Cardiac resynchronization therapy delivers stimulation to which ventricles?

Cardiac resynchronization therapy delivers stimulation to which ventricles?

• A. Right atrium and left ventricle
• B. Left ventricle and right atrium
• C. Right ventricle and left ventricle
• D. Aorta and pulmonary artery

Answer: (C)

Cardiac resynchronization therapy is used to correct dyssynchronous ventricular contraction in heart failure, especially when the ventricles do not beat together due to conduction delay. By delivering pacing signals to both ventricles, it coordinates their contraction so the heart ejects more effectively and stroke volume improves. The typical setup places a lead in the right ventricle and another lead in the left ventricle (via the coronary sinus), creating biventricular pacing that resynchronizes ventricular contraction. Some CRT devices also have an atrial lead for maintaining atrioventricular timing, but the key ventricular targeting is the right and left ventricles. Stimulating the atrium or great vessels would not achieve the same resynchronization of the ventricles.

Cardiac resynchronization therapy is used to correct dyssynchronous ventricular contraction in heart failure, especially when the ventricles do not beat together due to conduction delay. By delivering pacing signals to both ventricles, it coordinates their contraction so the heart ejects more effectively and stroke volume improves. The typical setup places a lead in the right ventricle and another lead in the left ventricle (via the coronary sinus), creating biventricular pacing that resynchronizes ventricular contraction. Some CRT devices also have an atrial lead for maintaining atrioventricular timing, but the key ventricular targeting is the right and left ventricles. Stimulating the atrium or great vessels would not achieve the same resynchronization of the ventricles.