Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, this twitching sensations can be due to
arrhythmia (rhythm disturbances in heart).
He is known case of
hypertension, so he is at risk of arrhythmia.
So we should definitely rule out arrhythmia first in his case.
So
consult cardiologist and get done blood pressure monitoring, ecg, 2d echo and Holter monitoring (24 hours continuous recording of ecg).
He may need anti arrhythmia drugs too.
Along with this, strict control of blood pressure and salt restricted diet are required.
Don't worry, he will be alright.
But first rule out arrhythmia.
Hope I have solved your query. I will be happy to help you further. Wishing good health to your father. Thanks.