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

Abstract

To evaluate possible occult myocardial disease in 18 patients whose only major manifestation of heart disease was spontaneous ventricular tachycardia or fibrillation, right ventricular endomyocardial biopsies were performed. None of the patients had symptoms of ischemic or congestive heart disease, and at catheterization none had significant lesions of the coronary arteries or regional wall motion abnormalities of the left ventricle. The mean left ventricular ejection fraction (65 + 7%), mean right ventricular ejection fraction (55 + 9%), mean cardiac index (3.0 ± 0.5 1/min/m2), mean right atrial pressure, mean pulmonary capillary wedge pressure, and mean pulmonary artery systolic pressure were normal. However, right ventricular endomyocardial biopsy specimens were abnormal in 16 of 18 (89%) patients: nine (50%) had changes of a significant, although nonspecific, cardiomyopathy with myocellular hypertrophy, interstitial and perivascular fibrosis, and vascular sclerosis; three (17%) had subacute inflammatory myocarditis; two (11%) had diffuse abnormalities of the intramyocardial arteries; and two (11%) had pathologic changes consistent with arrhythmogenic right ventricular dysplasia. In the two (1 %) patients with normal biopsy specimens, one had Wolff-Parkinson-White syndrome and the other had mitral valve prolapse. Although histologic abnormalities were found in 89% of these patients, performance of right ventricular endomyocardial biopsies in this group of patients should be considered a research procedure. We conclude that the majority of patients who have serious ventricular arrhythmias but no apparent structural cardiac abnormalities have abnormal right ventricular biopsy specimens and that the arrhythmias may be the first manifestation of a variety of primary myocardial abnormalities.

Cathepsin B inhibition attenuates cardiac dysfunction and remodeling following myocardial infarction by inhibiting the NLRP3 pathway

“…The predilection for fibrosis in the subendocardium of the NIZ is viewed as a significant contributory factor to mechanical dysfunction (29) and propensity for dysrhythmia (30) following MI. In the present study, in contrast to its neutral effect on fibrosis in the infarct zone, CA-074Me treatment significantly reduced ECM deposition in the areas remote from the site of infarction, particularly the subendocardial region, which was associated with a reduction in the level of in LV function.…”

The Role of Endomyocardial Biopsy in the Management of Cardiovascular Disease

“…Many of these studies were conducted in the 1980s, and most involve only modest numbers of patients (Table 4). 144,[157][158][159][160][161][162] Most studies reported a high incidence of abnormal findings, although these were usually nonspecific findings; the incidence of histologically diagnosed myocarditis varied widely in these reports, and only rarely were other specific disease entities diagnosed. One authoritative review questioned the "strikingly high" incidence of reported histological myocardial abnormalities in the literature, and the review authors comment that they suspect the true incidence of abnormalities described in these reports to be lower.…”

Effects of beta-adrenergic blockade on verapamil-responsive and verapamil-irresponsive sustained ventricular tachycardias.

“…This inferred that the presence of a low sympathetic threshold and/ or an arrhythmia-prone anatomic substrate was responsible for the occurrence of VT. Although 9 ofthe 14 patients had no clinically demonstrable heart disease, the possibility of their having subclinical cardiac diseases such as healed myocarditis and/or cardiomyopathy could not be excluded with certainty (65,66).…”