Implantation of a pacemaker is most likely to benefit a client with which of the following cardiomyopathies?

Dilated cardiomyopathy (DCM) is characterized by dilation and impaired systolic function of one or both ventricles, leading to reduced ejection fraction and heart failure. A significant subset of DCM patients develop serious conduction abnormalities — including left bundle branch block, atrioventricular block, and ventricular dyssynchrony — which further worsen cardiac output. Cardiac resynchronization therapy (CRT) via a biventricular pacemaker, as well as implantable cardioverter-defibrillators (ICDs), are established treatments for select DCM patients because they correct mechanical dyssynchrony and protect against sudden cardiac death from malignant dysrhythmias. Myocarditis is an inflammatory condition of the heart muscle that may resolve with treatment; pacemaker implantation is not a primary intervention and is considered only if persistent conduction disease develops. Endocardial myopathy (also called endomyocardial fibrosis) involves fibrosis of the endocardium rather than conduction system disease, and pacemaker therapy is not its primary management. Takotsubo cardiomyopathy is a transient stress-related cardiomyopathy typically triggered by emotional or physical stress; it is usually reversible and does not primarily require permanent pacemaker placement. DCM's chronic conduction defects and risk of sudden death make it the condition most likely to benefit from pacemaker or ICD implantation.