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Heart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos.
The heart is the first functional organ to develop and starts to beat and pump blood at around 22 days. [21] Cardiac myoblasts and blood islands in the splanchnopleuric mesenchyme on each side of the neural plate give rise to the cardiogenic region. [11]: 165 This is a horseshoe-shaped area near to the head of the embryo.
The first heart sound, or S 1, forms the "lub" of "lub-dub" and is composed of components M 1 (mitral valve closure) and T 1 (tricuspid valve closure). Normally M 1 precedes T 1 slightly. It is caused by the closure of the atrioventricular valves , i.e. tricuspid and mitral (bicuspid), at the beginning of ventricular contraction, or systole .
A Doppler fetal monitor, informally known as sonicaid (generic trademark), is a hand-held ultrasound transducer used to detect the fetal heartbeat for prenatal care. It uses the Doppler effect to provide an audible simulation of the heart beat. Some models also display the heart rate in beats per minute (BPM).
A Zigzag pattern of fetal heart rate (FHR) is defined as FHR baseline amplitude changes of more than 25 beats per minute (bpm) with a minimum duration of 2 minutes and maximum of 30 minutes. [19] However, according to another study, even a >1 min duration of the zigzag pattern is associated with an increased risk of adverse neonatal outcomes ...
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. [1] In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. [1] Heart rates above the resting rate may be normal (such as with exercise) or abnormal (such as with electrical problems within the heart).
The blood pressure in the fetal aorta is approximately 30 mmHg at 20 weeks of gestation, and increases to ca 45 mmHg at 40 weeks of gestation. [16] The fetal pulse pressure is ca 20 mmHg at 20 weeks of gestation, increasing to ca 30 mmHg at 40 weeks of gestation. [16] The blood pressure decreases when passing through the placenta.
A slow heart rate of 60 or less beats per minute is defined as bradycardia. A fast heart rate of more than 100 beats per minute is defined as tachycardia. An arrhythmia is defined as one that is not physiological such as the lowered heart rate that a trained athlete may naturally have developed; the resting heart rates may be less than 60 bpm.