QRS Voltage Changes in Heart Failure: A 3-Compartment Mechanistic Model and its Implications

A 3-compartment mechanistic model is proposed to explain the attenuation of the electrocardiographic QRS complexes (↓QRSV) observed in patients with heart failure (HF). This includes the effects of increased intracardiac blood volume and decreased hematocrit due to blood dilution (1st compartment), the heart's alteration in electrogenesis due to possible ischemia or inflammation, leading to myocardial edema, (2nd compartment), and the passive volume conductor of the tissue and organ constituents of the thorax and the entire body, with their resistivity changes due to increased fluid content (pulmonary and peripheral edema) (3rd compartment). The clinical implications of the model are outlined.