CD4 and ventricular fibrillation: However, the fact that patients with CHF are more likely to develop ventricular arrhythmia—such as ventricular tachycardia (VT) or ventricular fibrillation (VF) at the end-staged disease needs to be kept in mind (as a potential ventricular manifestation of aggravated CD4+CD28null cell mediated macro-scar formation) (see Fig. 1—Sect.