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PubMed1996

-Recanalization of chronic coronary artery occlusions: effect on clinical symptoms and left ventricular function-.

UNLABELLED: Angioplasty of chronically occluded coronary arteries is discussed controversially. This study was performed to investigate the potential benefit of recanalization procedures. Between 1/91 and 10/93 occlusion angioplasty was attempted in 408 patients. 322 persons were followed with repeat angiography performed in 177 patients. Quantitative analysis of left ventricular function was performed in 34 patients before and after successful occlusion angioplasty. Primary reopening rate was about 71% with highest success rate for occluded LAD (82%). Angiographic controls showed open arteries in 80 (45.2%) patients, 53 (30.0%) had restenosis and 44 (24.8%) reocclusion. Anginal status was improved by one CCS-class or more in 197 patients (61%), mean exercise workload increased from 115.8 watts to 136.1 watts (p < 0.0001). Out of 34 patients, 25 (73.5%) showed improvement of regional ventricular function, mean ejection fraction increased from 56.9% to 64.1% (p < 0.001). Follow-up angiography revealed open arteries in 58% of patients if dissection was absent. When dissection type B, C or D NHLBI was present, only 32% of the vessels were open. CONCLUSION: In selected patients occlusion angioplasty is feasible with acceptable primary results. Anginal complaints and functional status were influenced positively, left ventricular function showed improvement indicating the presence of hibernating myocardium. In patients with suboptimal primary results (dissection) repeat angiography may be indicated.

Adult↗
PubMed1971

Left ventricular function in acute myocardial infarction.

Left ventricular catheterization was carried out in 40 patients with acute myocardial infarction. Left ventricular end-diastolic pressure (LVEDP) was elevated in 85% of the patients studied. In 14 patients with apparently uncomplicated infarcts, LVEDP averaged 15 mm Hg, and cardiac index (2.98 liter/min/m(2)), stroke volume (38.3 ml/m(2)), and stroke work (49.2 g-m/m(2)) were within normal limits. In 12 patients with clinical signs of left ventricular failure, LVEDP averaged 29.9 mm Hg, cardiac index was at the lower limit of normal (2.79 liter/min/m(2)), but stroke volume (31.6 ml/m(2)) and stroke work (37.3 g-m/m(2)) were reduced. In 14 patients with clinical signs of shock, LVEDP averaged significantly lower than in the heart failure group (21.1 mm Hg), but cardiac index (1.59 liter/min/m(2)), stroke volume (16.5 ml/m(2)), and stroke work (11.1 g-m/m(2)) were markedly reduced. A large presystolic atrial "kick" (average amplitude 9.5 mm Hg) was an important factor in the high LVEDP in the patients with heart failure but not in those with shock. The first derivative of left ventricular pressure was significantly lower in shock than in the nonshock group. Although right atrial pressure (RAP) and LVEDP were significantly correlated (r = 0.49), wide discrepancies in individual patients rendered the RAP an unreliable indicator of the magnitude of left ventricular filling pressure. THESE DATA SHOW THE FOLLOWING: (a) LVEDP is usually elevated in acute myocardial infarction, even in absence of clinical heart failure; (b) cardiac output apparently is supported by increased LVEDP and compensatory tachycardia; (c) in patients with shock, left ventricular function usually is markedly impaired, but inadequate compensatory cardiac dilatation or tachycardia could contribute to the reduced cardiac output in some individuals; (d) lower LVEDP in shock than in heart failure may represent differences in left ventricular compliance.

Adult↗
PubMed1987

Operative management of coronary artery disease with poor left ventricular function.

In order to evaluate CABG in patients with depressed left ventricular function, 117 patients with an EF under 35 percent were analyzed. All patients had angina pectoris. Congestive heart failure was present in 38 percent, and one or more myocardial infarctions in 90 percent. The period of followup was up to 72 months. The hospital mortality rate was 4 percent and the late mortality rate 6 percent. Although ideal randomized trials comparing surgical and medical therapy in patients with angina and depressed left ventricular function are not available, we nevertheless believe that CABG should be available to this subset of patients. The majority of these patients will derive clinical benefit from CABG.

Adult↗
PubMed2000

Nitric oxide inhibition intensifies the depressant effect of cocaine on the left ventricular function in anaesthetized pigs.

Myocardial ischaemia and left ventricular dysfunction have been described in cocaine users. Whether nitric oxide (NO) inhibition may potentiate the effects of cocaine on coronary circulation and ventricular function is still unknown. In order to test this hypothesis, 38 pentobarbital-anaesthetized pigs were instrumented for systolic blood pressure, coronary blood flow, left ventricular dp/dt, cardiac output, left ventricular end-diastolic and end-systolic lengths and shortening fraction. The pigs were randomized into three groups: control group: i.v. saline (n = 5); group 1: i.v. cocaine, 10 mg kg-1 over 20 min (n = 17); group 2: the same doses of cocaine 30 min after i.c. L-NAME 20 microg/kg min-1 infusion (n = 16). In order to know whether the observed effects were specific of NO inhibition, in five pigs i.c. L-arginine was simultaneously infused with L-NAME, in five pigs i.c. NTG, an endothelial-independent vasodilator, was simultaneously infused with L-NAME before cocaine was administered, and in nine additional pigs the proximal left anterior descending (LAD) flow was reduced to around 20% of the basal value by means of a mechanical occluder before cocaine was administered. Cocaine i.v did not change the coronary blood flow, while it induced a significant reduction in cardiac output, left ventricular dp/dt and shortening fraction (15 +/- 4-8 +/- 4%, P < 0.05). When cocaine was administered after L-NAME infused i.c. during 30 min, a significantly more severe reduction of the shortening fraction (12 +/- 3-4 +/- 2%, P < 0.0001) was induced; this effect was abolished by simultaneous perfusion of L-arginine i.c. NTG. The results when cocaine was administered after the 20% LAD flow reduction by mechanical occluder did not differ from those of cocaine alone. NO inhibition intensifies the cocaine-induced left ventricular dysfunction.

Anesthesia↗
PubMed1995

[Right ventricular function in patients with obstructive sleep apnea].

Obstructive sleep apnea often affects the cardiovascular system. So far, only few data are available on its influence on the function of the right ventricle that can be evaluated by gated radionuclide ventriculography. This technique was performed on 68 patients with polysomnographically verified obstructive sleep apnea. 27.9% of the patients showed an impairment of right ventricular function. There was no correlation between right ventricular function and degree of obstructive sleep apnea or pulmonary artery pressures--as evaluated by right heart catheterization. Gated radionuclide ventriculography thus seems to be suitable for early detection of pathological effects of obstructive sleep apnea on the function of the right ventricle.

Adult↗
PubMed1998

Effects of exposure to altitude on men with coronary artery disease and impaired left ventricular function.

The effects of altitude on coronary patients with impaired left ventricular function are virtually unknown and the question arises whether an exposure to altitude poses a risk to such patients. Twenty-three patients with coronary artery disease (mean age 51 +/- 9 years; group H) with a mean ejection fraction of 39 +/- 6% were compared with 23 normal subjects (mean age 53 +/- 6 years; group N). Both groups underwent a maximal symptom-limited bicycle stress test at 1,000 m and 2 days later at 2,500 m. In both groups, exercise capacity decreased significantly (group H, 1,000 m 162 +/- 28 W, 2,500 m 155 +/- 28 W, p = 0.02; group N, 1,000 m 205 +/- 28 W, 2,500 m 198 +/- 25 W, p = 0.02). Maximal heart rate and blood pressure did not differ between 1,000 and 2,500 m; oxygen saturation at rest and during exercise remained unchanged. At 2,500 m, the test was terminated more often because of dyspnea, but the level of perceived exertion (Borg) was similar to that at 1,000 m. There were no complications or signs of ischemia. Thus, patients with coronary artery disease with impaired left ventricular function without residual ischemia have good tolerance to exposure to altitude. The effects in patients are comparable to those in a group of normal subjects and the risk for an adverse event is not increased.

Adult↗
PubMedDate not supplied

Beneficial effects of streptokinase on left ventricular function after myocardial reoxygenation and reperfusion following global ischemia in the isolated rabbit heart.

To determine the effect of streptokinase on the ischemic myocardium independent of its effects on the occluding thrombus, the isolated rabbit heart, perfused with Krebs-Henseleit solution, was subjected to a 45-min period of ischemia--83% reduction in myocardial (perfusion) flow--plus anoxia (95% N2 and 5% CO2), followed by restoration of perfusion and reoxygenation. Streptokinase, 75 or 150 IU/min, was infused starting 15 min before reperfusion and continuing for 30 min after reperfusion. Compared with the control group, streptokinase was associated during reperfusion with a significant dose-dependent greater restoration or smaller depression of ventricular function, dP/dt, and developed pressure. To determine if streptokinase effects were mediated during the ischemic or reperfusion phase, the high streptokinase dose was administered in either the last 30 min of the ischemia or the first 30 min of reperfusion. The improvement in recovery of left ventricular function was primarily in the group having streptokinase administered only during the ischemic period. Thus, streptokinase affects the ischemic myocardium so that there is an acceleration in the recovery of ventricular function or a reduction of the impairment in ventricular function during myocardial reperfusion.

Animals↗
PubMed1994

[Ambulatory monitoring of left ventricular function in patients with ischemic heart disease: effects of coronary revascularization].

The aim of this study was to assess the efficacy of coronary artery bypass using an ambulatory radionuclide monitoring system of left ventricular function (VEST) during daily activities in patients with previous myocardial infarction and coronary artery disease. Ten patients with previous myocardial infarction, clinical evidence of residual angina and angiocardiographically proven coronary artery disease of at least two epicardial vessels were studied by VEST 8 +/- 2 days before and 15 +/- 3 days after surgical myocardial revascularization. VEST allows to monitor both left ventricular function and 2 ECG leads. During the radionuclide monitoring (at least 60 min) all patients underwent handgrip test (compression of a dynamometer for 2 min at the 75% of maximal capacity), a mental stress (arithmetic operation consisting in subtracting 17 from 17,000 for 4 min), walking (140 yards) and climbing stairs (8 flights). No significant changes in left ventricular function during mental stress and handgrip both before and after the surgical procedure were observed. In the preoperative evaluation, walking induced a significantly increase in heart rate from rest to peak exercise (73 +/- 13 versus 79 +/- 11 b/min, respectively; p < 0.01). After coronary artery bypass, heart rate (rest: 92 +/- 18 b/min, effort: 98 +/- 19 b/min; p < 0.01), ejection fraction (rest: 47 +/- 8%, effort: 53 +/- 10%; p < 0.01), cardiac output (rest: 43 +/- 8 edv/min, effort: 51 +/- 11 edv/min, p < 0.01), and stroke volume (rest: 47 +/- 9%, effort: 53 +/- 9%; p < 0.01) increased at maximal effort compared to the control conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Effect of the degree of revascularization on left ventricular function after aortocoronary bypass operation].

BACKGROUND: The extent of myocardial revascularisation by aortocoronary bypass surgery can only be quantitatively evaluated by using precise criteria. In this retrospective study the effect of coronary surgery on left ventricular function was analyzed. PATIENTS AND METHODS: In 161 patients, 148 male and 13 female, aged 52.5 +/- 7.0 years (33 to 69 years) with 1 (7%), 2 (38%) or 3 vessel disease (55%) the left ventricular function was analyzed by Swan-Ganz catheterization at rest and on exercise, five months before and after coronary bypass operation. Coronary artery and bypass lesions were quantified according to a new detailed score including diseased main or side branches, segment 1 to 3, type of irrigation and area reduction of the artery cross-section. Pulmonary capillary wedge pressure and cardiac index were measured and related to the grade of revascularisation (RG) and pre-operative ejection fraction (EF), classified in the groups RG1 < 50%, n = 54; RG2 50 to 74%, n = 52; RG3 > or = 75%, n = 55, EF1 < 60%, n = 30 and EF2 > or = 60%, n = 129. RESULTS: The change in pulmonary capillary wedge pressure on exercise was in RG1, RG2 and RG3 -26.2%, -29.0% and -40.9%, respectively (p < 0.001). It was significantly higher in RG2 and RG3 than in RG1. The increase in cardiac index on exercise was significant only in groups RG2, RG3 and EF2 (p < 0.005). CONCLUSION: Adequate improvement of left ventricular function can be expected when a grade of revascularisation of 50% and more is achieved.

Adult↗
PubMed1996

Limiting lipid peroxidation in the nonischemic zone of infarcted rat hearts by indomethacin improves left ventricular function without affecting myocardial healing and remodeling.

We recently showed that indomethacin reduces lipoperoxidation occurring in the nonischemic zone (right ventricle + septum; RVS) of rat hearts with permanent coronary occlusion. The purpose of this study was to determine whether this biochemical effect is associated with an improvement of residual cardiac function or with modifications of delayed ventricular remodeling, or both. Rats received either indomethacin (1 mg/kg i.p.) or a placebo 5 min before coronary occlusion, and then twice a day for 48 hours. Six hours after ligation, myeloperoxidase (MPO) activity (leukocyte infiltration index) was measured in the ischemic zone (left ventricle; LV) and in RVS. Forty-eight hours after ligation, left ventricular function was assessed in vivo. Alterations in myocardial geometry were estimated 21 days after ligation on histologic cross-sections. In the indomethacin group, cardiac function was improved compared with that with placebo, and the indexes of ventricular remodeling were not affected by the treatment. Finally, indomethacin at the dose used did not affect MPO activity in the LV. It is concluded that indomethacin treatment leads to a better maintenance of residual nonischemic tissue contractility without worsening late ventricular shape changes. These results could in part be explained by the ability of the treatment to decrease inflammatory mediator-induced oxidative stress in RVS without affecting infarct healing caused by leukocyte infiltration in LV.

Animals↗
PubMed1982

[Amyl nitrite test in the evaluation of left ventricular function: application to ischemic heart disease and Duchenne's progressive muscular dystrophy].

The effect of amyl nitrite (AN) inhalation on the left ventricular function was evaluated by mechanocardiography and echocardiography. The patient's group consisted of 110 cases with ischemic heart disease (IHD) and 25 cases of dystrophia musculorum progressiva (DMP) of Duchenne type. The former was a representative of impairment of blood supply and myocardial involvement, and the latter was of predominant myocardial disease. The control was age-matched 32 normals for IHD group and 17 cases for DMP group. Left ventricular function was mainly evaluated by systolic time intervals (STI) and the echocardiographic correlates. Fifty-five cases of IHD group were tested by coronary angiography and left ventriculography and these data were compared with the noninvasive measures. The results were as follows: I. IHD group: The ratio of ejection time (ET) to pre-ejection period (PEP), ET/PEP, did not change so much as in controls after AN inhalation, and this percent change was much smaller in cases with lesions of the left anterior descending artery (LAD) than in cases with lesions of the right coronary artery (RCA). On the other hand, mean posterior wall velocity (mPWV) and posterior wall excursion (PWE) changed greater in patients with LAD lesion than in those with RCA lesion. In cases with LAD stenosis, percent change in ET/PEP was smaller in cases with asynergy than in cases without it, disclosing more significant impairment of the left ventricle in the former. II. DMP group: In severe cases, ET/PEP was small even at rest, and percent change by AN inhalation was smaller than control in mild cases and smallest in severe cases. This seems to be useful in evaluating the severity of the diseased process. The mPWV and PWE showed impairment of left ventricular motion even at rest, but it was clearly showed in severe cases after AN inhalation. These results indicate that impairment of left ventricular function induces the poor response to AN inhalation and this, in turn, results in the lack of hyperactivity of the heart produced by this drug.

Adolescent↗
PubMed1988

The acute effects of intravenous nisoldipine on left ventricular function 24 to 72 hours after uncomplicated acute myocardial infarction.

The acute effects on left ventricular function of nisoldipine were studied in six patients 56 +/- 12 hours (range 44 to 72 hours) after the onset of uncomplicated acute myocardial infarction. Nisoldipine was administered as a 4.5 micrograms/kg intravenous bolus over 3 minutes followed by an infusion of 0.2 microgram/kg during 60 minutes. Radionuclide angiography and two-dimensional echocardiography were performed before and during infusion with nisoldipine. The left ventricular ejection fraction increased significantly from 38% +/- 10% to 49% +/- 10% (P = 0.028) during nisoldipine infusion. Regional wall motion index was determined both by radionuclide and by two-dimensional echocardiography and showed a significant change during nisoldipine infusion from 1.9 +/- 0.3 to 1.5 +/- 0.3 (p = 0.028, radionuclide angiography) and from 0.7 +/- 0.2 to 0.3 +/- 0.2 (p = 0.043, two dimensional echocardiography). Heart rate increased significantly from 78 +/- 12 min-1 to 92 +/- 13 min-1 (p = 0.028), but mean double product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine significantly improves global and regional left ventricular function in patients shortly after acute myocardial infarction. This beneficial effect may, however, be partially offset by an increase in heart rate. Since mean double product did not change, it is suggested that nisoldipine may improve coronary blood flow in patients with acute myocardial infarction.

Acute Disease↗
PubMed1997

Collagen scar formation after acute myocardial infarction: relationships to infarct size, left ventricular function, and coronary artery patency.

BACKGROUND: Left ventricular function after acute myocardial infarction (AMI) is determined by the expansion of the infarct zone and remodeling of the noninfarcted myocardium. An occluded infarct-related artery (IRA) is an independent risk factor for remodeling. METHODS AND RESULTS: Changes in myocardial collagen metabolism were evaluated in 36 patients with suspected AMI. The plasma creatine kinase MB fraction and myoglobin release curves were analyzed for assessment of early reperfusion and infarct size. Collagen scar formation was evaluated by measurement of serum concentrations of the aminoterminal propeptide of type III procollagen (PIIINP), the aminoterminal propeptide of type I procollagen (intact PINP), and the carboxyterminal propeptide of type I procollagen (PICP). Plasma renin activity and urine excretion of cortisol and aldosterone were also measured. Coronary angiography and left ventricular cineangiography were performed during early hospitalization. The serum concentration of PIIINP increased from 3.50+/-0.20 to a maximum of 5.08+/-0.36 microg/L (n=32) in the patients with AMI, whereas the concentrations of intact PINP and PICP tended to decrease. The area under the curve (AUC) of PIIINP during the first 10 postinfarction days was larger in patients with severe heart failure or ejection fractions < or = 40% than in those with no heart failure or with an ejection fraction > 40% (P<.05 and P<.01, respectively), and it was also larger in the patients with TIMI grade 0 to 2 flows than in those with TIMI 3 flows (P<.05), despite similar enzymatically determined infarct sizes. No significant correlations between PIIINP and neurohumoral parameters were observed. The AUC of PIIINP and the change in PIIINP during the first 4 days were significantly correlated with indices of cardiac function. CONCLUSIONS: Collagen scar formation after AMI can be quantified by measurement of serum PIIINP concentrations. Scar formation is more prominent in large infarctions causing left ventricular dysfunction and in patients with occluded IRAs.

Adult↗
PubMed1989

Noninvasive evaluation of left ventricular function in chronic severe anemia.

Left ventricular function was evaluated noninvasively in cases of chronic severe anemia (CSA) by recording systolic and diastolic time intervals (STI and DTI). These time intervals were recorded in 38 patients with CSA (hemoglobin below 7 g%), without cardiac decompensation, and in 30 control subjects. STI and DTI were measured from the simultaneous recordings of the apexcardiogram, carotid arterial pulse, electrocardiogram and phonocardiogram. The left ventricular ejection time was significantly prolonged (p less than 0.02), and associated with marked shortening of the PEP and reduction of the PEP/LVET ratio (p less than 0.001 in each case) in cases of CSA as compared to controls. Regarding the DTI, there was significant shortening of total filling time, slow filling time (p less than 0.001 in each case) and atrial systole (p less than 0.01) with no appreciable change in rapid filling time and isovolumic relaxation time. The SFT/RFT ratio and a/H ratio (the amplitude of the a-wave relative to the total height of the apexcardiogram) showed significant reductions (p less than 0.001 in each case). These changes in STI and DTI indicate enhanced left ventricular performance during diastole followed by faster and more complete relaxation during diastole in CSA.

Adult↗
PubMed2004

[Relationship between redox state of whole arterial blood glutathione and left ventricular function after acute myocardial infarction].

OBJECTIVES: To investigate the role of oxidative stress in left ventricular function after acute myocardial infarction. METHODS: We studied 41 patients with acute myocardial infarction (30 men and 11 women, mean age 61.7 +/- 11.6 years) with Thrombolysis in Myocardial Infarction grade 3 recanalization of occluded coronary arteries within 12 hr after onset. Cardiac catheterization was performed at the time of admission and before discharge. Three markers for oxidative stress were measured: plasma lipid hydroperoxide, plasma creatol and whole arterial blood glutathione at the time of admission. RESULTS: Mean time from onset to recanalization was 5.2 +/- 0.6 hr. The patients were divided into two groups according to the changes in left ventricular wall motion (LVWM); patients who showed improvement in LVWM and those without improvement. There were no significant differences in age, sex, coronary risk factors, severity of coronary artery disease, time from onset to recanalization or ejection fraction between two groups. Maximum creatine kinase and C-reactive protein levels in patients without LVWM improvement were significantly higher than in patients with improvement. Plasma levels of lipid hydroperoxide and creatol did not differ significantly between two groups. On the other hand, reduced glutathione/oxidized glutathione ratio in arterial blood in patients without LVWM improvement was significantly lower than in patients with LVWM improvement (69.8 +/- 3.4 vs 85.5 +/- 2.9, p < 0.05). CONCLUSIONS: Our results suggest that whole arterial blood glutathione is more oxidized in acute myocardial infarction patients without LVWM improvement than in patients with improvement. Redox state of arterial blood can be a predicting factor for left ventricular function after acute myocardial infarction.

Aged↗
PubMed1994

Exercise capacity and systolic and diastolic ventricular function after recovery from acute dilated cardiomyopathy.

OBJECTIVES: This study was undertaken to determine whether abnormalities in exercise capacity or ventricular function persist after recovery from acute dilated cardiomyopathy. BACKGROUND: Persistent ventricular structural abnormalities could cause abnormalities in exercise capacity or ventricular function. METHODS: The results of rest and exercise first-pass radionuclide ventriculography in 18 patients who were seen within 6 months of the onset of dilated cardiomyopathy and subsequently had a normal rest left ventricular ejection fraction were compared with those of age- and gender-matched control subjects. RESULTS: Patients were studied 144 +/- 34 (mean +/- SEM) days after the onset of left ventricular dysfunction at a time when heart failure symptoms had resolved. Patients with myocyte necrosis, as assessed by endomyocardial biopsy (n = 13) or antimyosin scintigraphy (n = 12), recovered more rapidly than did those without necrosis. Oxygen consumption both at peak exercise (17.7 +/- 1.2 vs. 26.1 +/- 1.5 ml/kg per min, p < 0.05) and at the anaerobic threshold (11.1 +/- 0.5 vs. 17.1 +/- 1.3 ml/kg per min, p < 0.05) was lower in the patients who had recovered from cardiomyopathy than in control subjects. Rest and exercise end-systolic and end-diastolic left ventricular volumes were greater in the patients than in the control subjects, although stroke volumes were similar. Left ventricular filling at rest was lower at diastolic filling intervals of 40% and 90%, and rest and exercise left ventricular early peak filling rate normalized for end-diastolic volume was slower in the patients than in the control subjects. At long-term follow-up of 1,082 +/- 206 days, two patients had a return of heart failure symptoms and a decrease in left ventricular ejection fraction. CONCLUSIONS: Despite the apparent normalization of rest left ventricular ejection fraction, patients who have recovered from dilated cardiomyopathy have abnormalities in aerobic exercise capacity and in left ventricular systolic and diastolic performance.

Acute Disease↗
PubMed1999

Relationship between running speed, isoenzymes of serum creatine kinase and lactate dehydrogenase and left ventricular function in stallions.

The purpose of this study was to assess the possible relationship between maximal running speed, serum isoenzyme patterns of creatine kinase (CK) and lactate dehydrogenase (LDH) and echocardiographic indices of left ventricular function. A group of 15 healthy, 3-year-old Maremmano stallions were given a 100 day training programme. At the end of this the animals carried out a maximum speed test and were divided into 2 groups (A and B) according to whether or not they had attained a speed of 15 m/s. Venous blood samples were taken from each horse before exercise (T0), 2 min (T1) and 24 h (T2) after exercise. Total serum activity of CK and LDH was measured and their isoenzyme distribution pattern determined. The day before the speed test echocardiographic examination was carried out at rest to assess the left ventricular function by calculating telediastolic, telesystolic and stroke volume, ejection fraction and stroke index. Statistically significant differences were found for the CK isoenzyme pattern at T2, where Group A showed an increase in the MM fraction (P = 0.003) and a decrease in the MB fraction (P = 0.014). These changes were thought to be linked to an increased membrane leakage due to exercise and not to muscle fibre disruption because the CK and LDH total activities remained within the normal range. In Group A there was also greater left ventricular telediastolic volume (P = 0.044) and length (P = 0.033) at rest as well as a greater stroke index (P = 0.032). We concluded that the evaluation of CK pattern after exercise and of echocardiographic left ventricular function indices at rest made it possible to select for the fastest horses (Group A).

Animals↗