TY - JOUR
T1 - Miniseries 2-Septal and paraseptal accessory pathways-Part III: Mid-paraseptal accessory pathways-revisiting bypass tracts crossing the pyramidal space
AU - Farre, Jeronimo
AU - Anderson, Robert H.
AU - Rubio, Jose-Manuel
AU - Garcia-Talavera, Camila
AU - Sanchez-Quintana, Damian
AU - Bansal, Raghav
AU - Lokhandwala, Yash
AU - Cabrera, Jose-Angel
AU - Wellens, Hein J. J.
AU - Sternick, Eduardo Back
PY - 2022/4/5
Y1 - 2022/4/5
N2 - The mid-paraseptal region corresponds to the portion of the pyramidal space whose right atrial aspect is known as the triangle of Koch. The superior area of this mid-paraseptal region is also para-Hisian, and is close to the compact atrioventricular node and the His bundle. The inferior sector of the mid-paraseptal area is unrelated to the normal atrioventricular conduction pathways. It is, therefore, a safe zone in which, if necessary, to perform catheter ablation. The middle part of the mid-paraseptal zone may, however, in some patients, house components of the compact atrioventricular node. This suggests the need for adopting a prudent attitude when considering catheter ablation in this area. The inferior extensions of the atrioventricular node, which may represent the substrate for the slow atrioventricular nodal pathway, take their course through the middle, and even the inferior, sectors of the mid-paraseptal region. In this review, we contend that the middle and inferior areas of the mid-paraseptal region correspond to what, in the past, was labelled by most groups as the 'midseptal' zone. We describe the electrocardiographic patterns observed during pre-excitation and orthodromic reciprocating tachycardia in patients with pathways ablated in the middle or inferior sectors of the region. We discuss the modification of the ventriculo-atrial conduction times during tachycardia after the development of bundle branch block aberrancy. We conclude that the so-called 'intermediate septal' pathways, as described in the era of surgical ablation, were insufficiently characterized. They should not be considered the surrogate of the 'midseptal' pathways defined using endocardial catheter electrode mapping.
AB - The mid-paraseptal region corresponds to the portion of the pyramidal space whose right atrial aspect is known as the triangle of Koch. The superior area of this mid-paraseptal region is also para-Hisian, and is close to the compact atrioventricular node and the His bundle. The inferior sector of the mid-paraseptal area is unrelated to the normal atrioventricular conduction pathways. It is, therefore, a safe zone in which, if necessary, to perform catheter ablation. The middle part of the mid-paraseptal zone may, however, in some patients, house components of the compact atrioventricular node. This suggests the need for adopting a prudent attitude when considering catheter ablation in this area. The inferior extensions of the atrioventricular node, which may represent the substrate for the slow atrioventricular nodal pathway, take their course through the middle, and even the inferior, sectors of the mid-paraseptal region. In this review, we contend that the middle and inferior areas of the mid-paraseptal region correspond to what, in the past, was labelled by most groups as the 'midseptal' zone. We describe the electrocardiographic patterns observed during pre-excitation and orthodromic reciprocating tachycardia in patients with pathways ablated in the middle or inferior sectors of the region. We discuss the modification of the ventriculo-atrial conduction times during tachycardia after the development of bundle branch block aberrancy. We conclude that the so-called 'intermediate septal' pathways, as described in the era of surgical ablation, were insufficiently characterized. They should not be considered the surrogate of the 'midseptal' pathways defined using endocardial catheter electrode mapping.
KW - Pre-excitation
KW - Accessory pathway
KW - Electrocardiogram
KW - Para-Hisian pathway
KW - Intermediate septal pathway
KW - Mid-paraseptal pathway
KW - Midseptal pathway
KW - Pyramidal space
KW - Triangle of Koch
KW - ELECTROPHYSIOLOGIC CHARACTERISTICS
KW - FREE-WALL
KW - ABLATION
KW - BLOCK
KW - LOCALIZATION
KW - CONDUCTION
KW - RISK
U2 - 10.1093/europace/euab294
DO - 10.1093/europace/euab294
M3 - Article
C2 - 34999785
SN - 1099-5129
VL - 24
SP - 662
EP - 675
JO - EP Europace
JF - EP Europace
IS - 4
ER -