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PubMed2004

Curcumin ameliorates left ventricular function in rabbits with pressure overload: inhibition of the remodeling of the left ventricular collagen network associated with suppression of myocardial tumor necrosis factor-alpha and matrix metalloproteinase-2 expression.

OBJECTIVE: Curcumin is a wide-spectrum cellular protector with antiinflammatory, antioxidizant, and antifibrotic effects. This study was conducted to investigate its effects on myocardial collagen remodeling in pressure overloaded rabbits. METHODS AND RESULTS: Pressure overloaded rabbits were established by partial abdominal aorta ligation. The rabbits were divided into the sham-operation group, vehicle group and curcumin group. Curcumin was administered orally at a dose of 100 mg/kg.d in 10 ml of 2.5% polyethylene glycol solution and the other 2 groups were given the same dose of polyethylene glycol solution. Compared with the vehicle group, left ventricular function in the curcumin group was significantly ameliorated, as indicated by decreased left ventricular end-diastolic pressure, left ventricle weight to body weight ratio, and the left ventricular posterior wall thickness. The collagen volume fraction in the curcumin group was also reduced. Myocardial tumor necrosis factor (TNF)-alpha and matrix metalloproteinase (MMP)-2 expression were significantly overexpressed in the vehicle group and markedly suppressed in the curcumin group at both the 4th and 8th weeks. At the end of the 8th week, the ejection fraction in the curcumin group was increased compared with that in the vehicle group. CONCLUSION: Curcumin improved left ventricular function in pressure overloaded rabbits. This might be due to inhibition of collagen remodeling associated with suppression of myocardial expression of tumor necrosis factor-alpha, and matrix metalloproteinase-2.

Animals↗
PubMedDate not supplied

Quantitative angiocardiography--evaluation of left ventricular function in mitral stenosis.

Investigations of left ventricular function were carried out in 59 patients with mitral stenosis and 8 healthy subjects by means of one-plane quantitative angiocardiography. A statistically significant increase of the left-ventricular systolic volume was observed in patients (x=74.9 +/- 29,8 ml) as compared with the control group (x=35.2 +/- 12,7 ml), the systolic ejection fraction decreased (patients: x=49% +/- 12, controls: x=74% +/-3), similarly as the stroke volume (patients x=74.8 +/- 29.6 ml, controls: x=104 +/- 42 ml). The diastolic volume of the left ventricle was similar in both groups (patients: x=143 +/- 43 ml, controls: x=134 +/- 47.9 ml). A significant decrease of the systolic ejection fraction and an increase of the systolic volume of the ventricle were observed with higher grades of mitral stenosis evaluated according to the classification of the New York Heart Association. A negative correlation was demonstrated between the systolic volume of the left ventricle and the systolic ejection fraction (r=-0.707) and the work of the left ventricle (r=-0.237). On the other hand, a positive correlation was found between the left-ventricular work and the systolic ejection fraction (r=+0.227). The results indicate unequivocally impairment of left ventricular function in mitral stenosis and a considerable role played in it by the myocardial factor.

Adolescent↗
PubMed1984

Left ventricular function in mitral valve disease.

Approximately one-third of all patients with mitral stenosis can be found to have an impaired left ventricular ejection fraction attributable to a reduction in preload subsequent to inflow obstruction, that is, with a lack of adequate Frank-Starling compensation together with increased afterload, rather than to an impairment of left ventricular function. The left ventricular function is, thus, generally not a factor exerting influence on the natural history of mitral stenosis or on the surgical results. The easy unloading of the left ventricle via both aortic and mitral valves during systole is the hallmark of chronic mitral regurgitation. The volume overload in mitral regurgitation leads to eccentric hypertrophy of the left ventricle while the mass-to-volume quotient remains within normal limits. There is an increase in compliance. Since left ventricular pressure and radius decrease rapidly due to the regurgitation, the myocardial wall stress of the left ventricle at the end of systole is reduced. Even in the presence of substantially reduced contractility, however, the left ventricular function appears adequate. If the left atrium is distensible enough to act as a buffer against backward transmission of the left ventricular systolic pressure, the patient may have only mild symptoms in spite of severe regurgitation. At end-systole, due to the diminished afterload, near normal volumes are reached such that, in association with an increased end-diastolic volume, an increased stroke volume and normal ejection fraction are present. In many patients with decreased contractility, the end-systolic volume may be slightly or moderately increased but, generally, the ejection fraction remains satisfactory at values in excess of 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Test↗
PubMed1982

[Comparison of exercise capacity with resting left ventricular function evaluated by various non-invasive methods in patients with old myocardial infarction].

The purpose of this study was to investigate the relationship between exercise capacity and resting left ventricular function assessed by several non-invasive methods in patients with old myocardial infarction. Subjects were 25 male patients whose endpoint was either dyspnea or general fatigue at the symptom-limited maximal graded treadmill exercise test according to Bruce protocol. The indices obtained by non-invasive cardiac examinations included left ventricular fractional shortening (% FS), scintigraphic infarct size (% SIS) by 201Tl myocardial scintigraphy and PEP/ET (so-called Weissler's index). A significant correlation of exercise duration with % FS (r = 0.67, p less than 0.001) or with % SIS (r = -0.55, p less than 0.02) indicated that the more was impaired resting left ventricular function, the more was decreased exercise capacity. Also, a significant correlation of systolic blood pressure at the end-point in exercise test with % FS (r = 0.58, p less than 0.005) or with % SIS (r = 0.69, p less than 0.001) indicated that inadequate blood pressure response might be partially attributed to impaired left ventricular function during exercise. The response of heart rate at the Bruce protocol stage I correlated with % FS (r = -0.67, p less than 0.001) and with % SIS (r = 0.53, p less than 0.02), respectively. These findings may be interpreted as chronotropic compensatory mechanism for limited stroke volume during exercise in patients with imparied left ventricular function. Thus, it was concluded that resting left ventricular function assessed by non-invasive cardiac examinations may predict exercise capacity prior to the test to some extent. These informations can be utilized for the decision of the planning at cardiac rehabilitation and also for the guidance in daily activities. Additionally, low level exercise test with treadmill is considered to be valuable for screening cases with impaired left ventricular function in old myocardial infarction.

Adult↗
PubMed1979

Impaired left ventricular function in chronic aortic valve disease: survival and function after replacement by Björk-Shiley prosthesis.

Postoperative survival and left ventricular function were studied in 128 patients who underwent isolated aortic valve replacement by the Björk-Shiley valve between 1973 and 1977. The average follow-up was 2.1 years. Patients with associated coronary artery disease or mitral valve disease were excluded. Preoperative ejection fraction ranged from 15-84%. Forty-two patients were restudied by cardiac catheterization 9.1 +/- 1.1 months (mean +/- SEM) after valve replacement. The hospital mortality was 11%. Preoperative type of valve lesion, functional class, cardiothoracic ratio, and ejection fraction (EF) had no significant effect on postoperative survival up to 4 years. After operation, left ventricular mass (LVMI) and peak systolic wall stress (PSWS) fell significantly, while EF and mean normalized systolic ejection rate (MNSER) increased in aortic stenosis and in aortic insufficiency. Neither in aortic stenosis nor in aortic insufficiency was there a significant relation between preoperative ejection fraction and postoperative LVMI, EF, MNSER and PSWS. We attributed this to a marked improvement of left ventricular function in patients with preoperative impaired ventricular function. Six patients with paravalvular leak to restudy has a significantly lower EF and MNSER, and a higher PSWS than patients without leak. Patients without leak had normal EF, MNSER and PSWS when compared with 10 normal persons, but LVMI remained moderately elevated. Postoperative transprosthetic gradient was 11.9 mm Hg (range 0-64 mm Hg). We conclude that impaired cardiac function is completely restored after aortic valve replacement by Björk-Shiley valve, if valve function is good. Patients with impaired cardiac function preoperatively did not have a poorer prognosis after operation than patients with normal function.

Adolescent↗
PubMed1995

Closed mitral valvotomy and elective ventilation in the postoperative period: effect of mild hypercarbia on right ventricular function.

OBJECTIVES: It is customary to extubate patients immediately after closed mitral valvotomy. These patients often have deranged respiratory function caused by chronic lung congestion. The left ventricular function may also be subnormal after valvotomy in some patients. Therefore, elective ventilation for some duration in the postoperative period can be beneficial to these patients. This work is an attempt to find whether elective ventilation should be preferred over immediate extubation in these patients. DESIGN: A prospective randomized study. SETTING: The study was performed in a tertiary care hospital, and the patients are referred from the northern states of India. PARTICIPANTS: One hundred patients undergoing elective closed mitral valvotomy were included in the initial part of the study. Ten more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after closed mitral valvotomy. INTERVENTIONS: One hundred patients were divided into two groups of 50 each. Group 1 consisted of patients in whom the neuromuscular blockade was reversed at the end of surgery with neostigmine and atropine and the trachea was extubated. In group 2, the residual neuromuscular paralysis was not reversed and the patients were electively ventilated in the postoperative period for an average duration of 5 hours and 29 minutes +/- 1 hour and 58 minutes. In all the patients in both the groups, electrocardiogram, direct arterial blood pressure, and oxygen saturation were continuously monitored, and arterial blood gases were measured intermittently throughout the study period. Because the results showed that there was mild hypercarbia, 30 minutes after extubation in group 1, 10 more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after surgery. Patients were ventilated after surgery (F1O2 = 1) to maintain normocarbia (PaCO238.6 +/- 3.4 mmHg). Mild hypercarbia PaCO251.5 +/- 3.7 mmHg) followed by normocarbia (PaCO2 40 +/- 2.5 mmHg) was induced by adjusting the ventilator rate with a constant tidal volume. Standard hemodynamic measurements were performed at each stage. MEASUREMENTS AND MAIN RESULTS: Although all the patients maintained satisfactory and stable hemodynamics in the postoperative period, the PaCO2 at the end of 30 minutes of extubation was significantly higher in group 1 (48.1 +/- 5.3 mmHg) as compared with group 2 (40.2 +/- 4.3 mmHg, p < 0.001). Mild hypercarbia significantly increased pulmonary vascular resistance (p < 0.01), mean pulmonary arterial pressure (p < 0.001), right ventricular stroke work (p < 0.01), right ventricular systolic pressure (p < 0.01), and right ventricular end-diastolic pressure (p < 0.001). The effect was not totally reversible with CO2 washout as all parameters except right ventricular end-diastolic pressure and pulmonary vascular resistance continued to remain significantly higher when normocarbia was restored. The significant changes in systemic hemodynamics produced by hypercarbia were increases in cardiac index, mean arterial pressure, and pulmonary capillary wedge pressure. CONCLUSIONS: Avoidance of even mild hypercarbia, therefore, appears advisable in the early postoperative period because of potential impedence to right ventricular ejection. Continuous monitoring of end-tidal CO2 and frequent blood gas analyses should be practiced, and elective ventilation should be considered in patients with long-standing disease and pulmonary hypertension.

Adolescent↗
PubMed1986

Radionuclide left ventricular function curve during atrial pacing in normal subjects and in patients with coronary artery disease.

We used radionuclide angiography during right atrial pacing to assess left ventricular function in 7 normal subjects and 20 patients with coronary artery disease. A left ventricular function curve relating stroke volume to end-diastolic volume was plotted for each patient. The normal pacing ventricular function curve was a straight line passing through the origin of axes. The pacing ventricular function curve was abnormal in 18 of the 20 patients with coronary artery disease, and three different shaped curves were obtained, reflecting decreased contractile force for the same end-diastolic volume during ischemia. Cardiac output and blood pressure do not change during atrial pacing, thus the Frank-Starling relationship is evaluated by this method during almost experimentally controlled conditions. Relating stroke volume to end-diastolic volume, and not end-diastolic pressure, distinguishes between overall left ventricular systolic function and left ventricular compliance.

Adult↗
PubMed1995

Amino acid-enriched glucose-insulin-potassium infusion improves hemodynamic function after coronary bypass surgery. A double-blind study in patients with unstable angina and/or compromised left ventricular function.

OBJECTIVE: The goal of this study was to assess the effects of a combination of glucose-insulin-potassium (GIK) and the amino acids aspartate and glutamate upon perioperative hemodynamics in coronary surgery patients with unstable angina and/or compromised left ventricular function. DESIGN: Prospective, randomized, and double-blind clinical study. SETTING: Operating theatre and intensive care unit (ICU) of a university hospital. PATIENTS: 44 coronary artery bypass graft (CABG) patients with unstable angina and/or compromised left ventricular function. INTERVENTIONS: 22 patients (group A) were given 1l of an infusion with 250g glucose, 100 I.U. fast-acting human insulin, 72 mmol potassium, 32 mmol magnesium, 20 mmol phosphate, 65 mmol aspartate, and 65 mmol glutamate, while another 22 patients (group C) were given 1l of an infusion with 50 g glucose, 72 mmol potassium, 32 mmol magnesium, and 8 mmol phosphate. The infusion rate was 1.2 ml/kg/h from the anesthesia induction onward to the commencement of cardiopulmonary bypass, when it was reduced to 0.8 ml/kg/h. When 11 had been infused, but not later than 4 a.m., the infusion was continued by giving 10% glucose at the same rate to both groups. Additional insulin (median: 14.2 I.U., range: 0-41.5) or saline was given during bypass to the A and C patients, respectively. A blood cardioplegia technique containing aspartate and glutamate was used in both groups. RESULTS: At aortic cannulation, the cardiac index (CI) had increased from the pre-anesthetic level by 15.3% (mean) (SD: 31.7%) in group A and decreased by 7.7% (15.1%) in C patients, p = 0.0069. Also the changes in stroke index (SI; p = 0.022), left (LVSWI; p = 0.0037) and right ventricular stroke work index (RVSWI; p = 0.0097) were more favorable in group A. Despite longer aortic cross-clamp, p = 0.031, and perfusion times, p = 0.042, in A patients, the change in cardiac index was also better in this group after bypass: At decannulation, the difference between mean values was 31.8%, p = 0.0001, and at arrival in the ICU it was 16.1%, p = 0.028. The same was also seen 8 h postoperatively and on the 1st and 2nd postoperative mornings; p = 0.034, 0.040, and 0.037, respectively (Wilcoxon test). Favorable changes were seen for the A patients also regarding SI at decannulation (p = 0.0002) and after 8 h (p = 0.017); LVSWI at decannulation (p = 0.0002), at arrival in the ICU (p = 0.0023), and after 8 h (p = 0.0011); and RVSWI at decannulation (p = 0.0027), at the ICU (p = 0.021), after 8 h (p = 0.014), and on the 1st postoperative morning (p = 0.039). However, the response to a hemodynamic loading test (6% hydroxyethyl starch 5 ml/kg) was similar in the 2 groups, and there was no difference in the need for inotropic support. CONCLUSIONS: Amino acid-enriched GIK infusion improves hemodynamic function in CABG patients with unstable angina and/or compromised left ventricular function.

Aged↗
PubMed1997

[Effect of late revascularization of the responsible artery after infarction on left ventricular function and remodeling].

The effects of late angioplasty of the culprit artery after myocardial infarction on the decisive prognostic factors of left ventricular function and remodeling are not well known. When the culprit artery is narrowed but patent, angioplasty leads to improvement in segmental contractility and global left ventricular function: it does not seem to influence left ventricular end-diastolic volume. When the artery remains occluded, global and regional left ventricular function is also improved when the recanalised artery remains patent. Moreover, restoration of satisfactory artery patency prevents ventricular remodeling whereas in failed angioplasty or reocclusion, there is a progressive increase in left ventricular volume. However, these results observed in unselected patients could be improved: it would seem that the different beneficial effects only occur when there is residual myocardial viability; in the absence of signs of myocardial viability, the ventricular effects of limitations of angioplasty (incidence of restenosis or reocclusion in this specific context, lower primary success rate in complete arterial occlusion) explain the negativity of rare randomised studies comparing the outcome of left ventricular function depending on whether a conventional attitude or systematic revascularisation of the culprit artery is adopted.

Angioplasty, Balloon, Coronary↗
PubMed1999

[Using the internal thoracic artery of patients with reduced left ventricular function].

Todate internal mammary artery (IMA) is routinely used in coronary artery bypass grafting even in elder patients. However in patients with poor left ventricular function use of the IMA is discussed controversely in Germany. Main arguments against IMA are an increased operation time, initially lower blood flow, higher rates of reoperation for bleeding and more perioperative complications. In this study we investigated use of the IMA in patients with poor left ventricular function (LVEF < 40%) compared to exclusively veingraft bypass surgery. 137 patients (105 m/32 f) suffering from coronary artery disease with reduced LVEF (12-40%) were randomized in the study. 67 patients received exclusively vein grafts (group I), 70 patients routinely obtained an IMA graft. Criteria used for evaluation of IMA graft were operation time, postoperative bleeding, need for catecholamines, requirement of intensive care, perioperative myocardial infarction and mortality. The number of distal anastomoses in each group was 3.1 (2-5). The operation time varied in compliance with the number of distal anastomoses, but there were no significant differences between both groups. Postoperative bleeding until the second postoperative day was 905 ml in group II versus 569 ml in group I; the difference was significant (p < 0.05). The need of catecholamines after operation and hemodynamic parameters were comparable in both groups, there were no significant differences. Intensive care was required for a mean of 1.6 days in both groups, postoperative ventilation was 5.8 hours in group I versus 7.9 hours in group II, differences not significant. Ischemia or myocardial infarction could be demonstrated in 2 patients of group I (3%) versus 4 patients of group II (5.7%). The differences between the groups were not significant. Cardiac low output syndromes without sights of myocardial infarction were apparent in 9 patients of group I (13.5%) versus 2 patients of group II (2.9%), this difference being significant (p < 0.05). Mortality after operation in both groups was higher than in patients with normal ventricular function, however the differences between the evaluated groups were not significant (5.9% in group I versus 4.3% in group II). Summarizing the above it can be concluded that patients with poor left ventricular function are at a higher risk when subjected to bypass operation; the use of IMA did not show any disadvantages in comparison to exclusively veingraft surgery, except of a higher perioperative bleeding risk. Due to better long term results IMA should be used routinely also in bypass-patients with poor left ventricular function.

Aged↗
PubMed1993

[Sequential changes in the left ventricular function during ramp exercise in patients with ischemic heart disease: continuous assessment of the left ventricular radioactivity with wireless telemetric cardiac monitoring system].

The left ventricular function during ramp exercise was assessed using 99mTc-labeled red blood cells and a Wireless Telemetric Cardiac Monitoring System (WTCMS) in 34 patients who received coronary angiography. Sequential changes in the left ventricular ejection fraction (EF) during exercise, were classified into the two types, normal response (up slope pattern) and abnormal response (horizontal, down slope and up-down slope pattern) when defined the response as 5 percent or more increment of EF as normal. Six patients without significant stenosis by coronary angiography showed normal response. Seventeen of 28 patients with coronary disease showed abnormal response (sensitivity 61%). Eight of 11 patients (73%) with coronary disease and normal response showed no redistribution on the stress thallium myocardial scintigraphy. Twelve of 17 patients (71%) with coronary disease and abnormal response showed redistribution by the stress thallium scintigraphy. Horizontal and down slope patterns of EF during exercise were more often noted in the groups with redistribution and multivessel coronary disease. After the exercise, the times to the over shoot was significantly longer in groups with redistribution (p < 0.01) in comparison with groups without redistribution. From these results, we conclude that the monitoring the changes in left ventricular activity during ramp exercise with the WTCMS is a very useful method for the evaluation of the sequential changes in left ventricular function in patients with ischemic heart disease.

Adult↗
PubMed1984

[Left ventricular function at rest and during exercise in patients with arterial hypertension. Studies using digital subtraction angiocardiography].

Using digital subtraction angiography, left ventricular function and pulmonary artery pressure at rest and during submaximal exercise (98 +/- 33 watts) were examined in 25 patients with systemic hypertension. All patients had normal coronary arteries and a normal left ventricular function at rest. Heart rate increased in all patients (from 82 +/- 14 to 134 +/- 20 min-1, p less than 0.001). Systolic blood pressure also increased significantly in all patients (from 153 +/- 12 to 190 +/- 14 mmHg, p less than 0.001). End-diastolic and end-systolic volumes did not change on average (89 +/- 22 and 87 +/- 19 ml/m2, 28 +/- 8 and 28 +/- 10 ml/m2, respectively), neither did stroke volume nor ejection fraction (61 +/- 18 and 59 +/- 16 ml/m2, 68 +/- 7 and 67 +/- 9%, respectively). The increase in end-systolic volumes and concomitantly the decrease in ejection fraction during exercise in 8 patients points to an impairment of left ventricular function. This effect is frequently found in ventricles with less distinct hypertrophy. Cardiac index increased in each patient (from 5.1 +/- 2.1 to 8.2 +/- 2.9 I/min/m2, p less than 0.001). This is caused by the increase in heart rate while stroke volume remains unchanged. Mean pulmonary artery pressure increased in all patients from 19 +/- 6 to 35 +/- 10 mmHg on average (p less than 0.001). A pathologic increase could be observed in 18 patients. There was no correlation to angiographic parameters of left ventricular function. The exercise test was stopped in 12 patients mainly because of dyspnea. In 11 of these patients a pathologic increase of mean pulmonary artery pressure was found. As in these patients the angiographic parameters of left ventricular function were normal, the increase in pulmonary pressure is related to an impairment of diastolic function caused by hypertrophy.

Adult↗
PubMed1990

[Left ventricular function in young type I diabetic patients. A Doppler echocardiography study].

Systolic and diastolic left ventricular function was assessed by M-mode and pulsed Doppler echocardiography in 10 young type I diabetic patients without late complications and maximal diabetes duration of 5 years and in 10 healthy persons. Fractional shortening, a measure of systolic ventricular function, was significantly lower in diabetics than in controls (33.9 +/- 2.9 vs. 37.9 +/- 4.9; p less than 0.05). Fractional shortening decreased significantly with advancing diabetes duration (R = -0.819; p less than 0.01). Indexes of diastolic ventricular function (isovolumetric relaxation period and transmitral flow velocity pattern) were not significantly different in the two groups, but 3 patients had 1 parameter (3x isovolumetric relaxation period) and another patient had 2 parameters (isovolumetric relaxation period and early diastolic peak velocity E-E') outside the normal range. Follow-up studies should define the clinical significance of these alterations of systolic and diastolic left ventricular function.

Adolescent↗
PubMed2001

Early prediction of 30-day mortality after Q-wave myocardial infarction by echocardiographic assessment of left ventricular function--a pilot investigation.

BACKGROUND: The GUSTO angiographic substudy demonstrated that left ventricular function measured 90 min after thrombolytic therapy was given had important prognostic implications at 30 days in patients with an acute myocardial infarction (MI). HYPOTHESIS: Thirty-day prognosis after Q-wave MI can be determined by early echocardiographic assessment of left ventricular function. METHODS: Using transthoracic echocardiography, semiquantitative ejection fraction and wall motion score index was assessed prospectively in 201 consecutive patients within 24 h following Q-wave MI. Independent experts blinded to the patient's status performed the echocardiographic assessment. All patients received standard medical care as dictated by the attending cardiologist. RESULTS: Of the 201 patients, 24 (11.9%) died within 30 days, with 70% of the deaths occurring within 10 days after the infarction. Three deaths occurred in the 120 patients with an ejection fraction > or = 45% (2.5% mortality rate). In contrast, 21 deaths occurred among the 81 patients with an ejection fraction <45% (25.9% mortality rate) p = 0.0003. Two of the three patients who died in the high ejection fraction group died as a result of intracerebral hemorrhage from thrombolytic therapy. Ejection fraction was lower in nonsurvivors (32.3+/-10.3 vs. 46.3+/-13%) than in survivors, p < 0.0002. Wall motion score index (WMSI) of < 1.4 was associated with a 2.9% 30-day mortality (two deaths in 76 patients); WMSI of > or = 1.4 was associated with a 17.6% 30-day mortality (22 deaths in 125 patients), p = 0.0007. Average WMSI was higher in the nonsurvivors (1.95+/-0.5) than in survivors (1.52+/-0.45), p = 0.00001. CONCLUSIONS: Echocardiographic assessment of left ventricular function during the first 24 h after an acute Q-wave MI can be performed in all patients regardless of stability. High-risk patients are identified early in the hospital course, with relative ease, at no risk and at an acceptable cost. An ejection fraction < 45% or WMSI > or = 1.4 identifies patients who are at a high risk of dying within 30 days. These are the patients who may benefit most from aggressive medical therapy and early angiography to assess coronary pathology.

Humans↗
PubMed1991

Diastolic stiffness impairs left ventricular function during hypovolemic shock in pigs.

To determine the causes of impaired left ventricular function during hypovolemic shock we measured diastolic and end-systolic pressure-volume relationships and hemodynamics. Left ventricular pressure (Millar catheter) and volume (3 ultrasonic crystal pairs) were measured in six open-chest, chloralose-morphine anesthetized, juvenile pigs. After baseline measurements, the pigs were bled and maintained at a mean aortic pressure of 50 cmH2O for 7 +/- 1 h. After resuscitation with all shed blood, left ventricular function was markedly impaired as indicated by increased end-diastolic pressure (20.3 vs. 8.7 cmH2O at baseline, P less than 0.05), decreased aortic pressure (36% of baseline, P less than 0.01), and decreased stroke volume (50% of baseline, P less than 0.01). Systolic contractility was increased (P less than 0.05), but diastolic compliance was greatly reduced due to decreased diastolic maximum (52% of baseline, P less than 0.01) and equilibrium volumes (57% of baseline, P less than 0.01). We conclude that impaired left ventricular function during hypovolemic shock is due entirely to increased diastolic stiffness. These results can theoretically be accounted for by a 20% reduction in myocardial muscle length with no change in muscle stress-strain characteristics. This may be the physiological expression of morphologically observed myocardial "zonal lesions" of hypovolemic shock.

Animals↗
PubMed1998

A randomized comparison of exercise training in patients with normal vs reduced ventricular function.

BACKGROUND: Exercise training is recommended after myocardial infarction (MI) or bypass surgery in order to improve exercise tolerance. In some patients, the decrement in exercise capacity secondary to deconditioning and the left ventricular stunning associated with MI or coronary artery bypass graft (CABG) spontaneously improves after the event. However, the impact of the status of the left ventricle on these improvements is unknown. METHODS: Sixty-seven patients 1 month after MI or CABG were randomized to a training (n=34; age, 59+/-7 years) or a control group (n=33; age, 55+/-6 years). Forty-two patients had an ejection fraction >50% (22 in the training group and 20 in the control group), and 25 patients had an ejection fraction <40% (12 in the exercise group and 13 in the control group). After stabilization for approximately 1 month after the event, patients in the exercise group underwent 8 weeks of twice daily exercise at a residential rehabilitation center, while control patients received usual care. Initially and after 8 weeks, patients in both groups underwent maximal exercise testing with gas exchange and lactate analysis. RESULTS: Exercise training increased peak oxygen consumption (VO2) only in the reduced ejection fraction group (19.4+/-3.0 to 23.9+/-4.8 mL/kg/min; p<0.05); the exercise group with normal ventricular function did not change significantly. Changes in VO2 at the lactate threshold paralleled those of peak VO2 for both groups. Conversely, control patients with normal ventricular function increased peak VO2 spontaneously (20.8+/-3.9 to 24.8+/-3.5 mL/kg/min; p<0.01), whereas control patients with reduced ventricular function did not improve peak VO2. CONCLUSION: These data suggest that patients with depressed left ventricular function strongly benefit from rehabilitation, whereas most patients with preserved left ventricular function following MI or CABG tend to improve spontaneously 1 to 3 months after the event.

Coronary Artery Bypass↗
PubMed1995

Echocardiographic assessment of systolic and diastolic left ventricular function using an automatic boundary detection system. Correlation with established invasive and non invasive parameters.

Systolic and diastolic left ventricular function was assessed using an echocardiographic automatic boundary detection system (ABD) in 50 unselected patients undergoing left cardiac catheterisation. Automatic boundary detection system derived parameters (fractional area change [FAC], peak positive rate of area change [+dA/dt] and peak negative rate of area change [-dA/dt]) were compared with invasively (left ventricular angiography and pressures) and non invasively (Doppler mitral filling velocities and isovolumic relaxation time) acquired conventional indices of ventricular function. Adequate detection of endocardial boundaries and subsequent measurements using the ABD system were achieved in 40/50 (80%) patients in the short axis parasternal view, in 41/50 (82%) in the apical four chamber view and in 34/50 (68%) in both views. For the whole group of patients the FAC (maximal left ventricular diastolic area--minimal left ventricular systolic area/maximal left ventricular diastolic area) estimated in the short axis view correlated with the angiographic ejection fraction (EF) measured in the right oblique projection (r = 0.51, p < 0.001). There was only a weak correlation of the FAC estimated in the apical four chamber view with the EF (r = 0.36, p < 0.01). The mean FAC (mean value of the FAC in the short axis and apical four chamber views) correlated reasonably with the EF (r = 0.62, p < 0.0001). There was no correlation between ABD derived parameters and left ventricular end diastolic pressure (LVEDP) in these patients. In a subgroup of patients with normal coronary arteries and left ventricular function (n = 17), although there was no correlation between EF and FAC, there was a strong positive correlation between FAC (apical four chamber and mean) and LVEDP (r = 0.77, p < 0.01 and r = 0.87, p < 0.01 respectively). No correlation was found in these patients between EF and LVEDP. In a further subgroup of patients with angiographically abnormal left ventricular function (EF < 45%), there was a positive correlation between FAC (short axis, apical four chamber and mean) and EF (r = 0.52, p < 0.05, r = 0.83, p < 0.0001 and r = 0.80, p < 0.001 respectively) and a negative correlation between FAC (short axis and mean) and LVEDP (r = -0.52, p < 0.05 and r = -0.60, p < 0.01 respectively). There was also a negative correlation between LVEDP and EF in the same subgroup of patients (r = -0.65, p < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

Case study of the anemic patient: epoetin alfa--focus on improving ventricular function.

Multiple factors, including chronic anemia, can impair left ventricular function and lead to serious or fatal consequences. Correcting anemia with Epoetin alfa is an important step in improving compromised left ventricular function. Continuous management of fluid status, blood pressure, and hematocrit is the best way for nephrology nurses to help patients improve their cardiac function and quality of life.

Anemia↗