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PubMed1997

Effects of transdermal nitroglycerin on left ventricular function after acute myocardial infarction.

Progressive left ventricular dysfunction in acute myocardial infarction patients is associated with a poor prognosis. It has been shown that some therapeutic measures which have the potential for limiting the infarct size and preserving ventricular function, are also able to reduce the incidence of congestive heart and improve survival. The aim of this protocol was to assess the effects of transdermal nitroglycerin administered within 72 hours after the onset of acute myocardial infarction and for the following 6 months, on left ventricular function. A total of 98 consecutive acute myocardial infarction patients were randomly allocated, within 72 hours of onset of symptoms, to a double-blind 6-month-therapy with either 10 mg/24 hour transdermal nitroglycerin or placebo. Patients underwent two-dimensional echocardiography at entry, after 2 weeks, 3 months and 6 months. In the nitroglycerin group, end-diastolic volume increased during the follow-up (+6.7%, p < 0.05) while end-systolic volume remained nearly unchanged; ejection fraction and stroke volume increased progressively (+6.3%, p < 0.05, +14.2%, p < 0.05, respectively) and a important reduction of percent of dyssynergic segments was present (-19.2%, p < 0.005). In the placebo group end-diastolic volume and end-systolic volume slightly increased during the follow-up (+2% and +4.9% respectively); ejection fraction and stroke volume remained nearly unchanged during the study; percent of dyssynergic segments showed an important decrease after 2 weeks and 6 months (-21.3%, p < 0.005). A clinically relevant increase (> 20%) in ejection fraction was present more frequently in the nitroglycerin than in the placebo group (p < 0.001). In conclusion, the early (within 72 hours) and prolonged (6 months) administration of transdermal nitroglycerin in acute myocardial infarction improves ejection fraction and stroke volume but does not modify ventricular remodeling.

Acute Disease↗
PubMed1985

[Histologically detectable myocarditis in patients with impaired left ventricular function].

In patients with impaired left ventricular function in whom dilated cardiomyopathy is initially suspected after performance of comprehensive diagnostic studies, histologic evidence of myocarditis or status-post myocarditis is being documented with increasing frequency since the systematic use of endomyocardial biopsy has been incorporated into the work-up. This investigation was undertaken to analyze the histologic, clinical, hemodynamic and immunologic findings in these patients to delineate possible relationships between histologically-documented myocarditis and dilated cardiomyopathy. Incidence of histologically-documented myocarditis. In our patient population, 41 of 150 patients with impaired left ventricular function, the etiology of which had been unknown, histologic evidence of myocarditis was documented. In seven of eight in whom active myocarditis was diagnosed at initial biopsy, after a mean follow-up period of two years the histologic findings were consistent with dilated cardiomyopathy. In similar groups of patients comparable incidences of myocarditis have been reported by Parrillo et al. in 19 of 100 (19%) and Fenoglio et al. in 34 of 135 patients (25%). A higher incidence has been reported by Zee-Cheng et al. in 22 of 35 patients (63%). Accordingly, pooled data indicate that the overall incidence of histologically-documented myocarditis was 30% in 528 patients initially suspected to have dilated cardiomyopathy. The variances in the incidence reported by the respective authors may be attributable to differences in the histologic definition of myocarditis, number of biopsies obtained, size of the patient population and the epidemiologically-related incidence of viral disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1980

[Maximum rate of left ventricular volume change--a parameter of ventricular function (author's transl)].

Peak left ventricular ejection rate (dV/dtsyst) and peak left ventricular filling rate (dV/dtdiast) were determined from biplane cineangiographies in patients with normal left ventricular function (n = 8), pressure overload (n = 11), aortic regurgitation (n = 7), mitral regurgitation (n = 9), mitral stenosis (n = 6), hypertrophic obstructive cardiomyopathy (n = 10), congestive cardiomyopathy (n = 9) and coronary heart disease (n = 17). dV/dtsyst (normal 642 +/- 187 ml s-1) was reduced in mitral stenosis (447 +/- 77 ml s-1) and was increased significantly in aortic regurgitation (1085 +/- 162 ml s-1) and mitral regurgitation (744 +/- 232 ml s-1). dV/dtsyst/EDV was correlated linearly with ejection fraction and was reduced significantly in mitral stenosis, aortic and mitral regurgitation, congestive cardiomyopathy and coronary heart disease. Ventricles with pressure overload and coronary heart disease could be separated better from normal ventricles by dV/dstsyst/EDV than by ejection fraction. dV/dtdiast (normal 549 +/- 205 ml s-1) was decreased significantly in mitral stenosis and increased in aortic regurgitation (1141 +/- 557 ml s-1) and mitral regurgitation (946 +/- 349 ml s-1). Peak left ventricular filling rate and diastolic stiffness were correlated by a hyperbolic function. The results show that peak left ventricular ejection and filling rates allow a more detailed analysis of ventricular function than the usually applied parameters. Quantification of the factors which determine the rate of change of left ventricular volume was only partially possible.

Aortic Valve Insufficiency↗
PubMed1983

Effects of propranolol on resting and postextrasystolic potentiated left ventricular function in patients with coronary artery disease.

The effect of propranolol on global and segmental left ventricular function at rest and after postextrasystolic potentiation was studied in 12 patients with chest pain. Heart rate was controlled with atrial pacing, and left ventricular cineangiograms were performed before and after 0.15 mg/kg of propranolol. During each ventriculogram a premature ventricular stimulus was introduced by means of a programmed stimulator. Propranolol decreased global left ventricular ejection fraction from 64 +/- 4.5 to 58 +/- 4.6 (p less than 0.03). Postextrasystolic potentiated global ejection fraction was not affected by propranolol (78 +/- 3.5 vs 73.6 +/- 3.4; p = NS). The area ejection fraction of the anteroapical region was decreased after propranolol (64 +/- 4.8 vs 52 +/- 6.5; p less than 0.01); however, the postextrasystolic potentiated area ejection fraction was not affected by propranolol (78 +/- 2.6 vs 71 +/- 4.6; p = NS). Frame by frame analysis of the ventriculograms demonstrated that propranolol depressed global and segmental left ventricular function by affecting the second one-third ejection fraction without influencing the first or third one-third ejection fraction. Propranolol has a small depressant effect on global and segmental left ventricular function in patients with coronary artery disease. Postextrasystolic potentiated global and segmental left ventricular function and early systolic ejection phase indices are not altered by propranolol and therefore may be useful in assessing left ventricular function in patients with coronary artery disease who are taking propranolol.

Cardiac Catheterization↗
PubMed1989

[Physical work capacity and left ventricular function assessed using an impedance cardiographic method in patients with a rheumatic mitral valve defect].

The interrelations between physical working capacity and left ventricular function were studied in 51 patients with mitral valvular disease (17 men and 34 women) by impedance cardiography. A number of physical working capacity indices and the impedanve cardiographic indices of the ejection and contractile functions of the left ventricle were determined. As an approximate assessment of the left ventricular function the degree of the changes of the impedance cardiographic indices from the state of rest to physical loading was used. A better correlation was established between the physical working capacity and the increase if the impedance cardiographic indices of the ejection and contractile left ventricular functions from the state of rest to physical loading than with the same indices determined in the state of rest only. The impedance cardiographic indices of the left ventricular function by physical loading increase to a lesser degree in patients with diminished left ventricular function at rest (combined mitral valvular disease) while in the patients with normal left ventricular function at rest ("pure" mitral stenosis) the changes are like those in healthy persons.

Adult↗
PubMed2003

Comparison of effectiveness of excimer laser angioplasty in patients with acute coronary syndromes in those with versus those without normal left ventricular function.

Depressed left ventricular (LV) ejection fraction (EF) adversely affects procedural outcome during percutaneous coronary revascularization. This study examined the acute results, effectiveness, and safety of excimer laser coronary angioplasty (ELCA) in patients with acute coronary ischemic syndromes whose LVEF was depressed (<40%) versus those with preserved LVEF. One hundred patients with acute coronary syndromes (51 with unstable angina and 49 with acute myocardial infarction) underwent ELCA. Twenty-five patients (group 1) (29 lesions; 72% thrombotic) had decreased LVEF (mean 28 +/- 6%) and 75 patients (group 2) (81 lesions; 60% thrombotic) had preserved LVEF (mean 53 +/- 8%). Group 1 had a higher incidence of 3-vessel disease, Q-wave acute myocardial infarction, cardiogenic shock, diabetes, and hypertension. High laser success (87% group 1 vs 93% group 2, p = NS) and procedural success (93% group 1 vs 98% group 2, p = NS) were achieved in both groups. Minimal luminal diameter in group 1 increased from 0.7 +/- 0.5 to 1.4 +/- 0.5 mm after the laser procedure and finally to 3.0 +/- 0.4 mm; in group 2, minimal luminal diameter increased from 0.7 +/- 0.4 to 1.3 +/- 0.5 mm after the procedure to a final of 3.0 +/- 0.5 mm. The laser energy vaporized 75% of thrombus burden from the target lesion in group 1 versus 79% in group 2 (p = NS). Thrombolysis In Myocardial Infarction flow in group 1 increased from 1.4 +/- 1.2 to 2.7 +/- 0.7 by laser and finally to 2.9 +/- 0.3, and in group 2 from 2.0 +/- 1.0 to 2.8 +/- 0.6 after the laser procedure to a final of 2.9 +/- 0.4. There were no deaths, emergency bypass surgeries, strokes, or acute vessel closures in either group. Thus, ELCA is a safe and feasible revascularization modality for patients with acute coronary syndromes whose LVEF is depressed. The laser energy vaporizes a large thrombus burden from the treated plaque. Angiographic intracoronary thrombus does not adversely affect device and procedural success in these select patients.

Acute Disease↗
PubMed2003

Effects of acute left ventricular unloading on right ventricular function in normal and chronic right ventricular pressure-overloaded lambs.

OBJECTIVE: Right ventricular pressure overload occurs in several types of (congenital) heart disease, as well as in pulmonary disease. Clinical outcome in some of these patient groups might in part be related to left ventricular loading conditions. The effects of left ventricular unloading on the function of the hypertrophic right ventricle have not been studied. We aimed to study the effects of left ventricular unloading on right ventricular hemodynamics and contractility in an animal model of chronic right ventricular pressure overload. METHODS: In lambs the pulmonary artery was chronically banded to increase right ventricular pressure to systemic levels. After 8 weeks, right ventricular contractility and hemodynamic function were assessed in these lambs, as well as in age-matched control animals, by using a combined pressure-conductance catheter in the right ventricle during baseline conditions and during complete bypass of the left ventricle. RESULTS: In both groups acute left ventricular unloading significantly decreased left ventricular pressure to low levels while aortic pressure was maintained. In the right ventricle of the control group, both end-systolic and end-diastolic volumes increased with left ventricular unloading (P <.01) while end-systolic pressure was maintained. Cardiac output was unchanged despite decreased right ventricular contractility. In the banding group acute left ventricular unloading also decreased right ventricular contractility but increased cardiac output. During acute left ventricular unloading, diastolic stiffness was unchanged in the control group, whereas it was significantly decreased in the banding group. CONCLUSIONS: Both in normal hearts and in hearts subject to chronic right ventricular pressure overload, acute left ventricular unloading decreases right ventricular contractility. Although no effects on cardiac output are encountered in normal hearts during left ventricular bypass, cardiac output is improved in right ventricular pressure-overloaded hearts, most likely related to improved right ventricular diastolic compliance.

Acute Disease↗
PubMedDate not supplied

Chronic effect of left ventricular assist pumping on right ventricular function.

We evaluated right ventricular (RV) function during left ventricular assist device (LVAD) pumping during acute and chronic experiments in both normal hearts and hearts with left ventricular failure. An LVAD was implanted between the left atrium and the descending aorta of goats. The LVAD was pumped in a counterpulsation mode and at maximum bypass flow for 4-6 weeks in chronic experiments. The following results were obtained: 1) LVAD pumping itself did not affect RV function, even after 6 weeks of pumping, 2) the dimensions of the RV free-wall segments measured by sonomicrometers showed a gradual and small increase during the early postoperative days, which was due to an increase in volume returned to the RV and the deformity of the RV cavity derived from reduction in LV volume, and 3) the same tendencies were seen even with LV failure hearts. These results suggested that 1) LVADs can assist not only the LV but also the RV by reducing RV afterload, 2) excessive and prolonged assistance by an LVAD seems to dilate the RV free-wall, and 3) preexisting RV dysfunction is the main cause of signs of RV failure during LV pumping.

Animals↗
PubMed2003

Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction.

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% +/- 16.3% at baseline to 57.3% +/- 20.1% at 6-month follow-up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% +/- 13.7% to 67.3% +/- 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% +/- 16.2% to 50.5% +/- 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% +/- 17.4% to 50.8% +/- 17.5% (P < 0.05) in the subgroup of recanalization in infarct-related vessel that had rich collateral circulation and had long-term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct-related vessel that has good collateral circulation for improving the left ventricular function.

Aged↗
PubMed1991

[Coronary surgery in patients with severely impaired left ventricular function].

Views on surgical treatment of patients with coronary disease and severely restricted left ventricular function are still controversial. In the present work the authors compare the results of direct reconstruction of the coronary arteries in 184 patients with satisfactory or medium restricted left ventricular function (SLV) with a group of 77 patients with severely restricted left ventricular function (RLV). Twenty-three clinical, angiographic, peroperative and postoperative indicators were compared. Patients with RLV had more frequently a myocardial infarction before operation, on average a more restricted functional capacity and lower ejection fraction of the left ventricle than patients with SLV. The mortality during hospitalization was 1.1% in patients with SLV and 5.2% in patients with RLV. These results confirm that reconstruction of the coronary arteries is safe also in patients with a significantly restricted left ventricular function. An essential prerequisite of successful operation is perfect peroperative protection of the heart muscle by the method of continuous local cooling.

Coronary Disease↗
PubMed1982

Assessment of left ventricular function by resting and exercise radionuclide angiocardiography following acute myocardial infarction.

Left ventricular function was evaluated by first-pass radionuclide angiocardiography in 42 patients at 3 and 8 weeks following acute myocardial infarction. Left ventricular ejection fraction, diastolic volume, and wall motion were measured at rest and submaximal exercise at 3 weeks and at rest, submaximal and maximal exercise at 8 weeks. The mean ejection fraction, end-diastolic volume, and wall motion index did not change between 3 and 8 weeks in any group either at rest or during submaximal exercise. Ventricular function was decreased at rest in patients with previous and anterior myocardial infarctions, but not in patients with inferior and subendocardial myocardial infarctions. During maximal exercise at 8 weeks, nine patients (21%) had ST segment depression, whereas 25 patients (60%) had a decrease in ejection fraction or a deterioration in wall motion. These abnormalities of ventricular function during exercise occurred equally among the infarct groups. Radionuclide angiography in patients with recent myocardial infarction demonstrated highly variable ventricular function at rest and/or during exercise in each infarct subgroup.

Adult↗
PubMed1994

The cardiovascular changes associated with equipotent anaesthesia with either propofol or isoflurane. Particular emphasis on right ventricular function.

The differences in effects of anaesthetic agents on right ventricular function have not been studied. We have developed a cross-over study design to compare the effects of propofol and isoflurane on cardiac and specifically right ventricular function. Ten patients were anaesthetised with equivalent MAC of isoflurane to MIR of propofol. After measurements had been taken on the randomly assigned first agent the patients were crossed over to the other agent and measurements were repeated. Cardiac function was assessed using a pulmonary artery catheter with a fast response thermistor. There were no differences in heart rate or blood pressure between the two agents suggesting that equivalent anaesthetic doses had been given. There were significantly (P < 0.05) higher cardiac output (4.0 to 4.5 l.min-1), right ventricular ejection fraction (35.1 to 39.4%), stroke volume (35.4 to 39.6 ml) and right ventricular end-diastolic volume index (102 to 110 ml.m2-1) with propofol compared to isoflurane. We conclude that propofol results in improved right ventricular performance compared to isoflurane. We have also shown that anaesthetic agents can be compared using a cross-over study design, and have demonstrated that MAC of isoflurane and MIR of propofol can be directly compared. We suggest that propofol may be a more suitable agent than isoflurane for anaesthesia in patients who may already have impaired right ventricular function and in whom maintaining high cardiac output may be beneficial.

Aged↗
PubMed2002

[Are there effects due to the existence of coronary collateral circulation on left ventricular function in patients with coronary artery disease?].

OBJECTIVE: The role of coronary collateral circulation (CCC) on the improvement of left ventricular function in coronary artery disease is controversial. The aim of this study is to investigate the effect of CCC on left ventricular function in patients with ischaemic heart disease. METHODS: Accordingly, 76 patients (39 female, 37 male, mean age--61 +/- 17 years) who had single vessel disease with > 85% narrowing in left anterior descending coronary artery were enrolled in this study. Coronary collateral circulation was determined according to the Rentrop classification (Class 0 = no collateral circulation; class 1 = small branches of occluded vessel fill with CCC; class 2 = epicardial segment of the occluded vessel partially fills with CCC; class 3 = epicardial segment of the occluded vessel totally fills with CCC). Left ventricular function was assessed with echocardiography and left ventricular regional wall motion score (0 = normokinetic; 1 = hypokinetic; 2 = akinetic; 3 = dyskinetic; 4 = aneurysmatic). Rentrop classification of the patients were compared with left ventricular regional wall motion scores and ejection fractions. RESULTS: Twenty one of 76 patients had no collateral circulation. The regional wall motion score of class 0 patients was similar with that of patients with CCC (class 1,2,3) (2.28 +/- 2.1 vs 3.39 +/- 2.1, p > 0.05). Particularly, the regional wall motion score was positively correlated with Rentrop classes (p < 0.05). Class 3 patients had the highest wall motion score (4.24 +/- 2.5, p < 0.05). Patients with and without CCC had similar left ventricular ejection fractions (49 +/- 11 vs 46 +/- 17, p > 0.05). CONCLUSION: This study showed that development of CCC has no preventive effect on left ventricular functions in patients with coronary artery disease. Interestingly as the stage of CCC increases left ventricular function worsens. It may be the result of the fact that patients with well developed CCC have more severe coronary artery disease.

Collateral Circulation↗
PubMed1993

Right ventricular decompression and left ventricular function in pulmonary atresia with intact ventricular septum. The influence of less extensive coronary anomalies.

BACKGROUND: Right ventricular decompression (RVD) may cause myocardial ischemia in patients with pulmonary atresia with intact ventricular septum and associated coronary artery abnormalities. Although we have previously shown that mortality is very high when two or more coronary arteries are obstructed, the effects of lesser degrees of coronary abnormalities are unknown. We therefore evaluated the effect of RVD on left ventricular (LV) function in those with less extensive coronary artery abnormalities. METHODS AND RESULTS: Preoperative cineangiograms demonstrated fistulas with or without one coronary artery stenosis in 12 of 24 patients aged 2 days to 33 months at the time of RVD. Preoperative and postoperative two-dimensional echocardiograms were analyzed for global and regional LV function. One infant with fistulas involving two coronary arteries and stenosis of the right coronary artery died from severe global LV dysfunction after RVD. Despite this, mean LV end-diastolic volume (66 +/- 17 mL/m2) and mean LV ejection fraction (60 +/- 9%) were similar in patients with and without coronary artery abnormalities before and after RVD. Before RVD, regional LV dysfunction was seen in 8 of 132 (6%) regions in those with coronary artery abnormalities and in 3 of 132 (2%) in those without coronary artery abnormalities. After RVD, there were 16 of 132 (12%) abnormal regions in those with coronary artery abnormalities and 1 of 132 (< 1%) in those without coronary artery abnormalities. In regions with normal wall motion before RVD, the presence of coronary artery abnormalities was related to regional LV dysfunction after RVD (P < .001). CONCLUSIONS: Regional LV dysfunction was rare in patients without coronary artery abnormalities. In those with less extensive coronary artery abnormalities not involving obstruction to multiple coronary arteries, regional LV dysfunction was common before and increased after RVD, but severe global LV dysfunction was unusual.

Child, Preschool↗
PubMed1981

Left ventricular function in mitral valve prolapse: assessment with radionuclide cineangiography.

Abnormalities of left ventricular contraction in patients with mitral valve prolapse have suggested a myocardial factor in this disease. To determine systolic left ventricular function in mitral valve prolapse, technetium-99m gated equilibrium radionuclide cineangiography was performed in 47 patients with this diagnosis. In 39 patients without mitral regurgitation the average ejection fraction was normal at rest (average [+/- standard error of the mean] 57 +/- 3 percent, normal 57 +/- 1 percent, difference not significant) and exceeded the lower limits of normal in all but 1 patient, whose ejection fraction was 41 percent. However, ejection fraction during maximal exercise was lower for the group of patients with mitral prolapse without mitral regurgitation than for normal subjects (average 64 +/- 2 percent, normal 71 +/- 2 percent, p < 0.005). In eight patients with mitral prolapse and mitral regurgitation, the average ejection fraction was normal at rest but was diminished with exercise in comparison with both normal subjects and patients with mitral valve prolapse without mitral regurgitation. Chest pain, arrhythmia and the pattern or extent of mitral valve prolapse on echocardiography were not independently associated with impaired left ventricular functional reserve. We conclude that, although many patients with mitral valve prolapse have normal left ventricular function, there is a subgroup without mitral regurgitation in whom diminished left ventricular functional reserve is suggestive of a cardiomyopathic process.

Adolescent↗
PubMed2002

Left ventricular function in varicose veins.

Left ventricular function (LVF) was evaluated noninvasively by recording systolic time intervals (STIs) in 25 patients suffering from varicose veins (VV) of lower limbs and compared with 25 age--sex matched controls. STI was measured from simultaneous recordings of electrocardiogram (ECG), carotid arterial pulse (CAP) and phonocardiogram (PCG). The left ventricular ejection time (LVET) was significantly shortened with marked increase in pre-ejection period (PEP) and increase in PEP/LVET ratio (P < 0.001) without any variation in electromechanical systoles (QS2) in VV patients compared to controls. These changes in STI suggest contractility of heart is adversely affected in VV patients.

Adult↗
PubMed1993

Left ventricular function in experimental mitral regurgitation with intact chordae tendineae.

Left ventricular function in mitral regurgitation has typically been studied in models that either sever the chordae tendineae or create a ventriculoatrial shunt. These methods may have adverse effects on left ventricular function independent of the regurgitant lesion. An animal model of chronic mitral regurgitation was therefore developed that both preserves annuloventricular continuity and avoids the use of external shunts. A circular 0.16 to 0.24 mm/kg defect was created in the anterior mitral valve leaflet of weanling sheep under direct vision with the aid of cardiopulmonary bypass. Six animals were studied preoperatively and immediately postoperatively (acute regurgitation group), and 20 animals were studied 8.1 +/- 0.2 (mean +/- one standard deviation) months postoperatively (chronic regurgitation group). Animals with chronic mitral regurgitation were compared with an age- and weight-matched control group that was not operated on (n = 7). Volumetric data and ejection fraction were derived from digitalized cineangiographic images. Maximal elastance was calculated from pressure-volume loops obtained from the simultaneous recording of left ventricular pressure by micromanometer-tipped left ventricular catheters, and volumes were obtained from digitalized images of epicardial echocardiographic recordings. Mitral valve perforation resulted in 3+ to 4+ mitral regurgitation and a calculated regurgitant fraction of 37% +/- 7% (mean +/- one standard deviation). Acute mitral regurgitation was associated with an increase in left ventricular end-diastolic volume from 110 +/- 17 to 121 +/- 23 ml (p < or = 0.05) and no change in end-systolic volume. These changes were associated with an increase in fractional shortening, from 29% +/- 11% to 40% +/- 10% (p < or = 0.05), and an increase in velocity of circumferential shortening, from 1.5 +/- 0.7 to 2.9 +/- 0.7 circ/sec (p < or = 0.05). However, there was no change in maximal elastance, a load-independent index of left ventricular function. Conversely, animals with chronic mitral regurgitation exhibited an elevated end-diastolic volume (202 +/- 32 versus 145 +/- 34, p < or = 0.05), an elevated end-systolic volume (104 +/- 17 versus 63 +/- 20 ml, p < or = 0.05), and a reduced ejection fraction (48% +/- 6% versus 57% +/- 9%, p < or = 0.05) compared with controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1993

Right ventricular function after normothermic versus hypothermic cardiopulmonary bypass.

Normothermic systemic perfusion in patients undergoing cardiopulmonary bypass may compromise myocardial hypothermia, a mainstay for preservation of ventricular function during iatrogenic cardiac arrest. The right ventricle is the area of the heart most susceptible to rewarming. We prospectively evaluated myocardial rewarming and indexes of right ventricular function in 30 patients undergoing coronary artery bypass grafting randomized to receive moderate hypothermic (bladder temperature 25 degrees C) or normothermic perfusion and multidose cold blood cardioplegia during cardiopulmonary bypass. All patients had significant stenosis (> 70%) of the right coronary artery, and in 27 of 30 the right coronary artery was revascularized. A right ventricular ejection fraction/volumetric catheter was used to assess right ventricular function by right ventricular ejection fraction and a preload (right ventricular end-diastolic volume) normalized right ventricular stoke work index in the prebypass and postbypass periods. Findings included the following: (1) Greater rewarming of all areas of the heart occurs with normothermic bypass, with the mean temperature difference at the end of each intracardioplegic period ranging from 4.0 degrees to 6.3 degrees C warmer than with hypothermic bypass; (2) the right ventricle was not more susceptible to rewarming than the posterior left ventricle or interventricular septum in either group; (3) right ventricular function did not differ between groups at any time in the study, including the immediate postarrest period; and (4) right ventricular function was preserved and equivalent to the prebypass baseline. We conclude that the moderate myocardial rewarming that occurs with normothermic perfusion does not compromise right ventricular preservation in patients with right coronary artery disease undergoing revascularization with multidose cold blood cardioplegia to maintain electromechanical arrest.

Aged↗