ºÎÁ¤¸ÆV10N³»Áö

Size: px

Start display at page:

Download "ºÎÁ¤¸ÆV10N³»Áö"

영배 장
6 years ago
Views:

1 A case of atrioventricular dissociation with interference ABSTRACT Interference dissociation is one of the most interesting arrhythmias. Once thought to be a rare arrhythmia, it is now considered a very common one. A 69-year-old female patient presented to our hospital with a chief complaint of dizziness and dyspnea on exertion that worsened since a month ago. On electrocardiogram, marked bradycardia (VR [ventricular rhythm] = 42 beat/min) was noted. P waves, without QRS correlation were seen, and the QRS complex was narrow. As the same rhythm was detected on 24-hour Holter monitoring with the patient experiencing dizziness, stress testing was performed upon which chronotropic incompetence was found. During an electrophysiology study, the abnormal finding of sinus node recovery time (RAP 500 ms) of 4,964 ms was noted. Therefore, a pacemaker of AAI type was inserted. Interference dissociation is defined as one of the dissociations caused by repetitive contradirectional interference, which leads to A-V dissociation. In general, as the ventricular rhythm is faster than the atrial rhythm, the P wave is seen progressively closer to the QRS complex, then disappears altogether, When passing through the QRS complex, to re-appear after the QRS complex. The P wave passing through the QRS complex is seen as ventricular capture, atrial capture, synchronization, or accrochage. Key words: interference dissociation ventricular capture chronotropic incompetence Correspondence: Jung-Hoon Sung, MD, PhD. Division of Cardiology, Department of Internal Medicine, CHA Bundang Medical Center, CHA University, 351 Yatap-dong, Bundang-gu, Seongnam-si, Gyeonggi-do , Korea Tel: , Fax: interspital@cha.ac.kr 52 Journal of Cardiac Arrhythmia

ECG & EP CASES A B P1 P2 P3 P4 P5 P6 P7 1640 1720 1640 1640 1600 1680 280 640 1520 1600 1560 1600 1600 R1 R2 R3 R4 R5 R6 R7 Figure 1-A.

Intermittent sinus capture occurs (arrow) and produces incomplete AV dissociation. Figure 1-B. Interference dissociation between an S-A and A-V nodal rhythm is present.

2 ECG & EP CASES A B P1 P2 P3 P4 P5 P6 P R1 R2 R3 R4 R5 R6 R7 Figure 1-A. The 12-lead electrocardiogram showes a sinus bradycardia allowing the escape of an AV junctional rhythm that does not capture the atria retrogradely. Intermittent sinus capture occurs (arrow) and produces incomplete AV dissociation. Figure 1-B. Interference dissociation between an S-A and A-V nodal rhythm is present. The rate of both the S-A and A- V nodal foci vary independently. In the first 2 cycles, the P-P interval lengthens progressively while the A-V nodal rate is fairly constant. As a result, P2 comes far enough beyond R2 to fall in the relative refractory phase of the bundle, and it is conducted to the ventricular after a P-R interval of 0.28 and an R-R interval of 0.64 second. VOL.11 NO.2 53

3 Table 1. Secondary A-V Block, or interference (normal refractory period) I. Ipsedirectional interference A. delayed conduction B. dropped beats II. Contradirectional interference A. Isolated 1. direct 2. delayed B. repetitive (interference dissociation, A-V dissociation due to interference) 1. undirectional with block in opposite direction, which may be: a. primary, complete or incomplete b. secondary, due to ipsedirectional interference 2. bidirectional C. interference dissociation with capture 1. atrial 2. ventricular 3. both atrial and ventricular D. combinations of primary or secondary heart block with interference dissociation 1. block above level of A-V nodal pacemaker 2. block below level of A-V nodal pacemaker (from Circulation 1957;16: ) 54 Journal of Cardiac Arrhythmia

4 ECG & EP CASES Figure 2. Relationships of overdrive pacing into sinoatrial exit block. Atrial overdrive pacing at a cycle length of 500 msec demonstrates a long pause of approximately 4964 msec. Figure 3. Posteroanterior radiographic view of a AAI pacemaker in a patient. The atrial lead is in the right atrial appendage. VOL.11 NO.2 55

5 References 1. MILLER R, SHARRETT RH. Interference dissociation. Circulation. 1957;16: PHILIP J. PODRID, PETTER R. KOWEY. CARDIAC ARRHYTHMIA: mechanisms, diagnosis, and management. 2 nd ed. 2001; Peter Libby, Robert O. Bonow, Douglas P. Zipes, Douglas L. Mann. Braunwald s Heart Disease: a textbook of cardiovascular medicine. 8 th ed. 2008; Journal of Cardiac Arrhythmia

<B0E6C8F1B4EBB3BBB0FA20C0D3BBF3B0ADC1C E687770>

<B0E6C8F1B4EBB3BBB0FA20C0D3BBF3B0ADC1C E687770> 심전도연수강좌 : 처음시작하는사람들을위한심전도 연세대학교원주의과대학순환기내과학교실 안민수 Cardiac Electrophysiology I : Automaticity : 60-100 회 /min, His bundle : 40-60 회 /min Bundle branch : 20-40 회 /min Purkinje fiber : 20 회 /min Cardiac Electrophysiology