[Significance of right ventricular dimensions in the differential diagnosis of primary and secondary dilated cardiomyopathy]. / Znacenje promjera desne klijetke u differencijalnoj dijagnostici primarnih i sekundarnih dilatacijskih kardiomioptija.

ABSTRACT

Numerous analyses are used in the differential diagnosis between primary and secondary dilated cardiomyopathy (PDC, SDC). The aim of this study was to assess the dimensions of heart cavities in patients with dilated cardiomyopathy (DC) by 1-D and 2-D echocardiography. Thirty-six consecutive patients who satisfied the PDC criteria, and 103 patients with criteria of SDC, were followed-up clinically, radiographically, electrocardiographically and by 1-D and 2-D echocardiography, in the period from December 1991 to April 1994, at the Department of Internal Medicine of the Clinical Hospital Split. The patients with PDC were significantly younger than those with SDC (44.4 +/- 10.4 64.4 +/- 8.4 year). There were significantly more males than females in both DC subgroups. NYHA classification, sinus rhythm and atrial fibrillation did not differ considerably in both DC subcategories. The etiologic factor was ischaemic DC in 85.4% (88/103), systemic arterial hypertension in 11.6% (12/103), and thyrotoxicosis in 2.9% (3/103) of patients with SDC. Alcoholic DC in one patient, peripartal DC in two female patients and viral myocarditis in six patients with PDC were suspected. In the total of 75% (27/36) patients with PDC, a clear etiological factor in case histories was not defined. Left ventricular ejection fraction, diameter and myocardial thickness, as well as left atrium diameter, did not differ significantly in patients with PDC, at variance with SDC patients. Right ventricular enddiastolic diameter (31.55 +/- 4.8 mm 26.62 +/- 8.6 mm, p < 0.05) and the ratio between enddiastolic diameters of the right and left ventricle were significantly larger in patients with PDC than in those with SDC (0.45 +/- 0.03 0.37 +/- 0.05, p < 0.05). We conclude that right ventricle is significantly wider in PDC than in SDC patients. Compared with other noninvasive methods, 1-D and 2-D echocardiography is probably the method of choice (particularly in our environment) in the differentiation of primary and secondary DC.