Trẻ sơ sinh, trẻ em và thanh thiếu niên (Hình 27A) Các tính năng quan trọng nhất của điện tâm đồ của trẻ em khỏe mạnh so với người lớn bình thường có thể được tóm tắt như sau: 1 Có một nhịp tim nhanh hơn và ngắn hơn khoảng PR. 2 Do phì đại tâm thất phải sinh lý của trẻ sơ sinh, tim thường theo chiều dọc với các AQRS quyền và tiêu cực hoặc hai đỉnh sóng | 30 Chapter 5 Electrocardiographic changes with age Figure 27 Infants children and adolescents Figure 27A The most important features of the ECG of healthy children as compared to normal adults can be summarised as follows 1 There is a faster heart rate and shorter PR intend. 2 Due to the physiological right ventricular hypertrophy of infants the heart is usually vertical with AQRS to the right and negative or bimodal T waves in VI to V3-V4 and has a characteristic morphology infantile repolarisation that can be seen until adolescence particularly in females. The QRS loop goes tothe leftbefore goingback which explains whythennorphology of V6 looks Normal ECG characteristics 31 like the adult s morphology before VI there is higher R in VI compared with q in V6 . Sometimes the rsr pattern is observed in VI. In infants especially if they are post-term even R or qR patterns can be seen at birth with a somewhat positive T wave. The Rs pattern persists for a time perhaps even years even until adulthood. However the T wave usually becomes flattened or negative in the rs following birth. 3 In some adolescents an R wave with high voltage in precordial leads Sv2 RV5 60 mm without the existence of left ventricular enlargement may be seen. 4 Sometimes evident increase in the heart rate with inspiration. Elderly subjects Figure 27B The followmg phenomenacan beconsideredage-related loriantsinECCs of the elOerly VA slowee henet satened lonqer ORínterval oeoonhsl. OOceenionsllya more right-nemiiog APis pesseno booause el pulmoneee fmphysfmowith the n wavoid Isadmfafd an mQhSehatfin geneeal-aomt-more tithe left from ac fo 30 . 3 A poos-p onoene ien taom Vito vs p-olcaHyeli t- to sep0alfibsoois. Thio caaprodoce preblsmsinthgdifferential niagnesiswitnsepealnenaosi-. hOamn oileaation of repolarisation slightly depressed ST segment and or flattened Twhne .AS-equeeiiU wevgpo-tleuiofiy in the inOermeaiate precordial leads. CHAPTER 6 Electrocardiographic diagnostic criteria
