Premature ventricular contractions can occur in a healthy person of any age, but are more prevalent in the elderly and in men. They frequently occur spontaneously with no known cause. Heart rate turbulence (HRT) is a phenomenon representing the return to equilibrium of the heart rate after a PVC.
Microcycle is the training work unit that can be various on lasting, structure and contents. In praxa microcycles last 2-14 days, but the most often variant is 7 days.ecause of that it can be told that there is no unique, universal microcycle structure that can be thought to be equally good for each possible cases. In the theory of sports training there is multiple microcycles classifications.
heterocycle - a ring of atoms of more than one kind; especially a ring of carbon atoms containing at least one atom that is not carbon. heterocyclic ring. closed chain, ring - (chemistry) a chain of atoms in a molecule that forms a closed loop.