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The normal range has since been revised in textbooks to 50–90 bpm for a human at total rest. Setting a lower threshold for bradycardia prevents misclassification of fit individuals as having a pathologic heart rate. The normal heart rate number can vary as children and adolescents tend to have faster heart rates than average adults.
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
The respiratory rhythm contributes to sinus arrhythmia in normal unanesthetized subjects during mechanical hyperventilation with positive pressure. [ 37 ] Low-frequency oscillations [ 41 ] are associated with Mayer waves (Traube–Hering–Mayer waves) of blood pressure and is usually at a frequency of 0.1 Hz , or a 10-second period.
In healthy adults, there are two normal heart sounds, often described as a lub and a dub that occur in sequence with each heartbeat. These are the first heart sound (S 1) and second heart sound (S 2), produced by the closing of the atrioventricular valves and semilunar valves, respectively.
Cardiac reserve refers to the difference between the rates at which the heart pumps blood - at any given time versus its maximum capacity. A measurement of the cardiac reserve may be a health indicator for some medical conditions.
The instantaneous wave-free ratio (iFR, sometimes referred to as the instant wave-free ratio or instant flow reserve) is a diagnostic tool used to assess whether a stenosis is causing a limitation of blood flow in coronary arteries with subsequent ischemia. iFR is performed during cardiac catheterisation (angiography) using invasive coronary pressure wires which are placed in the coronary ...
Tricuspid atresia is the complete absence of the tricuspid valve which can lead to an underdeveloped or absent right ventricle. Pulmonary atresia is the complete closure of the pulmonary valve. Ebstein's anomaly is the displacement of the septal leaflet of the tricuspid valve causing a larger atrium and a smaller ventricle than normal.
Cœur en sabot (French for "clog-shaped heart" or "boot-shaped heart" [1]) is a radiological sign seen most commonly in patients with tetralogy of Fallot, [2] a cyanotic congenital heart disease.