Objective evidence of occult myocardial dysfunction in patients with frequent ventricular ectopy without clinically apparent heart disease

Results of endomyocardial biopsy in patients with spontaneous ventricular tachycardia but without apparent structural heart disease.

“…Abnormalities in biopsy specimens from these patients are indistinguishable from those of biopsy specimens from patients with idiopathic, dilated, congestive cardiomyopathies. lX Figure 1 is from the biopsy specimen of patient 6 and shows changes categorized as nonspecific cardiomyopathy. Inflammatory myocarditis was diagnosed in three patients ( 17%) on the basis of a subjectively evaluated increase in the number of inflammatory cells present in association with myocellular damage and/or necrosis.…”

Prognostic significance of frequent premature ventricular contractions originating from the ventricular outflow tract in patients with normal left ventricular function

“…Several reports have suggested a mechanism involving tachycardia-induced cardiomyopathy as the cause of the LV dysfunction,8 – 10 14 15 but that can be questioned because the total number of heart beats during Holter monitoring in patients with frequent PVCs would be expected to be at a level similar to that for normal patients. In contrast, a similar mechanism as bradycardia-induced LV dysfunction might be a possible mechanism16 17 because each PVC could not produce an effective cardiac output due to the premature excitation resulting in a much lower pulse rate than in normal subjects. For example, in a patient with 30 000–40 000 PVCs/day, that patient might lose as much as almost a third of the effective cardiac output daily and might develop a similar condition as severe bradycardia, such as sick sinus syndrome or atrioventricular block.…”

Premature ventricular contraction-induced cardiomyopathy: Related clinical and electrophysiologic parameters

“…While the cardiologist's attitude facing premature ventricular contraction (PVC) in healthy subjects had been historically principally reassuring (1)(2)(3), it was only fifteen years ago that the concept of premature ventricular contractions induced cardiomyopathy (PVCi-CMP) emerged. These cardiomyopathies are characterized by an alteration in left ventricular ejection fraction (LVEF) and left ventricular dimensions which are regressive after elimination of frequent PVCs, for example after radio-frequency (RF) ablation (3,4).…”