Electrocardiology Adv. Cardio!., vo!. 16, pp. 490-494 (Karger, Base11976)
Left Anterior Hemiblock Versus Healed Old Diaphragmatic Myocardial Infarction C. GIUSTI, G. eINI and C. GRACI Medical Clinic, University of Pisa, Pisa
On the basis of serial studies on patients with diaphragmatic myocardial infarction we previously have observed that, in spite of the disappearance of Q wave on EeG, signs can persist of the previous necrosis, i.e. an initial positivity of aVR or a decreasing R wave from D3 to D2 and aVF [1,2]. In the final stage, the EeG can show a pattern of left axial deviation which in some cases can be identified with a left anterior hemiblock. In order to differentiate these patterns, the more peculiar characters of the two entities will be considered here.
Two groups of patients were selected for this study: 20 with electrical (healing) and 50 with left anterior hemiblock. In the first group the diagnosis of myocardial infarction was established in the acute phase, on the basis of classical clinical, laboratory or ECG findings showing a typical Q wave of diaphragmatic necrosis, but the patient was included in this series only when other causes of disappearance of the Q wave on ECG could be excluded (bundle branch block, another necrosis, etc.). In the second group we have attempted to exclude the patients with some evidence of coronary artery disease based both on clinical grounds or, in some cases, on coronarographic studies (it is well-known, however, that a normal coronarography can be present in a patient with myocardial infarction). In all patients, beside an ECG comprehensive of the standard leads, a vectorcardiogram was registered by the method of Frank.
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Material and Methods
GruSTI/CINI/GRACI
491
The ECG parameters taken into consideration (all cases showed a left axial deviation) are: progression of R wave from D3 to aVF and D2, a tiny initial Q wave in D2, small, notched double peaked r in D2, polyphasic patterns of QRS complex in D3 and aVF, an initial positivity in aVR.
In case of electrical healing the considered parameters showed the following behaviour: (1) An increasing r wave or polyphasic QRS complexes extremely variable on breath, so that it is difficult to evaluate the progression of amplitude of the r wave from one lead to another (3 cases, 15% of the total). (2) A decreasing r wave from D3 to aVF and D2 is present in 14 patients (70%) excluding those with a small q wave in D2. This finding is quite typical and is due to a clockwise rotation of the QRS loop on the frontal plane of VCG, a very unusual finding in the left axial deviation which differentiates on vectorcardiogram the left axial deviation from the diaphragmatic myocardial infarction. When this clockwise rotation is associated with abnormal upward and rightward projection of the QRS loop, there is a significant positivity in aVR. In 20% of the patients a small notched, double peaked r wave in lead D2 is present. (3) A tiny Q wave in D2 is present in only 3 cases (15%) and follows a r wave in aVF smaller than in D3, which can be explained with a clockwise rotation of the QRS loop on the frontal plane and with downward and rightward projection of the initial vectors of the process of ventricular activation. The small q wave then may be present in D2 lead, since this is the extreme lead. (4) An initial r in aVR (98 %), however, the presence of this finding is not important but his amplitude which must be 1.25 ± 0.4 mm. It is due to the upward and rightward projection of the initial part of the QRS loop. Not always, however, can a clockwise rotation on the frontal plane match a large initial r wave in aYR. If the upward and rightward projection of the QRS loop is not important, the initial r waves have a reduced amplitude. This is a consequence of an early turning to the left of the QRS loop even though the clockwise rotation and the upward displacement persist. (5) Serial studies on a group of patients have suggested that all these ECG patterns are the various stages of the same process which leads to
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Results
492
GIUSTI/ CiNI/ GRACI
III
B
aVR
.
aVL
aVF
_
.
~~~'"1""\--LL..~ C
JII
.
-=-j- -~
'
~'--
.
.
-
-
III
I
D·
aVR
aVF
aVL
. .
aVR
aVL
'.
T+-:--=~~H ~-~ -- - ~ -- , I - " -1 _ .'-
Ell!! d!
"
III
aVR
aVL
.
aVF
~~--r -r-----L-.r I
II
III
aVR
aVL
aVF
the disappearance of the signs of the previous necrosis. The initial positivity, which masks the q wave, appears in D3 and is due to the presence of initial vectors shortly directed downward and rightward ; later the amplitude of r wave in D3 increases, while a small r wave in aVF appears and the Q wave is reduced in D2 so that it appears as a small q wave. In this stage, the initial vectors on the frontal plane are directed in a more vertical position. In the following stage, together with another increase of the amplitude of the r wave in D3 and aVF, a 2 wave in D2 or a small double peaked initial r wave appears. In these leads instead of only one welldefined r wave with a morphology rS a polyphasic morphology, rsrs can be shown. In the hemiblocks the following patterns have been observed : (1) An increasing r wave from lead D3 to aVF and D2 which can be explained with a leftward projection, and a counterclockwise inscription of the QRS loop in the frontal plane. This is the typical finding of left
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Fig. 1. In the strips A, B, C, and D, several patterns of the electrical healing of the diaphragmatic myocardial infarction are represented. In the strip E the electrocardiographic pattern of the left anterior hemiblock is represented.
LAH, Healed DMI and ECG
493
anterior hemiblock. The initial vectors of the QRS loop are directed inferiorly, slightly rightward, then, with counterclockwise inscription, inferiorly and leftward, finally superiorly and leftward. (2) A decreasing r wave from D3 to aVF and D2. Such a finding is present in three patients (6%). Since we lack autopsy of those patients it is not possible to exclude theoretically a myocardial fibrosis or a myocardial infarction, however, the anamnesis is negative, the EeG changes were occasionally found and the effort EeG showed a normal response. The presence of a decreasing r wave has been observed in the absence of a myocardial infarction. Such a finding by itself is in favour of a myocardial infarction (70%), however, if the other parameters are considered, an initial positivity in aVR is not appreciable. The EeG pattern is justified by the QRS-Ioop behaviour which shows a very small projection above the 0-180 line. (3) Initial positivity in aVR 0.3 ± 0.15 mm of amplitude, observed in 12 patients; 24% is not always associated with a decreasing r wave; in fact, in spite of the counterclockwise rotation on the frontal plane, the initial vectors are directed for the first part of the activation process, more rightward and not necessarily upward. The short duration of the rightward projection justifies the small amplitude of positivity in aVR which is the differential finding from electrical healing. (4) A small q wave in D2 or a double-peaked r wave has never been observed; on the basis of these data such findings seem specific of the electrical healing.
In the left axial deviation the vectorcardiogram differentiates the left anterior hemiblock from an old healed myocardial infarction with morphology of left axial deviation type. In the first case on frontal plane the inscription of the QRS loop ,is counterclockwise, in the second it is clockwise. The inscription of the QRS loop can be deduced by the amplitude of the initial r wav~ in D3, aVF, and D2. If the inscription is counterclockwise the r wave increases from D3 to aVF and D2 and vice versa. The amplitude of r wave in aVR is in relationship to the entity of upward or rightward projection of initial vectors of the QRS loop. In the myocardial infarction the entity of such projection can be remarkable,
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Conclusion
GIUSTI/CINI/GRACI
494
in fact the different amplitude of the initial r wave in the left anterior hemiblock and in myocardial infarction is very significant. A small q wave in D2, due to a downward and rightward projection of initial vectors of the QRS loop, as well as a small notched, doublepeaked r wave, are also significant findings of healed old diaphragmatic myocardial infarctions.
References
2
GIUSTI, C.; MARIANI, M.; CIONOTTI, G. e MICHELI, G.: II vettocardiogramma spaziale in individui con guarigione elettrocardiografica dell'infarto miocardico. Folia Cardiol. 23: 309-325 (1964). PENTIMONE, F.; ZAMPIERI, A.; DE MOLO, G. e GIUSTI, C.: Sulla diagnosi di infarto miocardico in soggetti con quadro elettrocardiografico di guarigione elettrica. Boll. Soc. Med. Chir., Pisa 36: 660-666 (1968).
Prof. COSTANTINO GIUSTI, MD, Via Traini 4, Medical Clinic, University of Pisa, /-56100 Pisa (Italy)
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
1
Left Anterior Hemiblock Versus Healed Old Diaphragmatic Myocardial Infarction C. GIUSTI, G. eINI and C. GRACI Medical Clinic, University of Pisa, Pisa
On the basis of serial studies on patients with diaphragmatic myocardial infarction we previously have observed that, in spite of the disappearance of Q wave on EeG, signs can persist of the previous necrosis, i.e. an initial positivity of aVR or a decreasing R wave from D3 to D2 and aVF [1,2]. In the final stage, the EeG can show a pattern of left axial deviation which in some cases can be identified with a left anterior hemiblock. In order to differentiate these patterns, the more peculiar characters of the two entities will be considered here.
Two groups of patients were selected for this study: 20 with electrical (healing) and 50 with left anterior hemiblock. In the first group the diagnosis of myocardial infarction was established in the acute phase, on the basis of classical clinical, laboratory or ECG findings showing a typical Q wave of diaphragmatic necrosis, but the patient was included in this series only when other causes of disappearance of the Q wave on ECG could be excluded (bundle branch block, another necrosis, etc.). In the second group we have attempted to exclude the patients with some evidence of coronary artery disease based both on clinical grounds or, in some cases, on coronarographic studies (it is well-known, however, that a normal coronarography can be present in a patient with myocardial infarction). In all patients, beside an ECG comprehensive of the standard leads, a vectorcardiogram was registered by the method of Frank.
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Material and Methods
GruSTI/CINI/GRACI
491
The ECG parameters taken into consideration (all cases showed a left axial deviation) are: progression of R wave from D3 to aVF and D2, a tiny initial Q wave in D2, small, notched double peaked r in D2, polyphasic patterns of QRS complex in D3 and aVF, an initial positivity in aVR.
In case of electrical healing the considered parameters showed the following behaviour: (1) An increasing r wave or polyphasic QRS complexes extremely variable on breath, so that it is difficult to evaluate the progression of amplitude of the r wave from one lead to another (3 cases, 15% of the total). (2) A decreasing r wave from D3 to aVF and D2 is present in 14 patients (70%) excluding those with a small q wave in D2. This finding is quite typical and is due to a clockwise rotation of the QRS loop on the frontal plane of VCG, a very unusual finding in the left axial deviation which differentiates on vectorcardiogram the left axial deviation from the diaphragmatic myocardial infarction. When this clockwise rotation is associated with abnormal upward and rightward projection of the QRS loop, there is a significant positivity in aVR. In 20% of the patients a small notched, double peaked r wave in lead D2 is present. (3) A tiny Q wave in D2 is present in only 3 cases (15%) and follows a r wave in aVF smaller than in D3, which can be explained with a clockwise rotation of the QRS loop on the frontal plane and with downward and rightward projection of the initial vectors of the process of ventricular activation. The small q wave then may be present in D2 lead, since this is the extreme lead. (4) An initial r in aVR (98 %), however, the presence of this finding is not important but his amplitude which must be 1.25 ± 0.4 mm. It is due to the upward and rightward projection of the initial part of the QRS loop. Not always, however, can a clockwise rotation on the frontal plane match a large initial r wave in aYR. If the upward and rightward projection of the QRS loop is not important, the initial r waves have a reduced amplitude. This is a consequence of an early turning to the left of the QRS loop even though the clockwise rotation and the upward displacement persist. (5) Serial studies on a group of patients have suggested that all these ECG patterns are the various stages of the same process which leads to
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Results
492
GIUSTI/ CiNI/ GRACI
III
B
aVR
.
aVL
aVF
_
.
~~~'"1""\--LL..~ C
JII
.
-=-j- -~
'
~'--
.
.
-
-
III
I
D·
aVR
aVF
aVL
. .
aVR
aVL
'.
T+-:--=~~H ~-~ -- - ~ -- , I - " -1 _ .'-
Ell!! d!
"
III
aVR
aVL
.
aVF
~~--r -r-----L-.r I
II
III
aVR
aVL
aVF
the disappearance of the signs of the previous necrosis. The initial positivity, which masks the q wave, appears in D3 and is due to the presence of initial vectors shortly directed downward and rightward ; later the amplitude of r wave in D3 increases, while a small r wave in aVF appears and the Q wave is reduced in D2 so that it appears as a small q wave. In this stage, the initial vectors on the frontal plane are directed in a more vertical position. In the following stage, together with another increase of the amplitude of the r wave in D3 and aVF, a 2 wave in D2 or a small double peaked initial r wave appears. In these leads instead of only one welldefined r wave with a morphology rS a polyphasic morphology, rsrs can be shown. In the hemiblocks the following patterns have been observed : (1) An increasing r wave from lead D3 to aVF and D2 which can be explained with a leftward projection, and a counterclockwise inscription of the QRS loop in the frontal plane. This is the typical finding of left
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Fig. 1. In the strips A, B, C, and D, several patterns of the electrical healing of the diaphragmatic myocardial infarction are represented. In the strip E the electrocardiographic pattern of the left anterior hemiblock is represented.
LAH, Healed DMI and ECG
493
anterior hemiblock. The initial vectors of the QRS loop are directed inferiorly, slightly rightward, then, with counterclockwise inscription, inferiorly and leftward, finally superiorly and leftward. (2) A decreasing r wave from D3 to aVF and D2. Such a finding is present in three patients (6%). Since we lack autopsy of those patients it is not possible to exclude theoretically a myocardial fibrosis or a myocardial infarction, however, the anamnesis is negative, the EeG changes were occasionally found and the effort EeG showed a normal response. The presence of a decreasing r wave has been observed in the absence of a myocardial infarction. Such a finding by itself is in favour of a myocardial infarction (70%), however, if the other parameters are considered, an initial positivity in aVR is not appreciable. The EeG pattern is justified by the QRS-Ioop behaviour which shows a very small projection above the 0-180 line. (3) Initial positivity in aVR 0.3 ± 0.15 mm of amplitude, observed in 12 patients; 24% is not always associated with a decreasing r wave; in fact, in spite of the counterclockwise rotation on the frontal plane, the initial vectors are directed for the first part of the activation process, more rightward and not necessarily upward. The short duration of the rightward projection justifies the small amplitude of positivity in aVR which is the differential finding from electrical healing. (4) A small q wave in D2 or a double-peaked r wave has never been observed; on the basis of these data such findings seem specific of the electrical healing.
In the left axial deviation the vectorcardiogram differentiates the left anterior hemiblock from an old healed myocardial infarction with morphology of left axial deviation type. In the first case on frontal plane the inscription of the QRS loop ,is counterclockwise, in the second it is clockwise. The inscription of the QRS loop can be deduced by the amplitude of the initial r wav~ in D3, aVF, and D2. If the inscription is counterclockwise the r wave increases from D3 to aVF and D2 and vice versa. The amplitude of r wave in aVR is in relationship to the entity of upward or rightward projection of initial vectors of the QRS loop. In the myocardial infarction the entity of such projection can be remarkable,
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
Conclusion
GIUSTI/CINI/GRACI
494
in fact the different amplitude of the initial r wave in the left anterior hemiblock and in myocardial infarction is very significant. A small q wave in D2, due to a downward and rightward projection of initial vectors of the QRS loop, as well as a small notched, doublepeaked r wave, are also significant findings of healed old diaphragmatic myocardial infarctions.
References
2
GIUSTI, C.; MARIANI, M.; CIONOTTI, G. e MICHELI, G.: II vettocardiogramma spaziale in individui con guarigione elettrocardiografica dell'infarto miocardico. Folia Cardiol. 23: 309-325 (1964). PENTIMONE, F.; ZAMPIERI, A.; DE MOLO, G. e GIUSTI, C.: Sulla diagnosi di infarto miocardico in soggetti con quadro elettrocardiografico di guarigione elettrica. Boll. Soc. Med. Chir., Pisa 36: 660-666 (1968).
Prof. COSTANTINO GIUSTI, MD, Via Traini 4, Medical Clinic, University of Pisa, /-56100 Pisa (Italy)
Downloaded by: University of Cambridge 131.111.164.128 - 3/18/2019 5:11:11 AM
1
