Pulso vs. pulsação
In Portuguese, pulso and pulsação share the meaning of the rhythmic beating of the heart, but they function differently in practice. generally, pulso can refer to the anatomical wrist or the physical presence of a beat, while pulsação typically refers to the rate, frequency, or the active sensation of the throbbing.
Pulso
A2This word has two primary meanings. Anatomically, it refers strictly to the wrist (the joint). Medically, referring to the heart, it denotes the physical thump you feel when checking for vital signs. It is often used when asking if a pulse exists or checking the quality of the beat (strong/weak).
O médico colocou os dedos no meu braço para verificar o pulso.
(The doctor placed his fingers on my arm to check the pulse.)
Ele caiu e machucou o pulso direito.
(He fell and hurt his right wrist.)
A vítima não tem pulso, comece a reanimação.
(The victim has no pulse, start resuscitation.)
Sinto o meu pulso muito acelerado hoje.
(I feel my pulse is very fast today.)
É preciso ter pulso firme para controlar a situação.
(One needs a steady hand (figuratively: authority/control) to control the situation.)
Pulsação
B1This implies the activity or the rate of the beating. It describes the rhythm, the frequency (beats per minute), or the sensation of throbbing. It is more dynamic than pulso and is the preferred term when discussing heart rate numbers or musical rhythm.
Durante a corrida, minha pulsação subiu para 150.
(During the run, my heart rate went up to 150.)
O monitor mostrava uma pulsação regular e estável.
(The monitor showed a regular and stable pulse rate.)
Sinto uma pulsação forte na minha cabeça quando tenho enxaqueca.
(I feel a strong throbbing in my head when I have a migraine.)
Esta música tem uma pulsação muito lenta.
(This song has a very slow beat.)
Os atletas medem a pulsação logo após o treino.
(Athletes measure their pulse rate right after training.)
Summary
Use pulso when referring to the wrist (body part) or the mere existence/checking of the beat (e.g., finding a pulse). Use pulsação when referring to the speed, frequency, or the active rhythmic throbbing of the heart.