Genotypic effect of a mutation of the MYBPC3 gene and two phenotypes with different patterns of inheritance.

BACKGROUND: MYBPC3 mutations have been described in dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). A mutation, c.3373G>A, has been reported to cause autosomal recessive form of HCM. Here, we report that this mutation can cause autosomal dominant form of DCM. METHODS: Next-generation sequencing using targeted panel of a total of 23 candidate genes and following Sanger sequencing was applied to detect causal mutations of DCM. Computational analyses were also performed using available software tools. In silico structural and functional analyses including protein modeling and prediction were done for the mutated MYBPC3 protein. RESULTS AND CONCLUSION: Targeted sequencing showed one variant c.3373G>A (p.Val1125Met) in the studied family following autosomal dominant inheritance. Computational programs predicted a high score of pathogenicity. Secondary structure of the region surrounding p.Val1125 was changed to a shortened beta-strand based on prediction of I-TASSER and Phyre2 servers with high confidence value for the mutation. cMyBP-C protein was modeled to 3dmkA. Our findings suggest that one single mutation of MYBPC3 may have different effects on the cellular mechanisms based of its zygosity. Various factors might be considered for explaining this phenomenon. This gene may have an important role in Iranian DCM and HCM patients.

Reverse Δ-wave as a possible sign in electrocardiography to diagnose mitral valve prolapse.

BACKGROUND: Mitral valve prolapse (MVP) is defined as superior displacement of the mitral valve leaflets more than 2 mm into the left atrium during systole. Easier and cheaper assessment of this common disease is a priority in cardiac health care facilities. PRESENTATION OF THE HYPOTHESIS: In this study I addressed electrocardiographic presentation in 300 patients with MVP compared with 100 healthy individuals. I faced a novel finding in electrocardiogram (ECG) examination of these patients. It was a notch (reverse Δ-wave) in descending arm of QRS observed in 79% (237/300) of patients, consisting of 58% (174/300) in inferior leads and 21% (63/300) in I and aVL leads. The notch was identified only in 6 men in control group. TESTING THE HYPOTHESIS: Considering the relatively higher prevalence of disease, a population-based diagnostic clinical trial study is appropriate to test the hypothesis. IMPLICATIONS OF THE HYPOTHESIS: The hypothesis on diagnostic value of reverse Δ-wave in MVP may help in decreasing the rate of unnessessary echocardiography in some patients.

Prevalence and intensity of hyperglycemia in non-diabetic patients undergoing coronary artery bypass graft surgery with and without cardiopulmonary bypass.

OBJECTIVE: To study the prevalence and severity of hyperglycemia in nondiabetic patients undergoing cardiac operation. METHODS: In an observational prospective study, 282 non-diabetic patients underwent elective off-pump (n=101) or on-pump (n=181) coronary artery bypass grafting (CABG) surgery from March 2006 to July 2007 in Madani Heart Hospital, Tabriz, Iran. Blood glucose (BG) levels were measured during and 24 hours after operation. Frequencies of hyperglycemia (BG>or=126 mg/dl) and severe hyperglycemia (BG>or=180 mg/dl) and postoperative complications were compared in the 2 study groups. RESULTS: Prevalence of at least one episode of severe hyperglycemia was 54.6% (154/282) in our patients during, and 24 hours after operation. Intra-operative hyperglycemia was slightly higher in on-pump group. Frequency of post-operative hyperglycemia was higher, although not significantly different between the 2 groups. The 2 study groups were not significantly different in frequency of severe hyperglycemia during operation, although were different within 24 hours postoperative period. CONCLUSION: Prevalence of hyperglycemia especially severe hyperglycemia was high during, and after operation in both off-pump and on-pump CABG in non-diabetic patients. There was a borderline difference in blood glucose level between on-pump and off-pump CABG patients. It may be prudent to consider glycemic control protocols in these patients especially in early post-operative period.

Measurement of coronary sinus blood flow after first anterior myocardial infarction with transthoracic echocardiography and its correlation with wall motion scoring index.

OBJECTIVE: To measure the coronary sinus blood flow (CSBF) and coronary sinus velocity time integral (CSVTI) via transthoracic echocardiography (TTE) in patients with acute myocardial infarction (AMI) in association with the left ventricular ejection fraction (LVEF), and wall motion scoring index (WMSI). METHODS: In this case-control study, 20 patients with anterior AMI and 20 healthy individuals as the control group, were studied in 6 months period from March to September 2005 in Madani Heart Center, Tabriz, Iran. All patients received the same treatment for AMI (such as fibrinolytic). The CSBF, CSVTI, WMSI, and tissue Doppler imaging (TDI) data were obtained via TTE and compared between the 2 groups. RESULTS: Baseline variables were similar between the 2 groups (p>0.05). The CSBF in AMI group was 287.8 +/- 128 ml/min and in the control group was 415 +/- 127 ml/min (p=0.001). Also, CSVTI was significantly lower in AMI group than control group (11.16 +/- 2.85 and 17.56 +/- 2.72 mm, p=0.003). There was a significant correlation between CSBF and LVEF (r=0.52, p=0.01), WMSI (r=-0.77, p=0.0001) and CSBF and in-hospital mortality (r=0.58 p=0.03), also between CSVTI and LVEF (r=0.85, p=0.0001), WMSI (r=-0.57, p=0.0009) and in-hospital mortality rate (r=0.69, p=0.02). The CSBF and CSVTI had a good correlation with TDI findings: peak early diastolic velocity in the myocardium and peak systolic velocity in the myocardium). CONCLUSION: Our study demonstrated a good correlation between measured CSBF and CSVTI by 2D- Doppler TTE and LVEF, WMSI, in-hospital mortality and TDI findings.