction. After the disappearance of the Q wave, the analysis of repolarization is the only criterion to evaluate this traps of electrocardiogram. In 158 cases of myocardial infarction with the disappearance of necrosis Q wave, 86 were with 1 myocardial infarction  (A) and 72 with 2(3) myocardial infarction (B). In each of these, A and B, the analysis of repolarization have evidenced 4 groups: 1-normalization of repolarization; 2-persistence of the repolarization disturbances in the infarcted areas; 3- persistence of the repolarization disturbances outside the infarcted areas; 4- persistence of the repolarization disturbances in the infarcted areas and outside of them. The results was correlated with clinical evolution. The analysis of these cases permits to notice: in the cases with 1 myocardial infarction (A), in the group 1, the  cases with the normalization of repolarization, have a better evolution: heart failure and deceases are 2.77%, than in those with persistence of repolarization disturbances: heart failure is 48% and deceases 6.00%. In the cases with 2(3) myocardial infarction (B), in the group 1, there is a subgroup with normalization of repolarization and better evolution: heart failure 20.00% and deceases 10.00% and another subgroup with cancellation of two opposite myocardial infarction, with severe evolution: heart failure 92.30% and deceases 30.76%, relatively similar to the cases with the persistence of repolarization disturbances: heart failure 70.83% and deceases 41.66%.

INTRODUCTION

The disappearance of the necrosis Q wave seems to be a good sign in evolution of myocardial infarction, especially in the cases with only one myocardial infarction, because in these cases, it is possible a morphofunctionally and electrophisiologicaly recovery (1,2). In such cases the late spontaneous recovery and the functionally improvement of viable myocard in areas of necrosis was demonstrated (3). It was noticed that simple electrocardiogram may offer informations on myocardial viability after acute myocardial infarction, early on late, by spontaneous normalization of T wave and Q wave regression (4). In this paper our aim is to evaluate if the normalization or the persistence of repolarization disturbances, in the myocardial infarction with disappearence of the necrosis Q wave can influence the clinical evolution.

METHODS

We have collected in the last 30 years 158 cases of myocardial infarction, after acute phase and we have fallowed-up the regression or the disappearance of the Q wave and at the same time the change of repolarization. For each case we have analized a variable number of electrocardiograms, which were correlated with the presence or absence of complications. The cases with left bundle branch block, right bundle branch block and with Wolff-Parkinson-White syndrome aren’t included in this paper.

RESULTS

The results reflect aspects of the analysed cases and not the indices of therapeutic efficiency. These 158 cases have mean age of 56, 30: 92 m and 66 f. These 158 cases with 1, 2, 3 myocardial infarctions summarize 253 myocardial infarctions.  In those 86 cases with 1 myocardial infarction and in those 72 cases with 2(3) myocardial infarctions too, the aspects of repolarization evolution have permitted the separation of 4 groups: 1-normalization of repolarization; 2-persistence of the repolarization disturbances in the infarcted areas; 3- persistence of the repolarization disturbances outside the infarcted areas; 4- persistence of the repolarization disturbances in the infarcted areas and outside of them. From all these multiple aspects of clinical evolution, we present in detail only the major ones: the heart failure and the deceases. In the 86 cases (A) with 1 myocardial infarction, heart failure was present in 25 cases (29.06%) and deceases in 4 cases (4.65%). In the group 1, with 36 cases, heart failure appeared in 1 case (2.77%) and deceases in 1 case too (2.77%). In the group 2 with 8 cases, heart failure was present in 4 cases (50.00%) without deceases. In the group 3, with 28 cases, heart failure appeared in 11 cases (39.28%) and deceases in 1 case (3.57%). In the group 4, with 14 cases, heart failure was present in 9 cases (64.28%) and deceases in 2 cases (14.28%). All together, in the group of 50 cases with the persistence of repolarization disturbances (2, 3, 4) the heart failure appeared in 48.00% and the deceases in 6.00%.

In the 72 cases (B) with 2(3) myocardial infarctions, heart failure was present in 51 cases (70.83%) and deceases in 30 cases (41.66%). In the group 1, with 23 cases, heart failure appeared in 14 cases (60.86%) and deceases in 5 cases (21.73%); in this group, one separates a subgroup of 10 cases, with normalization of repolarization of the 1^st infarction and succesively, the appearance and the normalization of the 2^nd myocardial infarction, in which, heart failure appeared in 2 cases (20.00%) and deceases in 1 case (10.00%)- and another subgroup with 13 cases with reciprocal cancellation of repolarization  in which heart failure was present in 12 cases (92.30%) and deceases in 4 cases (30.76%). In the group 2 with 16 cases, heart failure appeared in 10 cases (62.50%) and deceases in 7 cases (43.75%). In the group 3 with 8 cases heart failure was present in 6 cases (75.00%) and deceases in 4 cases (50.00%). In the group 4, with 25 cases, heart failure appeared in 21 cases (84.00%) and deceases in 14 cases (56.00%). Other clinical and electrocardiographical aspects: different forms of angina pectoris 64 cases, evolution without pain and immobile repolarization 22 cases, silent evolution with dynamic aspect of repolarization in rest (without pain) 17 cases, disturbances of atrial rhythm 46 cases and of ventricular rhythm 35 cases, atrio-ventricular blocks of different degrees 14 cases and electrical hypertrophy of left ventricul 24 cases.

DISCUSSION

The repolarization is a very important and useful criterion in daily practice, available to each physician and is the only  available criterion in trap electrocardiograms, in myocardial infarction with the disappearance of necrosis Q wave. It was  noted the severity, in the evolution of myocardial infarction with the disappearance of the necrosis Q wave and with the persistence of repolarization disturbances (5). Even in the acute phase of myocardial infarction the changes of ST-segment permit the assesement of early evolution and long-term also (6). The disturbances of ventricular repolarization play a critical role in different mechanisms of arrhythmogenicity. The evolution is not the same in all our cases with 1 myocardial infarction with disappearance of the Q wave;  In the group with the normalization of the  repolarization by natural evolution which supposes a recovery too, the evolution in obviously better (heart failure and deceases, each of 2.7%) compared to the group with persistence of repolarization disturbances (heart failure 48.00% and deceases 6.00%). In the cases with 2(3) myocardial infarction and disappearance of the necrosis Q wave, the risk is higher (heart failure 70.83% and deceases 41.66%). Because there are few cases in each of these 4 groups it is difficult to make a distinct discussion concerning their evolution; in general in these cases, from the electrical aspects point of view, there is a great probability of multiple coronary injuries. However, in the group 1, we can separate a subgroup of 10 cases with a succesivelly and parallel normalization of the depolarization and repolarization of the two succesively myocardial infarctions with a better evolution, (heart failure 20% and deceases 10.00%), different of 13 cases subgroup, with “normalization” by reciprocaly cancellation of the electrical vectors, with similar severe evolution as in the groups with the persistence of the repolarization disturbances.  There are other clinical and electrocardiographical aspects also in all these 158 cases: different forms of angina pectoris (40.50%), evolution without pain and immobile repolarization (13.92%), silent evolution- dynamic aspects of repolarization in rest (without pain)  (10.75%), disturbances of atrial (29.11%) and of ventricular rhythm (22.15%), atrio-ventricular blocks of different degrees (8.86%), electrical hypertrophy of left ventricul (15.18%). The persistence of repolarization disturbances and the silent dynamics of repolarization may be  related to the different mechanisms of arrhythmogenicity. So, in the group with 1 myocardial infarction and in the group with 2(3) myocardial infarction with persistence of repolarization disturbances the atrial and ventricular arrhythmias where present in 29 cases (58.00%), respectively in 27 cases (55.16%) higher then in the group with 1 myocardial infarction and the normalization of repolarization, 11 cases (30.55%). This aspect permits to correlate with the better evolution of heart failure and the deceases, in the same group and supposes the recovery of myocardial infracted. Conclusions: In the cases with 1 myocardial infarction (A), the group with parallel normalization of depolarization and repolarization has a good clinical evolution, comparing to the groups with the persistence of repolarization disturbances. In the cases with 2(3) myocardial infarctions (B) there are a few cases with two succesive myocardial infarctions with a succesive normalization of the Q wave and of repolarization, and have a good clinical evolution, comparing to those with “normalization” by reciprocaly cancelation of the vectors and comparing with those with persistence of the repolarization disturbances, both with severe evolution. So, in the myocardial infarction with disappearance of necrosis Q wave, by a simple electrocardiogram analysis of repolarization is possible to make a long-term prognostic.

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