Abstract
Cardiac interstitial fibrosis may contribute to ventricular dysfunction and the prognosis of patients with dilated cardiomyopathy. The objective of the present study was to determine if total myocardial collagen content and collagen type III/I (III/I ratio) mRNAs differ in hypertensive, alcoholic, and idiopathic dilated cardiomyopathy subjects. Echocardiography and exercise cardiopulmonary testing were performed in patients with idiopathic (N = 22), hypertensive (N = 12), and alcoholic (N = 11) dilated cardiomyopathy. Morphometric analysis of collagen was performed in fragments obtained by endomyocardial biopsy with picrosirius red staining. The collagen III/I ratio was determined by reverse transcription polymerase chain reaction. Samples of controls (N = 10) were obtained from autopsy. Echocardiographic variables and maximal oxygen uptake were not different among dilated cardiomyopathy groups. Collagen was higher in all dilated cardiomyopathy groups (idiopathic, hypertensive and alcoholic, 7.36 +/- 1.09%) versus controls (1.12 +/- 0.18%), P < 0.05. Collagen was lower in idiopathic dilated cardiomyopathy (4.97 +/- 0.83%) than hypertensive (8.50 +/- 1.11%) and alcoholic (10.77 +/- 2.09%) samples (P < 0.005 for both). The collagen III/I ratio in all samples from dilated cardiomyopathy patients was higher compared to that in controls (0.29 +/- 0.04, P < 0.05) but was the same in the samples from idiopathic (0.77 +/- 0.07), hypertensive (0.75 +/- 0.07), and alcoholic (0.81 +/- 0.16) dilated cardiomyopathy groups. Because of the different physical properties of the types of collagen, the higher III/I ratio may contribute to progressive ventricular dilation and dysfunction in dilated cardiomyopathy patients.
Highlights
Left ventricular systolic dysfunction represents the final common pathway of several heart injury disorders [1]
34.1 ± 0.88% and were assigned to the idiopathic dilated cardiomyopathy (N = 22), hypertensive (N = 12), or alcoholic heart disease (N = 11) group according to the criteria described in Methods
Collagen volume fraction As expected, myocardial collagen volume fraction was higher in samples from patients with dilated cardiomyopathy from all causes (7.36 ± 1.09%) versus controls (1.12 ± 0.18%, P < 0.05)
Summary
Left ventricular systolic dysfunction represents the final common pathway of several heart injury disorders [1]. Despite recent major therapeutic advances, chronic heart failure still has a poor prognosis. Mortality in patients with similar degrees of congestive heart failure and left ventricular dilatation due to alcoholic cardiomyopathy is significantly lower than that for patients with idiopathic cardiomyopathy [5]. The cause of this difference is unknown. In the normal adult heart, approximately 2-4% of the myocardium is collagen. Of the main collagen types, the major fibrillar collagens are types I and III, which are essential components of the cardiovascular extracellular
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
