There are two types of pacemakers that can improve heart function and blood circulation:

1.    A regular cardiac resynchronization therapy pacemaker or CRT-P.

2.    A cardiac resynchronization therapy defibrillator, or CRT-D, can detect when an arrhythmia is life-threatening and automatically shock the heart back into a normal rhythm. Doctors normally recommend the cardiac resynchronization therapy defibrillator (CRT-D), but the final decision on the appropriate device will depend on the individual patient.

1. Bleeding or hematoma, and infection where the cardiac resynchronization therapy (CRT) device was implanted.
2. Allergic reaction to the medications used during the procedure.
3. Damage to blood vessels.
4. Collapsed lung.
5. Bleeding in the pericardium.
6. Stroke, heart attack, or other serious complications, which are uncommon.
7. Death (rare).

1. Bleeding, swelling, or increased pain at the implantation site
2. Fever
3. Dizziness or fainting
4. Chest pain
5. Difficulty breathing

Medication.