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
Heart rate at rest. Bradycardia is a slow heart rate, defined as below 60 bpm at rest. During sleep a slow heartbeat with rates around 40–50 bpm is common and is considered normal. When the heart is not beating in a regular pattern, this is referred to as an arrhythmia. Abnormalities of heart rate sometimes indicate disease. While heart rhythm is regulated entirely by the sinoatrial node under normal conditions, heart rate is regulated by sympathetic and parasympathetic input to the sinoatrial node. The accelerans nerve provides sympathetic input to the heart by releasing norepinephrine onto the cells of the sinoatrial node