Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The accurate quantification of right ventricular (RV) mass has eluded conventional imaging modalities. Accordingly, cine magnetic resonance imaging was used for quantification of RV as well as left ventricular (LV) mass in 10 normal subjects and in 10 patients with dilated cardiomyopathy with an LV ejection fraction less than 0.40. Hearts were imaged with 10 mm thick short-axis slices from apex to base with a short echo delay time of 5 ms. Each slice was partitioned into 3 sections: RV free wall, ventricular septum and LV free wall, for calculation of end-diastolic and end-systolic mass and LV:RV free wall ratio. RV end-diastolic mass in normal subjects was 45 +/- 8 g, which was similar to the values determined in previously published postmortem studies, mean 46 g (range 23 to 68). The value determined in patients with dilated cardiomyopathy was higher (50 +/- 11 g), but this difference was not significant. LV:RV free wall ratio in cardiomyopathy (3.6 +/- 1.0) was greater than in normal subjects (2.4 +/- 0.3), because of the greater LV free wall mass in dilated cardiomyopathy, where LV free wall end-diastolic mass was 173 +/- 40 g vs 107.1 +/- 19.9 g in normal subjects (p less than 0.05). RV mass measurements had 6.4 +/- 3.6% interobserver and 7.3 +/- 6.1% intraobserver variability. There were no significant differences between end-diastolic and end-systolic mass measurements. Thus, cine magnetic resonance imaging can reproducibly calculate RV mass. The values in normal subjects correspond to previously reported postmortem values for a population without heart disease.
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PMID:Measurement of right ventricular mass in normal and dilated cardiomyopathic ventricles using cine magnetic resonance imaging. 157 94

A tool was developed to assess attitudes of patients with cardiac disease toward performing prescribed behaviors of their medical regimen. Two groups of subjects with heart disease were used to examine validity and reliability of the Miller Attitude Scale. One group included 480 members of Mended Hearts, Inc., and the second group consisted of 35 patients diagnosed with a first myocardial infarction. The second group repeated the attitude scale six months post-hospitalization. Performance of the medical regimen by this group was verified at the six-month follow-up period. Using Spearman Rank Correlation, there was a significant relationship between attitudes and adherence behaviors for three of the five subscales. Alpha reliabilities revealed a high degree of internal consistency of scale items for all five subscales when testing both groups. A factor analysis resulted in eight factors accounting for the majority of the variance. Each of the five behaviors of the medical regimen clearly defined a factor supporting used of the Miller Attitude Scale for assessing attitudes of heart patients toward behaviors of their medical regimen.
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PMID:Development of a health attitude scale. 691 17

Many infants who require cardiac surgery have cyanotic heart disease. We assessed the relative tolerances to ischemia of hearts from immature normoxemic rabbits versus hearts from immature rabbits subjected to hypoxemia since birth. Normoxemic animals were raised from birth in an environment where the inspired fractional concentration of oxygen (FIO2) was 0.21; for the hypoxemic studies FIO2 was reduced to 0.09. Hearts (n = 6/group) from normoxemic and chronically hypoxemic rabbits at 7-12, 21-28, 35-44, and 51-56 days of age underwent aerobic "working" perfusion with Krebs bicarbonate buffer, and cardiac function was measured. Hearts were then arrested by a 3-min infusion with either cold (14 degrees C) Krebs buffer (hypothermia alone group) or St. Thomas' Hospital II solution (hypothermia plus cardioplegia group) before 6 h of hypothermic (14 degrees C) global ischemia. Hearts were reperfused, and postischemic creatine kinase leakage and recovery of function were measured. For hearts protected with hypothermia alone, recovery of aortic flow was better in hearts hypoxemic from birth compared with normoxemic controls at 7-12 days (78 +/- 7 vs. 60 +/- 6%, P < 0.05) and 21-28 days old (81 +/- 12 vs. 26 +/- 28%, P < 0.05). Protection with hypothermia plus cardioplegia was also better in hearts hypoxemic from birth compared with normoxemic controls at 7-12 days (74 +/- 8 vs. 63 +/- 10%, P < 0.05) and 21-28 days old (84 +/- 3 vs. 71 +/- 5%, P < 0.05). Protection with hypothermia alone and hypothermia plus cardioplegia was no different within chronically hypoxemic age groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tolerance of the developing heart to ischemia: impact of hypoxemia from birth. 790 Aug 70

Because many infants who require cardiac operation have cyanotic heart disease, we determined whether the existing calcium content of St. Thomas' II solution (1.2 mmol/L) is optimal to protect the immature rabbit heart hypoxemic from birth during subsequent ischemia. Modified hypothermic St. Thomas' II solutions (calcium content, 0 to 2.4 mmol/L) were compared with hypothermic Krebs bicarbonate buffer in protecting chronically hypoxemic (PaO2 = 34 +/- 11 mmHg, SaO2 = 63% +/- 3%) versus normoxemic (PaO2 = 76 +/- 11 mmHg, SaO2 = 92% +/- 3%) immature hearts (7 to 12 days old) during ischemia. Hearts (n = 6 per group) underwent aerobic 'working' perfusion with Krebs bicarbonate buffer and cardiac function was measured. The hearts were then arrested with a 3 minute infusion of either cold (14 degrees C) Krebs buffer (1.8 mmol calcium/L) as hypothermia alone or modified St. Thomas' II solution before 6 hours of hypothermic (14 degrees C) global ischemia. Hearts were reperfused and postischemic enzyme leakage and recovery of function were measured. A bell-shaped dose-response profile was observed for recovery of postischemic aortic flow but not for postischemic creatine kinase leakage, with improved protection occurring at lower calcium concentrations. Optimal myocardial protection occurred at a calcium content of 0.4 mmol/L, which was significantly better than with hypothermia alone or standard St. Thomas' II solution. We conclude that the existing calcium concentration of St. Thomas' II solution is responsible, in part, for its inadequate protection of immature myocardium hypoxemic from birth during ischemia.
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PMID:Calcium and cardioplegic protection of the ischemic immature heart: impact of hypoxemia from birth. 794 63

Apoptosis is a potentially important myocardial response to pathology including ischemia and reperfusion. Na-H exchange (NHE) represents an important mechanism for mediating such injury. The present study was done to determine if NHE inhibition can affect early apoptosis in an acute model of ischemia and reperfusion. Isolated rat hearts were subjected to zero-flow ischemia for various durations with or without subsequent 30 min of reperfusion. Nick-end-labelling of biotin-dUTP (TUNEL staining), as well as DNA extraction followed by agarose gel electrophoresis, were used to semiquantify apoptotic cells and identify DNA laddering, respectively. Apoptosis first appeared after 10 min of ischemia and reached a maximum level after 30 min. The number of apoptotic cells after 30 min of ischemia was 31 +/- 3 per 100 high power microscopic fields, whereas in reperfused hearts the number of cells was 34 +/- 3. To determine the effect of NHE inhibition, hearts were pretreated 15 min prior to ischemia with HOE 642, a potent and specific inhibitor of the isoform (NHE-1) found in myocardium. HOE 642 significantly reduced the number of apoptotic cells in the ischemic and reperfused heart to 2 +/- 1 and 6 +/- 1, respectively (P<0.05 from untreated hearts). DNA laddering was not observed with electrophoretic DNA analysis, likely owing to the small number of apoptotic cells involved. Hearts recovered nearly 100% of function in both groups, although there was a significantly higher recovery after 1 and 2 min of reperfusion in those hearts treated with HOE 642. Our study shows that apoptosis, albeit very mild in nature, can be rapidly induced in isolated hearts by a relatively brief period of ischemia without reperfusion, which can be markedly attenuated by the NHE inhibitor HOE 642. The ability of HOE 642 to markedly attenuate apoptosis may be important in terms of understanding the drug's cardioprotective properties as well as the overall role of NHE in heart disease.
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PMID:A rapid ischemia-induced apoptosis in isolated rat hearts and its attenuation by the sodium-hydrogen exchange inhibitor HOE 642 (cariporide). 940 90

Myosin is a chemomechanical motor that converts chemical energy into the mechanical work of muscle contraction. More than 40 missense mutations in the cardiac myosin heavy chain (MHC) gene and several mutations in the two myosin light chains cause a dominantly inherited heart disease called familial hypertrophic cardiomyopathy. Very little is known about the biochemical defects in these alleles and how the mutations lead to disease. Because removal of the light chain binding domain in the lever arm of MHC should alter myosin's force transmission but not its catalytic function, we tested the hypothesis that such a mutant MHC would act as a dominant mutation in cardiac muscle. Hearts from transgenic mice expressing this mutant myosin are asymmetrically hypertrophied, with increases in mass primarily restricted to the cardiac anterior wall. Histological examination demonstrates marked cellular hypertrophy, myocyte disorganization, small vessel coronary disease, and severe valvular pathology that included thickening and plaque formation. Skinned myocytes and multicellular preparations from transgenic hearts exhibited decreased Ca2+ sensitivity of tension and decreased relaxation rates after flash photolysis of diazo 2. These experiments demonstrate that alterations in myosin force transmission are sufficient to trigger the development of hypertrophic cardiomyopathy.
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PMID:Cardiac myosin heavy chains lacking the light chain binding domain cause hypertrophic cardiomyopathy in mice. 1036 99

Left ventricular assist devices (LVAD) may improve cardiac function. The pathogenesis of this phenomenon, called 'reverse remodelling', is not completely elucidated. To examine the hypothesis that LVAD support eliminates tissue stress by reducing local hypoxia, the distribution of heme oxygenase-1 (HO-1), a stress protein inducible by hypoxia, was examined in vivo and in vitro. The immunoreactivity for HO-1 was semi-quantitatively analysed in left ventricular tissue of 23 patients (14 dilated cardiomyopathy (DCM), six ischaemic heart disease (IHD), three myocarditis/congenital heart disease) with end-stage heart failure before and after LVAD support, while two unused donor hearts served as controls. Control hearts stained almost negative for HO-1, while failing hearts showed immunoreactivity mainly in cardiomyocytes, but also in endothelial cells, some smooth muscle cells and fibroblasts. Hearts with IHD showed significantly higher HO-1 immunoreactivity than hearts with DCM or myocarditis/congenital heart disease. After LVAD support, the HO-1 content decreased significantly in the DCM and IHD group and was significantly higher in the subendocardium than in the subepicardium. In vitro, under hypoxic conditions, neonatal rat cardiomyocytes showed an increase of HO-1 protein content up to sixfold above the normal level, which returned to normal values after normoxic cultivation. Mechanical support reduces the HO-1 content of the failing heart and HO-1 is inducible in vitro under hypoxia and is reversible under normoxia. This supports the concept that restoration of cardiac normoxia by mechanical unloading, particularly in the subendocardium, may be in part responsible for the phenomenon of 'reverse remodelling'.
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PMID:Reduction of hypoxia-inducible heme oxygenase-1 in the myocardium after left ventricular mechanical support. 1201 48

Chagas' disease is caused by Trypanosoma cruzi, which is transmitted by reduviid bugs. The World Health Organization has estimated that about 16-18 million people in the Americas are infected, and that more than 100 million are at risk. In the present study we have used a murine model to analyse if particular T. cruzi strains (Tulahuen strain and SGO-Z12 isolate from a chronic patient) and/or re-infection may determine, during the indeterminate phase of experimental Chagas' disease, changes that could explain the different evolution of cardiac lesions. Re-infected mice reached higher parasitaemias than those infected for the first time. The survival in the indeterminate phase of mice infected with Tulahuen strain was 50.0%, while the SGO-Z12-infected group presented a significantly higher survival rate (77.1%; P <0.01). The SGO-Z12-re-infected group showed a survival rate (70.9%) significantly higher than that of the Tulahuen-re-infected group (37.0%; P <0.01). Electrocardiographic abnormalities were found in 66% of Tulahuen-infected mice, while in SGO-Z12-infected group such abnormalities were found in only 36% of animals ( P <0.01). The two groups exhibited similar percentages of electrocardiographic dysfunction on re-infection, although intraventricular blocks were more frequent in Tulahuen-re-infected mice ( P <0.01). Hearts from infected or re-infected mice with either parasite showed mononuclear infiltrates. The SGO-Z12-re-infected and Tulahuen-re-infected groups exhibited a significantly diminished affinity ( P <0.05) and a significantly increased density ( P <0.05) of cardiac beta-adrenergic receptors compared with the infected and non-infected groups. The indeterminate phase of Chagas' disease is defined as a prolonged period that is clinically silent, but the present findings show that different T. cruzi strains and re-infection are able to alter the host-parasite equilibrium, and these factors may be responsible for inducing progressive cardiopathy.
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PMID:Indeterminate Chagas' disease: Trypanosoma cruzi strain and re-infection are factors involved in the progression of cardiopathy. 1265 87

Sorcin is a Ca2+ binding protein implicated in the regulation of intracellular Ca2+ cycling and cardiac excitation-contraction coupling. Structural and human genetic studies suggest that a naturally occurring sequence variant encoding L112-sorcin disrupts an E-F hand Ca2+ binding domain and may be responsible for a heritable form of hypertension and hypertrophic heart disease. We generated transgenic mice overexpressing L112-sorcin in the heart and characterized the effects on Ca2+ regulation and cardiac function both in vivo and in dissociated cardiomyocytes. Hearts of sorcin(F112L) transgenic mice were mildly dilated but ventricular function was preserved and systemic blood pressure was normal. Sorcin(F112L) myocytes were smaller than control cells and displayed complex alterations in Ca2+ regulation and contractility, including a slowed inactivation of L-type Ca2+ current, enhanced Ca2+ spark width, duration, and frequency, and increased Na+-Ca2+ exchange activity. In contrast, mice with cardiac-specific overexpression of wild-type sorcin displayed directionally opposite effects on L-type Ca2+ channel function and Ca2+ spark behavior. These data further define the role of sorcin in cardiac excitation-contraction coupling and highlight its negative regulation of SR calcium release. Our results also suggest that additional factors may be responsible for the development of cardiac hypertrophy and hypertension in humans expressing the L112-sorcin sequence variant.
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PMID:Expression of a sorcin missense mutation in the heart modulates excitation-contraction coupling. 1713 Mar 2

Treatment of Chagas disease is a controversial issue because the available drugs are highly toxic. Clomipramine is a tricyclic antidepressant drug that inhibits Trypanosoma cruzi's trypanothione reductase, provoking the death of the parasite and preventing the cardiac damage when used for the treatment of acutely infected mice. Here, we studied the effectiveness of clomipramine (5 mg/kg/day for one month) as chemotherapy for T. cruzi-infected mice in the chronic indeterminate stage of the infection. The animals were analyzed in the cardiac chronic phase. Survival of treated animals was 84% while for the untreated ones was 40%; most of the animals presented electrocardiographic abnormalities. Affinity and density of cardiac beta receptors from infected and treated mice were similar to those in the indeterminate phase, showing that clomipramine treatment stopped the increment of functional alterations provoked by the infection, while untreated mice presented affinity and density significantly diminished. Hearts from infected and untreated mice in the chronic stage presented mononuclear cells, necrosis and fiber dissolution while hearts from treated animals showed only isolated inflammatory infiltrates. Present results demonstrate that clomipramine used in the chronic indeterminate phase of the T. cruzi infection modified the natural evolution of the chagasic cardiopathy.
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PMID:Chemotherapy of chronic indeterminate Chagas disease: a novel approach to treatment. 1851 75


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