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At least 217 records · Page 12Linked to original sources
PubMed1996

Recovery of systolic and diastolic left ventricular function early after cardiopulmonary bypass.

BACKGROUND: Impairment of left ventricular function after cardiopulmonary bypass (CPB) is well recognized, but little is known about the time course of recovery of cardiac function early after separation from CPB. Therefore, recovery of left ventricular function was evaluated early after separation from CPB in patients undergoing coronary artery surgery. The authors tried to determine whether this recovery might be attributed to autoregulation of function by preload. METHODS: Left ventricular pressure was measured with fluid-filled catheters. Data were digitally recorded during increased pressure induced by elevating the legs. Transgastric short-axis echocardiographic views of the left ventricle were simultaneously recorded on videotape. Systolic function was evaluated with the slope (Ees, mmHg/ml) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, ml-1) of the diastolic pressure-volume relation. Cardiac function was assessed before CPB, after termination of CPB, and 5, 10, and 15 min later. Two different separation procedures from CPB were compared: in protocol 1, left ventricular function was documented during the standard procedure (n = 24); in protocol 2, the heart was optimally filled 10 min before separation from CPB (n = 12). RESULTS: In protocol 1, Ees was 2.88 +/- 0.21 mmHg/ml (mean +/- SEM) and Kc was 0.012 +/- 0.001 ml-1 before CPB. Within 10 min after separation from CPB, Ees increased from 1.10 +/- 0.32 to 2.92 +/- 0.34 (P = 0.001) and Kc decreased from 0.022 +/- 0.002 to 0.011 +/- 0.001 (P = 0.001). The parameters remained stable thereafter. In protocol 2, Ees was 2.92 +/- 0.51 mmHg/ ml and Kc was 0.011 +/- 0.002 ml-1 before CPB. Depression of systolic and diastolic function was not observed in these patients. At time 0, Ees was 2.46 +/- 0.16 and Kc was 0.012 +/- 0.002. These values remained stable throughout the entire observation period. CONCLUSIONS: Significant functional recovery was observed early after separation from CPB, which was suggestive of time-dependent changes in both systolic and diastolic left ventricular function induced by preload restoration.

Anesthesia↗
PubMed1999

Influence of right ventricular stimulation site on left ventricular function in atrial synchronous ventricular pacing.

OBJECTIVES: The study investigates the correlation between left ventricular function and QRS duration obtained by alternate right ventricular pacing sites. BACKGROUND: 1. Right ventricular apical pacing is associated with alterations of left ventricular contraction sequence. 2. A stimulation producing narrow QRS complexes is supposed to provide for better left ventricular contraction patterns. METHODS: Fourteen patients with third degree AV block received one ventricular pacing lead in apical position. The alternate lead was attached to that site on the septum that produced the smallest QRS complex as measured from the earliest to the last deflection in any of the orthogonal Frank leads (xyz). During atrial synchronous ventricular pacing, the AV delay was optimized individually and for each stimulation site using mitral valve doppler or impedance cardiography. By radionuclide ventriculography, the phase distribution histogram of left ventricular contraction was evaluated as area under the curve (AuC); systolic function was determined as ejection fraction (EF) and as absolute ejected counts (EC) in random order. The difference (delta) in QRS duration between apical and septal stimulation (deltaxyz) was correlated with the difference in phase distribution (deltaAuC) and ejection parameters (deltaEF, deltaEC). RESULTS: QRS duration was shorter with septal than with apical pacing in 9 out of 14 patients (64%); it was longer in 4 (29%), and no difference was seen in 1 patient. There was a significant positive correlation between the change in QRS duration (deltaxvz) and phase distribution (deltaAuC: r = 0.66393, p = 0.010) and a significant negative correlation to systolic function (deltaEF: r = 0.70931, p = 0.004; deltaEC: r = 0.74368, p = 0.002). CONCLUSIONS: In atrial synchronous right ventricular pacing, if the AV delay is adapted individually, decreased QRS duration obtained by alternate pacing sites is significantly correlated with homogenization of left ventricular contraction and with increased systolic function in acute tests.

Aged↗
PubMedDate not supplied

[Left ventricular function in chronic obstructive lung disease (author's transl)].

Left ventricular function was studied at rest and during post-extrasystolic potentiation in 18 patients with chronic obstructive lung disease. The contractility indices used were obtained from pressures recorded in the isovolumetric period (left ventricular end-diastolic pressure, Vmax., VECmax., dP/dtmax.) and from volume variations during ejection (end-diastolic volume, ejection fraction, VCF). Left ventricular diastolic compliance was also evaluated. All patients were hypoxic (PaO2 = 58 +/- 7 torr); six of them had cor pulmonale (group B); the remaining 12 patients constituted group A. Left ventricular function of groups A and B was similar; we conclude that right cardiac failure, in cor pulmonale, is not secondary to left ventricular failure. However, left ventricular dysfunction exists; the left ventricle is hypertrophied (probably resulting from chronic hypoxia). Pump function is altered (abnormal ventricular function points are found), but left ventricular kinetics is normal or exaggerated (ejection fraction and VCF are increased). Isovolumetric phase contractility indices are diminished; however, they may increase normally during post-extrasystolic potentiation. Left ventricular compliance is abnormal due to left and right ventricular hypertrophy and to paradoxical movement of the interventricular septum which impedes diastolic expansion of the left ventricle. These changes are responsible for decreased left ventricular output. There seems to exist an impairment of left ventricular function related to both intrinsic (secondary to hypoxia, hypercapnia, left ventricular hypertrophy) and extrinsic factors (right ventricula hypertrophy deviating interventricular septum, lowering of left ventricular preload).

Adult↗
PubMed1990

Ultrastructural pathological study of left ventricular myocardium in patients with isolated rheumatic mitral stenosis with normal or abnormal left ventricular function.

An electron microscopic study of left ventricular myocardium was carried out in 15 patients who had isolated rheumatic mitral stenosis, with particular reference to the relation among ultrastructural pathological findings, the severity of mitral stenosis and left ventricular function. They were divided into 2 groups based on left ventricular performance evaluated by 2-dimensional echocardiography and angiocardiography. The severity of mitral stenosis was determined by hemodynamic data and mitral valve areas measured by 2-dimensional echocardiography. Regardless of the level of left ventricular contractile function we consistently demonstrated varying degrees of ultrastructural pathological alterations of left ventricular muscle cells, involving the myofibrils, mitochondria, nuclei and other elements of the sarcoplasm and membranes surrounding the myocardial cells in all specimens examined. The ultrastructural pathological findings did not correlate with the severity of mitral stenosis reflected in the echocardiographic and hemodynamic data. However, those patients with abnormal left ventricular function always exhibited more extensive loss of myofibrils resulting from either disproportion of the mitochondria-to-myofibril ratio or myofibrillar degeneration. The present investigation provides the morphological data at the ultrastructural level to support the widely held concept of a myocardial factor i.e., the extent of myocardial involvement by the rheumatic process as the basic pathogenetic mechanism responsible for left ventricular dysfunction in patients with isolated rheumatic mitral stenosis. Furthermore, it is suggested that pathological alterations of myocardial ultrastructure were related to the extent of myocardial involvement by the rheumatic process rather than being structural adaptations in response to the hemodynamic derangement.

Adult↗
PubMed1991

Effects of nisoldipine on systolic and diastolic function in postinfarction patients with reduced left ventricular function: a randomized, double-blind, placebo controlled study.

The long-term effects of oral nisoldipine or placebo on clinical variables, exercise test results and echo Doppler-determined systolic and diastolic functions were studied in 30 consecutive patients with reduced left ventricular function (predischarge echocardiographic wall motion score greater than or equal to 8) following myocardial infarction. Groups were comparable in clinical variables, exercise results, echo Doppler measurements and coronary anatomy. During 6 months follow-up, death, reinfarction and bypass surgery or balloon angioplasty were equally distributed. A significant increase in exercise duration and time to onset of ST-depression was found in the nisoldipine treatment group, compared to the placebo group after 3 and 6 months. Time to onset of angina was not significantly different. Echocardiographic indices of left ventricular systolic function (ejection fraction and wall motion score) were unaltered; however, the time-velocity integral of the early diastolic filling phase and the early vs late diastolic flow velocity ratio were significantly increased while the atrial time-velocity integral vs total time-velocity integral was significantly decreased in the nisoldipine treatment group after 3 and 6 months of follow-up. In conclusion, nisoldipine reduced exercise-induced ischaemia, improved exercise capacity and diastolic left ventricular function in postinfarction patients with reduced left ventricular function.

Cardiac Catheterization↗
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↗
PubMed1976

Normalized first derivative ofthe left apex cardiogram in assessment of left ventricular function.

The relation between the left displacement apex cardiogram and the left ventricular pressure during isovolumic contraction was studied in 30 patients with cardiac disease. Using the instantaneous relation between the first time derivative and the magnitude of both the left apex cardiogram and the left ventricular pressure, normalized derivatives were obtained. These noramized velocities were correlated with each other and with several indexes of left ventricular function. The normalized derivatives of the left apex cardiogram (dD/dt/D) and the left ventricular pressure (dP/dt/P) were similar in magnitude, standard deviation and variation coefficient. No such similarity was present when the first time derivatives of each tracing (dD/dt and dP/dt) were compared. A highly significant relation was found between normalized displacement velocity and normalized pressure velocity using both total (r = 0.76, P less than 0.001) and developed (r = 0.75, P less than 0.001) displacement and pressure. Significant correlations with several other indexes of left ventricular function (end-diastolic pressure, peak dP/dt, maximal velocity of the contractile elements at zero load[Vmax]) were also observed. It is concluded that the index dD/dt/D of the left apex cardiogram is an important noninvasive tool for assessing left ventricular function in man.

Adult↗
PubMed2002

Tissue Doppler imaging in hypertrophic cardiomyopathy: impact of intraventricular obstruction on longitudinal left ventricular function.

BACKGROUND: In non-obstructive hypertrophic cardiomyopathy, tissue Doppler imaging of the mitral annulus shows severe systolic and diastolic dysfunction, with marked heterogeneity and asynchrony. In obstructive forms, the complexity of pathophysiological interactions makes conventional echocardiographic functional assessment extremely difficult and complex. OBJECTIVE: To study longitudinal left ventricular function with tissue Doppler imaging in the obstructive forms of hypertrophic cardiomyopathy. METHODS: Twenty-six patients with hypertrophic obstructive cardiomyopathy and 23 patients with the non-obstructive form of the disease, matched by age, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony indexes. Data were compared between the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to the non-obstructive forms, patients with intraventricular obstruction showed: Systolic function: similar velocities and integrals, the relations between the different sides of the annulus usually being preserved; longer isovolumic contraction time, time to peak s and PEP/LVET. Diastolic function: similar rapid filling and e/a velocities and integrals, lower atrial contraction velocity and integral, similar number of sides with e/a higher than or equal to 1 on the lateral and inferior side of the annulus; similar diastolic time intervals, except diastolic time. CONCLUSIONS: This study shows that the presence of dynamic intraventricular obstruction and the loading conditions of obstructive forms of hypertrophic cardiomyopathy do not significantly influence most annular tissue Doppler imaging parameters, showing the relative load independence of the technique. So, in obstructive hypertrophic cardiomyopathy patients: 1--Longitudinal systolic function (velocities) is similar to the non-obstructive forms--longitudinal systolic dysfunction. 2--Longitudinal diastolic function (velocities and time intervals) is similar to the non-obstructive forms--longitudinal diastolic dysfunction. 3--Left atrial dysfunction is more severe than in non-obstructive forms. 4--The inferior and lateral sides of the annulus should be those selected in order to identify pseudonormalization of the transmitral flow.

Aged↗
PubMed1994

[Effects of amrinone on left ventricular function following open heart surgery--analysis with left ventricular pressure volume loops].

The effects of Amrinone on cardiac function soon after extracorporeal circulation (ECC) were studied in 5 patients including mitral valvuloplasty, VSD closure, Fontan operation and coronary AV fistel closure. In all patients, left ventricular volume load decreased postoperatively. To evaluate the efficacy, we obtained left ventricular pressure-volume loops (P-V loop) before and after ECC and after intravenous administration of Amrinone (1 mg/kg) following ECC. P-V loops were produced by measuring left ventricular pressure using a Miller catheter which was retrogradely advanced from the ascending aorta into the left ventricle and by measuring left ventricular diameter to calculate left ventricular volume with Teichholtz' formula. Although no apparent difference of Emax was recognized before and after ECC, Emax increased from 3.2 +/- 2.5 mmHg/cm3 to 5.9 +/- 4.7 mmHg/cm3 after the administration of Amrinone. The left ventricular "systolic" pressure-volume area (PVA) which is the sum of stroke work (SW) and elastic potential energy decreased from 34.4 +/- 16.4 gm to 30.9 +/- 17.8 gm after Amrinone. No difference was also recognized in left ventricular end-diastolic pressure. Ejection fraction increased from 50 +/- 17.5% to 56.1 +/- 17.3%. These results suggested that Amrinone could improve the left ventricular function without prominent change in myocardial oxygen consumption immediately after open heart surgery.

Adult↗
PubMed1978

Noninvasive assessment of left ventricular function in myotonic muscular dystrophy.

In order to assess left ventricular function, measurements of left ventricular internal dimension and its rate of change have been made by echocardiography in 7 patients with myotonic dystrophy and the three children of one of them, who were clinically normal but had abnormal muscle biopsies. Electrocardiograms and systolic time intervals were also recorded in all. Only one patient had signs of overt heart disease and an abnormal electrocardiogram (type B WPW). Systolic time intervals were normal in all 7 patients. Five subjects had echocardiographic abnormalities, which were of minor degree except in the patient with overt heart disease who had considerable impairment of both systolic and diastolic left ventricular function. Another patient had abnormalities of both systolic and diastolic function; systolic abnormalities occurred alone in one patient and diastolic abnormalities alone in one relative. It is concluded that patients with myotonic dystrophy and no clinical signs of heart disease may have minor abnormalities of left ventricular function as shown by echocardiography. Echocardiography is more sensitive than systolic time intervals in detecting these abnormalities; both systolic and diastolic function abnormalities, alone or together, can occur. There seems to be no relation between involvement of skeletal and cardiac muscle.

Adolescent↗
PubMed1999

ACE inhibition with ramipril improves left ventricular function at rest and post exercise in patients with stable ischaemic heart disease and preserved left ventricular systolic function.

AIMS: To assess the effects of 6 months intervention with +ramipril on resting and post exercise left ventricular function in patients with stable ischaemic heart disease and preserved left ventricular systolic function. METHODS AND RESULTS: Patients (n=98, age 65+/-9 years, 37% women) were randomized to double-blind treatment with ramipril 5 mg. day(-1)(n=32), ramipril 1.25 mg. day(-1)(n=34), or placebo (n=32). Resting and post maximum exercise echocardiography/Doppler examinations were performed at baseline and after 6 months. Changes over 6 months in resting transmitral E-wave deceleration time (Edt) and Edt adjusted for heart rate (Edt/RR) differed between the ramipril 5 mg, ramipril 1.25 mg, and placebo groups: Edt 24+/-82, -1+/-69, and -29+/-64 ms, respectively, P=0. 012; Edt/RR 30+/-105, 2+/-61, and -28+/-69 ms, respectively, P=0.015. Changes in the difference between resting and post exercise Edt/RR also varied between groups: -53+/-137, -28+/-118, and 35+/-101 ms, respectively, P=0.029. No differences in E/A indices were noted. Resting atrioventricular plane displacement improved in the combined ramipril groups vs the placebo group: 0.2+/-0.8 vs -0.2+/-1.3 mm, P<0.05.Conclusion Six months ramipril treatment in patients with stable ischaemic heart disease and preserved left ventricular systolic function improved resting left ventricular function and reduced the exercise induced diastolic filling abnormalities usually seen in these patients.

Aged↗
PubMedDate not supplied

Gated planar technetium 99m-labeled sestamibi myocardial perfusion image inversion for quantitative scintigraphic assessment of left ventricular function.

BACKGROUND: Quantitative assessment of left ventricular systolic performance in conjunction with myocardial perfusion scintigraphy would significantly expand the clinical information obtained from these studies. METHODS AND RESULTS: Left ventricular function was evaluated in 264 patients in whom planar 99mTc-labeled sestamibi myocardial perfusion images were obtained in the best septal left anterior oblique projection. Digital inversion of these perfusion images allows semiautomated evaluation of the left ventricular cavity, with the commonly available edge-detection software designed for equilibrium blood pool imaging. In this study, ejection fractions derived from this technique were compared with those obtained from a myocardial perfusion phantom, first-pass radionuclide angiography, and contrast ventriculography. In vitro validation demonstrated that the myocardial perfusion image inversion ejection fractions correlated linearly with those obtained from a double-chamber phantom (r = 0.999). In vivo, there was good linear correlation between image inversion and first-pass (r = 0.88; image inversion = 0.98 first-pass +0.11), with 95% agreement on the presence or absence of significant left ventricular systolic dysfunction. There was also very good correlation between image inversion and contrast ventriculographic ejection fractions (n = 35; r = 0.85; image inversion = 0.8 contrast +0.05). Intraobserver and interobserver variability of the image inversion ejection fractions was very small (mean difference of 0.4 +/- 0.8 and 2.8 +/- 4.7 units, respectively). CONCLUSION: Gated 99mTc-labeled sestamibi myocardial perfusion image inversion allows evaluation of the dynamics of the left ventricular chamber changes during the cardiac cycle, providing a method for evaluation of systolic function during myocardial perfusion imaging, with highly reproducible results that correlate well with established techniques.

Adult↗
PubMed1999

Estimation of left ventricular function in right ventricular volume and pressure overload. Detection of early left ventricular dysfunction by Tei index.

Although the effects of right ventricular (RV) volume and pressure overload (RVVO and RVPO) on ventricular septal motion are different, the differential effect on left ventricular (LV) function is still controversial. The Doppler-derived index (Tei index) combining systolic and diastolic ventricular function, defined as the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) divided by ejection time (ET), has been demonstrated to be a useful index to estimate LV function and to predict the prognosis of patients with congestive heart failure. This study was designed to evaluate the differential effects of RVVO and RVPO on LV function using the Tei index. Study patients consisted of 26 age-matched normal subjects, 22 patients with atrial septal defect (ASD) with normal or borderline RV pressure and 25 with primary pulmonary hypertension (PPH). All subjects had normal LV ejection fractions measured with 2-dimensional echocardiogram using biplane Simpson's method (61 +/- 4 vs 61 +/- 4 vs 63 +/- 8%, normal vs ASD vs PPH). Tei index was easily obtained in all subjects from transthoracic Doppler echocardiogram of LV inflow and outflow. Patients with ASD had normal ICT, IRT and ET, resulting in normal Tei index, however, patients with PPH had significantly prolonged ICT and IRT with shortened ET, resulting in a significant increase in Tei index (0.38 +/- 0.04 vs 0.36 +/- 0.03 vs 0.61 +/- 0.22, p < 0.001). Although RVVO due to ASD has no significant effects on LV function, RVPO due to PPH can adversely affect LV function. The Tei index is a simple and sensitive measure to assess LV function caused by RVVO or RVPO.

Adult↗
PubMed1988

Left ventricular function in double inlet left ventricle before the Fontan operation: comparison with tricuspid atresia.

Fourteen patients with double inlet left ventricle and nine patients with tricuspid atresia had biplane left ventricular angiography with simultaneous measurement of left ventricular pressure by micromanometer. Age distribution, haemodynamic function, and previous palliative operation were similar in the two groups. Left ventricular volumes were calculated frame by frame throughout the cardiac cycle by Simpson's rule. The end diastolic volume index was similar in the two groups, but the ejection fraction was significantly lower in tricuspid atresia. Left ventricular peak filling and emptying rates were also lower in tricuspid atresia, although heart rates in the two groups were similar. End diastolic shape index was significantly higher in patients with tricuspid atresia, indicating a more globular shape, and changed less during systole, suggesting differences in the mechanism of ejection between the two groups. Analysis of pressure-volume loops showed normal phase relations between pressure and volume, but systolic stroke work was reduced in tricuspid atresia and correlated with stroke volume and shape change. Left ventricular function was impaired in patients with tricuspid atresia when compared with those with double inlet left ventricle and this finding may reflect structural differences caused by the absence of one atrioventricular connection.

Adolescent↗
PubMed1999

Temporal dissociation of left ventricular function and remodeling following experimental myocardial infarction in rats.

BACKGROUND: Left ventricular function early after myocardial infarction (MI) predicts subsequent clinical outcome. Nevertheless, the relationship between early changes in left ventricular function and subsequent left ventricular remodeling has not been well defined. METHODS AND RESULTS: To explore the temporal relationship between left ventricular function and remodeling after MI, rats (n = 63) underwent coronary artery ligation with and without reperfusion at 45 or 180 minutes or a sham operation. All animals were followed up by serial echocardiography preligation; 4, 24, and 48 hours; and 1, 2, 3, 4, 6, and 9 weeks after MI. Measures of global left ventricular size and function and regional wall motion were obtained at physiological heart rates. Histological infarct sizes (range, 0% to 52%) were determined in all animals. Within 4 hours of MI, fractional area change (FAC) decreased dramatically in association with an increase in left ventricular systolic cavity area, whereas diastolic area increased more gradually. Early FAC was related to infarct size (r = -0.82; P < .000), predicted the extent of left ventricular enlargement (P = .0001), and remained depressed throughout the duration of follow-up. Regional wall motion excursion and systolic wall thickness decreased in the infarcted and noninfarcted regions in animals with large infarctions. CONCLUSIONS: The rate of left ventricular dilatation after MI in rats is proportional to initial left ventricular function, although left ventricular function remains relatively constant as the ventricle progressively enlarges. Regional myocardial function after a large MI is abnormal in noninfarcted as well as infarcted regions.

Animals↗
PubMed1984

Studies on left ventricular function during sustained ventricular tachycardia.

The acute effects of rapid ventricular pacing and sustained ventricular tachycardia on left ventricular function were examined in patients with recurrent sustained ventricular tachycardia. Programmed electrical stimulation and left ventricular hemodynamic measurements were performed in 20 patients (19 men and 1 woman), with an age range of 49 to 79 years (mean 63 +/- 9). Indexes of left ventricular function that were analyzed included left ventricular peak systolic pressure, end-diastolic pressure, first derivative of peak left ventricular pressure (dP/dt) and negative left ventricular dP/dt. Measurements were obtained during sinus rhythm, after paced premature ventricular depolarizations, during rapid ventricular pacing (cycle lengths 600 to 250 ms) and immediately after induction of sustained ventricular tachycardia. Mean left ventricular peak systolic blood pressure was 123 +/- 19 mm Hg during sinus rhythm, decreased to 77 +/- 23 mm Hg (p less than 0.05) at the induction of ventricular tachycardia and remained decreased during arrhythmia (p less than 0.01). Mean left ventricular end-diastolic pressure was 22 +/- 5 mm Hg during sinus rhythm, did not change after arrhythmia induction (22 +/- 9 mm Hg, p greater than 0.2) and remained unchanged during sustained ventricular tachycardia (p greater than 0.2). Mean peak left ventricular dP/dt was 1,400 +/- 620 mm Hg/s in sinus rhythm, decreased to 810 +/- 580 mm Hg/s (p less than 0.05) at ventricular tachycardia induction and remained decreased during sustained ventricular tachycardia (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗