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PubMed1977

Effect of digitalis on left ventricular function in exercising dogs.

The effect of ouabain on left ventricular function in nonfailing hearts was assessed in 14 chronically instrumented dogs during graded treadmill exercise. At rest, ouabain increased the maximum first derivative of the left ventricular pressure (dp/dtmax) and stroke volume by 38% and 16%, respectively. No change occurred in end-diastolic left ventricular diameter or peak systolic left ventricular pressure. During exercise, ouabain reduced maximum running speed and limited the increments in heart rate and systolic pressure but did not alter dp/dtmax, stroke volume, or end-diastolic diameter. When atropine and ouabain were given and severe exercise was performed, there were no differences from controls in running speed, heart rate, dp/dtmax, or other parameters. When ouabain and propranolol were given dp/dtmax increased at rest and during exercise, compared with results with propranolol alone. It is concluded that the inotropic effect of ouabain is negligible during strenuous physical activity because of the presence of high levels of sympathetic stimulation. However, during exercise in the presence of beta-adrenergic blockade, increases in myocardial contractility do occur in response to ouabain.

Animals↗
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↗
PubMed1985

Improved right ventricular function following late pulmonary valve replacement for residual pulmonary insufficiency or stenosis.

Residual severe pulmonary insufficiency or stenosis may result in significant myocardial dysfunction late after repair of tetralogy of Fallot. Although pulmonary valve replacement has been advocated for selected patients, objective improvement in right ventricular function has been difficult to demonstrate. We undertook pulmonary valve replacement in 11 patients to treat residual insufficiency (n = 8) or stenosis (n = 3) and evaluated them before and after operation by radionuclide ventriculography and M-mode echocardiography. Patients' age at the original repair was 6.6 +/- 0.6 years (range 2 to 8 years) and at subsequent valve replacement was 14.6 +/- 1.5 years (range 5 to 20 years). Indications for pulmonary valve replacement were conduit stenosis indicated by a gradient greater than or equal to 75 mm Hg (n = 3), symptoms (n = 2), progressive cardiomegaly (n = 3), and new onset of tricuspid insufficiency (n = 3). Prior to pulmonary valve replacement, right ventricular ejection fraction was 0.29 +/- 0.12 (range 0.12 to 0.48) and rose to 0.35 +/- 0.10 (range 0.19 to 0.48) at a mean of 10.5 +/- 2.3 months after operation (p less than 0.05). Improvement (defined as an increase in ejection fraction greater than 0.05) was noted in seven patients whereas four demonstrated no change. Left ventricular ejection fraction before operation (0.55 +/- 0.12) was unchanged after pulmonary valve replacement (0.54 +/- 0.06). M-mode echocardiography demonstrated significant reduction in right ventricular dilatation. Right ventricular/left ventricular end-diastolic dimension fell from 1.03 +/- 0.30 to 0.73 +/- 0.13 after operation (p less than 0.01). Cardiothoracic ratio fell from 0.59 +/- 0.02 to 0.55 +/- 0.02 at a mean of 12 months after pulmonary valve replacement (p less than 0.01). Subjective improvement in exercise tolerance was noted in all seven patients who showed an increase in right ventricular ejection fraction. Of the remaining four patients, two had no improvement, one felt symptomatically improved, and one was too young for evaluation. These data demonstrate objective improvement in right ventricular function following pulmonary valve replacement and confirm the usefulness of this procedure in patients with significant right ventricular dysfunction secondary to residual pulmonary insufficiency and stenosis.

Adolescent↗
PubMedDate not supplied

[Thrombolysis and beta-block in acute myocardial infarct. Their effects on left ventricular function].

The effects of metoprolol or streptokinase or the combination of both drugs on left ventricular function and the rescue of the jeopardized myocardium in patients with acute myocardial infarction (AMI) were compared. Thirty-seven patients with AMI were allocated in 3 different groups: 19 received 15 mg of metoprolol i.v. in 15 minutes, 7 were treated with 1.5 million IU i.v. of streptokinase and 11 more received both drugs. The following variables were studied at control and one and twenty-four hours after treatment; blood pressure, heart rate, "double product", systolic time intervals, diastolic time and the sum of ST-segment elevation and the sum of the R wave in the EKG. Blood pressure, heart rate and "double product" decreased in the groups treated with metoprolol. The pre-ejection time/ejection time index did not change in any group. The diastolic time increased with metoprolol and the sum of ST-segment elevation was more reduced with the combined treatment. Also in this group, the sum of R wave did not decrease as it happened in the other 2 groups. It is concluded that the combination of streptokinase and metoprolol was more effective in the rescue of jeopardized myocardium than metoprolol or streptokinase administered alone.

Adult↗
PubMedDate not supplied

An open environment for quantitative analysis of left ventricular function using ultrasound images.

We have developed an open environment for quantitative analysis of left ventricular function using ultrasound images. The system is primarily intended for experimental purposes, i.e. clinical research and the evaluation of quantification algorithms. The modular design allows easy expansion with new analysis methods. The core of our system is the user-interface and image presentation. Image analysis methods are included as a set of tools available to the operator. Using this approach, the expensive, expert knowledge of the cardiologist is used more efficiently than in most delineation systems. During delineation, images of a complete heart cycle can be simultaneously displayed dynamically ('cine mode') in a separate window. This feature improves visual edge perception and enables accurate determination of the endocardium even in cases of very poor echogenicity. The resulting contour can be corrected locally by interactive modification using 'rubber banding'. After delineation of the images from different echocardiographic views, volume, ejection fraction, and regional wall motion are determined. Studies using contrast-enhanced echocardiography can be quantified by image intensity analysis in a region of interest in order to determine myocardial perfusion. We evaluated our method by quantifying echocardiographic studies from 12 healthy volunteers. We compared the results with magnetic resonance imaging and concluded that there was no significant difference in volume and ejection fraction calculated from both modalities. Moreover, the image display features and contour correction methods were greatly appreciated by the cardiologists who used the system.

Echocardiography↗
PubMed2000

[Short- and long-term changes in left ventricular function after surgical correction of mitral regurgitation].

After surgical treatment of mitral regurgitation (MR) left ventricular dysfunction (LVD) can appear, which is an important predictive factor of long-term morbidity and mortality. The aim of our retrospective study was the assessment of left ventricular function (LVF) with M-mode echo measurement in the early and late postoperative period. Between 01. 01. 1992. and 31. 12. 1996. 70 patients with MR (29 men, 41 women, mean age 53.8 years) had at least three M-mode echoes: before surgery (I.), after surgery within 1 year (II.) and after the first postoperative year (mean 2.4 years) (III.). The patients were divided into subgroups: a) prosthetic valve replacement (MB) 58 patients, valvuloplasty (PL) 12 patients, b) coronary bypass grafting (C) 12 patients, no coronary disease (NC) 58 patients, c) chordal rupture (R) 24 patients, other etiology (NR) 46 patients. The evaluation of LVF was based on the ejection fraction (EF) calculated from the end-diastolic (Dd) and end-systolic (Ds) diameters on M-mode echo. Statistical analysis was made by paired and unpaired t test and with correlation analysis. The Dd decreased in the whole group (T) and in all subgroups in the II. and III. measurements compared to the I. (T: 58.9 vs. 52.6 vs. 53.2 mm; p < 0.0001, p < 0.0001). The Ds did not change in any group. In all groups except C the EF decreased at the II. measurement compared to the I. values (T: 57.7 vs. 47.8%, p < 0.0001; MB: 56.6 vs. 46.6%, p < 0.0001; PL: 62.8 vs. 53.8%, p = 0.05; NC: 59.6 vs. 48.3%, p < 0.0001; R: 61.5 vs. 50.4%, p < 0.0003; NR: 55.6 vs. 46.5% p = 0.0002), and it remained significantly lower in the III. measurement as well. At the III. measurement the EF was below 55% in all groups. In the groups T, MB, NC, NR the EF increased at the III. measurement compared to the II. (W: 47.8 vs. 51.3%, p = 0.002; PVR: 46.6 vs. 51.4%, p = 0.001; NC: 48.3 vs. 52.8%, p = 0.005; NR: 46.5 vs. 49.9%, p = 0.05). In the group C the I., II., III. EF values were not significantly different. There were 33 patients with preoperative EF more than 60%. In this group the EF decreased at the II. measurement, but the III. measurement showed normalization of the EF (67.03 vs. 52.58 vs. 59.27%, p < 0.0001, p < 0.01). There was no strong correlation between the preoperative EF, Ds and early or late postoperative EF (r = 0.54, r = -0.58; r = 0.62, r = -0.56). In patients operated for MR the postoperative EF is diminished independently on the preoperative EF, the operative technique or etiology. Left ventricular dysfunction concealed by the volume overload is unmasked by the decreased EF in the early postoperative period. LVD is partly reversible in the majority of the cases, however complete reversibility takes place only in cases with preoperative EF over 60%. Hence the operation of MR in patients with EF less than 60% is considered to be too late for the reversibility of LVD.

Adult↗
PubMedDate not supplied

[Ventricular function in animals undergoing renal mass ablation. Effect of blood pressure control].

The causes of left ventricular hypertrophy (LVH) in chronic renal failure are multifactorial. The tail arterial pressure, heart weight, maximum developed pressure and pressure-volume relationship in animals with 5/6 nephrectomy (CRF, n = 16) and CRF animals who received furosemide by oral gavage (CRF-F, n = 17) were studied. All CRF animals increased their blood pressure (Basal: 117.2 +/- 0.8; 6th week: 184.8 +/- 2.9, p < 0.001) but in those treated with furosemide the blood pressure stayed within normal levels (Basal: 118.23 +/- 1.3; 6th week = 118.8 +/- 1.6, p = 0.5734). SHAM animals served as control (SHAM, n = 15). All CRF and CRF-F animals increased their levels of serum creatinine (CRF = 1.81 +/- 0.05; CRF-F = 1.75 +/- 0.05; SHAM = 0.72 +/- 0.09 mg/dL p < 0.001). Cardiac weight was elevated in CRF and CRF-F when compared with SHAM rats. The operational maximum developed pressure was similar in the three groups (CRF = 221.2 +/- 7.04; CRF-F = 255.7 +/- 10.1; SHAM = 239.9 +/- 5.5 mmHg, n.s.). However, the end-diastolic volume was significantly increased in both CRF and CRF-F when compared with SHAM rats (CRF = 91.4 +/- 9.44; CRF-F = 70.9 +/- 6.22; SHAM = 28.75 +/- 3.12 microL. p < 0.001). These data demonstrate that LVH in chronic renal failure is not dependent of the arterial hypertension, that accompanies this condition. Moreover, the systolic work of LVH animals is similar to that of normal animals, but a greater utilization of Frank-Starling mechanism to maintain normal ventricular function is needed.

Animals↗
PubMed2000

Improved right ventricular function after intracoronary administration of a C1 esterase inhibitor in a right heart transplantation model.

OBJECTIVE: Myocardial injury from ischemia can be augmented after reperfusion due to proinflammatory events including complement activation, leukocyte adhesion, and release of various chemical mediators. It has been shown that intracoronary administration of a C1 esterase inhibitor (C1 INH) significantly reduces myocardial necrosis in an experimental model of ischemia. Our study addresses the question whether the most susceptible region of the heart for ischemic injury, the right ventricle (RV), can benefit from the protective effects of C1 esterase inhibition after transplantation. METHODS: To precisely control RV volume in vivo an isovolumic model was used in which the RV volume was regulated using an intracavity high compliance balloon inserted into donor hearts of domestic pigs (34+/-4 kg). After 4 h of ischemia, donor hearts were transplanted into recipient pigs (44+/-4 kg). Treatment groups, each with six animals, consisted of C1 INH treatment or control. After opening the cross clamp, the C1 INH group animals received 20 IU/kg body weight of C1 INH intracoronary over a 5 min period. The control animals received no drug therapy. The hearts were reperfused for 60 min, and thereafter the RV balloon volume was increased in 10 ml increments until RV failure occurred. These measurements were repeated after 120 min of reperfusion. RESULTS: There was no significant difference in maximal RV developed pressure between the two groups (after 1 h, 35.7+/-5.9 vs. 40.6+/-12.7 mm Hg; after 2 h, 41.5+/-10.7 vs. 46.3+/-15.2 mm Hg; for C1 INH and control animals, respectively). However, the RV could be loaded with a significantly higher volume after both 1 h (60.0+/-20.0 ml (C1 INH) vs. 46.7+/-13.7 ml (control) balloon volume, P<0.05), and 2 h of reperfusion (70.0+/-8.9 ml vs. 60.0+/-6.3 ml; C1 INH and control animals, respectively; P<0.05). CONCLUSIONS: Intracoronary administration of a C1 INH significantly improves right ventricular function in an experimental transplant model. Thus, inhibition of the classic complement cascade may be a promising therapeutic approach for effective protection of myocardium from reperfusion injury after transplantation.

Animals↗
PubMed1985

Two-dimensional echocardiographic evaluation of right ventricular function during left heart bypass.

Right ventricular (RV) function in terms of hemodynamics and RV wall motion was studied in 14 mongrel dogs during left heart bypass (LHB) using a centrifugal blood pump. The wall motion was analyzed by two-dimensional echocardiography (2D-echo). Incremental changes in LHB flow ratios of 0% (controls), 25%, 50%, 75% and a maximum 85-100% were accompanied by decrements of segmental shortening of the interventricular septum (IVS) by 54 +/- 12%, 43 +/- 5%, 42 +/- 2%, 35 +/- 0% and 0%, respectively. In addition to akinesis of the IVS during maximum flow, a specific part of the RV free wall adjacent to the IVS also had marked depression of contractions and overall RV contraction was nearly dependent on the RV free wall opposite to the IVS. Maximum LHB flow induced complete depression of the left ventricular cavity, a marked increase in RV volume, and depression of the RV ejection fraction on 2D-echo. Excessive or prolonged LHB reduces the RV wall motion capability and may lead to right heart failure. Our results suggest that an LHB ratio of about 75% is optimum to maintain normal cardiac function, particularly that of the right heart.

Animals↗
PubMed1999

Quantitative systolic and diastolic transmyocardial velocity gradients assessed by M-mode colour Doppler tissue imaging as reliable indicators of regional left ventricular function after acute myocardial infarction.

AIMS: The aim of this study was to determine whether myocardial velocity gradients assessed by M-mode colour Doppler tissue imaging could be of clinical relevance and represent reliable indicators of regional left ventricular function after acute myocardial infarction. METHODS AND RESULTS: Among 64 consecutive patients with a first acute myocardial infarction, in 50 who had a marked asynergy in the parasternal short-axis view at the mid-papillary muscle level, myocardial velocities and velocity gradients were assessed in the anteroseptum and posterior wall by M-mode Doppler tissue imaging. Similar measurements were obtained in 11 matched healthy volunteers who served as a control group. In patients with anterior myocardial infarction, the peak myocardial velocity gradient in the anteroseptum was significantly lower when compared with controls (mean +/- [SD] 0.0 +/- 0.5 vs 1.1 +/- 0.7 s-1 during systole, P < 0.01; and 0.3 +/- 0.6 vs 2.0 +/- 0.5 s-1 during diastole, P < 0.01). Conversely, the peak systolic myocardial velocity gradient in the posterior wall was significantly higher than in controls (2.6 +/- 1.2 vs 1.8 +/- 1.2 s-1, P < 0.05). In patients with inferior myocardial infarction, the peak velocity gradient in the posterior wall was significantly lower when compared with healthy subjects (0.9 +/- 0.6 vs 1.8 +/- 1.2 s-1 during systole and 1.4 +/- 1.4 vs 4.9 +/- 1.2 s-1 during diastole, both P < 0.01). The peak systolic tissue velocity gradient in the anteroseptum was significantly higher than in controls (2.1 +/- 1.0 vs 1.1 +/- 0.7 s-1, P < 0.01). CONCLUSION: The present study indicates that myocardial velocity gradients assessed by M-mode Doppler tissue imaging are of clinical relevance for the characterization of ischaemic myocardial dysfunction after infarction and may provide quantitative assessment of segmental left ventricular function in this clinical setting.

Aged↗
PubMed1995

[Evaluation on the perioperative left ventricular function of aortic valve replacement in patients with chronic aortic regurgitation].

To evaluate the perioperative left ventricular function in 36 patients undergoing aortic valve replacement (AVR) in patients with isolated chronic aortic regurgitation (AR), hemodynamic variables before and within the first 24 hours and one month after operation were measured with Swan-Ganz catheter and echocardiography. The patients were divided into two groups based on preoperative left ventricular end-systolic volume index (LVESVI): 5 patients had a LVESVI of 90 ml/m2 and greater (group I), 31 had a LVESVI smaller than 90 ml/m2 (group II). Left ventricular dimension at end-diastole and end-systole, left ventricular end-diastolic volume index at one month after operation significantly decreased in comparison with that of preoperation. However, left ventricular ejection fraction in the two groups were not improved, and left ventricular mass index in group I did not decreased. On the other hand, changes of cardiac index, stroke volume index and left ventricular stroke work index within the first 24 hours after operation were not significantly different between the two groups. The incidence of postoperative premature ventricular contraction in group I was significantly higher than that of group II. However, there was no difficult problems in postoperative management of the two groups. It is suggested that AVR in AR with left ventricular dysfunction can safely be operated and its postoperative management is similar to AVR in AR with no left ventricular dysfunction.

Adult↗
PubMed2006

Angiotensin-converting enzyme inhibition reduces lipid deposits in myocardium and improves left ventricular function of obese zucker rats.

OBJECTIVE: Alterations in the renin angiotensin system, cardiac lipotoxicity, and left ventricular (LV) dysfunction have been reported in obese rats. The present study examined whether angiotensin-converting enzyme inhibition could ameliorate lipid deposition and ventricular function in the myocardium of obese Zucker rats (OZRs). RESEARCH METHODS AND PROCEDURES: For 6 months, rats were treated as follows: Group (G) 1, OZR, no treatment; G2, OZR + ramipril (R); G3, OZR + amlodipine (AML); and G4, lean Zucker rats. LV function was assessed by echocardiogram and lipid deposits in cardiomyocytes (LDCM) by light microscopy using Oil red O. RESULTS: At the end of the experiment, both OZR + R and OZR + AML groups presented similar reduction in blood pressure in comparison with untreated OZR (p < 0.01). OZR with R presented lower insulin-to-glucose ratio and lower serum triglycerides and cholesterol when compared with both untreated OZR and OZR with AML (p < 0.01). Fractional shortening by echocardiogram was as follows: G1, 25.4 +/- 3.8 (vs. G2 and G4, p < 0.05); G2, 37.2 +/- 2.4; G3, 29.3 +/- 4.4 (vs. G2 and G4, p < 0.05); and G4, 40.8 +/- 2.3. Percentage LDCM was as follows: G1, 12.4 +/- 2.7 (vs. G2 and G4, p < 0.05); G2, 0.8 +/- 0.2; G3, 11.1 +/- 2.1 (vs. G2 and G4, p < 0.05); and G4, 0.1 +/- 0.1. There was a negative correlation between fractional shortening and LDCM percentage in OZR (r = -0.93) and in OZR + AML (r = -0.87). DISCUSSION: AML reduced blood pressure significantly; however, it failed to modify both metabolic parameters and LDCM. In contrast, R showed a substantial reduction in LDCM, together with LV function preservation.

Amlodipine↗
PubMed1991

[Evaluation of left ventricular function using gated planar myocardial imaging with Tc-99m-MIBI].

A quantitative index of left ventricular wall motion obtained from ECG-gated planar myocardial images has been developed. Five normal controls and 39 patients with heart disease received an injection of Tc-99m-MIBI (550-740 MBq) at rest, and ECG-gated planar scintigraphy (LAO view) was performed 3 h later. Mean End-diastolic (ED) and end-systolic (ES) myocardial activities were measured using circumferential profile analysis and %count increase (CI) was determined according to the following formula; (ES count-ED count)/(ED count) x 100. The global %CI was compared with the EF obtained from contrast ventriculography (LVG; n = 29) and radionuclide ventriculography using Tc-99m-labelled RBC (RNV; n = 24). The regional %CI was compared with left ventricular wall motion assessed by LVG. The global %CI was correlated well with EF by LVG (r = 0.70) and EF by RNV (r = 0.75). The regional %CI significantly decreased in accordance with wall motion on LVG worsened at impaired region. In conclusion, gated perfusion imaging with Tc-99m-MIBI provides useful information on ventricular function in addition to myocardial perfusion.

Adult↗
PubMedDate not supplied

Modeling ventricular function during cardiac assist: does time-varying elastance work?

The time-varying elastance theory of Suga et al. is widely used to simulate left ventricular function in mathematical models and in contemporary in vitro models. We investigated the validity of this theory in the presence of a left ventricular assist device. Left ventricular pressure and volume data are presented that demonstrate the heart-device interaction for a positive-displacement pump (Novacor) and a rotary blood pump (Medos). The Novacor was implanted in a calf and used in fixed-rate mode (85 BPM), whereas the Medos was used at several flow levels (0-3 l/min) in seven healthy sheep. The Novacor data display high beat-to-beat variations in the amplitude of the elastance curve, and the normalized curves deviate strongly from the typical bovine curve. The Medos data show how the maximum elastance depends on the pump flow level. We conclude that the original time-varying elastance theory insufficiently models the complex hemodynamic behavior of a left ventricle that is mechanically assisted, and that there is need for an updated ventricular model to simulate the heart-device interaction.

Animals↗
PubMed2003

Correlation of the Tei index with invasive measurements of ventricular function in a porcine model.

BACKGROUND: The Doppler myocardial performance (Tei) index has been reported to be clinically useful in assessing left ventricular systolic and diastolic function in both adults and children. However, there are limited data to compare the Tei index with invasive measurements of ventricular function. We used a porcine model to directly correlate the Tei index with invasive indices of systolic and diastolic function. METHODS: Pressure volume loops were obtained from 10 pigs (32-45 kg). A micromanometer and a conductance catheter were placed in the left ventricle to record pressure and volume, respectively. A flow probe was placed around the ascending aorta to record cardiac output. Baseline pressure volume loops were generated during preload reduction through caval occlusion. Epicardial echocardiograms were performed just before the caval occlusion. Invasive indices including preload recruitable stroke work, ventricular stiffness constant, and cardiac output were assessed, as were noninvasive echocardiographic indices including Tei index and ejection fraction. An ischemic insult, ventricular fibrillation, was induced to alter ventricular function. After cardioversion and 40 minutes of reperfusion, echocardiographic and invasive measurements were repeated. RESULTS: There was a statistically significant inverse relationship between the percent change in Tei and the percent change in preload recruitable stroke work after ventricular fibrillation (r = -0.70, P =.02), although the correlation between the actual values of Tei and preload recruitable stroke work were not statistically significant. There was a statistically significant inverse relationship between the percent change in Tei and the percent change in cardiac output (r = -0.65, P =.03). There was a direct correlation between the value of Tei and the ventricular stiffness constant at baseline (r = 0.63, P <.05). As anticipated, the value of Tei was inversely related to ejection fraction by epicardial echocardiogram at baseline (r = -0.85, P <.001). The percent change in Tei was inversely related to the percent change in ejection fraction as well (r = -0.69, P <.05). CONCLUSIONS: This animal model is one of the first studies to demonstrate a direct correlation between the Tei index and systolic and diastolic invasive measurements of ventricular function. This supports the clinical use of this index as a measure of global ventricular function.

Animals↗
PubMed1980

Perioperative assessment of segmental left ventricular function in man. Effects of nitroprusside after bypass operations.

Direct on-line assessment of postoperative ventricular function has not been possible. We assessed the feasibility of using pulse-transit sonomicrometry to measure regional function in man postoperatively. Ultrasonic transducers (3 mm in diameter) were implanted along the minor axis of the left ventricle at midwall depth into a region supplied by a bypass graft. All wires were tunneled subcutaneously. Pressures, ECG, and regional dimensions were monitored in eight patients continuously, and at 48 to 72 hours postoperatively, the effects of sodium nitroprusside were assessed. The transducers were withdrawn with no complications. Nitroprusside was associated with an increase in systolic shortening from 1.60 +/- 0.19 to 1.92 +/- 0.25 mm and rate of shortening from 12.13 +/- 1.85 to 15.34 +/- 2.38 mm/s at constant end-diastolic lengths. Using this technique for recording regional dimensions, nitroprusside therapy augmented function at a constant preload.

Adult↗
PubMed2004

Quantitative assessment of right ventricular function using doppler tissue imaging in fetuses with and without heart failure.

BACKGROUND: Previous reports have established the use of Doppler tissue imaging (DTI) for noninvasive assessment of ventricular function, but the technique has not been validated for diagnosis of fetal cardiac failure. OBJECTIVE: The purpose of this study was to assess right ventricular (RV) function in fetuses with heart failure using DTI. METHODS: In all, 43 fetuses (36 control, 7 heart failure) were assessed using pulsed Doppler echocardiography combined with DTI. RV peak myocardial velocities during early diastole (Ea), atrial contraction, and systole were measured; and tricuspid peak velocities during early diastole (E) and atrial contraction. The ratio of E/Ea was used as an index of filling pressure were measured. From DTI, a Doppler-derived index of combined systolic/diastolic myocardial performance (DTI-Tei index) was measured. RESULTS: Compared with control fetuses, the mean Ea was significantly lower and the mean E was significantly higher in fetuses with heart failure, although these parameters did overlap between the 2 groups. The mean RV myocardial wall-motion velocity during atrial contraction, ratio of Ea/RV myocardial wall-motion velocity during atrial contraction, and RV myocardial wall-motion velocity during systole did not differ between the 2 groups. Compared with control fetuses, the mean E/Ea was significantly higher (9.71 +/- 0.91 vs 6.20 +/- 0.97; P <.0001) and the mean DTI-Tei index was significantly greater (0.79 +/- 0.11 vs 0.55 +/- 0.05; P <.0001) in fetuses with heart failure. In addition, the DTI-Tei index z score was >2 in all fetuses with heart failure. CONCLUSIONS: This study demonstrated a clinically important application of DTI-derived tricuspid annular velocities in fetuses with heart failure. Although DTI velocities were not sufficiently sensitive to identify fetuses with heart failure versus control fetuses, DTI-Tei index and E/Ea were useful and sensitive indicators of global RV dysfunction.

Blood Flow Velocity↗
PubMed1985

Left ventricular function in uremia: echocardiographic and radionuclide assessment in patients on maintenance hemodialysis.

Echocardiography and radionuclide ventriculography were performed in 37 uremic patients on maintenance hemodialysis with no apparent coronary artery disease, pericardial effusion, valvular heart disease or heart failure. These non-invasive studies were performed during the interdialytic period (about 18 hours after a dialysis). Sixty-two percent of our patients had abnormal left ventricular function with one or more abnormal echocardiographic parameters. The significant abnormalities were enlargement of the left ventricular cavity, a reduction of myocardial contractility, and thickening of the left ventricular posterior wall. Similar findings were found in 10 undialyzed uremic patients. Measurement of cardiac index and ejection fraction were found to be inadequate for a full assessment of left ventricular function and other parameters such as the mean velocity of circumferential fiber shortening and mean normalized posterior wall velocity should be included. There is a significant number of hemodialysis patients (7/37) with congestive cardiomyopathic features on the echocardiogram. Their clinical features are no different from the other patients in this study, except they have a significantly higher prevalence of uremic hyperparathyroidism. Our findings support that the existence of a specific uremic cardiomyopathy and uremic hyperparathyroidism may play an important role in the pathogenesis.

Adult↗