(1)
Pediatric Cardiology, Policlinico S.Orsola-Malpighi, Bologna, Italy
Fig. 10.1
(a) Twelve-year-old male, asymptomatic, diagnosed as “WPW ” during sports participation screening. There is an intermittent pre-excitation. (b) In the upright position, the slight increase in HR abolishes the pre-excitation (due to a right posterior AP), denoting a bypass tract with long refractory period and therefore little risk of life-threatening arrhythmias (see atrial fibrillation conducted along the pathway with high ventricular rate); all leads are delta-free. The negative T waves in the inferior and lateral leads are an “electric memory” phenomenon. The stress test was done for arrhythmic risk stratification and not for ischemia. It is well recognized that pre-excitation may affect the repolarization making the assessment of ischemic changes of the ST segment
Fig. 10.2
(a) Another example of intermittent pre-excitation (IP) in a 13-year-old boy. The pre-excitation is HR dependent. In IP the delta wave usually disappears at faster HR (shorter R–R cycle), a behavior that on the conduction properties of the accessory pathways (AP) regarding the risk of life-threatening arrhythmias. (b) Close-up
Fig. 10.3
Thirteen-year-old male with multiple APs proven during the endocavitary electrophysiological study (EPS) . (a) Right inferoposterior AP. (b) Right anteroseptal AP
Fig. 10.4
Sixteen-year-old female with right lateral AP who underwent radiofrequency catheter ablation (RFCA) . Delta is negative in leads III and aVR. The vector of AP runs away from right to left. In lead I and in the precordial leads, the pattern is LBBB-like, consistent with the AP site
Fig. 10.5
Ten-year-old male with left lateral AP, the opposite site to the previous case. Here too, the ECG is fairly coherent, showing a negative delta wave in aVL and lead I, due to the vectors that fly off from left to right. Among APs, the left-sided APs are more common
Fig. 10.6
(a) Another case of IP in a 6-year-old female. (b) Close-up: “just two beats of” pre-excitation
Fig. 10.7
(a) Again an IP in a 10-year-old male. (b) Close-up: this time, “just two beats off ” pre-excitation
Fig. 10.8
(a) Eight-year-old male with incidental finding of intermittent pre-excitation due to a right postero-septal AP. Almost all QRS are pre-excited (the one with asterisk is not pre-excited), but the morphology varies with the degree of pre-excitation, which in turn depends on the cycle length (P–P interval or delta-delta!). There is a sort of “concertina effect.” (b) Close-up
Fig. 10.9
Thirteen-year-old female. Right anteroseptal AP
Fig. 10.10
Eleven-year-old male. Left lateral AP
Fig. 10.11
A case of neonatal SVT . (a) In the first year of life, he was symptomatic but not pre-excited. (b) At 2 years of life he was pre-excited but not symptomatic. This means that in the first year of life the AP was able to conduct only retrogradely; in other words it was occult or concealed
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
