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PubMed1999

Usefulness of dobutamine radionuclide ventriculography for prediction of left ventricular function improvement after coronary artery bypass grafting for ischemic cardiomyopathy.

Ventricular function may improve after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy depending on the amount of contractile myocardial reserve. Based on the studies using dobutamine echocardiography to predict regional wall improvement after revascularization, we investigated the benefit of low-dose dobutamine radionuclide ventriculography for assessing functional contractile reserve in this population. The study group included 56 patients with ischemic cardiomyopathy (mean left ventricular [LV] ejection fraction [EF] of 23 +/- 5%) and multivessel disease, who were referred for viability assessment. All underwent radionuclide ventriculography before and during infusion of 5 and 10 microg/kg/min of dobutamine. An increase in global LVEF from rest to dobutamine was calculated, and 10% was considered the cutoff value to predict ventricular improvement after CABG. Of the 35 patients who underwent CABG 1 month later, 29 were available for repeated radionuclide ventriculography after 12 +/- 5 months. Of these, 15 showed improvement (delta LVEF > or = 5%, mean 10 +/- 5%) and 14 did not (delta LVEF < 5%, mean -1 +/- 3%). The increase in EF with dobutamine had the highest univariate predictive value of all parameters evaluated. The sensitivity, specificity, and positive and negative predictive values of dobutamine radionuclide ventriculography were 67%, 93%, 91%, and 72%, respectively. We conclude that dobutamine radionuclide ventriculography is a useful method to assess contractile reserve and predict ventricular functional improvement after CABG in patients with ischemic cardiomyopathy.

Adrenergic beta-Agonists↗

PubMed1997

Highland mountain hiking and coronary artery disease: exercise tolerance and effects on left ventricular function.

Physical exercise has become a well-established concept in the secondary prevention of coronary artery disease. We investigated the exercise requirements of extensive highland mountain hiking (8.7 km, 470 m to 1220 m over sea level, average incline 8.5%, mean walking velocity < 3 km x h-1) in 11 regularly exercising male patients with history of MI and stable coronary artery disease (CAD; mean age +/- SD:61.0 +/- 3.9 yr) and 9 age-matched male healthy controls (CO; mean age +/- SD:61.2 +/- 5.0 yr). All subjects underwent continuous ECG monitoring; arterial blood pressure and blood lactate concentrations were measured several times during mountain hiking. Before and after exercise, cardiac dimensions and functions were assessed by two-dimensional echocardiography and Doppler echocardiography. The mean exercise levels for heart rate and blood lactate were compared with the corresponding data of a multistage upright cycle ergometry. Clinical manifestations of coronary insufficiency, left ventricular myocardial dysfunction, or cardiac arrhythmias > Lown IIIb were not observed in any case. No significant differences in left atrial and left ventricular dimensions and no changes in systolic left ventricular function compared with the preexercise values were found after the mountain hike tour. Doppler echocardiography demonstrated significant changes in diastolic left ventricular function in CAD, but not in CO. The peak exercise intensity during mountain hiking was equivalent to a workload of 100-125 W (1.25-1.5 W x kg-1 body weight) in a multistage upright cycle ergometry. Extensive highland mountain hiking may be a low risk alternative within the outpatient rehabilitation program for secondary prevention of CAD for MI patients with a cycle ergometric exercise tolerance > 1.5 W x kg-1 body weight.

Aged↗

PubMed2002

Effect of nebivolol on left ventricular function in patients with chronic heart failure: a pilot study.

BACKGROUND: Sympathetic activity is a significant predictor of a poor prognosis in heart failure. Beta-blockers have been shown to improve the prognosis of patients with heart failure. AIM: This pilot study examined the tolerability and efficacy of the new beta-blocker nebivolol on left ventricular function in patients with chronic heart failure. METHODS AND RESULTS: Twelve patients with an ejection fraction of 13-39% were included in this double blind, placebo-controlled randomized trial of nebivolol administered in addition to standard therapy. Exercise time, heart rate, left ventricular function and tolerability were examined at baseline and after 3 months of orally administered nebivolol (2.5 and 5 mg, n = 6) or placebo (n = 6). Nebivolol was well tolerated and the NYHA class improved in four patients. Heart rate decreased while the maximal exercise duration and performance remained stable. Left ventricular function increased (ejection fraction 31.5 +/- 10.11 to 42.0 +/- 10.99%, P < or = 0.01) after 12 weeks of nebivolol. The left ventricular end-systolic diameter decreased in the nebivolol-group from 56.5 +/- 9.40 to 50.2 +/- 9.43 mm (P < or = 0.02). CONCLUSION: These data indicate that nebivolol might improve cardiac function in patients with reduced left ventricular function.

Administration, Oral↗

PubMed1982

Dimensional characteristics of left ventricular function after coronary artery bypass grafting.

During coronary artery bypass grafting, 20 patients underwent epicardial placement of miniature ultrasonic dimension transducers across the minor-axis diameter of the left ventricle to monitor cardiac function postoperatively. Left atrial or left ventricular pressure was measured in all patients, and thermodilution cardiac outputs were obtained routinely. Data from 1, 6, 12 and 20 hours postoperatively were analyzed. Directional changes in systolic shortening of the left ventricular diameter correlated well with stroke volume measured by thermodilution techniques and could be used as an on-line index of cardiac output. In five patients who had preoperative abnormalities in wall motion, systolic bulging of the minor-axis diameter was seen initially after revascularization and then gradually resolved over the next 12 hours. Systolic bulging that did not resolve was the earliest indication of a perioperative myocardial infarction in another patient. The end-diastolic diameter increased progressively in all patients in the first 12 hours postoperatively and was associated with stabilization of cardiac function. This improvement in diastolic left ventricular filling was not reflected (p greater than 0.2) by changes in mean left atrial pressure. Therefore, ultrasonic assessment of left ventricular diameter is a simple, precise and safe method of monitoring systolic and diastolic ventricular function postoperatively.

Adult↗

PubMed1986

Changes in the left ventricular function after application of contrast media.

The authors studied at repeated ventriculographic examinations the changes in the left ventricular function after application of routinely used ionic contrast medium and of newer nonionic medium. They demonstrated that ionic medium does not significantly change the left ventricular volume and ejection fraction, but influences the left ventricular diastolic function. Nonionic contrast material does not significantly change the left ventricular function. The mechanism of side-effects of contrast agents and possible indications for the application of nonionic contrast media are discussed.

Contrast Media↗

PubMed1992

Identification of viable myocardium by dipyridamole-induced improvement in regional left ventricular function assessed by echocardiography in myocardial infarction and comparison with thallium scintigraphy at rest.

In patients with coronary artery disease and left ventricular impairment, the distinction between ventricular dysfunction due to myocardial fibrosis and postischemic, viable, although dys-synergic, myocardium has important clinical implications. Experimental studies have shown that dipyridamole can increase myocardial function in stunned segments, outlining a potential role of dipyridamole-induced functional recovery as an ultrasonic marker of myocardial viability. The aim of this study was to assess whether the increase of regional left ventricular function early during dipyridamole infusion in basally asynergic segments could identify viable myocardium recognized by rest injected, delayed (greater than 14 hours from tracer injection) thallium and (in a subset of patients) late functional recovery evaluated by a follow-up echocardiogram at rest. Twenty-two patients with angiographically documented coronary artery disease and regional dysfunction in resting conditions (average left ventricular ejection fraction 43 +/- 8%) were studied by echocardiography. All patients underwent a dipyridamole-echocardiographic test (up to 0.84 mg/kg over 10 minutes) and a delayed planar thallium study. A 13-segment model was used for both techniques. A score index ranging from 1 (normokinesia) to 4 (dyskinesia) was used for echocardiography. Thallium-201 activity was expressed in each segment as the percentage of maximal activity in the corresponding view. After dipyridamole, the wall motion score was assigned to each segment in resting conditions and at peak hyperkinesia before possible mechanical signs of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗

PubMed1990

Development of collateral circulation after acute myocardial infarction: its role in preserving left ventricular function.

The present study evaluated the effects of coronary collateral circulation developing after acute myocardial infarction on global and regional left ventricular function during the chronic stage. The study group consisted of 16 patients with initial myocardial infarction having total occlusion of the proximal left anterior descending coronary artery. To eliminate the effects of collateral circulation existing at the onset of infarction, patients with pre-infarction angina were excluded from this study. The patients were categorized in two groups depending on the extent of their collateral circulation (collateral index: CI 0-3): group A--patients with significant collateral circulation (CI = 2 or 3) to the infarct-related coronary artery; group B--patients without significant collateral circulation (CI = 0 or 1). Their heart rate, left ventricular peak systolic and end-diastolic pressures and cardiac index were similar in the two groups. The left ventricular end-systolic volume index in the group B was significantly greater than that in the group A (60 +/- 21 ml/m2 vs 34 +/- 9 ml/m2, p less than 0.05). Left ventricular ejection fraction in the group A was significantly greater than that of the group B (55 +/- 9% vs 39 +/- 15%, p less than 0.05), and a significant difference was observed in the percentage of segment shortening in the infarct area between the groups A and B (10.8 +/- 9.2% vs -0.2 +/- 5.4%, p less than 0.01). It was concluded that coronary collateral circulation which develops after acute myocardial infarction exerts beneficial effects on global and regional left ventricular function during the chronic stage.

Adult↗

PubMed1995

Physical work capacity with rate responsive ventricular pacing (VVIR) versus dual chamber pacing (DDD) in patients with normal and diminished left ventricular function.

To determine the benefit of atrial contribution on work capacity in relation to left ventricular ejection fraction, we studied 17 patients (68 +/- 13 years) with dual chamber pacemakers (DDD) implanted for high degree atrioventricular (AV) block. In random order they were assigned to rate responsive ventricular (VVIR) and to atrial triggered ventricular (VDD) stimulation. Maximum oxygen uptake (max VO2), that correlates best with work capacity, was measured by spiroergometry at a respiratory quotient of 1.1 during treadmill exercise test. Left ventricular ejection fraction at rest was determined by radionuclide ventriculography during VDD-stimulation and an AV delay of 150 ms. There were no differences between these two pacing modes relating heart rate, blood pressure, minute ventilation, exercise duration and maximal work load. In eight patients with an ejection fraction > 50% (60 +/- 10%), but not in nine patients with an ejection fraction < 50% (41 +/- 10%), maximum oxygen uptake was significantly higher (P < 0.01) during atrial triggered ventricular pacing (1440 +/- 533 ml/min) compared with rate responsive ventricular pacing (1328 +/- 536 ml/min). Thus, rate responsive single chamber pacemakers largely enable the same work capacity as dual chamber pacemakers in patients with high degree AV block. Patients with normal left ventricular function may profit most from preserved AV synchrony as shown by the higher maximum oxygen uptake on exercise.

Adult↗

PubMed1982

Left ventricular function in hospitalized geriatric patients.

Left ventricular ejection fraction was measured by gated wall motion in 62 patients, 75 years old or older, admitted to a Geriatric Acute Assessment Ward. From this group, 42 patients not taking digitalis or other cardioactive medication were selected for analysis. Thirty of them had clinically identifiable heart disease, whereas 12 did not. Resting left ventricular ejection fractions in the 12 patients without clinically identifiable heart disease averaged 0.60 +/- 0.09. None had an ejection fraction below 0.50. In the 30 patients with clinically identifiable heart disease, mean ejection fraction was 0.49 +/- 0.15 (range 0.17-0.84), P less than 0.01. In the patients with heart disease, reduction of ejection fraction was correlated with either cardiac enlargement or congestive heart failure. Neither age nor electrocardiographic abnormalities added to the strength of this correlation. Fifty-eight per cent of patients with congestive heart failure had ejection fractions greater than or equal to 0.40, suggesting that congestive heart failure in this age group is frequently related to diastolic left ventricular dysfunction unaccompanied by major systolic dysfunction. The prognosis of patients with congestive heart failure and ejection fractions above 0.35 was significantly better than of patients with congestive heart failure and ejection fractions below 0.35. From these data and other data available in the literature, it is proposed that the lower limit for ejection fraction be 0.50 for patients 75 years old or older. Congestive heart failure in patients 75 years old or older appears to be associated with relatively higher ejection fractions or even with ejection fractions within the normal range. In these patients, digitalis may not be indicated, and short term-prognosis is relatively favorable.

Aged↗

PubMed2007

Implantable cardioverter-defibrillators improve survival after coronary artery bypass grafting in patients with severely impaired left ventricular function.

OBJECTIVE: Patients with severe left ventricular (LV) dysfunction have a poor long term survival despite complete surgical revascularization. Recent data suggests that the use of Implantable Cardioverter-Defibrillator (ICD) improves survival in patients with severe LV dysfunction. We compared the survival impact of ICD implantation in patients with severe LV dysfunction who underwent CABG. METHODS: Between January 1996 and August 2004, 305 patients with LV ejection fraction (EF) < or = 25% had CABG surgery at our institution. Demographics of patients who had received an ICD (ICD+) in the post -operative period was compared to those without ICD (ICD-). Survival was evaluated by the Kaplan-Meier method. RESULTS: Of the entire group, 35 (11.5%) patients received an ICD with a median of 2 (+/-2) years after CABG. Indication for ICD implantation was clinical evidence of non sustained ventricular tachycardia (NSVT). There were no differences between the 2 groups with respect to age, gender, NYHA classification, number of bypasses, or other co-morbidities. Survival at 1, 3 and 5 years was 88%, 79%, and 67% for the ICD- group compared to 94%, 89% and 83% for the ICD+ group, respectively (figure, p < 0.05). CONCLUSION: Implantation of ICD after CABG confers improved short and long term survival benefit to patients with severe LV dysfunction. Prophylactic ICD implantation in the setting of severe LV dysfunction and CABG surgery should be considered.

Aged↗

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↗

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↗

PubMed1995

Left ventricular function after mitral valve replacement with or without chordal preservation.

The clinical significance of the chordae tendinae regarding postoperative left ventricular performance was evaluated in 148 patients with mitral regurgitation or mitral stenosis who underwent either mitral valve replacement using St. Jude Medical valve with complete chordal preservation, or with conventional mitral valve replacement, or valve repair. Mitral valve replacement preserving the autologous chordae tendinae (n = 28) or replacing them with Gore-Tex sutures (n = 16) was performed in 44 patients, 24 with mitral regurgitation and 20 with mitral stenosis. Their hemodynamic parameters were compared to those of patients who underwent conventional mitral valve replacement involving 25 with mitral regurgitation and 28 with mitral stenosis, or who underwent valve repair in 24 with mitral regurgitation, or commissurotomy in 27 patients with mitral stenosis. The LV performance was analyzed by cineangiography in the early (mean 1.2 months), and by multiple gated blood scintigraphy (MUGA), or echocardiography (UCG) in the late postoperative periods (mean 5.4 years) in the three groups of patients. In the mitral regurgitation group, the LV ejection fraction (EF) was unchanged in the chordal preserved group, but it was decreased in the conventional replacement and repair groups. The LV contractility index was better in the chordal preserved than in the conventional group. Both the LVEF by MUGA, and LV fractional shortening (FS) by UCG were significantly higher after chordal preservation or repair than after conventional valve replacement. The chordal preserved group exhibited superior LV performance than the conventional group, especially in those with mitral regurgitation and depressed preoperative left ventricular function (EF < 0.50). There were no significant difference between the three groups in patients with mitral stenosis. The results support the concept that maintenance of continuity between the mitral annulus and the papillary muscle has a beneficial effect on postoperative left ventricular performance, especially in patients with mitral regurgitation and depressed preoperative left ventricular function, but had no major effect in patients with mitral stenosis.

Adult↗

PubMed1983

Effect of age on left ventricular function during exercise in patients with coronary artery disease.

The purpose of this study was to assess the effect of age on left ventricular performance during exercise in 79 patients with coronary artery disease (greater than or equal to 50% narrowing of one or more major coronary arteries). Fifty patients under the age of 60 years (group I) and 29 patients 60 years or older (group II) were studied. Radionuclide angiograms were obtained at rest and during symptom-limited upright bicycle exercise. The history of hypertension, angina or Q wave myocardial infarction was similar in both groups. Multivessel coronary artery disease was present in 30 patients (60%) in group I and in 19 patients (66%) in group II (p = not significant). There were no significant differences between the two groups in the hemodynamic variables (at rest or during exercise) of left ventricular ejection fraction, end-diastolic volume, end-systolic volume and cardiac index. Exercise tolerance was higher in group I than in group II (7.8 +/- 0.4 versus 5.7 +/- 0.4 minutes, p = 0.009), although the exercise heart rate and rate-pressure product were not significantly different between the groups. There was poor correlation between age and ejection fraction, end-diastolic volume and end-systolic volume at rest and during exercise. Abnormal left ventricular function at rest or an abnormal response to exercise was noted in 42 patients (84%) in group I and in 25 patients (86%) in group II (p = not significant). Thus, in patients with coronary artery disease, age does not influence left ventricular function at rest or response to exercise. Older patients with coronary artery disease show changes in left ventricular function similar to those in younger patients with corresponding severity of coronary artery disease.

Adult↗

PubMed1984

Echocardiographic assessment of left ventricular function in patients with complete left bundle branch block.

To elucidate the mechanism, cardiac function and prognosis of complete left bundle branch block (CLBBB), 32 patients with CLBBB were studied using echocardiographic and vectorcardiographic methods. They were classified into 5 types: according to the presence or absence of early systolic notch and paradoxical motion of interventricular septum. Type I, an early systolic notch and paradoxical motion of the interventricular septum; type II, an early systolic notch and a flat septal motion, type III, an early systolic notch but no paradoxical motion; type IV, an early systolic notch of a slight degree but no paradoxical motion; type V, showed neither early systolic notch nor paradoxical motion. Type I patients had enlarged left ventricular dimension, severe cardiac damage and poor prognosis while type IV patients had a good ventricular function and prognosis with no complications. In type V patients, intraventricular conduction disturbances were apparent; a wide QRS loop in horizontal plane with no significant terminal delay. In type II and III, there were no typical findings. The histology revealed that the left bundle branch block was located at the bifurcation.

Adult↗

PubMed1997

Contractile reserve in patients with peripartum cardiomyopathy and recovered left ventricular function.

OBJECTIVES: Peripartum cardiomyopathy is a rare complication of pregnancy. Thirty percent of patients with this disorder are reported to recover baseline ventricular function within 6 months of delivery, but the ability of these ventricles to respond to hemodynamic stress is unknown. The aim of this investigation was to quantitatively assess the contractile reserve of patients with a history of peripartum cardiomyopathy and recovered left ventricular function. STUDY DESIGN: Baseline left ventricular contractility was assessed by use of the load and heart rate-independent relationship between end-systolic stress and rate-corrected velocity of fiber shortening. Data were acquired from "recovered" patients (10.5 +/- 11.6 months after delivery) and compared with data from matched nonpregnant controls with use of two-dimensionally targeted M-mode echocardiography and calibrated subclavian pulse tracings that were recorded over a wide range of afterloads (end-systolic stress) generated by methoxamine (1 mg/min) infusion. Contractile reserve was assessed by a dobutamine challenge (5 micrograms/kg/min) and quantified as the vertical deviation of the dobutamine end-systolic stress minus the corrected velocity of fiber shortening data point from the baseline contractility line. RESULTS: Patients with peripartum cardiomyopathy and matched controls had normal baseline heart rates, blood pressures, ventricular dimensions, and left ventricular function. Contractile reserve, however, was reduced in patients with recovered peripartum cardiomyopathy (0.30 +/- 0.12 vs 0.17 +/- 0.04 circ/sec, p < 0.03). CONCLUSIONS: Women with a history of peripartum cardiomyopathy who have regained normal resting left ventricular size and performance have decreased contractile reserve revealed by the use of a dobutamine challenge test. Ventricles of these women may respond suboptimally to hemodynamic stress in spite of evidence of recovery by routine echocardiographic evaluation.

Adrenergic beta-Agonists↗

PubMed1994

Acoustic quantification: new diastolic indices of left ventricular function in hypertension correlation with Doppler echocardiography.

A study of left ventricular diastolic function in early hypertension was performed by the new method of acoustic quantification and Doppler echocardiography. A total of 23 untreated patients, five males and 18 females (mean age 53.52 +/- 9.10 years) with mild or moderate hypertension (160 +/- 13/98 +/- 10 mmHg) and 12 normal, age- and heart-rate-matched, control subjects were studied. All subjects showed normal left ventricular systolic function and wall thickness on two-dimensional echocardiography. The following indices were obtained. (1) Acoustic quantification (AQ): the time rate of area change in early diastole (dA/dt)E, in late diastole (dA/dt)A and their ratio (dA/dt)E/(dA/dt)A. (2) Doppler echocardiography: the early peak E, the late peak A flow velocities, their ratio E/A and deceleration E-F slope in early diastole. Measurements of left ventricular diastolic function by acoustic quantification showed, in the patient group, that the time rate of area change in early diastole (dA/dt)E was significantly lower (64.7 +/- 11.0 cm2/second versus 74.3 +/- 5.9 cm2/second; P < 0.01), the rate of area change in late diastole (dA/dt)A was not significantly higher (43.3 +/- 9.2 cm2/second versus 38.4 +/- 6.0 cm2/second; P > 0.05), and the ratio between the above indices (dA/dt)E/(dA/dt)A was significantly lower (1.55 +/- 0.42 versus 1.95 +/- 0.20; P < 0.01), compared with normal values. Doppler diastolic indices were all significantly abnormal in patients, in comparison with the values of the control group. Reduced left ventricular diastolic function was found in nine of 23 patients (39.1%) by the AQ method and eleven of 23 patients (47.8%) by Doppler echocardiography. Acoustic quantification was in agreement with Doppler echocardiography in identifying left ventricular diastolic dsyfunction in nine of 11 hypertensive patients with reduced Doppler diastolic values (82% sensitivity, 100% specificity). The correlation between the two methods showed that the time rate of area change in early diastole (dA/dt)E correlated well with the early peak E flow velocity (r = 0.59), the ratio between the time rates in early and late diastole (dA/dt)E/(dA/dt)A also correlated well with the Doppler E/A ratio (r = 0.89), while a poor correlation was found between the time rate of area change in late diastole (dA/dt)A and peak A flow velocity (r = 0.26). Thus abnormal diastolic filling of the left ventricle can be seen in the early stages of hypertension, even in the presence of normal systolic function and wall thickness, while acoustic quantification could be considered as a useful noninvasive modality for the early identification of left ventricular diastolic abnormalities.

Algorithms↗

PubMed1992

[Acute myocardial infarction: recent physiopathological data. 2: Left ventricular function].

Myocardial infarction is an anatomical and therefore functional amputation of some of the myocardial tissues. Moments after acute coronary occlusion, a cascade of metabolic, mechanical and electrical ischaemia related events is observed. Contraction stops and regional left ventricular akinesis (then dyskinesis) occurs in the zone at risk of irreversible myocardial damage. This is partially compensated by hyperkinetic motion of non-ischaemic myocardium. The degree of alteration of the global ejection fraction is the resultant of these akinetic and hyperkinetic wall motions. It is lower in cases of anterior myocardial infarction, of occlusion of the proximal segment of the left anterior descending artery and of multivessel disease. Its eventual outcome depends on coronary blood flow. If the artery responsible is recanalized early, the global ejection fraction stabilises or improves. When this does not happen, the global ejection fraction decreases. The end-diastolic volume, an indicator of left ventricular remodeling, increases in relation to the size of the infarct and to the persistence of coronary artery occlusion. The delay before the appearance of the first irreversible lesions, the rate of their propagation within the myocardial wall and the presence of reperfusion lesions are poorly understood factors in the clinical setting and influence the efficacy of methods of myocardial protection.

Coronary Disease↗