Influence of recipient auricular contraction on the left ventricle filling pattern of the transplanted heart studied with pulsed Doppler echocardiography

OBJECTIVES: to evaluate the influence of recipient atrial contraction (RAC) timing on left ventricular filling pattern (LVFP), assessed by Pulsed Doppler, in orthotopic transplant recipients (OTR). STUDY DESIGN: prospective study of OTR. SETTING: patients (pts) submitted to orthotopic heart transplantation at Hospital de Santa Marta, from April/87 to March/89, in routine evaluation. PARTICIPANTS: nine pts, aged 21 to 55 years (mean = 32 +/- 11), 0.5 to 20 (mean = 7.4 +/- 6.9) months post-operatively. METHODS: in each pt 40 to 60 (mean 52) consecutive cardiac cycles were analysed; five groups (Gr.) were considered, according to RAC (P wave) position in the cardiac cycle: Gr. I--Early systole, GR. II--late systole, Gr. III--early diastole, Gr. IV--late diastole and Gr. V--absent. The following parameters were studied: peak early diastolic mitral flow velocity (Evel), peak late diastolic mitral flow velocity (Avel), ratio Evel/Avel, (E/A) and pressure half time (PHT). RESULTS: 1) Evel and E/A were significantly higher, Avel lower, and PHT shorter, in Gr II and III; 2) Avel was higher and E/A smaller in Gr. IV; 3) no statistically significant differences were found betwenn Gr. I and V, for any of the parameters analised. CONCLUSIONS: the timing of RAC significantly influences LVFP and it must be considered on Echo-Doppler analysis of diastolic function in OTR.     

Haematocrit profoundly affects left ventricular diastolic filling as assessed by Doppler echocardiography

BACKGROUND: The main determinants of diastolic function--pre- and afterload of the heart--are affected by the haematocrit, but the relation between haematocrit and diastolic function is unclear. OBJECTIVE: To study the association between interindividual haematocrit values and diastolic function, by echocardiography. DESIGN: In a cross-sectional survey, blood pressure, haematocrit values, and high-quality Doppler indexes of left ventricular filling were obtained in 1297 individuals, 25-74 years of age, and analysed by regression analyses. RESULTS: Haematocrit and systolic blood pressure were strongly correlated (r = 0.23; P < 0.0001). Moreover, haematocrit was inversely correlated with the peak velocity of early left ventricular filling and with the peak velocity of early filling divided by late filling (E/A ratio; both P< 0.005). Left ventricular isovolumic relaxation time (IVRT) was positively associated with haematocrit (r= 0.18, P< 0.001). In individuals with an abnormal Doppler filling pattern (E/A(< 50 years) < 1, E/A(> 50 years) < 0.5, or IVRT(< 30 years) > 92 ms, IVRT30-50 years > 100 ms or IVRT> 50 years > 1 05 ms; n = 119), greater haematocrit values were observed than in those with normal diastolic parameters (P< 0.001). Conversely, individuals with an increased haematocrit (> 50% in men, > 45% in women; n = 16) had a greater risk of presenting with abnormal left ventricular filling (31.3%) compared with individuals with normal (12.1%; n = 898;) or low (< 40% in men, < 35% in women: 10.5%, n = 38; P = 0.07) haematocrit. Strong and significant associations between haematocrit and Doppler indexes of left ventricular filling were confirmed after adjustment for multiple potential confounders including blood pressure, antihypertensive medication and body mass index. Similarly, blood pressure and parameters of diastolic filling were strongly associated correlations that were not affected by inclusion of haematocrit values into the regression model. CONCLUSION: The data point to substantial adaptations of diastolic filling in response to both blood pressure and the characteristics of the medium that is propelled by the heart Therefore, in addition to blood pressure values, the variability of haematocrit values should be considered when diastolic function is being evaluated by Doppler echocardiography.     

Effects of isometric exercise and heart rate on left ventricular filling pattern assessed by pulsed Doppler echocardiography

Left ventricular filling pattern was assessed by pulsed Doppler echocardiography at rest and during handgrip exercise in 33 healthy middle-aged subjects. The peak mitral flow-velocities during the early rapid filling phase (E) and during late (atrial) filling (A) were measured and the ratio of these peak flow-velocities (E:A ratio) was calculated. The E:A ratio was inversely related to age (r = -0.50), heart rate (r = -0.47) and septal thickness (r = -0.36) at rest. Exercise caused a significant (P less than 0.001) decrease in E:A ratio as a result of an increase in the peak A velocity. No significant change in the peak E velocity was observed during exercise. The exercise E:A ratio was related to heart rate (r = -0.53), but not to resting E:A ratio or age, since the decrease in E:A ratio tended to be less in the older subjects. Our study shows that isometric exercise augments the relative contribution of atrial contraction of left ventricular filling and this increase may 'mask' minor changes in resting transmitral flow pattern associated with, e.g. ageing. Secondly, in addition to age, heart rate must be taken into account when studying populations with different heart-rate levels or interventions associated with simultaneous heart rate changes.     

Influence of right ventricular pressure overload on left and right ventricular filling in cor pulmonale assessed with Doppler echocardiography

We evaluated the influence of right ventricular (RV) pressure overload on RV and left ventricular (LV) filling using Doppler echocardiography in cor pulmonale. The LV and RV inflow signals were recorded by Doppler flowmetry. The end-diastolic (ED) and end-systolic (ES) LV short axis images were detected by 2-dimensional echocardiography in 20 healthy subjects and in 36 cases of chronic pulmonary disease (CPD) with pulmonary hypertension. We measured (1) the ratio of the peak velocity of inflow due to atrial contraction to the peak velocity of rapid inflow (A/R), (2) the deceleration half-time of rapid inflow (delta TD), (3) the corrected radius of curvature (cRC) of the interventricular septum (IVS) at ES and ED, and (4) the percent change of length of 16 radial grids (%CL) using the fixed method on the ED and ES short axis images. In 17 of 36 patients with CPD, we measured the systolic pulmonary artery pressure (sPAP), the cardiac index (CI), the mean pulmonary capillary wedge pressure (mPCWP), the end-diastolic right ventricular pressure and the partial oxygen pressure of arterial blood (PaO2). The results were as follows: in CPD, (1) both the RV and the LV diastolic behavior were impaired as shown by increased A/R (1.04 +/- 0.20, 0.98 +/- 0.17, respectively) and prolonged delta TD (115 +/- 20, 100 +/- 17 msec, respectively), (2) the IVS was flattened at ED (cRC of IVS = 0.67 +/- 0.12), (3) the IVS wall motion was impaired (%CL of IVS = 133 +/- 13), (4) the sPAP had an adequate correlation with RV A/R (r = 0.80, p less than 0.01), RV delta TD (r = 0.59, p less than 0.05), LV A/R (r = 0.82, p less than 0.01), LV delta TD (r = 0.61, p less than 0.05), cRC of IVS (r = 0.67, p less than 0.01), %CL of IVS (r = -0.59, p less than 0.05). There was no significant correlation between the LV diastolic behavior and the CI, the mPCWP, the PaO2. It is concluded that the impairment of RV diastolic behavior was caused by the decreased RV compliance due to RV free wall hypertrophy. Moreover, the RV pressure overload interfered with the IVS motion during diastole, this regional impairment of diastolic behavior of the IVS subsequently causing impairment of LV diastolic filling.     

Influence of alteration in preload on the pattern of left ventricular diastolic filling as assessed by Doppler echocardiography in humans

We examined the influence of alterations in preload on pulsed Doppler indexes of left ventricular diastolic function in 50 patients including 12 without cardiovascular disease, 29 with coronary artery disease, and nine with critical aortic stenosis. Micromanometer left ventricular pressure was recorded simultaneously with pulsed Doppler echocardiography of left ventricular inflow and M-mode echocardiography of left ventricular diameter. Chamber stiffness constants, kd and kv, were obtained from the diastolic pressure-diameter and pressure-volume relations, respectively. Relaxation was measured by the isovolumic relaxation time constants, TL and TD, derived from the exponential left ventricular pressure decay and maximum negative dP/dt. In 41 patients after nitroglycerin treatment, left ventricular end-diastolic pressure decreased from 18 +/- 5 to 13 +/- 4 mm Hg (p less than 0.001). The ratio of peak early to peak atrial filling velocities and time-velocity integral ratios decreased from 1.08 +/- 0.57 to 0.90 +/- 0.42 (p less than 0.001) and from 1.77 +/- 0.95 to 1.41 +/- 0.71 (p less than 0.001), respectively. The peak early filling velocity and time-velocity integral decreased from 56.1 +/- 15.7 to 49.9 +/- 14.5 cm/sec (p less than 0.001) and from 7.9 +/- 2.7 to 6.8 +/- 2.8 cm (p less than 0.001), respectively. Relaxation (TL, TD, and maximum negative dP/dt) and chamber stiffness (kd and kv) were not impaired after nitroglycerin administration. In 48 patients after ventriculography, left ventricular end-diastolic pressure increased from 18 +/- 6 to 22 +/- 8 mm Hg (p less than 0.001). The peak early and peak atrial filling velocities increased from 57.4 +/- 15.2 to 68.3 +/- 19.7 cm/sec (p less than 0.001) and from 61.0 +/- 22.7 to 69.4 +/- 23.2 cm/sec (p less than 0.01), respectively. As a result, the ratio of peak early to peak atrial filling velocity was unchanged. However, in the aortic stenosis group, the ratio of peak early to peak atrial filling velocity increased from 0.95 +/- 0.64 to 1.10 +/- 0.72 (p less than 0.02). Relaxation and chamber stiffness were unchanged. Thus, a reduction or increase in preload may induce a diastolic filling pattern that mimics or masks diastolic dysfunction, respectively. Preload conditions need to be accounted for when the status of diastolic function is extrapolated from the pulsed Doppler mitral inflow velocity profile.     

Effects of atrioventricular interval on left ventricular diastolic filling assessed with pulsed Doppler echocardiography

Effects of changes in atrioventricular interval on left ventricular diastolic filling were studied using pulsed Doppler echocardiography in 14 patients with programmable dual chamber pacemakers. Peak early diastolic filling velocity (E) and peak atrial filling velocity (A) were measured from the transmitral flow velocity pattern at three different atrioventricular intervals under the same pacing rate of 80 beats.min-1 in each patient. When the atrioventricular interval was switched from intermediate [148(SD10) ms] to short [68(11) ms], stroke volume did not change significantly [60(14) to 58(13) ml], but E increased from 39(12) to 44(11) cm.s-1 (p less than 0.05), and A decreased from 48(8) to 38(9) cm.s-1 (p less than 0.05). At the short atrioventricular interval, incomplete atrial emptying by the atrial contraction seemed to cause a reciprocal increase in the early diastolic filling. When the atrioventricular interval was switched from intermediate to long [234(16) ms], stroke volume, E and A did not change significantly [57(14) ml, 37(13) cm.s-1, 51(8) cm.s-1 respectively]. At the short and long atrioventricular intervals, atrial filling always changed in the direction opposite to that of early diastolic filling. Changes in stroke volume as well as peak early diastolic filling velocity caused by altering atrioventricular interval were pronounced in aged patients and patients with decreased early diastolic filling. In conclusion, left ventricular diastolic filling patterns can be affected by atrioventricular interval even without any concomitant pathological changes in the left atrial or ventricular function. These effects should not be taken lightly, especially in patients with decreased left ventricular early diastolic filling.     

Effects of changes in coronary stenosis on left ventricular diastolic filling assessed with pulsed Doppler echocardiography

To determine the effects of changes in coronary stenosis on left ventricular diastolic filling, diastolic filling was serially examined before and after percutaneous transluminal coronary angioplasty using pulsed Doppler echocardiography in 50 patients with stable exertional angina pectoris. Peak rapid filling velocity and the ratio of peak atrial filling to peak rapid filling velocities were measured from the transmitral flow velocity pattern before and 2 and 9 days after coronary angioplasty. Peak rapid filling velocity increased and the ratio of peak atrial filling to peak rapid filling velocities decreased gradually after coronary angioplasty. The improvement in left ventricular diastolic filling was greater in patients with severe (greater than 90%) coronary stenosis than in patients with mild (less than or equal to 90%) coronary stenosis. In the long-term follow-up period, the improved left ventricular diastolic filling worsened in only 11 patients with marked progression to greater than 90% coronary stenosis. Thus, left ventricular diastolic filling improved gradually after coronary angioplasty, possibly reflecting post-ischemic "stunned" myocardium. Serial examinations of left ventricular diastolic filling with pulsed Doppler echocardiography may be a means of noninvasively assessing the temporal changes in the coronary stenosis and predicting the occurrence of coronary restenosis after coronary angioplasty.     

Influence of preload changes on the filling function of the left heart ventricle studied by Doppler echocardiography

Left ventricular filling may be studied non-invasively by Doppler echocardiographic recording of transmitral blood flow. This study reports the variations in this flow induced by changing cardiac preload by administering trinitrin or by vascular filling in 27 patients undergoing catheterisation. Left ventricular end diastolic pressure (LVEDP) was measured by the pig-tail catheter used for ventriculography. Transmitral flow was recorded by pulsed Doppler using the apical view. The parameters studied were those of the early diastolic E wave and the end diastolic A wave. The hemodynamic and echocardiographic measurements were performed under basal conditions, after trinitrin and after vascular filling. Trinitrin was given to 14 patients and led to a fall in LVEDP from 17.6 +/- 4.5 to 6.7 +/- 1.4 mmHg (p less than 0.001). The amplitude of the mitral E wave decreased and the E/A ratio fell from 0.93 +/- 0.37 to 0.71 +/- 0.32 (p less than 0.001). Thirteen patients underwent vascular filling which increased LVEDP from 10.9 +/- 5 to 27 +/- 4 mmHg (p less than 0.001). The mitral E wave increased and the E/A ratio rose from 0.96 +/- 0.32 to 1.27 +/- 0.23 (p less than 0.01). The patients received trinitrin and then underwent vascular filling. The LVEDP decreased from 16 +/- 3.9 to 8 +/- 2.9 mmHg (p less than 0.001) and then rose to 28.3 +/- 3.5 mmHg (p less than 0.001). The E/A ratio fell after trinitrin from 0.91 +/- 0.40 to 0.58 +/- 0.30 (p less than 0.01) and then rose to 1.42 +/- 0.60 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Association of left ventricular filling parameters assessed by pulsed wave Doppler and color M-mode Doppler echocardiography with left ventricular pathology, pulmonary congestion, and left ventricular end-diastolic pressure

Among 90 consecutive patients with various degrees of left ventricular (LV) dysfunction (normal patients, LV hypertrophy, LV ejection fraction <50%, and <30%), the mitral valve pulse-wave E/A ratio showed a characteristic U-shaped curve with increasing severity of LV dysfunction. In contrast, there was a significant progressive decrease in flow propagation velocity of the E-wave (Vp) and a significant increase in E/Vp values with increasing severity of LV dysfunction. The E/Vp ratio was the best predictor of pulmonary congestion, and in a subgroup of patients who underwent cardiac catheterization, it was the only significant predictor of LV end-diastolic pressure.     

Evaluation by pulsed Doppler echocardiography of the atrial contribution to left ventricular filling in patients with DDD pacemakers

To evaluate the significance of the left atrial (LA) contribution to left ventricular (LV) filling in cardiac pacing, LV inflow velocity was recorded with pulsed Doppler echocardiography in 20 patients with a DDD pacemaker. The pacemaker was programmed to atrioventricular (AV) sequential pacing with AV intervals of 50, 100, 150, 200 and 250 ms, and then to VVI pacing at a fixed rate of 70 beats/min. To evaluate the relative changes of LV filling volume in individual patients, the percent change in time-velocity integral of LV inflow velocity in each pacing mode was calculated as the ratio to that of AV sequential pacing with an AV interval of 150 ms. To estimate the degree of LA contribution to LV filling, the ratio of time-velocity integral during LA ejection phase to that during total LV filling phase was measured at the optimal AV interval. The percent LV inflow volume in AV sequential pacing was 74% for an AV interval of 50 ms, 87% for 100 ms, 98% for 200 ms and 90% for 250 ms. The percent LV inflow volume in VVI pacing was 72%. The percent LV inflow volume at AV intervals of 150 ms was significantly greater than that at an AV interval of 50, 100 and 250 ms, and in VVI pacing (p less than 0.05). The degree of LA contribution to LV filling showed a positive correlation with the percent increase of LV inflow volume with mode conversion from VVI to AV sequential pacing (p less than 0.005) and also with age (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Intracavitary filling pattern in the failing left ventricle assessed by color M-mode Doppler echocardiography

Objectives. The present study aimed to investigate the mechanism of intracavitary changes in filling pattern during acute ischemic left ventricular failure and during beta-adrenergic blockade.Background. Recent clinical studies with color M-mode Doppler imaging have shown abnormal intracavitary filling patterns in the diseased ventricle.Methods. In open chest anesthetized dogs with intracardiac micromanometers and myocardial segment-length crystals, global ischemic left ventricular failure was induced (n = 8) by coronary microembolization. In nonischemic ventricles inotropy was decreased (n = 6) by intravenous propranolol and increased (n = 6) by intravenous isoproterenol. From color M-mode Doppler images we calculated the time difference between peak early diastolic filling velocity at the mitral tip and apex using computer analysis. The time difference of peak velocity was used as an index of the timing of apical filling.Results. There was marked retardation of apical filling with microembolization and propranolol. Time difference of peak velocity increased from 20 ± 6 (mean ± SEM) to 101 ± 17 ms (p < 0.05) and from 21 ± 8 to 80 ± 18 ms (p < 0.05), respectively. Time constant of isovolumic relaxation increased from 34 ± 3 to 43 ± 5 ms (p < 0.05) and from 31 ± 1 to 39 ± 3 ms (p < 0.05) during microembolization and beta-blockade, respectively. Isoproterenol tended to cause the opposite changes. Time difference of peak velocity showed a positive correlation with time constant of isovolumic relaxation (r = 0.89, p < 0.01) and a negative correlation with peak early transmitral pressure gradient (r = 0.88, p < 0.01 ). In the intact left ventricle, peak apical filling velocity coincided with peak early transmitral pressure gradient. During ischemic failure, however, peak apical filling velocity occurred 53 ± 14 ms after peak early transmitral pressure gradient had decreased to zero and at a time when transmitral flow had ceased, suggesting a change in intraventricular flow distribution.Conclusions. Color M-mode Doppler imaging revealed retarded apical filling during depression of myocardial function by global myocardiai ischemia or beta-blockade. The abnormal filling pattern may be a sign of impaired left ventricular relaxation.     

Evaluation of left ventricular filling dynamics by pulsed Doppler echocardiography during afterload stress in ischemic heart disease using angiotensin II infusion

To evaluate cardiac reserve in ischemic heart disease, we simultaneously investigated left ventricular filling parameters using pulsed Doppler echocardiography (PDE) and catheter-obtained hemodynamics before and during afterload stress (angiotensin II test) in 14 patients with ischemic heart disease. The patients were divided into two groups according to their left ventricular function, i.e., mean left ventricular ejection fraction (mLVEF): Group I (n = 7, mLVEF = 65%) and Group II (n = 7, mLVEF = 43%). The peak velocity of rapid filling (R), the peak velocity of atrial contraction (A), the ratio of the two peak velocities (A/R), flow velocity integrals of the rapid filling phase (IR) and atrial contraction phase (IA) were obtained by PDE. Results were as follows: 1. During afterload stress, blood pressure, pulmonary artery wedge pressure, and left ventricular end-diastolic pressures (LVEDP) were elevated in both groups (p less than 0.01). The stroke work index (SWI) increased (p less than 0.01) and the time constant of left ventricular isovolumic pressure decay (T) was unchanged in Group I. SWI did not increase and T was prolonged in Group II (p less than 0.05). delta SWI/delta LVEDP, the ratio of the SWI change to the LVEDP change, during afterload stress was larger in Group I than in Group II (p less than 0.02). 2. Before the infusion of angiotensin II, R and IR were larger in Group I than in Group II. The A/R in Group I was less than that in Group II (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of endurance training on left ventricular filling dynamics: a study using stress Doppler echocardiography]

To evaluate the impact of endurance training on left-ventricular (LV) filling dynamics Doppler mitral flow was derived in 23 amateur endurance-trained athletes (AT) aged 31 (24-39) years with a personal marathon record greater than or equal to 200 min, and in 20 ultra-endurance athletes (UEA) aged 38 (28-42) years with a personal marathon record less than 200 min during bicycle exercise in supine position. Twenty-two untrained healthy volunteers (UT) aged 27 (24-30) years served as control. In particular, atrial filling fraction (AFF) as the relative share of atrial contribution to LV filling was measured. At rest AFF was significantly higher in UT (29%) as compared to AT (25%) and UEA (25%). During exercise (150 watt) atrial fraction increased significantly more in UT (37%) as compared to AT (34%) and UEA (29%) (p less than 0.01). At this point of measurement UEA had significantly lower values for AFF than AT (p less than 0.001). Two min post exercise atrial filling fraction already reached baseline values in UEA (24%) and AT (26%), while it remained significantly elevated in UT as compared to baseline values (38%, p less than 0.001). Ten min post exercise atrial filling fraction showed still elevated values in UT (32%), but decreased under baseline values in UEA (23%). No differences in heart rate between the two athlete groups at all times of measurement were observed. Thus, while atrial filling fraction rose in all study groups during exercise, it returned earlier to baseline values in athletes than in untrained subjects. This indicates a better cardiac adaptation to physical stress and a better diastolic performance during exercise in endurance-trained athletes, being even more pronounced in ultra-endurance athletes.     

Effect of heart rate on left ventricular diastolic transmitral flow velocity patterns assessed by Doppler echocardiography in normal subjects

Although a number of factors, including age and ventricular loading, are known to influence the pattern of left ventricular (LV) filling as depicted by Doppler echocardiographic transmitral flow velocities, few and conflicting data are available regarding the influence of heart rate (HR). Therefore, 20 volunteers (mean age 30 years) were evaluated with pulsed-wave Doppler echocardiography, performed with the sample volume placed at the mitral anulus level in the apical 4-chamber projection. Transmitral flow measurements comprised peak and integrated early passive (E) and late atrial (A) filling velocities and the slope of velocity decline from peak E filling. Measurements were recorded during baseline (sinus rhythm, mean 70 beats/min) and during transesophageal atrial pacing (mean 88 beats/min). LV end-diastolic dimension, mean arterial pressure and PR interval (corrected for pacing-induced delay in interatrial conduction time) were unchanged during pacing versus baseline measurements. Peak and integrated E filling velocities averaged 0.59 +/- 0.09 m/s and 6 +/- 1 cm, respectively, at baseline and were not significantly greater at the higher HR. In contrast, baseline peak and integrated A velocities averaged 0.37 +/- 0.06 m/s and 2.3 +/- 0.7 cm, respectively, but were significantly greater at the higher HR (0.5 +/- 0.07 m/s and 3.2 +/- 1.1 cm, respectively [p less than 0.003 vs baseline for each]). Further analysis of a subgroup of 9 subjects for whom Doppler measurements were available at 3 HRs (sinus 70; pacing 80 and 90) yielded strong evidence for a linear relation between HR and peak A velocity (A = 0.008 HR - 0.21, with p less than 0.0001 for significance of the linear trend).(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in left ventricular diastolic filling patterns by Doppler echocardiography in cystic fibrosis

The onset of cor pulmonale is a common terminal finding in patients with cystic fibrosis. Since Doppler echocardiography can detect changes in diastolic filling patterns prior to the onset of either systolic dysfunction or clinical symptoms, we utilized this technique to determine whether detectable changes in left ventricular diastolic filling patterns exist in patients with cystic fibrosis. Among 25 patients, the proportion of left ventricular filling attributable to atrial contraction was significantly increased when compared with age-matched control individuals. When filling patterns were compared with severity of pulmonary disease, worsening pulmonary disease was directly correlated to shifts in left ventricular filling patterns. We conclude that changes in left ventricular patterns of relaxation are detectable early in the course of cystic fibrosis and that such changes are probably progressive. Early detection could lead to therapeutic trials designed to improve left ventricular filling and delay the onset of overt cor pulmonale.     

Influence of acute hyperglycemia on left ventricular function in diabetics assessed by echocardiography

Myocardial dysfunction in diabetes mellitus is reversed by proper correction of metabolic changes. To assess the role of hyperglycemia on cardiac dysfunction, 50 g of dextrose were intravenously infused to 15 subjects with stable type 2 diabetes. Echocardiographic measurements were made at 0, 60, 120, 180, and 240 minutes. In spite of the high levels of blood glucose reached in diabetics, left ventricular ejection fraction, fractional shortening, and stroke volume did not experience significant changes. Moreover, cardiac output significantly (p less than 0.01) increased in diabetics secondary to an increase in heart rate. No cardiac changes were noticed in 7 healthy subjects studied in a similar fashion. However, their induced hyperglycemia was not as elevated as in the diabetic patients. These results suggest that acute induced hyperglycemia per se does not appear to impair left ventricular contractility in diabetics at resting conditions.