Coronary Sinus Obstruction after Atrioventricular Canal Defect Repair

The coronary sinus can become obstructed with any instrumentation at or near the ostium such as in atrioventricular canal defect repairs. This complication may lead to a wide range of consequences including dyspnea, angina, myocardial infarction, and sudden death. The following report illustrates the importance of careful perioperative echocardiographic evaluation of the coronary sinus in procedures that may affect the sinus and its ostium.     

Health status and intimate partner violence: a cross-sectional study.

STUDY OBJECTIVE: We identify health variables associated with a history of intimate partner violence (IPV) using self-reported and laboratory measures. METHODS: This study used a cross-sectional design. Participants were a randomized sample of English-speaking women between the ages of 18 and 50 years who presented to a large urban emergency department. Potential participants were screened in the ED for a history of physical abuse and coded as having experienced no IPV (No IPV), as having a recent history of IPV (occurring in the previous 12 months; IPVA), or as having a remote history (most recent occurrence >12 months ago; IPVHx). Participants were interviewed several days later in an outpatient setting regarding demographics, medical care use, and physical and mental health variables. Participants also received urine and blood tests and a pelvic examination. RESULTS: Self-reported health was poorest among women reporting IPVA and best among women reporting no IPVA. Women in the IPVA group differed from women with no IPV history with respect to cocaine use (odds ratio [OR] 4.8; 95% confidence interval [CI] 1.4 to 17.3), sexually transmitted diseases (OR 5.1; 95% CI 1.5 to 20.3), and nightmare frequency (OR 11.6; 95% CI 2.3 to 83.4). Women reporting IPVHx were more likely to report a history of sexually transmitted diseases than women with no IPV history (OR 4.1; 95% CI 1.6 to 11.4) and had more frequent nightmares (OR 5.0; 95% CI 1.3 to 24.9). Urine and blood tests identified only 2 variables (hemoglobin levels, mean corpuscular volume) that differed significantly between groups by IPV history; these differences were not clinically significant. CONCLUSION: Women with a recent history of IPV reported a poorer health status than women with no IPV history; laboratory testing detected few differences.     

N-dimethylisopropyl propranolol. Effects on myocardial oxygen demands.

N-Dimethylisopropyl propranolol (DMP) is a quaternary derivative which lacks significant beta-adrenergic blocking and local anesthetic effects. It has been reported, nonetheless, to be effective in treating experimental arrhythmias and in limiting the extent of ST-segment elevations following experimental coronary occlusion. The present study examined the effects of DMP on the hemodynamics and myocardial oxygen demands of anesthetized dogs. After a single dose of 3 mg/kg, heart rate fell from 146 +/- 8 to 124 +/- 6 beats/min (P less than 0.0025), and aortic systolic pressure fell from 151 +/- 11 to 141 +/- 9 mm Hg (0.05 less than P less than 0.10), resulting in a 16.8% reduction in the tension-time index. Stroke volume was reduced by 10% despite a 54% increase in left ventricular end-diastolic pressure, suggesting a negative inotropic effect. This was supported by a decrease in maximum extrapolated contractile element velocity from 9.10 +/- 1.05 to 6.61 +/- 65 units/sec (P less than 0.0025). Myocardial oxygen consumption was reduced from 12.0 +/- 1.4 to 9.9 +/- 1.5 ml/min/100 g tissue (P less than 0.05). Myocardial oxygen extraction was unchanged, indicating that the decrease in oxygen consumption resulted from a reduction in myocardial oxygen demand. When heart rate and systolic pressure were artificially restored to control levels, after the administration of DMP, myocardial oxygen consumption remained significantly below the control level. DMP, therefore, appeared to reduce myocardial oxygen demands primarily by its negative inotropic effect. This drug may have application in the treatment of ischemic heart disease.     

MCIP1 overexpression suppresses left ventricular remodeling and sustains cardiac function after myocardial infarction

Pathological remodeling of the left ventricle (LV) after myocardial infarction (MI) is a major cause of heart failure. Although cardiac hypertrophy after increased loading conditions has been recognized as a clinical risk factor for human heart failure, it is unknown whether post-MI hypertrophic remodeling of the myocardium is beneficial for cardiac function over time, nor which regulatory pathways play a crucial role in this process. To address these questions, transgenic (TG) mice engineered to overexpress modulatory calcineurin-interacting protein-1 (MCIP1) in the myocardium were used to achieve cardiac-specific inhibition of calcineurin activation. MCIP1-TG mice and their wild-type (WT) littermates, were subjected to MI and analyzed 4 weeks later. At 4 weeks after MI, calcineurin was activated in the LV of WT mice, which was significantly reduced in MCIP1-TG mice. WT mice displayed a 78% increase in LV mass after MI, which was reduced by 38% in MCIP1-TG mice. Echocardiography indicated marked LV dilation and loss of systolic function in WT-MI mice, whereas TG-MI mice displayed a remarkable preservation of LV geometry and contractility, a pronounced reduction in myofiber hypertrophy, collagen deposition, and beta-MHC expression compared with WT-MI mice. Together, these results reveal a protective role for MCIP1 in the post-MI heart and suggest that calcineurin is a crucial regulator of postinfarction-induced pathological LV remodeling. The improvement in functional, structural, and molecular abnormalities in MCIP1-TG mice challenges the adaptive value of post-MI hypertrophy of the remote myocardium. The full text of this article is available online at http://circres.ahajournals.org.     

C-type natriuretic peptide of rainbow trout (Oncorhynchus mykiss): primary structure and vasorelaxant activities

Natriuretic peptides (NPs) play important roles in osmoregulatory and cardiovascular systems of vertebrates. For functional studies of NPs, rainbow trout (Oncorhynchus mykiss), a euryhaline fish, is an interesting model. The information on homologous NPs of salmonid fish is, however, still incomplete with respect to C-type NP (CNP). In this study, we isolated cDNAs encoding the precursor of CNP from the brain of trout. Predicted mature CNP (CNP-22) sequence was identical to that of killifish Fundulus heteroclitus, and only one amino acid was different from that of the eel Anguilla japonica, demonstrating a greater conservation among different teleost species than is found with atrial NP (ANP) and ventricular NP (VNP). While the preprosegment of trout CNP retained 57% similarity to the eel sequence, similarities were low to those of sharks and tetrapods. The major site of expression identified by RT-PCR was the brain with minor expression in the atrium. The putative mature CNP-22 was synthesized and its biological activity was compared with other trout NPs (ANP and VNP) using trout ventral aorta, efferent branchial and celiacomesenteric arteries and anterior cardinal vein in vitro. Synthetic trout CNP-22 relaxed all pre-contracted vessels with potencies comparable to trout ANP and VNP.     

Colonic biopsy practice for evaluation of diarrhea in patients with normal endoscopic findings: results from a national endoscopic database

BACKGROUND: The colonic biopsy is the only reliable method for identification of microscopic colitis in patients with chronic diarrhea and normal endoscopic findings. METHODS: The Clinical Outcomes Research Initiative national endoscopic database was analyzed to determine the rate at which colonic biopsy specimens were obtained in patients undergoing colonoscopy for the evaluation of diarrhea with no visible mucosal abnormality. RESULTS: Between January 2000 and December 2003, 5565 unique adult patients underwent colonoscopy for evaluation of diarrhea without detection of any mucosal abnormality. Colonic mucosal biopsy specimens were obtained in 4410 (79.2%) of these patients. The rates at which biopsy specimens were obtained differed among the sites where colonoscopy was performed; biopsy specimens were obtained from more patients undergoing colonoscopy in university-affiliated settings (86.8%) compared with Veterans Affairs Medical Centers (VAMC) (78.5%) or community sites (78.6%) ( p < 0.001). On multivariate analysis, biopsy specimens were more likely to be obtained in younger patients (OR 0.7: 95%CI[0.6, 0.8] for age >50 years vs. <50 years), women patients (OR 1.4: 95% CI[1.2, 1.6] in community setting; OR 4.1: 95% CI[1.6, 10.5] in VAMC setting), and patients seen in university-affiliated medical centers (university center OR 2.1: 95% CI[1.5, 3.0] vs. community setting). CONCLUSIONS: Biopsy specimens are obtained in four fifths of patients with diarrhea and normal colonoscopy findings to exclude microscopic colitis. Variation in biopsy practice exists among endoscopy site types and by gender. Clear guidelines are needed for the endoscopic approach to these patients.     

Pump dysfunction after myocardial infarction: Importance of location,extent and pattern of abnormal left ventricular segmental contraction

To delineate the relative effects on left ventricular function of the site, extent and nature of abnormal left ventricular segmental contraction (dyssynergy) and thereby determine the mechanism by which anterior myocardial infarction results in greater depression of left ventricular performance than does inferior infarction, 43 patients with remote myocardial infarction of similar extent (average 38 percent of left ventricular systolic perimeter) and associated hypokinesia or dyskinesia confined to either the anterior or inferior wall were compared; 10 additional patients were evaluated who exhibited generalized dyssynergy (72 percent of left ventricular perimeter). When the pattern of dyssynergy and extent of infarction were similar, the location alone of dyssynergy did not influence variables of left ventricular function. However, paradoxical outward systolic movement (dyskinesia) of the anterior or inferior wall resulted in greater depression (P < 0.05) of measures of left ventricular performance than did diminished inward systolic motion (hypokinesia) associated with infarction of similar extent and location. All measures of left ventricular performance were considerably more depressed (P < 0.05) in the 10 patients with generalized dyssynergy than in the 43 patients with localized dyssynergy. Thus, the location of infarction is not a unique determinant of left ventricular performance. Instead, the size of infarction is the principal characteristic of dyssynergy that impairs left ventricular function; the severity of the pattern of dyssynergy is significant but of lesser importance. It is therefore concluded that the greater reduction of left ventricular function in anterior than in inferior myocardial infarction is largely the result of the more extensive area of necrosis rather than of the location of the infarction.