This study found that ventricular arrhythmias in Boxers are inherited as an autosomal dominant trait. Researchers found that asymptomatic Boxers have frequent ventricular premature complexes (VPCs), a specific type of irregular heartbeat that is a common form of ventricular arrhythmia. They determined that a two- to three-minute electrocardiogram (ECG) is a poorly sensitive indicator of VCPs, and instead recommend the use of a 24-hour ambulatory ECG (Holter monitor), even on asymptomatic Boxers. In studying Doberman Pinschers, they ruled out some potential candidate genes for study by demonstrating that two specific proteins and a specific gene that are abnormal in some humans with dilated cardiomyopathy (DCM) a primary heart muscle disorder that can cause the heart to beat erratically are normal in Dobermans with DCM. Linkage analyses for both Boxers and Dobermans.