What is the name of the disease in which the sinus node fails to function properly?

What is the name of the disease in which the sinus node fails to function properly?

The sinus node is the normal pacemaker of the heart which gives out regular electrical signals for the functioning of the heart in an orderly way in response to body’s needs. It fails to do this function in a disease which is commonly known as sick sinus syndrome. Another name for this disease is structural nodal disease, as in some cases, it is not just the sinus node which is dysfunctional, but also the atrioventricular node (AV node). When the sinus node fails to produce regular electrical pulses, sometimes a lower pacemaker like the AV node takes over the function, though at a lower rate. Sometimes abnormal fast rhythms may also originate in other parts of heart so that it results in a tachy-brady syndrome (alternating episodes of fast and slow rhythms). In tachy-brady syndrome, if you treat the tachycardia (fast rhythm), the heart rate suddenly drops and results in bradycardia (slow rhythm). Hence it is difficult to treat tachy-brady syndrome with medications alone. An artificial pacemaker can be implanted to treat bradycardia so that medications can be given to suppress the tachycardia in tachy-brady syndrome.