Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0264733 (ventricular dilatation)
 2,163 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dynamics of acute mitral regurgitation were studied in six open-chest dogs in whom a portion of the anterior leaflet was excised. Phasic mitral and aortic flows were measured electromagnetically and left ventricular filling volume, regurgitant volume (RV) and forward stroke volume (SV) were calculated. The systolic pressure gradient (SPG) between the left ventricle (LV) and left atrium (LA) was obtained from high-fidelity pressure transducers. The effective mitral regurgitant orifice area (MRA) was calculated from the hydraulic equation of Gorlin. Volume infusion resulted in significant increases in both left atrial and left ventricular pressures; thus, the SPG was unchanged and the increase in RV was due primarily to the increase in MRA. Angiotensin infused to raise arterial pressure resulted in greater increments in left ventricular than left atrial pressure, so that SPG rose significantly. The increase in RV was due to increases in both MRA and SPG. Norepinephrine infusion increased systolic left ventricular pressure and SPG, while left ventricular end-diastolic pressure and left atrial pressure diminished. Despite a significant increase in SPG, RV did not increase, due to a substantial decrease in MRA. Thus, angiotensin and volume infusion induced a substantial increase in regurgitation due to the increase in MRA, while augmentation of contractility after norepinephrine infusion resulted in a decrease in regurgitation through reduction of MRA. These findings support the clinical view that maintaining a small LV with sustained myocardial contractility will reduce mitral regurgitation. Alternatively, left ventricular dilatation can enhance mitral regurgitation by increasing the effective regurgitant orifice independent of SPG.
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PMID:Dynamic aspects of acute mitral regurgitation: effects of ventricular volume, pressure and contractility on the effective regurgitant orifice area. 44 20

The mechanism of heart failure in patients with enterovirus 71 rhombencephalitis (brain stem encephalitis) remains unknown. Our previous reports hypothesized that a catecholamine storm induced by rhombencephalitis may account for the heart failure. The aim of this study was to develop a novel feline model of norepinephrine cardiotoxicity and compare the resulting heart failure to that in children with enterovirus 71 rhombencephalitis. Nine of 75 children (12%) with enterovirus 71 rhombencephalitis (5 boys and 4 girls; age, 4-28 months; median age, 16 months) were complicated with left ventricular hypokinesia (ejection fraction, 31 +/- 9%). Six cats (weight, 3.03 +/- 0.64 kg) were administered intravenous norepinephrine 30 microg/kg/min for 3 hours. Echocardiography assessed the left ventricular diameter and function before and after the administration of norepinephrine. Pathology studies included hematoxylin and eosin stain and in situ terminal deoxyribonucleotidyl transferase-mediated dUTP nick end-labeling assay. In the feline model, norepinephrine induced significant left ventricular dilatation (end diastolic diameter from 1.18 +/- 0.19 to 1.62 +/- 0.22 cm, p = 0.001; endsystolic diameter from 0.54 +/- 0.09 to 1.36 +/- 0.32 cm, p = < 0.001) and hypokinesia (ejection fraction from 87.5 +/- 4.1 to 35.2 +/- 16.3%, p = 0.001). Heart specimens from 4 patients and six cats showed similar pathology findings, including myocardial hemorrhage, cardiomyocyte apoptosis, and coagulative myocytolysis, which is characterized by sarcoplasmic coagulation, granulation, vacuolization, myofibrillar waving, and disruption. Both groups showed no significant inflammatory reaction. In conclusion, heart failure in patients with enterovirus 71 rhombencephalitis is similar to that in cats with norepinephrine cardiotoxicity. Norepinephrine cardiotoxicity may play a role in the pathogenesis of heart failure in enterovirus 71 rhombencephalitis.
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PMID:Comparison of heart failure in children with enterovirus 71 rhombencephalitis and cats with norepinephrine cardiotoxicity. 1693 70