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)

Left ventricular (LV) diastolic filling and left atrial (LA) contribution have been investigated in patients with heart disease. However, many of these studies were not conducted at a constant heart rate, and the effects of heart rate remain unclear. The purpose of this study was to clarify the effects of the heart rate on left atrial contractile performance and left ventricular filling during atrial systole. The changes in LA and LV dimensions and pulmonary venous (PV) flow were determined in 9 open-chest dogs by a sonomicrometer and an electromagnetic flowmeter. With a stepwise decrease in the pacing rate from 110 beats/minute to 70 beats/minute, the LA dimension just before atrial contraction increased from 21.4 +/- 0.6 mm to 23.1 +/- 0.7 mm (p < 0.01), and the LA systolic shortening increased from 1.6 +/- 0.1 mm to 2.1 +/- 0.1 mm (p < 0.01). However, the calculated LV filling volume during atrial systole decreased from 1.9 +/- 0.3 ml to 1.4 +/- 0.2 ml (p < 0.01). The PV flow during atrial systole was directed toward the LA, and the LA influx volume from PV decreased from 0.6 +/- 0.1 ml to 0.2 +/- 0.04 ml (p < 0.01). With a decrease in the pacing rate, the LA Frank-Starling mechanism operated. However, LV filling during atrial systole decreased because of the decrease in PV flow to the LV via the LA. Thus, LA contractile performance cannot always be evaluated from LV filling.
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PMID:Effects of heart rate on left atrial contractile performance and left ventricular filling during atrial systole in dogs. 765 Aug 43

A 57-year-old female with valvular heart disease and chronic idiopathic thrombocytopenic purpura (ITP) underwent successful open-heart surgery. Preoperative administration of steroids and high-dose gamma-globulin increased the platelet count from 3 x 10(4)/microgram at admission to 10 x 10(4)/microgram before the operation. Splenectomy followed by mitral valve replacement (SJM 27M) were performed simultaneously. No platelet transfusion needed during and after the operation owing to rapid increase in platelets that would occur following splenectomy. The postoperative course was uneventful. The present simultaneous splenectomy and open-heart operation appears to be a safe and effective procedure for minimizing perioperative blood loss in patients with ITP and heart disease.
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PMID:[Simultaneous mitral valve replacement and splenectomy in a patient with chronic idiopathic thrombocytopenic purpura]. 891 Oct 62

Dynamic Behavior of the Dispersion of Ventricular Repolarization. The aim of this study was to evaluate the circadian variation in the spatial dispersion of ventricular repolarization in continuously paced patients with congestive heart failure (CHF). Fourteen patients (10 males, 4 females, aged 65 +/- 8 years) with CHF due to dilated cardiomyopathy (DCM) and an echocardiographic ejection fraction of 28% +/- 3% were studied. All patients underwent AV junctional RF ablation and permanent pacemaker implantation for drug refractory chronic atrial fibrillation (AF). Patients were evaluated at 1 month postimplant with a three-channel 24-hour Holter monitor, using the three plane Frank orthogonal leads (X, Y, and Z), in VVI pacing mode at 70 beats/min. For each hour, the mean value of spike-T interval dispersion of the first five beats was measured. The control group consisted of 20 patients without structural heart disease, but with AF and complete AV block, continuously paced in VVI mode at 70 beats/min. The dispersion of the spike-T interval had a circadian behavior in the study population, with higher values at night and lower during the daytime. During the daytime, the mean value of spike-T interval dispersion was 39 +/- 5 ms and during the nighttime it was 45 +/- 7 ms (P = 0.003). Such a difference between day and night was not found in the control group (38 +/- 6 ms and 40 +/- 8 ms, respectively, P = NS). In the daytime period the mean value of spike-T interval dispersion of our study population was comparable to that of the control group (P = NS), while during the nighttime it was significantly higher (P = 0.0004). In conclusion, by evaluating the dispersion of ventricular repolarization in two dimensions, space and time, a circadian variation was found in paced patients with CHF due to DCM. The increased QT dispersion in these patients during the nighttime period was attributed to different effects of vagal activity in normal and abnormal myocardial areas.
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PMID:Congestive heart failure and VVI pacing mode: dynamic behavior of the dispersion of ventricular repolarization. 894 63

Changes in transmitral flow (TMF) and pulmonary venous flow (PVF) velocities during increases in preload were compared in patients with a higher peak atrial systolic velocity than peak early diastolic velocity (A/E > 1) for the TMF velocity to determine differences in hemodynamic response. Fifteen patients with dilated hearts, 22 with hypertrophied hearts and 15 control patients were studied. TMF and PVF velocities were recorded by transesophageal pulsed Doppler echocardiography before and during application of lower body positive pressure. The value for peak early diastolic velocity increased, while the isovolumic relaxation time decreased with increases in preload in all groups. The value for peak atrial systolic velocity decreased in the dilated-heart group, but increased in the hypertrophied-heart and control groups. The peak second systolic and early diastolic PVF velocities increased in the dilated- and hypertrophied-heart groups, but did not change in the control group. The peak atrial systolic PVF velocity and the difference in duration of the atrial systolic PVF and TMF velocities increased in the dilated- and hypertrophied-heart groups, and its changing rate was highest in the group with dilated hearts. These results suggest that both peak early diastolic and atrial systolic TMF velocities increase during increases in preload through the Frank-Starling mechanism in hypertrophied hearts. Furthermore, the left ventricular functional reserve was lower in the dilated-heart group. Thus, TMF and PVF velocities respond differently during increases in preload, depending on the underlying heart disease.
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PMID:Differences in transmitral flow velocity pattern during increase in preload in patients with abnormal left ventricular relaxation. 952 18

Signal averaging techniques are used for detection of low amplitude, high frequency signals in the surface ECG. P-wave signal-averaging has been used to predict the risk for development of atrial tachyarrhythmias in patients with structural heart disease. There is, however, a lack of prospective studies evaluating normal values of the P-wave signal-averaged ECG in healthy individuals. Moreover, day-to-day reproducibility of results of P-wave signal-averaging is not precisely known. Thus, the aim of this study was to determine normal values and reproducibility of time-domain P-wave signal-averaging in a large cohort of healthy volunteers. A commercially available device (MAC 5000, Marquette Hellige) was used for signal-averaging. A vector magnitude was calculated from Frank's orthogonal leads after P-waves were sampled and filtered with a spectral filter using fast fourier transform. We examined 123 volunteers without cardiovascular disease at two occasions. Mean P-wave duration was 114 +/- 13 ms for the overall study population. There was a slight but statistically significant increase in filtered P-wave duration with age (r = 0.32, p < 0.001). All values were reliably reproducible upon the second examination (r = 0.624 to 0.706, p < 0.0001). These results may serve as a future reference to other studies examining patients with structural heart disease.
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PMID:[P-wave signal averaging-ECG: normal values and reproducibility]. 1131 75

The demonstration of congenital heart disease at autopsy necessitates the careful preservation and examination of the heart, the vessels, and their connections. Techniques preserving these connections and using a reproducible and systematic approach are preferred. The Rokitansky method of organ block dissection, in combination with a system of heart examination termed sequential segmental analysis, provides such an approach. This study is based on the examination of heart specimens accessioned into the Frank E. Sherman, M.D., and Cora C. Lenox, M.D., Heart Museum (containing approximately 2400 specimens) of the Pathology Department, Children's Hospital of Pittsburgh. Specimens received in consultation during a 25-year period from hospitals and coroners'/medical examiners' offices were examined, and the corresponding reports were reviewed. Of 46 total heart specimens examined (1975-1999), 29 (63%) were dissected properly or left intact for dissection at Children's Hospital of Pittsburgh, and 17 (37%) were incorrectly dissected for the demonstration of congenital heart disease. Of these 17 cases, 11 (24%) displayed dissection errors, which did not hinder a complete diagnosis, 3 cases (6.5%) had errors that enabled only an incomplete diagnosis, and in 3 cases (6.5%), no diagnosis of congenital heart disease could be made. Dissection mistakes and means of avoiding them are discussed. Review of medical and family history, external and internal examination, and a reproducible and sequential method of examining the heart and its connections enables documentation of even the most complex cardiovascular anomalies.
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PMID:An approach to dissecting the congenitally malformed heart in the forensic autopsy: the value of sequential segmental analysis. 1176 11

Titin is the third myofilament of the cardiac muscle sarcomere, with a single molecule spanning the half sarcomere. Titin contains a molecular spring segment that generates passive force in sarcomeres stretched above the slack length and restoring forces in sarcomeres shortened below this length. The roles of titin in heart disease remain to be established. In this work we review recent developments in the understanding of titin's role in cardiac muscle. We focus on both short-term and long-term modulation of titin-based muscle stiffness, as well as on the recently discovered interplay between titin and actomysoin interaction, suggesting a possible role for titin in the Frank-Starling mechanism of the heart. Finally, we present evidence that suggests that titin plays a role in elevating passive stiffness of myocardium of dilated cardiomyopathy (DCM) hearts, via alterations in titin isoform expression.
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PMID:Titin: an endosarcomeric protein that modulates myocardial stiffness in DCM. 1255 33

Splenectomy is the only treatment of ITP known to have "curative" effects in a substantial fraction of patients. However, the true long-term outcome is uncertain and controversial because published series have not adjusted for the duration of follow-up. This IRB-approved retrospective study included all patients with ITP who underwent splenectomy between 1988-1993 at three major medical centers and required a minimum postoperative 5-year follow-up. Complete response (CR) was defined as all postsplenectomy platelet counts >150 x 10(9)/L without treatment; partial response (PR) as platelet counts > or =50 x 10(9)/L without treatment; and failure as platelet counts <50 x 10(9)/L or receiving therapy after splenectomy. Seventy-five patients identified with ITP underwent splenectomy from 1988 to 1993. Three patients died prior to 5-year follow-up, and 56 of the 72 patients (78%) were evaluable with follow-up for five years or longer, median 7.5 years. The immediate postoperative complete remission rate was 77%; 57% of patients have remained in prolonged CR. Thirty-seven patients (66%) have not required any therapy after splenectomy. Eight patients had platelet counts >150 x 10(9)/L for 4-8.5 years before relapsing; no clear plateau was attained in the remission curve. There was no operative mortality. Ten patients (18%) reported minor postoperative bleeding episodes. No life-threatening infections, significant heart disease, or pulmonary hypertension developed after splenectomy in the 434 patient-years of follow-up. This study helps to define the long-term results of splenectomy for ITP.
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PMID:Long term follow-up after splenectomy performed for immune thrombocytopenic purpura (ITP). 1475 83

The development of microconductance technology to study cardiac pressure-volume relations in mice in vivo has significantly advanced the haemodynamic assessment of gene-modified models of cardiovascular disease. In this study, we describe the application of microconductance analysis of cardiac function to the isolated murine ejecting heart. This ex vivo model is complementary to the previously described in vivo preparation, allows assessment without confounding effects of anaesthetic or neurohumoral influences and enables careful control of cardiac loading (particularly preload). Ex vivo pressure-volume relations in the isolated murine heart are sensitive to changes in myocardial contractility induced by beta-adrenoceptor stimulation or beta-adrenoceptor blockade, as well as the effects of chronic pressure overload induced by aortic banding. We present data for both steady-state analyses of the Frank-Starling relation and for assessment of the left ventricular pressure-volume relation over variably loaded beats, which allows investigation of the end-systolic and end-diastolic pressure-volume relations. The measurement of ventricular volume in addition to pressure under carefully controlled loading conditions in the isolated ejecting heart allows a comprehensive analysis of cardiac contractile function, and provides a useful complementary model for the assessment of cardiac performance in murine models of heart disease.
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PMID:Analysis of ex vivo left ventricular pressure-volume relations in the isolated murine ejecting heart. 1518 54

For many years, both the medical community and the general public have incorrectly associated eggs with high serum cholesterol and being deleterious to health, even though cholesterol is an essential component of cells and organisms. It is now acknowledged that the original studies purporting to show a linear relation between cholesterol intake and coronary heart disease (CHD) may have contained fundamental study design flaws, including conflated cholesterol and saturated fat consumption rates and inaccurately assessed actual dietary intake of fats by study subjects. Newer and more accurate trials, such as that conducted by Frank B. Hu of the Harvard School of Public Health (1999), have shown that consumption of up to seven eggs per week is harmonious with a healthful diet, except in male patients with diabetes for whom an association in higher egg intake and CHD was shown. The degree to which serum cholesterol is increased by dietary cholesterol depends upon whether the individual's cholesterol synthesis is stimulated or down-regulated by such increased intake, and the extent to which each of these phenomena occurs varies from person to person. Several recent studies have shed additional light on the specific interplay between dietary cholesterol and cardiovascular health risk. It is evident that the dynamics of cholesterol homeostasis, and of development of CHD, are extremely complex and multifactorial. In summary, the earlier purported adverse relationship between dietary cholesterol and heart disease risk was likely largely over-exaggerated.
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PMID:Dietary cholesterol and the risk of cardiovascular disease in patients: a review of the Harvard Egg Study and other data. 1975 43


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