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PubMed1997

[Restenosis after optimal coronary atherectomy and influence on left ventricular function].

The authors prospectively assessed 95 patients undergoing optimal guided atherectomy to assess the incidence of restenosis at 6 months. The coronary lesions were measured by a system of quantitative angiography to ensure reproducibility. Ventricular volumes, ejection fraction and segmental wall motion were assessed by ventriculography performed in the right anterior oblique projection. Sixty-three patients underwent atherectomy of the left anterior descending artery and 32 patients of the right coronary artery. The reference diameter was 3.58 +/- 0.65 mm. Atherectomy increased the minimal diameter of the lesion from 1.19 +/- 0.44 to 3.03 +/- 0.45 mm, with a residual stenosis of 14 +/- 10% of the diameter. At 6 months, 23% of patients had restenosed (> 50% stenosis) with a residual lumen at 1.16 +/- 0.39 mm. In the absence of restenosis, there was no significant change in left ventricular volumes or pressures and the global ejection fraction increased by +4 +/- 9% (p < 0.01), mainly in the group undergoing left anterior descending atherectomy. Moreover, fractional shortening increased in the anterior segments (+11 +/- 18%; p < 0.001). The authors conclude that optimal atherectomy is associated with acceptable rates of restenosis and that medium-term benefits of segmental wall motion are observed in patients without angiographic restenosis, mainly in those undergoing the procedure on the left anterior descending artery.

Adult↗

PubMed1989

[Left ventricular function a short time after myocardial revascularization surgery: radioisotope angiographic study].

The short-term effects after coronary bypass surgery on left ventricular function were studied in 65 patients with coronary artery disease. Each patient underwent gated radionuclide left ventriculography on the second-third day before and 5-7 days after coronary bypass surgery. After surgery, global ventricular ejection fraction had a significant increase, anteroseptal wall motion was unchanged, while apical motion and mainly inferoposterior motion were significantly increased. The most important improvement of inferoposterior motion was observed in 18 patients who had complete revascularization of the previously infarcted inferior segments, while in the 11 patients with incomplete revascularization of the same area, inferoposterior motion had a slight increase. There was a slightly significant direct linear correlation between size and direction of the anteroseptal and inferoposterior motion changes. The patients were divided in subgroups related to the site and number of obstructed coronary vessels as well as of implanted grafts; the computed parameters showed similar changes in all subgroups. After surgery, peak ejection rate showed an evident increase, and time to peak reciprocally shortened. Peak filling rate, which had reduced preoperative values, was found clearly improved, with a corresponding shortening of the time to peak; these results confirmed that diastolic ventricular damage was a reversible disturbance related to myocardial ischemia. In 8 of the 65 patients, 24 hours urinary catecholamine levels showed similar values at both pre and postoperative radionuclide controls. In conclusion, the radionuclide angiography showed an evident improvement of left ventricular function during a short period following surgery, suggesting a better myocardial perfusion after revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Effects of fructose on left ventricular function during hypoxia].

The effects of fructose on cardiac function and myocardial metabolism during hypoxia were compared with those of saline infusion in the anesthetized mongrel dogs. Hypoxia was induced with inhalation of low fraction of oxygen (PaO2 = 15 mmHg) for two hours. Fructose (N = 7) was infused intravenously at a rate of 1 g.kg-1.h-1 and saline (N = 7) was infused at 5 ml.kg-1.h-1, in the same volume as fructose infusion. Both infusions were started at the induction of hypoxia. In the fructose group, two of seven dogs died within 90 min, and other dogs within 120 min. After 120 min, only one dog survived. In saline group, three of seven dogs died within 60 min, another within 90 min, and three others died within 120 min. In both groups, the dogs with cardiac arrest at an early period tended to show low levels of blood glucose and high levels of lactic acid. Blood glucose levels were similar in both groups, but % increase of blood glucose from control and myocardial glucose uptake tended to be higher in fructose group than in saline group. Blood lactic acid (LA) levels increased significantly in both groups, but, in fructose group, LA levels were higher, and arterial pH decreased more than those in saline group. In fructose group maximum rate of rise of left ventricular pressure (LV dp/dt max) correlated with intramyocardial pH (r = 0.834, P < 0.01), but not with LA levels nor with difference of blood lactic acid from control (d-LA).(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Lactic↗

PubMed2006

The use of myocardial contrast echocardiography in the assessment of left ventricular function recovery after primary percutaneous coronary intervention in the setting of acute myocardial infarction.

BACKGROUND: Despite successful reperfusion therapy of acute myocardial infarction and complete restoration of infarct-related artery patency, the improvement of systolic function in long-term outcome depends on preserved microvasculature integrity. Myocardial contrast echocardiography (MCE) is a useful technique for identification of viable myocardium. AIM: To assess the value of real-time myocardial contrast echocardiography (rt-MCE) in prediction of left ventricular function improvement in patients with anterior wall acute myocardial infarction as well as selection of the optimal cut-off value for the number of dysfunctional segments with preserved complete perfusion, in order to predict the global left ventricular function improvement during one-month observation. METHODS: Rt-MCE was performed in 74 patients (50 men, aged 58+/-11 years) with anterior wall myocardial infarction, treated with primary percutaneous coronary intervention (PCI) within 12 hours from the onset of symptoms. After estimation of regional contractility disturbances and global systolic function of the left ventricle, rt-MCE was performed with contrast assessment of dysfunctional segments (normal contrast pattern=2, heterogeneous=1, lack of contrast=0). Regional perfusion score index (RPSI) was calculated by adding the perfusion indices and dividing by the number of dysfunctional segments. RESULTS: Of a total of 1184 visualised segments, 344 (29.1%) were dysfunctional (189 hypokinetic, 155 akinetic). Contractility improvement was observed in 192 segments (preserved viability in 105 hypokinetic and 37 akinetic segments). In a group of 44 patients with systolic function improvement, 34 of them had preserved viability, and in a group of 30 patients without LVEF improvement, in 22 of them myocardium viability was not observed. Sensitivity, specificity and accuracy of rt-MCE in prediction of left ventricular global improvement were 72.7%, 73.3% and 73%, respectively, whereas in prediction of regional function improvement these values were 73.9%, 77% and 75.5%, respectively. CONCLUSION: Rt-MCE performed in the early phase of myocardial infarction enables the prediction of left ventricular regional and global function improvement in patients treated with primary PCI.

Aged↗

PubMed2002

Left ventricular function in atrial fibrillation during overdrive pacing.

OBJECTIVE: Our purpose was to measure the effect of ventricular pacing in patients with atrial fibrillation (AF) on stroke volume and cardiac output. BACKGROUND: Unceasing variation in cycle length in AF decreases stroke volume and cardiac output. Because ventricular-inhibited pacing after atrioventricular node ablation has been reported to improve left ventricular performance, we tested the hypothesis that overdrive pacing would produce a similar benefit by regularizing cycle length. METHODS AND RESULTS: We studied 18 patients with chronic AF and permanent pacemakers. The aortic time velocity integral (TVI) was measured with continuous-wave Doppler and was used as a surrogate measure of stroke volume (stroke volume = TVI x aortic valve area, and aortic valve area is constant whether in AF or during pacing). For each patient, the linear relation between preceding cycle length and TVI in AF was used to estimate relative stroke volume (TVI compared within each patient) at a preceding cycle length of 666 ms in AF, and a similar comparison between AF and pacing was made at the minimum allowable pacing rate. Relative stroke volume in AF was then compared with relative stroke volume at both the fixed cycle (666 ms) and the minimum allowable rate. During pacing at 666 ms, relative stroke volume increased significantly by 18% (t = 2.8, P =.048), but there was no difference in cardiac output during pacing at the minimum possible rate and the corresponding preceding cycle length in AF. CONCLUSION: Our data suggest that regularization of ventricular rhythm by overdrive pacing in patients with AF only improves stroke volume (and by extension, cardiac output) at pacing rates at the outer limit of and above the normal physiologic range.

Adult↗

PubMed1983

Left ventricular function in persistent pulmonary hypertension of the newborn. Computer analysis of the echocardiogram.

Regional and global left ventricular function was assessed in 23 neonates with persistent pulmonary hypertension using computer assisted analysis of their left ventricular echocardiograms and compared with that in 50 healthy neonates. End diastolic left ventricular dimension was normal and end systolic dimension increased while percentage left ventricular shortening and peak velocity of circumferential fibre shortening decreased indicating impaired systolic performance. The peak rate of increase in left ventricular diameter in early diastole was significantly decreased and the durations of the rapid filling and isovolumic relaxation periods were prolonged suggesting resistance to left ventricular filling due to changes in diastolic myocardial properties. This abnormal left ventricular cavity function may have been due to a combination of increased diastolic wall thickness, reduced percentage systolic wall thickening, increased relative wall thickness, and pronounced reduction in peak rates of systolic wall thickening and diastolic wall thinning Seven neonates with persistent pulmonary hypertension died, and of the three examined at necropsy all had left ventricular hypertrophy and two extensive subendocardial haemorrhage and infarction affecting the right and left ventricular papillary muscles. Thus left ventricular dysfunction appears to be a common feature in neonates with this disorder and may be readily detected using computer analysis of left ventricular echocardiograms. Unfortunately, no single echo measurement was useful prognostically. Left ventricular dysfunction in persistent pulmonary hypertension probably results from a combination of hypoxaemia, acidaemia, and pulmonary hypertension, and although it may contribute to the high mortality in this syndrome, a correlation between the severity of left ventricular dysfunction and clinical outcome could not be shown.

Computers↗

PubMed2002

Myocardial enhancement on magnetic resonance imaging with gadolinium-diethylenetriamine pentaacetic acid and improvement of left ventricular function in patients with dilated cardiomyopathy.

OBJECTIVES: This study evaluated the significance of myocardial gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhancement on magnetic resonance imaging for the improvement of left ventricular function in patients with dilated cardiomyopathy. METHODS: Twenty-seven patients with dilated cardiomyopathy (mean age 59 +/- 11 years) were studied. The magnitude of myocardial Gd-DTPA enhancement was quantitatively assessed using signal intensity ratio and compared to changes in left ventricular function and adverse cardiac events during a relatively long follow-up period. RESULTS: Regional high signal intensity ratio, defined as > or = mean + 2SD in seven normal subjects, was found in 14 patients: in three or more regions out of five myocardial regions analyzed in six patients (extensive enhancement) and in only one or two regions in eight patients (limited enhancement). The remaining 13 patients had no high signal ratio in any of the five regions analyzed (no enhancement). During the follow-up period of 3.9 +/- 1.9 years, four patients died of cardiac causes. The incidence of cardiac death was 33.3% in patients with extensive enhancement, 12.5% in those with limited enhancement and 7.7% in those without enhancement, but there was no statistical difference. Mild improvement in fractional shortening was observed in patients without enhancement during the follow-up (19 +/- 4%-->27 +/- 10%, p = 0.03). CONCLUSIONS: Evaluation of myocardial Gd-DTPA enhancement on magnetic resonance imaging may provide useful prognostic information for patients with dilated cardiomyopathy.

Adult↗

PubMed1986

Hyperthyroidism and the heart: study of left ventricular function in preclinical hyperthyroidism.

To study the response of the target organs to minor increments of thyroid hormone levels, left ventricular ejection fraction (LVEF) the primary indicator of left ventricular function, was measured in patients with preclinical hyperthyroidism and the results were compared with those obtained in euthyroid subjects and in patients with toxic adenoma. In euthyroid subjects and in patients with preclinical hyperthyroidism LVEF in response to exercise involving an isometric static work load revealed a minor increase, whereas in manifest hyperthyroidism (toxic adenoma) an opposite response with an impairment of left ventricular functional capacity was found. The results showed that the pituitary responds more sensitively to minor changes in the circulating thyroid hormone levels than does the heart and indicated that the typical hyperthyroid heart changes associated with the evolution of toxic adenoma develop gradually.

Adenoma↗

PubMed1988

Spontaneous recovery of left ventricular function following acute anterior myocardial infarction.

Four patients with acute anterior wall myocardial infarction showing spontaneous and marked improvement in systolic left ventricular function are described. All 4 patients showed abnormal Q waves and severe wall motion abnormalities soon after acute infarction. In all 4 patients, at least some regeneration of R-wave forces occurred and the regional wall motion in the involved area of the left ventricle improved dramatically without coronary angioplasty or surgical revascularization during the intervening period. The improvement in left ventricular function was attributed to spontaneous increase in nutrient flow to the involved area. It is concluded that Q waves and severe wall motion abnormalities do not necessarily indicate irreversible scar formation.

Electrocardiography↗

PubMed1998

Left ventricular function and endomyocardial biopsy in early and advanced dilated cardiomyopathy.

We evaluated left ventricular function and endomyocardial biopsy in 20 patients with early and advanced dilated cardiomyopathy, with the purpose of assessing the correlation between histologic variables and systolic and diastolic filling indexes. Group 1 included 10 patients with no clinical history of heart failure and left ventricular ejection fraction > or = 45% and group 2, 10 patients with a clinical history of heart failure and left ventricular ejection fraction <45%. Group 1 showed lower left ventricular end-systolic and end-diastolic volumes indexes (49+/-14 versus 86+/-23 ml/m2, P<0.001; 98+/-25 versus 127+/-35 ml/m2, P=0.049), higher left ventricular ejection fraction (50+/-4 versus 32+/-4%, P<0.001) and lower coefficient of variation of percentage shortening of left ventricular transverse hemiaxes (0.3+/-0.1 versus 0.5+/-0.1, P=0.001) compared with group 2. Group 1 had higher A wave peak velocity (78+/-18 versus 60+/-20 cm/s, P=0.048), lower E/A ratio (0.9+/-0.3 versus 1.5+/-0.6, P=0.02) and slower E wave deceleration time (204+/-51 versus 155+/-50 ms, P=0.047) compared with group 2. Semiquantitative histologic scores did not differ significantly between groups. There was no significant correlation between histologic variables and left ventricular systolic and diastolic indexes. Thus, dilated cardiomyopathy shows borderline to severe left ventricular systolic impairment and distinct left ventricular diastolic filling abnormalities, according to the clinical stage. This study suggests a marked dissociation between histologic findings and functional abnormalities in early and advanced dilated cardiomyopathy.

Adult↗

PubMed1987

[Serial changes in cardiovascular dimensions and left ventricular function after surgery of valvular heart disease: a follow-up study by echocardiography].

Serial changes in cardiac function after surgery were studied in 84 patients with various valvular heart diseases using M-mode and two-dimensional echocardiography (2-DE). The results were as follows: 1. Serial postoperative changes in cardiac dimensions and left ventricular functions were well documented by M-mode and 2-DE. 2. The change in left ventricular function became most pronounced one month after surgery, and remained unchanged in many patients during the subsequent observation periods. 3. Open mitral commissurotomy (OMC) and mitral valve replacement (MVR) were compared as to their benefits for patients with isolated mitral stenosis (MS) accompanied by left ventricular dysfunction, and MVR proved superior to OMC in terms of magnitude of functional improvement. 4. (a) Ejection fraction (EF) in patients with left ventricular volume overload was overestimated due to the influence of increased preload. Accordingly, EF which tended to be depressed one month after surgery was judged to reflect altered loading conditions; it did not represent myocardial damage caused by valve replacement. (b) In patients who had MVR or aortic valve replacement (AVR) without postoperative heart failure, EF remained unchanged in the MVR group after a lapse of one month postoperatively, while it tended to improve in the AVR group. This difference was thought to be caused by changes in left ventricular systolic overload resulting from correction of regurgitation. (c) In patients with MR and postoperative heart failure, there was a tendency for EF to decrease after a lapse of one month postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Improvement in left ventricular function after rapid weight loss in obesity.

The effect of rapid weight reduction on left ventricular function and blood pressure was studied in 34 obese subjects, who all weighed more than 30% above their ideal body weight. Subjects with co-existing hypertension (N = 15) and proven coronary artery disease (N = 9) were included to assess contributions from these factors. Blood pressure (BP) was measured both indirectly and by direct ambulatory intra-arterial methods. Radionuclide ventriculography was performed at rest and at exercise, before and after dieting, which was supervised in hospital (daily intake 330 kCal day-1 for 4 weeks). Dieting induced a weight loss of (mean +/- SD) 9.6 +/- 3.5 kg (P less than 0.0001) in the whole group. The mean daytime intra-arterial blood pressure fell from 157 +/- 23/90 +/- 15 to 144 +/- 21/85 +/- 13 mmHg (P less than 0.0001). The fall in ambulatory intra-arterial diastolic blood pressure did not reach significance in the normotensive and ischaemic groups. The mean resting left ventricular ejection fraction (LVEF) in the whole group showed a significant reduction after weight loss from 61 +/- 10% to 56 +/- 6% (P less than 0.005). Although the individual groups showed a fall in LVEF, the effect was most marked in the hypertensive group, from 65 +/- 9% to 57 +/- 5% (P less than 0.002). Before dieting none of the groups achieved a 'normal' 5% rise in LVEF above basal in response to exercise, the hypertensive and the ischaemic groups both showing non-significant falls. This phenomenon was, however, reversed after weight loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Quantitation of global and regional left ventricular function by cine magnetic resonance imaging during dobutamine stress in normal human subjects.

Magnetic resonance imaging (MRI) provides high-resolution images of the heart. However, physical exercise during MRI is difficult due to space restriction and motion artefacts. To evaluate the feasibility of MRI during stress conditions, dobutamine was used as an alternative to exercise. Haemodynamics, ventricular volumes and wall thickening were measured at rest and during peak dobutamine infusion (15 micrograms.kg-1 x min-1) in 23 normal human subjects. To calculate left ventricular volumes, eight short-axis views were obtained encompassing the left ventricle from base to apex. At six levels, percent systolic wall thickening (%WTh) was measured in 18 segments (20 degrees intervals). Heart rate, systolic and diastolic blood pressures, stroke index, cardiac output and left ventricular ejection fraction increased significantly during dobutamine infusion (all P values < 0.001). In addition, %WTh increased significantly (P < 0.001) during dobutamine compared to the control state at all levels except in the apical and low-left ventricular levels. Both in control conditions and during dobutamine, segmental wall motion analysis showed the highest %WTh at the posterolateral area and the lowest %WTh at the septal region (P < 0.05). MRI clearly identifies wall motion dynamics and provides calculations of segmental wall thickening and haemodynamic parameters. Dobutamine is a useful stress agent by virtue of its safety, operator control and its effects which resemble physical exercise.

Adult↗

PubMed2000

Effects of insulin-glucose infusion on left ventricular function at rest and during dynamic exercise in healthy subjects and noninsulin dependent diabetic patients: a radionuclide ventriculographic study.

OBJECTIVES: The aim of this study was to evaluate: 1) the effects of insulin administration on left ventricular ejection fraction (LVEF) during exercise, and 2) the eventual impairment of the cardiovascular response to insulin in noninsulin dependent diabetes mellitus. BACKGROUND: Insulin influences the cardiovascular system, but its effect on left ventricular function has yet to be established. METHODS: The effects of normal saline (test A) and insulin-glucose (insulin = 1.7 mU x kg(-1) x min(-1); glucose = 6 mg x kg(-1)min(-1)) (test B) infusions on systolic and diastolic functions at rest and during dynamic exercise were examined by radionuclide ventriculography. Twenty-two noninsulin-dependent diabetic patients and 22 gender, age and body mass index matched healthy subjects were investigated. RESULTS: Both groups had normal scintigraphic parameters at rest and during dynamic exercise. Rest- and stress-LVEF as well as rest- and stress-peak filling rate were significantly (p < 0.001) lower in diabetic than in healthy subjects, both in test A and B. Rest-LVEF was significantly higher during test B than it was in test A only in diabetic subjects (p < 0.01). Stress-LVEF was significantly higher (p < 0.05) during test B than it was in test A, in both groups. Insulin-glucose infusion did not modify rest- and stress-peak filling rate in either group. No difference in left ventricular end diastolic volume and in mean blood pressure was found between test A and B at rest and during exercise in either group. A significant linear correlation between LVEF and the index of insulin sensitivity was found in diabetic patients. CONCLUSIONS: In both normal and diabetic humans, insulin induces a very important rise in LVEF after submaximal work. However, the rise is significantly lower in diabetic than in nondiabetic subjects. The increase in exercise-LVEF on insulin is likely due to an enhancement of ventricular contractility. Insulin resistance could justify the lower angioscintigraphic indexes in diabetic subjects.

Adult↗

PubMed1995

Prediction of improvement in left ventricular function with iodine-123-IPPA after coronary revascularization.

UNLABELLED: Iodine-123-phenylpentadecanoic acid (IPPA) is a synthetic fatty acid suitable for myocardial imaging. This study is the result of a Phase I/II trial to evaluate IPPA's ability to predict functional recovery in patients undergoing coronary revascularization. METHODS: Twenty-three patients with documented coronary disease underwent sequential SPECT imaging with IPPA before and radionuclide ventriculography both before and 8 wk after revascularization. Software was developed to evaluate myocardial IPPA metabolism and to determine the fraction of the left ventricle with intermediate metabolism. RESULTS: There was a significant correlation between initial IPPA uptake and final LVEF. The fractional area of the left ventricle demonstrating IPPA metabolism in the intermediate metabolic range was significantly higher in patients who demonstrated a 5% or greater increase in EF after revascularization (0.90 +/- 0.08 versus 0.78 +/- 0.17, p = 0.04). When only the patients who received complete revascularization were evaluated, there was a more significant difference (improved 0.92 +/- 0.05 versus 0.74 +/- 0.17, p = 0.011). Taking a lower limit of 1 s.d. from the mean, (87%) the six patients who had > or = 5% increase in LVEF after revascularization had more than 87% of the left ventricle in the intermediate metabolic range, whereas seven of ten patients whose change in LVEF was < 5% had less than 87% in the intermediate metabolic range (p = 0.011). CONCLUSION: In this initial experience, the amount of myocardium in the intermediate metabolic range is associated with improvement in LVEF after revascularization, especially in patients receiving complete revascularization.

Coronary Disease↗

PubMed2005

[Left ventricular function in congenital hypothyroidism neonates before and after thyroxine substitution therapy].

OBJECTIVE: To evaluate left the systolic and diastolic functions in neonates with congenital hypothyroidism (CH) as well as the effect of thyroxine substitution therapy on left ventricular function and its correlation with thyroid hormones serum levels. METHODS: M-mode echocardiography was used to examine the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), pulse wave Doppler was used to examine the peak early diastolic mitral inflow velocity (E(m)) and peak late diastolic mitral inflow velocity (A(m)), quantitative tissue velocity imaging (QTVI) was used to examine the systolic peak mitral annular velocity (s(m)), early diastolic peak mitral annular velocity (E(m)), and the late diastolic peak mitral annular velocity (a(m)), and tissue tracking imaging (TTI) was used to detect the systolic mitral annular displacement (MAD) in 40 neonates with congenital hypothyroidism aged 15-28 days before and after 1-month levothyroxine substitution treatment. Thirty normal neonates were used as controls. Chemiluminescent immunoassay was used to measure the TT(3), TT(4) and TSH levels. Correlation analysis was also made between the ventricular function parameters and the serum TT(3), TT(4), and TSH levels. RESULTS: The left systolic function parameters (LVEF, s(m), MAD, E(m) and e(m)) was 0.61 +/- 0.08, 2.60 cm/s +/- 0.60 cm/s, 0.29 cm +/- 0.06 cm, 0.59 m/s +/- 0.12 m/s and 2.72 cm/s +/- 1.43 cm/s respectively, in CH group, and 0.67 +/- 0.06, 3.25 cm/s +/- 0.51 cm/s, 0.41 cm +/- 0.08 cm, 0.72 m/s +/- 0.11 m/s and 4.51 cm/s +/- 1.23 cm/s in control group (P < 0.01). Left function in CH neonates before treatment were all lower than those of the controls (P < 0.01), which significantly increase after 1-months L-T(4) substitution therapy, 0.69 +/- 0.05, 3.46 cm/s +/- 0.64 cm/s, 0.45 cm +/- 0.08 cm, 0.82 m/s +/- 0.17 m/s and 5.09 cm/s +/- 1.37 cm/s, (P < 0.01). Those parameters were positively correlated with TT(4) serum levels (P < 0.01), and were negatively correlated with TSH (all P < 0.01). In particular, MAD, sm, E(m), and em were highly correlated with serum TT(4) and TSH (r = 0.667, 0.538, 0.478, and 0.599 respectively, all P < 0.001;and r = -0.670, -0.521, -0.490, and -0.583 respectively, all P < 0.001). CONCLUSION: Neonates with CH have lower left systolic and diastolic functions. Early L-T(4) substitution therapy can reverse these changes.

Congenital Hypothyroidism↗

PubMed2004

Improvement in diastolic left ventricular function after coronary artery bypass grafting as assessed by recordings of mitral annular velocity using Doppler tissue imaging.

AIMS: The aim of the study was to evaluate the changes in diastolic function after coronary artery bypass grafting (CABG), using pulsed-wave Doppler tissue imaging (DTI). METHODS: Fifty-three patients with coronary artery disease were studied before and 3 and 12 months after CABG. Using pulsed-wave DTI, the mitral annular velocities were determined at 4 sites in the left ventricle (LV). Patients were also examined with dobutamine stress echocardiography and myocardial scintigraphy before and 3 months after CABG. RESULTS: The conventional transmitral velocity profiles were unchanged after CABG. DTI showed a marked improvement in diastolic LV function after CABG (early diastolic velocity: 7.5+/-1.9, 8.2+/-1.7 and 9.3+/-2.7 cm/s before and 3 and 12 months after CABG, respectively, P < 0.01). The improvement in early diastolic velocity was more pronounced in patients showing no sign of residual ischemia in comparison to those with residual ischemia determined by myocardial scintigraphy (7.41+/-2.04 vs. 9.25+/-2.61 cm/s, P < 0.01 in the nonischemic group; 7.29+/-2.16 vs. 8.41+/-2.55 cm/s, n.s., in the ischemic group). Before CABG, a significant increase in the systolic velocity (6.4+/-1.3 vs. 8.7+/-2.5 cm/s, P < 0.001), but not the early diastolic velocity (7.6+/-1.9 vs. 8.0+/-2.2 cm/s), was noted during stress echocardiography. Three months after CABG, both the systolic (6.5+/-1.3 vs. 9.3+/-2.8 cm/s, P < 0.001) and the early diastolic velocities (8.1+/-1.8 vs. 10.3+/-2.2 cm/s, P < 0.001) improved during stress echocardiography. CONCLUSION: The results of the present study show that diastolic function improves at rest and under stress in patients after CABG. The improvement was seen only in patients without postoperative signs of reversible ischemia.

Aged↗

PubMed1981

Effect of PEEP on left ventricular function in right-heart-bypassed dogs.

Positive-pressure ventilation with positive end-expiratory pressure (PEEP) has been associated with elevation of left ventricular filling pressure for a stable or reduced cardiac output. To exclude the possibility that right ventricular distension due to increased pulmonary vascular resistance decreases left ventricular compliance (ventricular interdependence), we studied the effect of PEEP on left ventricular function in open-chest right-heart-bypassed dogs. A rightward shift of the left ventricular function curve was caused by 15 cmH2O PEEP without a change in the aortic pressure-flow relationship. The pericardial pressure, however, was found to exceed atmospheric pressure on 15 cmH2O even with the chest widely opened. This increase in the pressure surrounding the heart accounted for the increase in left ventricular filling pressure. We postulate, therefore, that the elevation in left ventricular filling pressure found with PEEP is due in part, if not entirely, to mechanical interaction of the heart and lungs by direct compression or pericardial traction.

Animals↗