The major beneffit is in case of patients who have cardiac failure with low ejection fraction (<35%; the ejection fraction is the measurement of how much blood is being pumped out of the left ventricle of the heart (the percentage)), wich are at high risk for developing severe arrythmias.
Indications for CRT -ICD include:
•symptomatic cardiac failure
•optimum treatment for heart failure, but still symtomatic
•delayed electrical activation of the heart (such as intraventricular conduction delay or bundle branch block)
•patient who have a history of cardiac arrest or are at risk for cardiac arrest
Indications for pacemakers include:
Absolute indications for pacemaker placement include the following:
•Sick sinus syndrome
•Symptomatic sinus bradycardia
•Tachycardia-bradycardia syndrome
•Atrial fibrillation with sinus node dysfunction
•Complete atrioventricular block (third-degree block)
•Chronotropic incompetence (inability to increase the heart rate to match a level of exercise)
•Prolonged QT syndrome
•Cardiac resynchronization therapy with biventricular pacing
Relative indications include the following:
•Cardiomyopathy (hypertrophic or dilated)
• Severe refractory neurocardiogenic syncope
Temporary emergency pacing is indicated for therapy of significant and hemodynamically unstable bradydysrhythmias and for prevention of bradycardia-dependent malignant dysrhythmias.
Examples include:
•refractory symptomatic sinus node dysfunction,
•complete heart block (see the image below), alternating bundle-branch block, new bi-fascicular block, and bradycardia-dependent ventricular tachycardia.
Examples of indications for prophylactic temporary pacing include:
•insertion of a pulmonary artery catheter in a patient with an underlying left bundle-branch block
•use of medications that may cause or exacerbate hemodynamically significant bradycardia
•prophylaxis during the perioperative period surrounding cardiac valvular surgery
•Lyme disease or other infections (Chagas disease) that cause interval changes, and prolonged PR intervals.