Correlation of cardiac troponin T gene mutations to hypertrophic cardiomyopathy in Chinese patients / 南方医科大学学报

<p><b>OBJECTIVE</b>To study cardiac troponin T (TNNT2) gene mutations in Chinese patients with hypertrophic cardiomyopathy (HCM) and analyze the correlation between the genotype and phenotype.</p><p><b>METHODS</b>Ninety-five unrelated Chinese patients with HCM and 120 control individuals were screened for TNNT2 gene mutations. Seven exons (8, 9, 10, 11, 14, 15, and 16) in the functional regions of TNNT2 gene were amplified using PCR and the products were sequenced. The patients with positive results underwent further family screening.</p><p><b>RESULTS AND CONCLUSION</b>This study did not find any HCM-caused mutations in TNNT2 gene, a result different from the reported rates of TNNT2 gene mutation ranging from 10% to 20% in other nations, suggesting that TNNT2 gene is not a susceptible gene for HCM in Chinese population.</p>

Link between cardiac myosin binding protein-C gene mutation of Pro1208fs and Gly507 Arg and hypertrophic cardiomyopathy in Chinese patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To detect gene mutations associated with hypertrophic cardiomyopathy (HCM) in Chinese patients and possible correlations between genotype and phenotype.</p><p><b>METHODS</b>Twenty-one unrelated patients with hypertrophic cardiomyopathy were studied. The clinical data including symptoms, physical examination, echocardiography and electrocardiography were collected. The full ecoding exons of cardiac myosin-binding protein C gene (cMYBPC3) were amplified with PCR and the products were sequenced.</p><p><b>RESULTS</b>Two mutations were identified in probands from two families. One mutation was frame shift mutation Pro1208fs in the exon 32 of the cMYBPC3 gene. Pro1208fs mutation was identified in a 59 years old female patient with familial hypertrophic cardiomyopathy. Symptom onset was late and a favorable clinical course was evidenced in this patient. Another mutation was missence mutation Gly507Arg in the exon 17 of the MYBPC3 gene identified in a 24 years old male patient. Diffuse thickness of left ventricular wall, impaired diastolic function and enlarged left atria were evidenced in echocardiography. No mutation was identified in the 80 control healthy individuals.</p><p><b>CONCLUSION</b>cMYBPC3 might be the disease-causing genes in Chinese patients with hypertrophic cardiomyopathy.</p>

The angiographic features of exercise-induced ST-segment elevation in patients without myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the incidence and angiographic features of exercise-induced ST-segment elevation in patients without prior myocardial infarction.</p><p><b>METHODS</b>Exercise-induced ST-segment elevation occurred in 15 out of 4601 consecutive patients without prior myocardial infarction underwent treadmill exercise testing during a 2-year period. The coronary angiographic features of the 15 patients (13 males, aged between 40 - 75 years) were analyzed.</p><p><b>RESULTS</b>Coronary angiography revealed one hemodynamically relevant stenotic vessel in 6 patients, two hemodynamically relevant stenotic vessels in 6 patients, three hemodynamically relevant stenotic vessels in 3 patients. Left anterior descending (LAD) coronary artery was affected in 12 patients. Left main coronary artery (LMCA) stenosis was evidenced in 1 patient and right coronary artery stenosis in 7 patients. Severe (90% - 100%) occlusions were visualized in 8 out of 13 patients with LAD or LMCA lesions. Elevated ST-segment leads were consistent with the ischemic area where the blood supply of myocardium was affected by diseased vessels.</p><p><b>CONCLUSIONS</b>The incidence of exercise induced ST-segment elevation in patients without prior myocardial infarction is very low and mostly due to severe fixed coronary artery stenosis, especially in LAD. The location of ischemic myocardium can be suggested by ST-segment elevation leads during exercise.</p>