Systemic ventricular function in patients with transposition of the great arteries after atrial repair: a tissue Doppler and conductance catheter study

OBJECTIVES: The aim of this study was to assess the utility of tissue Doppler echocardiography in the setting of repaired transposition of the great arteries when the right ventricle (RV) functions as the systemic ventricle. BACKGROUND: Myocardial acceleration during isovolumic contraction, "isovolumic myocardial acceleration" (IVA), has been validated as a sensitive non-invasive method of assessing RV contractility. Although traditional indexes may be less valid for the abnormal RV, the relative insensitivity of IVA to an abnormal load makes it a potentially powerful clinical tool for the assessment of RV disease. METHODS: We examined 55 controls and 80 patients (mean age 22 years) with transposition, who had undergone atrial repair at age 8 (0.3 to 72) months. A subgroup of 12 underwent cardiac catheterization. The RV systolic function was derived by analysis of pressure-volume relationships and IVA both at rest and during dobutamine stress. In all 80, myocardial velocities were sampled in the RV free wall. RESULTS: During dobutamine (10 microg/kg/min for 10 min), the increase of IVA mirrored the increase in end-systolic elastance (r = 0.69, p < 0.02). In the group as a whole, IVA was reduced compared with the subpulmonary RV and the systemic left ventricle of controls. There was abnormal wall motion in 44 patients, which was associated with reduced IVA. Diastolic myocardial velocities were also abnormal but unrelated to the presence of wall motion abnormalities. CONCLUSIONS: The IVA can accurately assess changes in RV contractile function in patients with an RV as the systemic ventricle. Global long-axis RV function is reduced in patients with transposition, and this is associated with abnormal regional function.     

Arterial hypertension: A neglected risk for bleeding

• The impact of arterial hypertension, one of the most common comorbidities in CAD patients, on bleeding risk after PCI must not be underestimated.
• More rigorous control of blood pressure during PCI procedure, radial artery access and alternative anticoagulant strategy may be considered in these patients.
• Further investigation in a more contemporary setting of PCI procedure is warranted.

     

Identifying Lynch Syndrome: We Are All Responsible

Purpose  The Amsterdam criteria and Bethesda guidelines are used to identify patients with Lynch syndrome. A family history of Lynch syndrome-related cancers or histopathology suggestive of microsatellite instability should prompt responses by the pathologist and clinician. This study evaluated the impact of microsatellite instability pathology findings on Lynch syndrome evaluation by clinicians. Methods  Microsatellite unstable tumors were identified from a maintained tissue bank, and MLH1 methylation was determined. Clinical information and management recommendations by the pathologist and clinician were collected from the medical record. Results  Fifty-one patients with microsatellite unstable colorectal tumors were identified between 2003 and 2006. Thirteen (25 percent) patients were appropriately referred for additional testing, including eight with documented microsatellite instability histology and five based on history alone. Thirty-seven (73 percent) patients with microsatellite unstable tumors were not detected by pathologists or clinicians, and no additional workup for Lynch syndrome was performed. Two patients met Amsterdam criteria and represent potentially missed Lynch syndrome. Conclusions  Microsatellite instability-H histology was the driving force for the Lynch syndrome evaluation. Histopathology alone failed to identify all potential Lynch syndrome patients. Omission of an adequate familial risk assessment may lead to missed diagnosis of Lynch syndrome when suspicious histopathology fails to trigger appropriate testing. Supported by Crile Foundation Fellowship, Cleveland Clinic, Cleveland, Ohio. Presented at the meeting of the Collaborative Group of the Americas on Inherited Colorectal Cancer, La Jolla, California, October 21 to 22, 2007.     

Inherited disorders of gamma‐aminobutyric acid metabolism and advances in ALDH5A1 mutation identification

Inherited disorders of gamma‐aminobutyric acid (GABA) metabolism include succinic semialdehyde dehydrogenase (SSADH) and gamma‐aminobutyric acid transaminase (GABA‐T) deficiencies. The clinical features, pathophysiology, diagnosis, and management of both, and an updated list of mutations in the ALDH5A1 gene, which cause SSADH deficiency, are discussed. A database of 112 individuals (71 children and adolescents, and 41 adults) indicates that developmental delay and hypotonia are the most common symptoms arising from SSADH deficiency. Furthermore, epilepsy is present in two‐thirds of SSADH‐deficient individuals by adulthood. Research with murine genetic models and human participants, using [¹¹C] flumazenil positron emission tomography (FMZ‐PET) and transcranial magnetic stimulation, have led to therapeutic trials, and the identification of additional disruptions to GABA metabolism. Suggestions for new therapies have arisen from findings of GABAergic effects on autophagy, with enhanced activation of the mammalian target of rapamycin (mTOR) pathway. Details of known pathogenic mutations in the ALDH5A1 gene, three of which have not previously been reported, are summarized here. Investigations into disorders of GABA metabolism provide fundamental insights into the mechanisms underlying epilepsy, and support the importance of developing biomarkers and clinical trials. Comprehensive definition of phenotypes arising as a result of deficiencies in both SSADH and GABA‐T may increase our understanding of the neurophysiological consequences of a hyper‐GABAergic state.     

Elective supported angioplasty: initial report of the National Registry

A National Registry of 14 centers performing elective supported angioplasty was formed to collate the initial experience with high-risk patients. Suggested indications were ejection fraction less than 25% and/or target vessels supplying greater than half of the viable myocardium. The data from 105 patients were entered into the Registry during 1988. This group included 30 patients who had dilation of their only patent coronary vessel and 20 patients whose disease was deemed too severe to undergo bypass surgery. Chest pain and ECG changes were uncommonly experienced during balloon inflation. The group experienced a high angioplasty success rate (95%) with an average of 1.7 dilatations per patient. Morbidity was frequently experienced, the majority of which was associated with cannula (18-20F) placement and/or removal. The overall hospital mortality was 7.6%, although half of the deaths occurred in patients who were both over 75 years of age and had left main coronary artery stenosis. Patients under the age of 75 years without left main coronary artery stenosis experienced a hospital mortality rate of 2.6%. Symptomatic improvement occurred in 91% of the patients surviving hospitalization. During the follow-up period of 1-12 months, three patients died of cardiac complications. This multicenter experience suggests that supported angioplasty can be performed safely in high-risk patients in several high-risk subgroups with the expectation of good symptomatic improvement and short-term survival.