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Influence of left ventricular function on changes in plasma volume during acetate and bicarbonate dialysis.

The effect of left ventricular function on changes in plasma volume during acetate and bicarbonate dialysis was studied in stable, chronic dialysis patients. Preservation of plasma volume in patients with a normal left ventricular function (mean circumferential fibre shortening velocity (VcF) greater than or equal to 1 circ/s) was significantly less during the first hour of acetate dialysis than during bicarbonate dialysis. However, in patients with impaired left ventricular function (VcF less than 1 circ/s) the decrease in plasma volume was more pronounced during acetate when compared to bicarbonate dialysis. This resulted in a decreased ultrafiltration volume and haemodynamic instability in these patients during acetate dialysis. The fibre shortening velocity increased during acetate and bicarbonate dialysis in patients with a normal left ventricular function, whereas in patients with impaired left ventricular function fibre shortening velocity increased only during bicarbonate dialysis. In conclusion, in patients with an impaired left ventricular function, bicarbonate is preferable to acetate in chronic dialysis.

Acetates↗

Usefulness of the myocardial performance index for assessing right ventricular function in congenital heart disease.

Quantitative assessment of ventricular function in patients with congenital heart disease is often challenging due to distorted ventricular geometry. A myocardial performance index (MPI) has been reported in adults and children that is a Doppler-derived nongeometric measure of ventricular function. The MPI measures the ratio of isovolumic time intervals (isovolumic contraction time and isovolumic relaxation time) to ventricular ejection time. The effects of altered ventricular preload or afterload on the MPI have yet to be determined. This study assesses the impact of altered preload or afterload on right ventricular (RV) function and the RV MPI in the clinical setting of congenital heart disease. Patient groups were compared with normal pediatric and adult populations before and after repair of their congenital heart lesion. Patients with large atrial septal defects (ASDs) represented the clinical setting of increased ventricular preload, whereas patients with isolated pulmonary valve stenosis represented increased RV afterload. Patients with congenitally corrected transposition of the great arteries (CC-TGA) with severe left atrioventricular valve regurgitation represented a combined increase in RV preload and afterload. The RV MPI in 152 normal children (ages 3 to 18 years) and 37 adults (ages 18 to 51 years) was 0.32 +/- 0.03 and 0.28 +/- 0.04, respectively. In pediatric patients (n = 45) and adult patients (n = 40) with ASD, the RV MPI was 0.35 +/- 0.09 (p = NS) and 0.38 +/- 0.04 (p < 0.01 compared with normal adults), respectively. Patients with pulmonary stenosis (n = 21, ages 1 day to 19 years) had a RV MPI of 0.32 +/- 0.06 (p = NS). CC-TGA patients had a RV MPI of 0.72 +/- 0.17 (p < 0.001). No significant change in the RV MPI was seen in any postoperative patient group despite relief of RV volume or pressure overload. Thus, the MPI is a quantitative measure of RV performance that is appears to be relatively independent of changes in preload or afterload in the clinical setting.

Adolescent↗

[Assessment of the left ventricular function in patients with pacemakers VVI and DDD, using non-invasive methods (systolic time)].

OBJECTIVE: Determination of left ventricular function, in patients with ventricular inhibited (VVI) and atrioventricular universal (DDD) pacemakers, by measurement of systolic time intervals. DESIGN: Twenty six patients were studied (six with DDD pacemakers and twenty with VVI pacemakers). In all of them systolic time intervals measurements were obtained the day before and one week after the implant. PATIENTS: We have studied twenty six patients consecutively, and all of them completed the study. INTERVENTIONS: The measurement of systolic time intervals was obtained, by the simultaneous recording of ECG, phonocardiogram and carotid arterial pulse. The recordings were obtained at a paper speed of 100 mm/sec. MEASUREMENTS AND RESULTS: The values obtained before the implantation were similar in both groups, but one week after implantation they show a closer to normal ventricular function, in patients with DDD pacemakers. CONCLUSIONS: The measurements of systolic time intervals, is a very easy method, to determine left ventricular function non invasively. In patients with DDD pacemakers, the left ventricular function, was better than in patients with VVI pacemakers.

Aged↗

Ultrastructural pathological study of left ventricular myocardium in patients with isolated rheumatic mitral stenosis with normal or abnormal left ventricular function.

An electron microscopic study of left ventricular myocardium was carried out in 15 patients who had isolated rheumatic mitral stenosis, with particular reference to the relation among ultrastructural pathological findings, the severity of mitral stenosis and left ventricular function. They were divided into 2 groups based on left ventricular performance evaluated by 2-dimensional echocardiography and angiocardiography. The severity of mitral stenosis was determined by hemodynamic data and mitral valve areas measured by 2-dimensional echocardiography. Regardless of the level of left ventricular contractile function we consistently demonstrated varying degrees of ultrastructural pathological alterations of left ventricular muscle cells, involving the myofibrils, mitochondria, nuclei and other elements of the sarcoplasm and membranes surrounding the myocardial cells in all specimens examined. The ultrastructural pathological findings did not correlate with the severity of mitral stenosis reflected in the echocardiographic and hemodynamic data. However, those patients with abnormal left ventricular function always exhibited more extensive loss of myofibrils resulting from either disproportion of the mitochondria-to-myofibril ratio or myofibrillar degeneration. The present investigation provides the morphological data at the ultrastructural level to support the widely held concept of a myocardial factor i.e., the extent of myocardial involvement by the rheumatic process as the basic pathogenetic mechanism responsible for left ventricular dysfunction in patients with isolated rheumatic mitral stenosis. Furthermore, it is suggested that pathological alterations of myocardial ultrastructure were related to the extent of myocardial involvement by the rheumatic process rather than being structural adaptations in response to the hemodynamic derangement.

Adult↗

Clinical assessment of ventricular function after surgical treatment of congenital heart defects.

The assessment of ventricular function has contributed to the current surgical evaluation and surgical treatment of congenital heart defects, but many issues remain unresolved. The challenge of assessing ventricular function after surgical repair of congenital heart defects includes not only the general problem of distinguishing adverse loading conditions from myocardial failure but also more unique problems of right heart function and developmental differences in ventricular function. The possibility and significance of diastolic dysfunction are essentially unexplored and contingent upon our better understanding of the determinants of diastolic indices. Many of the technologies and methods are currently available and there is the beginning of a move toward better designed clinical trials and analysis of results. The assessment of ventricular function will become increasingly important as surgical techniques are improved and we are left with the more difficult choices between competing approaches.

Cardiac Output↗

[Transesophageal echocardiography for evaluating left ventricular function].

By means of transesophageal echocardiography it is now possible to assess and to monitor left ventricular function during anesthesia and surgery. Furthermore, the determinants of the left ventricular function (preload, afterload and contractility) can also be evaluated in real time. Based on this information, a specific therapy can be started immediately should ventricular function become inadequate. In addition to global function, regional ventricular function can be analyzed at the same time. The detection of regional wall motion abnormalities can be most helpful for anesthetic management of patients with coronary heart disease and for the diagnosis of intraoperative myocardial ischemia.

Anesthesia Recovery Period↗

Triiodothyronine-enhanced left ventricular function after ischemic injury.

Hypothyroidism is associated with profound left ventricular dysfunction. Brain-dead organ donors and patients undergoing cardiopulmonary bypass are chemically hypothyroid with significantly reduced circulating free triiodothyronine (T3). To test the hypothesis that T3 enhances left ventricular function in a hormonally deficient environment, a total of 36 healthy New Zealand White rabbit hearts were studied using a modified Langendorff preparation with Krebs-Henseleit perfusate and intra-ventricular balloon. In 9 normal rabbit hearts a cumulative dose-response curve with logarithmically increasing doses of T3 was obtained. The vehicle solution for T3 dissolution served as control (n = 9). Left ventricular function was assessed from peak developed pressure at baseline and after T3 administration. Triiodothyronine had no effect in normal hearts on peak developed pressure or end-diastolic pressure. In 18 rabbits, the acute effect of T3 administration after ischemia was investigated. Preischemic left ventricular function was measured to serve as baseline, and hearts were subjected to 37 degrees C global ischemia. Triiodothyronine (n = 9) or vehicle (n = 9) was infused during reperfusion, and left ventricular peak developed pressure was measured at 30 and 60 minutes of reperfusion. Recovery of function (expressed as percent return of left ventricular peak developed pressure) was significantly improved within 15 minutes of reperfusion (65.0% +/- 2.1% versus 80.2% +/- 4.1%) and remained significantly improved throughout the reperfusion period (p less than 0.05 by analysis of variance). These data suggest that although T3 possesses no inotropic properties, it significantly improves postischemic left ventricular function. The rapidity of the functional improvement suggests that these effects may be due to plasma membrane-mediated mechanisms.

Animals↗

Long-term outcome of patients with depressed left ventricular function undergoing percutaneous transluminal coronary angioplasty. The NHLBI PTCA Registry.

BACKGROUND: Coronary revascularization with bypass has been shown to improve survival in patients with coronary artery disease and left ventricular dysfunction. In these patients, use of nonsurgical revascularization with percutaneous transluminal coronary angioplasty (PTCA) is increasing, although their long-term outcome has not been well delineated. The purpose of this investigation was to characterize the outcome of angioplasty in patients with decreased left ventricular function and contrast it with the results in patients with normal left ventricular function. METHODS AND RESULTS: In the 1985-1986 National Heart, Lung, and Blood Institute's PTCA Registry, of 1,802 patients undergoing PTCA, 244 patients (13.5%) had an ejection fraction of < or = 45% (mean, 39.6 +/- 6.8%). These patients had a higher incidence of prior infarction, a longer and worse history of manifestations of coronary disease, and more extensive coronary artery disease than patients with well-preserved function; 88% and 91%, respectively, had successful dilation of at least one lesion (nonsignificant difference). However, patients with decreased left ventricular function had a decreased frequency of successful dilation of all lesions in which PTCA was attempted (76% versus 84%, p < 0.01). There were no statistically significant differences in in-hospital complications--death occurred in 0.8% and 0.7%, nonfatal myocardial infarction occurred in 4.9% and 4.5%, and emergency surgical revascularization was performed in 4.5% and 3.2%, respectively. Patients were followed for a mean of 4.1 years; during this time, patients with decreased left ventricular function had significantly worse survival and combined event-free survival. Despite this, at 4 years, 87% of the patients with a mean ejection fraction of 39.6% remained alive, and 77% were alive and had not experienced infarction or required bypass. CONCLUSIONS: PTCA is effective in selected patients with depressed left ventricular function. Initial outcome and risk-benefit ratio are excellent. Successful dilation of at least one vessel was achieved in 88% of patients with depressed left ventricular function and in 91% of patients with more normal left ventricular function. The former group, however, had a decreased incidence of successful dilation in all lesions in which dilation was attempted (76% versus 84%, p < 0.01). There was no significant difference in in-hospital complications between the two groups. During follow-up, patients with decreased left ventricular function had worse event-free survival, although 77% were alive without infarction or bypass grafting at 4 years.

Angioplasty, Balloon, Coronary↗

Left ventricular function in patients with ventricular arrhythmias and aortic valve disease.

Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease.

Aortic Valve↗

Preservation of left ventricular function in patients with total occlusion of the left anterior descending coronary artery and wide-caliber distal vessel filling by collateral vasculature.

The segmental ventricular function of 76 patients with total occlusion of the left anterior descending coronary artery (LAD) was analyzed to establish the relationship between ventricular function and the presence and angiographic appearance of the collateral circulation. The relationship between function and collateral supply was found to be significant (P less than .01). The only angiographic feature of the collateral vasculature that was associated with preserved function was the caliber of the distal LAD. Wide-caliber vessels were more likely to be associated with preserved ventricular function than thin vessels (P less than .01). In contrast, both rapidly filling collateral arteries and slow filling vessels were associated with preserved ventricular function. Collateral supply maintenance was significantly associated with preserved ventricular function, even when the collaterals arose from stenotic coronary arteries. Furthermore, despite marked differences in ventricular function between the base and apex of the heart, there was a true relationship between preserved ventricular function and the presence of collateral vessels for all segments of the anterior wall. These findings may be relevant to clinical decision making and to proper interpretation of studies of ventricular function following LAD occlusion.

Angiography↗