
In the event of a rapid heartbeat, the cables from the heart to the machine relay signals to the ICD to control the heartbeat by transmitting electric pulses. The ICD may be coded for the following depending on the problem:
Low energy pacing: When ICD responds to moderate pulse fluctuations the patient can not experience any or no painless flutter in the chest.
A more energetic shock: The ICD will lead to an increased energy shock to more severe heart rhythm issues. This shock may be intense, and you can feel as if you were kicked into the face. The pain generally just takes a second, and once the shock stops, there should be no pressure.
In general, only one shock is required to restore a natural heartbeat. However, often within a 24-hour cycle, you can feel two or three shocks.
It is classified as an electric or arrhythmia storm that has three or more shocks in a short period. When that happens, you have to look for medical treatment to scan for an ICD deficiency or if you have a heart attack that abnormally hits you. The ICD may be modified if necessary to decrease shock numbers and frequencies. You may need extra drugs to beat the heart consistently and reduce the risk of an ICD storm.
An ICD may also monitor the movement and rhythm shifts of the heart. This knowledge assists the doctor in calculating the rhythm and reprogramming ICD if necessary. To prescribe one of the following forms of ICDs, a cardiologist can recommend a patient:
- One ICD (sends electric signals to the right ventricle) with one-chamber.
- A dual-camera ICD (transmission of electric signals to the right ventricle and atrium).
- A biventricular system (sends electrical impulses and all ventricles to the right atrium). Doctors use it on patients with cardiac insufficiency.
Up to four kinds of electrical signals can also be sent to the heart:
- Cardioversion: Cardioversion gives a powerful electrical signal which can sound like a chest thump. When a very high heart rate is observed, it resets heart rhythms to normal.
- Defibrillation: Defibrillation sends a very effective electric message restarting the heart. The feeling is uncomfortable and will sweep you off your feet, but lasts only for a second.
- Antitachycardia: Antitachycardia pacing gives a low-energy pulse to reset a fast pulse. Normally, when the pulse happens, the patient senses nothing. But a slight flood in the chest could be felt.
- Bradycardia: Bradycardia is a pulse that is too sluggish to regain normal rhythm. The ICD behaves as a pacemaker in this case. ICD patients generally get heart pounding too rapidly. Defibrillation can, however, often slow the heart down to a dangerous degree. The pace returns to normal with Bradycardia’s timing.