Left ventricular ejection fraction changes during recovery from treadmill exercise: A preliminary report of a new method for detecting coronary artery disease

To test the value of combining treadmill exercise with radionuclide angiography for detecting exercise-induced left ventricular dysfunction, ejection fractions were calculated at rest, peak supine bicycle exercise, and during three supine post-treadmill recovery periods (2-4 min, recovery 1; 4-6 min, recovery 2; 8-10 min, recovery 3) in ten coronary artery disease patients and eight normal subjects. Both the normal subjects and coronary artery disease patients had normal resting ejection fractions (>0.50). In the normal subjects the mean ejection fraction increased significantly (p<0.005) from rest (0.61 ± 0.03) to peak supine bicycle exercise (0.71 ± 0.04), and the mean ejection fraction also remained significantly higher (p<0.005) at rest than during 10 min post-treadmill exercise. However, the coronary artery disease patients did not significantly change the mean ejection fraction from rest (0.59±0.06) to peak supine bicycle exercise (0.55±0.08), and the average ejection fraction during each one of the post-treadmill recovery periods was not significantly different from rest. At the third recovery period all the normals but no coronary artery disease patients had higher ejection fraction than the resting ejection fraction. We thus conclude that the magnitude of change in ejection fraction from rest to 8-10 min post-treadmill exercise in patients with normal resting ejection fraction may be helpful in identifying those with coronary disease.     

Global and regional left ventricular response to bicycle exercise in coronary artery disease. Assessment by quantitative radionuclide angiocardiography.

The left ventricular response to bicycle exercise was evaluated in 60 patients with coronary artery disease and in 13 normal control subjects. Left ventricular ejection fraction, mean normalized ejection rate and regional wall motion were determined using first-pass radionuclide angiocardiograms obtained at rest and again during peak graded bicycle exercise. All normal subjects demonstrated improved left ventricular function with exercise. Left ventricular ejection fraction increased significantly from 67 ± 3 per cent (mean ± SE) at rest to 82 ± 4 per cent with exercise (p < 0.001). Similarly, the left ventricular ejection rate increased significantly from 3.47 ± 0.31 sec^?1 to 6.53 ± 0.42 sec^?1(p < 0.001). In contrast, in 44 of 60 patients with coronary artery disease, the ejection fraction or ejection rate either decreased or remained the same with exercise. New or exaggerated regional wall motion abnormalities were detected in 28 of 60 patients with coronary artery disease. Over-all, global or regional evidence of compromised left ventricular reserve was found in 48 of 60 patients with coronary artery disease.The major determinant of an abnormal left ventricular response to exercise was the presence or absence of electrocardiographic evidence of myocardial ischemia. Left ventricular ejection fraction decreased or remained the same with exercise in all patients with coronary artery disease and electrocardiographic ischemia. New regional wall motion abnormalities were detected in 20 of these patients. In this group, the left ventricular ejection fraction decreased from 66 ± 2 per cent at rest to 58 ± 2 per cent with exercise (p < 0.001), whereas the ejection rate was unchanged by exercise (rest 3.33 ± 0.21 sec^?1; exercise 3.34 ± 0.22 sec^?1, p > 0.05). Of the 30 patients with coronary artery disease who exercised to symptom-limiting fatigue without electrocardiographic ischemia, 18 demonstrated compromised left ventricular reserve with exercise. Twelve of the remaining patients with coronary artery disease had normal left ventricular reserve, in eight of whom ventricular function was completely normal both at rest and during exercise. In this group exercised to fatigue, the left ventricular ejection fraction increased from 53 ± 4 per cent at rest to 58 ± 2 per cent with exercise (p < 0.001). The ejection rate also increased from 2.48 ± 0.24 sec^?1 to 3.67 ± 0.39 sec^?1 (p < 0.001). The direction and magnitude of the left ventricular responses to exercise were not affected by long-term oral propranolol administration in 22 patients. Based upon either abnormal exercise left ventricular reserve or abnormal global and regional left ventricular function at rest, the over-all sensitivity of this radionuclide technic for the detection of coronary artery disease was 87 per cent (52 of 60 patients). These data demonstrate that exercise ventricular performance studies provide important physiologic insights into left ventricular functional reserve as well as a sensitive noninvasive approach for the detection of coronary artery disease.     

Effects of digoxin on left ventricular function in coronary artery disease patients

To assess whether digitalis modifies or prevents the deterioration of the left ventricular ejection fraction and wall motion during acute ischemia, we performed gated blood pool radionuclide ventriculograms in 15 patients with angiographically documented coronary artery disease. All patients were studied in the resting state and during maximal supine bicycle exercise, both before and 1 hour after 1 mg intravenous digoxin.There was no significant difference, pre-digoxin vs post-digoxin, in exercise tolerance (415 ± 84 vs 418 ± 107 seconds), number of segments with abnormal resting wall motion (12 vs 11) or exercise wall motion (21 vs 19). Ten patients developed angina during the same exercise load, irrespective of digoxin administration. Twelve patients had subnormal left ventricular ejection fraction during exercise pre-digoxin, vs 13 patients post-digoxin (P = ns). In the resting state, the left ventricular ejection fraction was higher after digoxin (53 ± 14% pre vs 58 ± 14% post, P < 0.05). During exercise, however, the left ventricular ejection fraction was not significantly improved after digoxin (50 ± 16% pre vs 53 ± 17% post, P = ns).These data indicate that although acute administration of digoxin improves the resting left ventricular function, it does not improve exercise tolerance to angina. Furthermore, intravenous digoxin does not appear to prevent the deterioration of left ventricular wall motion and ejection fraction during exercise induced ischemia.     

Relation of coronary artery stenosis and pressure gradient to exercise-induced ischemia before and after coronary angioplasty

The purpose of this investigation was to evaluate the relation of coronary artery stenosis and associated pressure gradient to the magnitude of exercise-induced left ventricular dysfunction in patients with single vessel coronary artery disease. The percent stenosis and minimal cross-sectional area were measured before and after percutaneous transluminal coronary angioplasty and compared with radionuclide measurements of left ventricular function before and after angioplasty in 41 patients with proximal left anterior descending coronary artery lesions, providing 82 points of comparison. The gradient could be measured for 75 comparisons. Forty stenoses less than 50% were associated with a mean left ventricular exercise ejection fraction of 0.66 +/- 0.08 (mean +/- SD), 25 stenoses from 50 to 75% with a mean ejection fraction of 0.59 +/- 0.12 and 17 stenoses greater than 75% with a mean ejection fraction of 0.49 +/- 0.08. Thirty-five stenoses with a gradient less than 20 mm Hg were associated with a mean ejection fraction of 0.65 +/- 0.09, 24 with a gradient from 20 to 50 mm Hg with a mean ejection fraction of 0.58 +/- 0.13 and 16 with a gradient greater than 50 mm Hg with a mean ejection fraction of 0.53 +/- 0.10. These data document a relation between the magnitude of coronary artery stenosis and associated gradient to exercise-induced left ventricular dysfunction in homogeneous patient groups. However, discordance of these variables occurs commonly in individual patients.     

Improvement of exercise-induced left ventricular dysfunction with oral propranolol in patients with coronary heart disease.

The effect of propranolol on global cardiac function during exercise was analyzed with equilibrium fadionuclide angiography in 10 patients with ischemic heart disease. All patients had angina pectoris and S-T segment depression of more than 0.1 mv during treadmill exercise when not taking propranolol. Each patient was stressed with supine bicycle exercise to the same work load on a maintenance dose of propranolol (120 to 400 mg/day) and on a second occasion without the drug, the two tests being separated by an average of 16 days. The mean heart rate was reduced both at rest and during exercise after propranolol, but propranolol caused no significant reduction of the left ventricular ejection fraction at rest. In the study without administration of propranolol the average ejection fraction during exercise decreased from 0.56 ± 0.09 (standard deviation) to 0.50 ± 0.14. With propranolol, the ejection fraction was improved from the control value in every patient, the average value during peak exercise reaching 0.60 ± 0.15. Thus, the average ejection fraction increased by 22 percent (±12 percent) relative to the value during the same exercise without propranolol (P < 0.001). In 16 other patients with ischemic heart disease who did not take propranolol, reproducibility of the ejection fraction both at rest and at peak exercise on two occasions within 15 days was good (r = 0.95 and 0.97, respectively). It is concluded that oral propranolol therapy in patients with coronary artery disease can ameliorate left ventricular dysfunction induced by exercise and thereby may reduce myocardial ischemia.     

Comparison of effects of isometric and supine bicycle exercise on left ventricular performance in patients with aortic regurgitation and normal ejection fraction at rest

The effects of handgrip and supine bicycle exercise on hemodynamics and left ventricular (LV) performance were compared in 25 patients with moderate to severe aortic regurgitation (AR) and normal LV ejection fraction at rest (greater than or equal to 50%) and in 10 control subjects. In both groups, heart rate, systolic blood pressure, rate-pressure product, and LV output were higher during supine bicycle exercise. Compared with the controls, in patients with AR, stroke volume was unchanged during supine bicycle exercise. LV end-diastolic volume increased during handgrip exercise but was unchanged during supine bicycle exercise. LV end-systolic volume increased and ejection fraction decreased during both forms of exercise. Of 25 patients with AR, 15 (60%) during handgrip exercise and 19 (76%) during supine bicycle exercise had an abnormal ejection fraction response (p less than 0.05). In patients with moderate to severe AR and normal LV ejection fraction at rest, both handgrip and supine bicycle exercise induced LV dysfunction. An abnormal LV ejection fraction response occurred more often with supine bicycle exercise. Handgrip exercise may be a useful alternative method for detecting LV dysfunction in patients with AR in whom adequate bicycle exercise cannot be accomplished.     

Superiority of supine bicycle over isometric handgrip exercise in the assessment of ischemic heart disease: An evaluation of left ventricular ejection fraction response using radionuclide angiography

Left ventricular ejection fraction (LVEF) response to supine bicycle and isometric handgrip exercise was evaluated in 15 patients with documented coronary artery disease (CAD) and stress-induced ischemia using radionuclide angiography. For purposes of analysis, the patients were divided into two groups: group I (n=7) with single-vessel disease and group II (n = 8) with multiple-vessel disease including 3 with left main artery disease. The studies were repeated 18 days later at similar external workloads to assess reproducibility of both tests. LVEF response to bicycle exercise was different for the two groups. The change in LVEF from rest to peak exercise was +0.04±0.02 for group I and -0.07±0.04 for group II (p <.001). LVEP response to isometric handgrip exercise was not different between the two groups. The change from rest to end of handgrip exercise was -0.02+0.02 for group I and -0.05 ±0.02 for group II. The reproducibility of LVEF response to bicycle exercise at similar workloads on day 1 and day 19 was good (r=0.85) while it was poor for isometric handgrip testing (r=0.67). Our data demonstrate that radionuclide angio-graphic measurement of LVEF response to supine bicycle exercise testing is superior to LVEF response to isometric handgrip testing in the evaluation of patients with CAD.     

Effect of nitrates on left ventricular size and function during exercise: Comparison of sublingual nitroglycerin and nitroglycerin paste

To compare the effects of sublingual nitroglycerin and nitroglycerin paste on left ventricular size and performance during supine bicycle exercise, equilibrium radionuclide angiography was performed in 36 persons classified into two groups of normal subjects and two groups of patients with angiographically proved coronary heart disease. Each group underwent a control exercise study, and then one group of normal subjects and one group of patients were restudied after the administration of 0.6 mg of nitroglycerin or 2 inches (5 cm) of nitroglycerin paste (but not both). Data were collected at rest and at peak exercise.In normal subjects exercise resulted in increased ejection fraction, decreased end-systolic volume and little change in end-diastolic volume. After either drug, volumes at rest markedly decreased, and during exercise, ejection fraction increased to levels comparable with pre-drug levels. After nitroglycerin paste the reduction in volume seen at rest persisted during exercise, but after sublingual nitroglycerin end-diastolic volume increased during exercise (88 ± 43 to 113 ± 30 ml [mean ± standard deviation]; p < 0.01). Peak exercise end-diastolic volume after nitroglycerin was still lower than that before nitroglycerin (113 ± 30 versus 120 ± 28 ml, p < 0.05).In patients with coronary disease, ejection fraction did not change during exercise, but both end-diastolic and end-systolic volumes increased. After either drug ejection fraction at rest was unchanged, although ventricular volumes were markedly lower (p < 0.05). Ejection fraction increased with exercise in both groups with coronary disease after either drug. After sublingual nitroglycerin, volumes increased during exercise although the peak exercise end-diastolic volume was still lower than the control value (113 ± 31 versus 145 ± 34 ml; p < 0.01). After paste administration, end-diastolic volume did not change during exercise, and end-systolic volume decreased (41 ± 20 to 36 ± 22 ml; p < 0.05).Thus, sublingual nitroglycerin and nitroglycerin paste improved left ventricular function during exercise. The effect of paste on end-diastolic volume appeared sustained, whereas that of sublingual nitroglycerin was transient, confirming the hypothesis that reduction in end-diastolic volume and, by implication, left ventricular wall tension, is a major mechanism of nitrate action.     

Silent left ventricular dysfunction during routine activity after thrombolytic therapy for acute myocardial infarction

To investigate prospectively the occurrence and significance of postinfarction transient left ventricular dysfunction, 33 ambulatory patients who underwent thrombolytic therapy after myocardial infarction were monitored continuously for 187 +/- 56 min during normal activity with a radionuclide left ventricular function detector at the time of hospital discharge. Twelve patients demonstrated 19 episodes of transient left ventricular dysfunction (greater than 0.05 decrease in ejection fraction, lasting greater than or equal to 1 min), with no change in heart rate. Only two episodes in one patient were associated with chest pain and electrocardiographic changes. The baseline ejection fraction was 0.52 +/- 0.12 in patients with transient left ventricular dysfunction and 0.51 +/- 0.13 in patients without dysfunction (p = NS). At follow-up study (19.2 +/- 5.4 months), cardiac events (unstable angina, myocardial infarction or death) occurred in 8 of 12 patients with but in only 3 of 21 patients without transient left ventricular dysfunction (p less than 0.01). During submaximal supine bicycle exercise, only two patients demonstrated a decrease in ejection fraction greater than or equal to 0.05 at peak exercise; neither had a subsequent cardiac event. These data suggest that transient episodes of silent left ventricular dysfunction at hospital discharge in patients treated with thrombolysis after myocardial infarction are common and associated with a poor outcome. Continuous left ventricular function monitoring during normal activity may provide prognostic information not available from submaximal exercise test results.     

Right and left ventricular dysfunction in patients with chronic obstructive lung disease: Assessment by first-pass radionuclide angiography

To evaluate the relationship between right and left ventricular function in patients with obstructive lung disease, we studied 10 normal subjects (group 1) and 37 patients with chronic obstructive pulmonary disease by first pass radionuclide angiography. These 37 patients were divided into three groups: nine with mild chronic obstructive pulmonary disease (group 2), 20 with severe chronic obstructive pulmonary disease (group 3) and eight with severe chronic obstructive pulmonary disease and primary left ventricular disease (group 4). In each subject right ventricular ejection fraction (RVEF), left ventricular ejection fraction (LVEF) and ejection fraction during first third of systole (first third LVEF) were calculated. LVEF RVEF First-Third LVEF Group 1 0.60 ± 0.05 0.52 ± 0.03 0.29 ± 0.04 Group 2 0.61 ± 0.08 0.52 ± 0.03 0.29 ± 0.02 Group 3 0.58 ± 0.09 0.46 ± 0.091 0.24 ± 0.061 Group 4 0.51 ± 0.061 0.44 ± 0.091 0.20 ± 0.031 1 p < 0.05 versus 1. All subjects in group 2 had normal left ventricular and right ventricular function. In group 3,11 of 10 (55 per cent) had a low RVEF and three of 20 (15 per cent) a low LVEF. However eight of 20 in this group (40 per cent) had a depressed first-third LVEF. The correlation between decline in RVEF and first-third LVEF was good r = 0.73. We conclude that (1) certain indices of early systolic left ventricular ejection are abnormal in many patients with chronic obstructive pulmonary disease and correlate with the decline in right ventricular function; (2) this is not seen in patients with mild chronic obstructive pulmonary disease and is worse in patients with underlying left-sided heart disease.     

Profiles of radionuclide left ventricular ejection fraction changes induced by supine bicycle exercise in normals and patients with coronary heart disease

This paper presents the profiles of left ventricular ejection fraction (EF) during and following supine bicycle exercise in normal subjects and in patients with coronary heart disease, as well as the relationship of the described patterns to clinical parameters. Twenty normal men and 40 patients with coronary artery disease were studied using gated equilibrium radionuclide angiography (EQ-EF). In the normals, during exercise, EF increased by a mean of 25% of the resting value, with an increase of no less than 11%. The exercise-limiting symptom in patients with coronary artery disease was angina pectoris in 20 and fatique in the other 20 patients. In the angina patients, there was a mean decrease in EF of 20%, and in the other coronary artery disease patients ejection fraction change little. Only two patients with coronary artery disease increased from a normal resting value to peak exercise by more than 11%, and they had isolated right coronary lesions. An "overshoot" elevation of ejection fraction above resting levels was demonstrated following termination of exercise in most patients. The patients with a significant fall in exercise ejection fraction more frequently had abnormal exercise-induced ECG changes as well as abnormal left ventriculograms and more severe coronary artery disease at cardiac catheterization than the patients with little change in ejection fraction. We conclude that 1) normals could be separated from most patients with significant coronary artery disease in this study population; 2) ejection fraction must be measured at maximal exercise for it to have diagnostic value, since there could be normal rise before and after peak exercise and an abnormal response missed; and 3) the ejection fraction response to exercise reflects the severity of the underlying coronary artery disease. The described patterns of exercise-induced changes in left ventricular ejection fraction are important to consider when using this new technique to diagnose and evaluate patients with coronary artery disease.     

Haemodynamic dose-response actions of cicloprolol in left ventricular dysfunction due to ischaemic heart disease

Cicloprolol is a cardioselective beta-1 partial agonist; its haemodynamic and radionuclide (nuclear stethoscope) effects were determined in 22 patients with impaired left ventricular function due to coronary artery disease. Following a 20 min stable control period, the effects of four doses of cicloprolol (0.025, 0.025, 0.05 and 0.1 mg/kg at 10 min intervals) were measured at rest 5-10 min after each intravenous injection. The effects of the cumulative 0.2 mg/kg dosage were assessed during supine bicycle exercise and compared with a control exercise period. At rest there were significant increases in systolic arterial without change in mean blood pressure. The heart rate and cardiac index were unchanged. There was a significant increase in left ventricular ejection fraction with a reduction in filling pressure and volume. Patients with resting heart rate below 75 beats/min and with ejection fraction greater than 35% showed the greatest improvement. During supine bicycle exercise, ejection fraction was increased compared to control (31 +/- 2 to 36 +/- 2; P less than 0.01), cardiac volume reduced and exercise tachycardia attenuated. These data suggest that cicloprolol may be of value where beta-blockade is considered in the presence of underlying left ventricular dysfunction due to ischaemic heart disease.     

Abnormal exercise hemodynamics in cardiac allograft recipients 1 year after cardiac transplantation. Relation to preload reserve

The well-established elevation in left ventricular filling pressures during exercise in patients after transplantation may contribute to decreased exercise tolerance. A proposed mechanism for this increase in filling pressures is an abnormal pressure-volume homeostasis of the transplanted heart. Twenty-three patients undergoing routine 1-year evaluations performed supine bicycle exercise during right heart catheterization. Within 24 hours, these patients underwent supine bicycle exercise to the identical work load during radionuclide ventriculography. For the group, resting hemodynamics and resting left and right ventricular ejection fractions were normal. With exercise, right atrial and pulmonary wedge pressure rose markedly (from 6 +/- 2 to 14 +/- 7 mm Hg, p less than 0.0001, and from 10 +/- 3 to 20 +/- 6 mm Hg, p less than 0.0001, respectively). Left ventricular ejection fraction increased appropriately with exercise (from 0.58 +/- 0.08 to 0.63 +/- 0.07, p = 0.004). End-diastolic volume also increased mildly (from 100 +/- 31 to 117 +/- 39 ml, p = 0.001), but change in end-diastolic volume was highly variable. Patients with little or no change in end-diastolic volume with exercise had the greatest resting and exercise left ventricular filling pressures resulting in significant negative correlations between filling pressures and change in end-diastolic volume (r = -0.64, p = 0.002 and r = -0.50, p = 0.025, respectively). Negative linear relations between exercise left ventricular filling pressures or resting heart rates and donor to recipient body weight ratio (r = -0.35, p = 0.10, and r = -0.37, p = 0.06, respectively) suggested that initial donor heart size influenced subsequent cardiac function.(ABSTRACT TRUNCATED AT 250 WORDS)     

Peak systolic blood pressure/end-systolic volume ratio: Assessment at rest and during exercise in normal subjects and patients with coronary heart disease

To assess the utility of a recently proposed index of left ventricular performance, the ratio of peak left ventricular systolic pressure to end-systolic volume, equilibrium radionuclide angiography was used to determine end-systolic volume and the systolic blood pressure obtained by cuff sphygmomanometer to determine peak systolic pressure. Data were analyzed at rest and during supine bicycle exercise in 15 normal subjects (Group 1), 50 patients with coronary artery disease (Group II) and 9 patients with obstructive lung disease and no evidence of coronary artery disease on clinical examination including exercise thallium imaging (Group III). In 15 subjects the correlation between the resting angiographic and radionuclide pressure/volume ratio was excellent (r = 0.929, p <0.005).Forty-seven (94 percent) of the 50 patients in Group II had a depressed pressure/volume ratio at rest or an abnormal change in this ratio during exercise, whereas only 43 (86 percent) of this group had an abnormal ejection fraction at rest or during exercise. Additionally, 3 of 15 subjects in Group I had an abnormal ejection fraction response, defined as less than 0.05 ejection fraction unit increase with exercise (specificity 80 percent), whereas all subjects in Group I had a normal increase in pressure/volume ratio (specificity 100 percent). At rest, neither index identified more patients with coronary artery disease than the other. Of the nine patients in Group III, six had an abnormal ejection fraction response to exercise, whereas only one had an abnormal pressure/volume ratio response.It is concluded that the end-systolic pressure/volume ratio is a useful index of left ventricular performance. In some patients during supine exercise stress it may be more sensitive than the ejection fraction response alone in identifying the presence of coronary artery disease.     

Rest and exercise ventricular function in adults with congenital ventricular septal defects

Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects (mean age 28 years, range 22 to 34) and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD) (mean age 27 years, range 20 to 40). The 34 patients with VSD were divided into 3 groups: those in Group 1 (17 patients) had pulmonary to systemic blood flow ratios of less than 2 to 1; those in Group 2 (12 patients) had prior surgical closure of VSD (mean interval from surgery 17 years, range 9 to 22), and those in Group 3 (5 patients) had Eisenmenger's complex. Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise (0.70 +/- 0.07 to 0.79 +/- 0.05 and 0.46 +/- 0.06 to 0.57 +/- 0.04; p less than 0.001 for left and right ventricles, respectively). All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects (0.59 +/- 0.09 and 0.54 +/- 0.06 versus 0.70 +/- 0.07; p less than 0.001) and resting right ventricular ejection fraction was lower in Group 3 versus control subjects (0.30 +/- 0.07 versus 0.46 +/- 0.06; p less than 0.001). Thus (1) left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; (2) rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; (3) resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; (4) lifelong volume overload may be detrimental to myocardial function.     

Right ventricular volumes and hemodynamics after successful orthotopic heart transplantation. A comparison to coronary artery disease using thermodilution.

Only few data exist concerning right ventricular function in the chronic stage after cardiac transplantation. Therefore, we investigated hemodynamic and right ventricular volumetric data by a computerized thermodilution Swan-Ganz catheter in 17 patients (median age: 53, range: 18-63 yr) at a median of 24 (4 to 44) months after cardiac transplantation during rest and supine bicycle exercise. Myocardial biopsy showed grade one or less according to the classifications of Billingham. Sixteen patients with coronary artery disease, but without prior myocardial infarction, served for comparison. While angiographic left ventricular ejection fraction was nearly identical in transplant recipients [77 (60-92)%, median (range)] and in patients with coronary artery disease [78 (64-94)%], right ventricular ejection fraction was lower (p < 0.001) in patients after cardiac transplantation [37 (16-58)%] as compared to patients with coronary artery disease [56 (46-62)%]. In transplant recipients right atrial pressure was significantly higher both at rest [10 (2-18) mmHg] and exercise [18 (8-30) mmHg] than in patients with coronary artery disease [5 (1-11) and 8 (3-18) mmHg]. Pulmonary capillary wedge pressure behaved similar in both groups. To further evaluate reasons for right ventricular impairment, a correlation analysis was performed. This showed a negative correlation between right ventricular ejection fraction and the time interval after transplantation (p < 0.0002). However, there was no correlation between right ventricular ejection fraction and acute rejection or a rejection score. In conclusion, right ventricular function may be severely altered in transplant recipients, in contrast to an only slight impairment of left ventricular function.     

Relation of right ventricular ejection fraction to exercise capacity in chronic left ventricular failure

Although the left ventricle is traditionally viewed as the heart's main pumping chamber, no correlation has been shown between left ventricular (LV) ejection fraction (EF) at rest and exercise capacity in patients with chronic LV failure. Because vasodilators with venodilating activity increase exercise capacity more than predominant arterial dilators in patients with LV failure, right ventricular (RV) function may relate to exercise capacity in these patients. In 25 patients with chronic LV failure, caused by coronary artery disease in 12 patients and idiopathic dilated cardiomyopathy in 13 patients, RVEF and LVEF at rest were measured by radionuclide angiography. Maximal upright bicycle exercise testing was also performed to determine maximal oxygen consumption, which averaged only 13 ± 4 ml/min/kg. The LVEF at rest was 26 ± 10% and did not correlate with maximal oxygen consumption (r = 0.08). However, the RVEF was 41 ± 12% and correlated with maximal oxygen consumption (r = 0.70, p < 0.001) in the same patients. The correlation was stronger (r = 0.88) in patients with coronary artery disease than in those with idiopathic dilated cardiomyopathy (r = 0.60). Thus, RVEF at rest is more predictive of exercise capacity than LVEF in the same patients with chronic LV failure. These results are consistent with the clinical observation that only venodilating agents increase exercise capacity of patients with chronic LV failure.     

Right and left ventricular function at rest and with exercise after the Mustard operation for transposition of the great arteries.

Right and left ventricular function was assessed in 25 children (mean age at study 12.2 years and at operation 2.6 years) after a Mustard repair for transposition of the great arteries. Gated first pass and gated equilibrium radionuclide ventriculography was performed on all patients at rest and during supine bicycle exercise. The mean right ventricular ejection fraction did not increase with exercise by either technique. Individual results for right ventricular ejection fraction showed that with the gated equilibrium technique 71% had an abnormal exercise response (normal response being an increase in ejection fraction greater than 5%) and with the gated first pass technique 61% had abnormal results. Although the mean left ventricular ejection fraction increased significantly with exercise, 35% of patients had an abnormal exercise response with the equilibrium technique and 41% with the first pass technique. There was no evidence of a predictive relation between ventricular function and any clinical or haemodynamic variable examined. Covert right and left ventricular dysfunction can frequently be detected by exercise radionuclide ventriculography in long term survivors of repair for transposition of the great arteries. The prognostic consequences of these findings are unclear at present.     

Right ventricular dysfunction and the exercise limitation of chronic obstructive pulmonary disease

This study examined right ventricular function during exercise in patients with chronic obstructive pulmonary disease to answer the following questions: Is there a significant correlation between oxygen consumption at maximal exercise and exercise right ventricular ejection fraction? Does the right ventricular ejection fraction response to exercise correlate with exercise changes in pulmonary artery pressure, total pulmonary resistance or pulmonary vascular resistance? Which combinations of cardiac, ventilatory and blood gas variables are the best predictors of oxygen consumption at maximal exercise? Twenty-six patients with stable chronic obstructive pulmonary disease performed symptom-limited supine bicycle exercise with simultaneous hemodynamic and radionuclide ventriculographic measurements. The oxygen consumption at maximal exercise correlated with the exercise right ventricular ejection fraction (n = 21, r = 0.66; p less than 0.005), exercise stroke volume (r = 0.68; p less than 0.001), exercise cardiac output (r = 0.77; p less than 0.00005) and exercise ventilation (r = 0.85; p less than 0.00001). The change in right ventricular ejection fraction from rest to exercise correlated inversely with the change from rest to exercise in total pulmonary resistance (r = -0.51; p less than 0.05) but not with the change in mean pulmonary pressure (r = -0.37) or in pulmonary vascular resistance (r = 0.09). Multivariate analysis showed that the variables giving the highest combined correlation with oxygen consumption were ventilation and right ventricular ejection fraction (r = 0.95, adjusted r2 = 0.88). These results suggest that exercise oxygen consumption of patients with chronic obstructive pulmonary disease is related to right ventricular systolic function, exercise right ventricular dysfunction is related, in part, to abnormal exercise total pulmonary resistance, and exercise limitation in chronic obstructive pulmonary disease occurs as a result of the dynamic interaction between disordered right heart function and ventilation.     

Exercise radionuclide ventriculography in children: normal values for exercise variables and right and left ventricular function.

Thirty two children (aged 5-19 years) with no clinical evidence of significant cardiovascular disease undertook continuous staged supine exercise on a bicycle ergometer. Multigated radionuclide ventriculography was performed at rest and during each exercise stage. Exercise duration and total workload both increased with age. Aerobic work correlated better with age than did total work. In most children the ejection fraction for both ventricles increased by at least 5% with exercise. Right ventricular ejection fraction did not decrease with exercise in any subject but left ventricular ejection fraction decreased by 2% and 9% in two. The response of end diastolic volume to exercise was variable, but there was a consistent decrease in mean (SD) end systolic volume of the left (29(22)%) and right (30(19)%) ventricles. Cardiac index (mean (SD)) increased by 234(65)% with exercise. The left ventricular:right ventricular end diastolic volume ratio (mean (SD)) at rest was 1.26(0.26). It is concluded that exercise radionuclide ventriculography is an excellent technique for a combined assessment of exercise capacity and an evaluation of ventricular size and performance in children. These values for supine bicycle exercise in children without significant cardiovascular disease will be useful for future comparisons with other groups.