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心力衰竭是婴儿死亡的重要原因之一,临床上必需袷予及时而正确的处理。但婴儿心力衰竭的表现常不如成人典型,而且发病快,在成人不引起心力衰竭的疾病在婴幼儿也易发生心力衰竭。在某些诊断和处理上也与成人有所不同。婴幼儿心脏血管的解剖生理特点小儿心脏体积相对地较成人大,新生儿心脏约为体重的0.8%,成人仅占0.5%。生后头两年心脏增长最快,1岁时心脏重量为新生儿的一倍,2～3岁时为新生儿的2～3倍。婴幼儿心脏呈椭圆形、圆锥形或球形,较居正中,故心音亦较居中。新生儿心室壁两侧几乎相等,以后左室厚度逐渐强于右室,小儿心肌纤维极细,相互交织很松,结缔组织和弹力纤维少,故易发生心力衰竭。以后心肌纤维生长,弹力纤维和结缔组织也随年龄而发育。婴幼儿毛细血管口径较粗,可以减轻心脏的工作,但当心机能减弱时,又能促进淤血现象的发生。小儿年龄越小脉搏越频。因小儿心肌有较快的收缩力和迷走神经作用较小,另一方面是物质代谢旺盛,新生儿脉搏为成人的二倍,每分钟140次,1岁时为120—130次,3岁时约106～110次。小儿脉搏极不稳定,少许刺激也能引起脉搏显著加速,活动、哭叫、发热可使脉搏加快。小儿发热1℃脉搏增加15～20次,而成人仅增加10次。小儿心力衰竭时易发生奔马率。小儿愈小共血压愈低,这是因心搏出量小、动脉口径大和动脉壁较柔软之故。新生儿血压约为76/34毫米汞柱,以后每增加一月,血压增加2毫米汞柱,故计算婴幼儿血压可用公式:月龄×2+68=收缩压,舒张
Heart failure is one of the important causes of infant death, which must be timely and correctly treated clinically. However, the performance of infantile heart failure is often not as good as that of adults, and the onset is fast. Heart failure is also prone to occur in infants and young children without causing heart failure in adults. In some of the diagnosis and treatment are also different with adults. Anatomical and physiological characteristics of infants and young children’s blood vessels Pediatric heart volume is relatively larger than adults, the newborn’s heart is about 0.8% of body weight, adults accounted for only 0.5%. The first two years after birth, the heart of the fastest growth, 1 year old heart double the weight of the newborn, 2 to 3 years old for newborns 2 to 3 times. Infant heart was oval, conical or spherical, compared with the median, so the heart sound is also more middle. Neonatal ventricular wall is almost equal on both sides, after the left ventricular thickness gradually stronger than the right ventricle, pediatric myocardial fibers very thin, intertwined very loose, less connective tissue and elastic fibers, it is prone to heart failure. After myocardial fiber growth, elastic fibers and connective tissue also with age and development. Capillaries infants and young children thicker calluses, can reduce the work of the heart, but when the performance is weakened, but also to promote the occurrence of congestion. The younger the younger the pulse frequency. Because of myocardial contractions in children with faster vagal and smaller role, on the other hand is the material metabolism, neonatal pulse rate of adult double, 140 times per minute, 1-year-old for 120-130 times, about 3 years old 106 ~ 110 times. Pediatric pulse is very unstable, a little stimulation can cause a significant pulse acceleration, activity, crying, fever can make the pulse faster. Pediatric fever 1 ℃ pulse increased 15 to 20 times, while adults increased only 10 times. Pediatric heart failure prone to gallop rate. The smaller the child, the lower the total blood pressure, which is due to a small amount of cardiac stroke, large arteries and arterial walls so soft. Neonatal blood pressure is about 76/34 mm Hg, for each additional January, blood pressure increased by 2 mm Hg, so the formula for calculating infant blood pressure: age × 2 +68 = systolic blood pressure, diastolic