(A) study of atrioventricular conduction using his bundle electrogram
다극도자를 이용하여 His 속전도를 용이하게 기록하게 된 이래 심전도상의 P-R 간격은
P-A, A-H, H-V의 3 간격으로 세분할 수 있게 되었으며 따라서 부정맥과 전도장애의 연구
에 획기적인 발전을 가져왔다.
저자는 35명의 환자를 대상으로 정상 방실전도를 측정하였고 각종 부정맥을 연구분석하
8명의 소아에서 정상 방실전도시간은 P-A, A-H, H-V의 간격의 범위가 각각 25-45 msec,
50-100 msec, 30-45 msec 이었다.
11명의 성인에서 정상 방실전도시간은 각각 25-50 msec, 65-110 msec, 20-50 msec로서
소아군과 비교할 때 통계학적으로 유의의 차를 보이지 않았다.
각종 전도장애와 부정맥을 가진 16명의 환자에서 His속전도를 기록하였는데 1도방실차
단이 4예, 2도방실차단(Mobitz typeⅠ) 1예, 3도방실차단(supra-His block) 2예, 심방세
동 5예, 발작성심방빈맥을 동반한 WPW증후군 2예 (type A, B가 각각 1예), 결절성빈맥 1
예, 그리고 결절성조율 1예였다.
Although considerable knowledge about cardiac conduction has been accumulated
through the study of external electrocardiogram, the most apparent limitation of
this method is that activity of the conductive system itself is not recorded.
Scherlag and coworkers introduced a simple technique for recording the electrical
activity of the His bundle in the human heart. With the development of a simple
catheter technique for recording of His bundle electrogram it has become possible
to subdivide the previously silent P-R interval into three subintervals, P-A, A-H,
and H-V intervals. The P-A, A-H, and H-V intervals are, respectively, measures of
intra-atrial (from high to low right atrium), atrioventricular nodal, and
intraventricular (distal His bundle and bundle branches) conduction. His bundle
recording contributes to understanding the electrophysiological mechanisms
underlying atrioventricular and intraventricular conduction disturbances. The sites
of conduction delay or block are anatomically and electrophysiologically localized
as being proximal, in, or distal to the His bundle. this in turn may allow us
greater specificity in the selection of the proper therapy for the patient with
abnormalities of cardiac rhythm.
The purpose of this study was to analyze A-V conduction in patient with normal
P-R interval and to define more precisely the areas of delay or block in conduction
disturbances and various arrythmias by means of the technique of His bundle
recording. The His bundle electrograms were recorded with tripolar electrode
catheter in 35 patients in Cardiac. Laboratory in Severance Hospital from January
1975 to November 1975. This study consisted 19 patients with normal
atrioventricular conduction and 16 patients with various conduction disturbance and
arrythmias. All patients except two with normal heart had underlying congenital and
acquired heart diseases.
A) Normal A-V conduction time in children and adults.
In 8 children aged 5 to 15 years with a mean age of 10.2 years P-A interval
ranged from 25 to 45 msec with a mean SE of 32 ± 3.1, A-H from 50 to 100 msec with
a mean of 68 ± 6.1, and H-V from 30 to 45 msec with a mean of 36 ± 1.9. In 11
adults aged 16 to 59 years with a mean age of 33.4 years P-A interval ranged from
25 to 50 msec with a mean of 36 ± 3.0, A-H from 65 to 110 msec with a mean of 84
± 4.8, and H-V from 20 to 50 msec with a mean of 37 ± 2.8. The P-A, A-H, and H-V
intervals did not differ statistically between children and adults.
B) Various conduction disturbances and arrythmias.
1) In 4 patients with first degree A-V block the P-A and H-V intervals were
normal but the prolonged H-V intervals were 140, 142, 170, and 175 msec,
2) In a patient with second degree A-V block (Mobitz type Ⅰ) His bundle
electrograms showed progressive lengthening of A-H intervals with P waves blocked
proximal to the His bundle recording sits (not followed by H potentials).
3) In two patients with complete heart block His bundle recordings demonstrated P
waves not followed by H potentials while QRS complexes were preceded by H
potentials. The sites of block might be proximal to the His bundle.
4) His bundle recordings were obtained in five patients with atrial fibrillation.
In 4 patients a single His bundle potential preceded each QRS complex and H-V
interval were constant from beat to beat during atrial fibrillation.
In two patients right bundle potential(RB) was recorded. RB-V intervals were 20
and 15 msec. respectively, which were shorter than normal H-V interval.
5) His bundle electrograms were recorded in 2 patients of WPW syndrome with
paroxysmal atrial tachycardia(PAT) which were type A and type B, respectively. In
all 2 patients A-H intervals were same as A-8 intervals. When episodes of PAT
occurred delta waves (8) disappeared with prolongation of A-H intervals.
6) In one patient with junctional tachycardia His bundle recording did not
demonstrate A potential. When episodes of atrial tachycardia disappeared the A
7) His bundle electrogram was recorded in a patient with junctional rhythm
(ventricular rate: 43/min.). The A potential was not demonstrated while QRS
complexes were preceded by H potentials.