Clinical Report


Authors: Grünig E, Tasman JA, Kücherer H, Franz W, Kubler W, and Katus HA.
Journal: J Am Coll Cardiol, 1998;31:186-94.
University of Heidelberg, Medizinishce Klinik III, Germany.
PubMed Link: PMID:9426039
Citation Type: phenotype (clinical data only).
Study Design: evaluation of relatives of patients with idiopathic dilated cardiomyopathy
Study Measurements: echocardiography, ECG.
Summary: 481 consecutive patients with IDC were investigated between 1988 – 1994, where angiography had excluded coronary artery disease. A detailed family history was obtained in 445 of the 481 subjects (92.5%), and pedigrees were constructed. 156 families had evidence to suspect familial disease, and 739 first and second degree relatives were examined; of the remaining 289 families with no evidence from family history, 231 relatives were examined (a total of 970 family members, or an average of 2.2 per family).  Dilated cardiomyopathy was diagnosed in 48 families (65 subjects), or 10.8% of the 445 families.  The authors noted that of the 65 family members observed to have dilated cardiomyopathy during the study, 38 of the 65 were newly identified by prospective screening. An additional 108 of the 445 families (24.2%) had FDC eventually diagnosed based on sudden cardiac death (75 families), heart failure (23 families) or abnormal echo (10 families). In the remaining 289 families (65%) no evidence of familial disease was observed. FDC pedigrees were classified into 5 phenotypes with a 6th nonspecific phenotype, as follows. Phenotype A (2 families):  X-linked FDC with muscular dystrophy, elevated creatine kinase (CK), a muscle specific enzyme, thought to be associated with abnormal dystrophin; phenotype B (5 families), possibly X-linked with juvenile onset with rapidly progressive course in males, and a normal CK; Phenotype C (5 families): dilated cardiomyopathy with segmental hypokinesis consistent with regionally impaired LV function and a relatively stable clinical course, and autosomal dominant inheritance; Phenotype D (6 families): dilated cardiomyopathy with early conduction system disease, particularly AV block and atrial fibrillation, and autosomal dominant inheritance; and Phenotype E (1 family) , dilated cardiomyopathy with sensorineural hearing loss and severely impaired RV and LV function, with maternal or autosomal dominant inheritance. A sixth phenotype, not classified (9 families), with autosomal dominant inheritance, occurred as dilated cardiomyopathy with a heterogeneous and highly variable clinical course.
Comment: This has been the largest number of families examined, and suggested that 35% of patients with IDC had FDC.