Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report
There are fibers in the left ventricle (LV) (LV middle network) that in around one third of cases may be considered a true septal fascicle that arises from the common left bundle. Its presence and the evidence that there are 3 points of activation onset in the LV favor the quadrifascicular theory of...
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2012
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00220736_v45_n5_p454_BayesDeLuna http://hdl.handle.net/20.500.12110/paper_00220736_v45_n5_p454_BayesDeLuna |
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paper:paper_00220736_v45_n5_p454_BayesDeLuna2023-06-08T14:45:25Z Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report Block of middle fibers/left septal fascicle Intraventricular blocks cardiac patient computer simulation conference paper congestive heart failure ECG abnormality heart left bundle branch block heart left ventricle heart left ventricle hypertrophy heart muscle cell heart right bundle branch block heart ventricle conduction heart ventricle septum human ischemic heart disease left septal fascicle block middle fibers block nonhuman priority journal Purkinje fiber Q wave QRS complex supraventricular premature beat vectorcardiography Bundle-Branch Block Consensus Electrocardiography Heart Conduction System Heart Ventricles Humans Ventricular Dysfunction, Left There are fibers in the left ventricle (LV) (LV middle network) that in around one third of cases may be considered a true septal fascicle that arises from the common left bundle. Its presence and the evidence that there are 3 points of activation onset in the LV favor the quadrifascicular theory of the intraventricular activation of both ventricles. Since the 70s, different authors have suggested that the block of the left middle fibers (MS)/left septal fascicle may explain different electrocardiographic (ECG) patterns. The 2 hypothetically based criteria that are in some sense contradictory include: a) the lack of septal "q" wave due to first left and later posteriorly shifting of the horizontal plane loop and b) the presence of RS in lead V 2 (V1-V2) due to some anterior shifting of the horizontal plane vectorcardiogram loop. However, there are many evidence that the lack of septal q waves can be also explained by predivisional first-degree left bundle-branch block and that the RS pattern in the right precordial leads may be also explained by first-degree right bundle-branch block. The transient nature of these patterns favor the concept that some type of intraventricular conduction disturbance exists but a doubt remains about its location. Furthermore, the RS pattern could be explained by many different normal variants. To improve our understanding whether these patterns are due to MF/left septal fascicle block or other ventricular conduction disturbances (or both), it would be advisable: 1) To perform more histologic studies (heart transplant and necropsy) of the ventricular conduction system; 2) To repeat prior experimental studies using new methodology/technology to isolate the MF; and 3) To change the paradigm: do not try to demonstrate if the block of the fibers produces an ECG change but to study with new electroanatomical imaging techniques, if these ECG criteria previously described correlate or not with a delay of activation in the zone of the LV that receives the activation through these fibers or in other zones. © 2012 Elsevier Inc. All rights reserved. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00220736_v45_n5_p454_BayesDeLuna http://hdl.handle.net/20.500.12110/paper_00220736_v45_n5_p454_BayesDeLuna |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Block of middle fibers/left septal fascicle Intraventricular blocks cardiac patient computer simulation conference paper congestive heart failure ECG abnormality heart left bundle branch block heart left ventricle heart left ventricle hypertrophy heart muscle cell heart right bundle branch block heart ventricle conduction heart ventricle septum human ischemic heart disease left septal fascicle block middle fibers block nonhuman priority journal Purkinje fiber Q wave QRS complex supraventricular premature beat vectorcardiography Bundle-Branch Block Consensus Electrocardiography Heart Conduction System Heart Ventricles Humans Ventricular Dysfunction, Left |
| spellingShingle |
Block of middle fibers/left septal fascicle Intraventricular blocks cardiac patient computer simulation conference paper congestive heart failure ECG abnormality heart left bundle branch block heart left ventricle heart left ventricle hypertrophy heart muscle cell heart right bundle branch block heart ventricle conduction heart ventricle septum human ischemic heart disease left septal fascicle block middle fibers block nonhuman priority journal Purkinje fiber Q wave QRS complex supraventricular premature beat vectorcardiography Bundle-Branch Block Consensus Electrocardiography Heart Conduction System Heart Ventricles Humans Ventricular Dysfunction, Left Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| topic_facet |
Block of middle fibers/left septal fascicle Intraventricular blocks cardiac patient computer simulation conference paper congestive heart failure ECG abnormality heart left bundle branch block heart left ventricle heart left ventricle hypertrophy heart muscle cell heart right bundle branch block heart ventricle conduction heart ventricle septum human ischemic heart disease left septal fascicle block middle fibers block nonhuman priority journal Purkinje fiber Q wave QRS complex supraventricular premature beat vectorcardiography Bundle-Branch Block Consensus Electrocardiography Heart Conduction System Heart Ventricles Humans Ventricular Dysfunction, Left |
| description |
There are fibers in the left ventricle (LV) (LV middle network) that in around one third of cases may be considered a true septal fascicle that arises from the common left bundle. Its presence and the evidence that there are 3 points of activation onset in the LV favor the quadrifascicular theory of the intraventricular activation of both ventricles. Since the 70s, different authors have suggested that the block of the left middle fibers (MS)/left septal fascicle may explain different electrocardiographic (ECG) patterns. The 2 hypothetically based criteria that are in some sense contradictory include: a) the lack of septal "q" wave due to first left and later posteriorly shifting of the horizontal plane loop and b) the presence of RS in lead V 2 (V1-V2) due to some anterior shifting of the horizontal plane vectorcardiogram loop. However, there are many evidence that the lack of septal q waves can be also explained by predivisional first-degree left bundle-branch block and that the RS pattern in the right precordial leads may be also explained by first-degree right bundle-branch block. The transient nature of these patterns favor the concept that some type of intraventricular conduction disturbance exists but a doubt remains about its location. Furthermore, the RS pattern could be explained by many different normal variants. To improve our understanding whether these patterns are due to MF/left septal fascicle block or other ventricular conduction disturbances (or both), it would be advisable: 1) To perform more histologic studies (heart transplant and necropsy) of the ventricular conduction system; 2) To repeat prior experimental studies using new methodology/technology to isolate the MF; and 3) To change the paradigm: do not try to demonstrate if the block of the fibers produces an ECG change but to study with new electroanatomical imaging techniques, if these ECG criteria previously described correlate or not with a delay of activation in the zone of the LV that receives the activation through these fibers or in other zones. © 2012 Elsevier Inc. All rights reserved. |
| title |
Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| title_short |
Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| title_full |
Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| title_fullStr |
Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| title_full_unstemmed |
Electrocardiographic manifestation of the middle fibers/septal fascicle block: A consensus report |
| title_sort |
electrocardiographic manifestation of the middle fibers/septal fascicle block: a consensus report |
| publishDate |
2012 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00220736_v45_n5_p454_BayesDeLuna http://hdl.handle.net/20.500.12110/paper_00220736_v45_n5_p454_BayesDeLuna |
| _version_ |
1768544118352379904 |