A total of 105 patients with idiopathic dilated cardiomyopathy (IDCM) underwent Holter monitoring. The prevalence of arrhythmias was as follows: ventricular premature beats (VPB) 100%, including complex VPB 58.1%, short runs of ventricular tachycardia (VT) 25.7%, A-VB or BBB 46.7%, atrial arrhythmias 38.1%, sinus node dysfunction 6.6%, ST-T change 38.1%. The incidence of ventricular arrhythmia (VA) was not related to severity of cardiac dysfunction (NYHA), duration of illness and sex. The most common arrhythmia was VA, the second one was heart block and atrial arrhythmia. Serum norepinephrine and epinephrine levels were 743.4 +/- 252.5 and 688.0 +/- 452.4 pg/ml, respectively, which were higher than those in control group (P < 0.01). Isoproterenol sensitivity test (ICD25) 8.43 +/- 11.21 micrograms, was also much higher than that in control group (P < 0.01). Average H-V interval was 69.4 +/- 13.3 msec in HBE. Eight patients died. Two died of congestive heart failure (class II-IV), and six cases were diagnosed as sudden cardiac death resulting from VT and VF.
HLA-DQB1,-DRB1 genes of 27 Chinese patients with dilated cardiomyopathy (DCM), 7 high risk individuals in a DCM kindred and 17 normal control subjects were analysed with the use of restriction fragment length polymorphisms (RFLP) with full length DQB1 and DRB1 cDNA probes according to the standard and nomenclature of the Xth International Histocompatibility Workshop. The resulting restriction patterns allowed genotyping of HLA-DR and HLA-DQw. D-DQw8 frequency increased significantly in patients with DCM as compared with that of the controls (P < 0.05). D-DQw4 also increased in patients although no statistical significance was shown when Chi-square value was corrected with Yate's correction, whereas D-DQw5 overrepresented in controls (P < 0.05). Over half of the high risk individuals (4/7) in the familial DCM kindred carry D-DQw8 and D-DQw4. These results support the hypothesis that HLA class II genes were associated with an increased risk for DCM, HLA-DQB rather than -DRB may confer genetic susceptibility to DCM.
The relation between the density of beta receptors on myocardial cells and lymphocytes and the pathologic change of myocardium in hypertensive-diabetic (HD) rats in various stages during development of dilated cardiomyopathy (DCM) was investigated and the alteration of lymphocytic beta receptors in 20 patients with DCM was also studied. The results showed that the density of beta receptors on lymphocytes in the patients with class I-II cardiac status appeared to be in up regulation. The same was found with the receptors on lymphocytes and myocardial cells in HD rats at early stage. Conversely, the receptors were in down regulation on lymphocytes in DCM patients with class III-IV cardiac status and the same with those on lymphocytes and myocardial cells in HD rats at late stage. The changes of the receptors on lymphocytes and myocardial cells in the rats and the patients were quite parallel. Up regulation of beta receptors happened earlier than the pathologic changes in the myocardium in HD rats. Thus, the changes of lymphocytic beta receptors did reflect the behaviour of the receptors on myocardial cells with these data, it is reasonable to use beta blocker at early stage in patients with DCM so as to slow down the disease process.
To evaluate the occlusion of arteries, 6 conic intravascular endoprosthetic stents of titanium-nickel alloy were implanted transluminally to the right external iliac arteries in 2 normal dogs and 4 normal pigs. The stent was characterized by ductility below 313 K (40 degrees C) and restoration memory-shape between 313-319 K. The diameter of the large end of conic stent was 4.0 mm (dog) and 4.5 mm(pig). The topographic anatomy showed that the external iliac artery was near complete occlusion, with a very small residual lumen (about 1 mm in diameter) in dogs at 6 months, with complete occlusion in pigs at 8 months. The histopathological examination indicated that the arterial intima of the upper branch from the stented site was smooth, and that neither inflammatory cell infiltration nor foreign giant cell reaction was found. The newly formed granulation tissue inside the stent came from emboli organization. These results suggest that the shape-memory alloy stent has good biocompatibility and the conic intravascular endoprosthetic stent might completely occlude arterial blood flow.
In order to study the left ventricular diastolic events in cardiomyopathy, carotid pulse tracing, electrocardiogram, phonocardiogram and apexcardiogram with its first derivatives (dA/dt) were simultaneously recorded in 240 normal subjects, 30 patients with dilated cardiomyopathy (DCM) and 44 patients with hypertrophic cardiomyopathy (HCM). Total relaxation time (TRT), total relaxation time index (TRTI), the ratio of A wave to total diastolic amplitude in apexcardiogram (A/D), diastolic amplitude time index (DATI), the ratio of RF wave in apexcardiogram to the total amplitude of apex tracing (F/H) and the variables reflecting the diastolic properties were measured to evaluate the left ventricular relaxation and compliance. Meanwhile, two variables reflecting the contractile ability of the left ventricle were measured in order to compare with the diastolic events. The results demonstrated that in normal subjects relaxation and compliance of the left ventricle showed a tendency of natural "decay" with aging and in patients with DCM and HCM these were significantly decreased, especially in patients with HCM. A/D, which reflects the left ventricular compliance, was increased in patients with HCM as compared with normal subjects (P less than 0.01) and also with patients with DCM. It means that a greater A/D is in favor of the diagnosis of HCM rather than DCM. In addition to abnormal diastolic events, systolic dysfunction, as evidenced by remarkable abnormalities of the contractile variables (PEP/LVET and R-dA/dt.I), was found as well in patients with DCM.
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