Cardiac contractility modulation for heart failure, such as pacemaker therapy or implantable cardioverter defibrillators (ICD), Cardiac contractility modulation does not affect the cardiac rhythm directly. Rather, the aim is to enhance the heart’s natural contraction (the native cardiac contractility) sustainably over long periods of time. Furthermore, unlike most interventions that increase cardiac contractility, the Cardiac contractility modulation is not associated with an unfavorable increase in oxygen demand by the heart (measured in terms of Myocardial Oxygen Consumption or MVO). This may be explained by the beneficial effect the therapy has in improving cardiac efficiency. A meta-analysis in 2014 and an overview of device-based
Cardiac output cycle that delivers oxygen, nutrients and chemicals to the body's cells and removes cellular waste. Because it pumps out whatever blood comes back into it from the venous system, the quantity of blood returning to the heart effectively determines the quantity of blood the heart pumps out – its cardiac output, "Q". Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as: In standardizing what CO values are considered to be within normal range independent of the size of the subject's body, the accepted convention is to further index equation () using Body surface area