Left-sided Heart Disease Research Articles

Influence of functional tricuspid regurgitation on right ventricular function

Background. Although right ventricular (RV) function has been extensively studied during the past decade, few reports have described the influence of functional tricuspid regurgitation (TR) on RV function.Methods. One hundred forty-two patients with left-side valvular heart disease associated with TR were enrolled in the study and divided into three groups according to tricuspid annular diameter: group 1 (n = 66), tricuspid annular diameter less than 40 mm; group 2 (n = 58), tricuspid annular diameter of 40 to 50 mm; and group 3 (n = 18), tricuspid annular diameter greater than or equal to 50 mm. In groups 2 and 3, the right heart parameters had deteriorated to the point that TR repair was necessary. The mean follow-up period was 102 months after the operation.Results. In each of the three groups, as pulmonary arteriolar resistance index increased, RV forward stroke work index increased in a linear fashion. The slope of the linear regression line was progressively less in group 1, 2, and 3 preoperatively. Postoperatively, this line moved in a parallel manner in group 1 and became steeper in group 2, consequently becoming similar in both groups. However, in group 3, although the slope became steeper in spite of a remarkable decrease of TR, it remained less when compared with groups 1 and 2. In addition, the right heart parameters also improved, but still remained worse in group 3 than group 2; 7 patients undergoing a flexible annuloplasty have shown gradual aggravations in TR and late postoperative clinical manifestations.Conclusions. Functional TR with severely dilated annulus may produce an irreversible deterioration of RV function. The preoperative relationship between pulmonary arteriolar resistance index and RV forward stroke work index, that is, RV systolic function to pressure afterload, might predict a postoperative fate of the right heart function.

Shortening of Doppler-Derived Deceleration Time of Early Diastolic Transmitral Flow in the Presence of Pulmonary Hypertension Through Ventricular Interaction

Deceleration time (DT) of the early transmitral flow velocity has recently been highlighted as a simple, noninvasive indicator of pulmonary arterial wedge pressure. In patients with pulmonary hypertension without left-sided heart disease, however, increased right ventricular pressure may result in an abnormal ventricular septal motion, which may impact on left ventricular (LV) early diastolic filling. We sought to determine if DT may be influenced by the severity of pulmonary hypertension in patients without left-sided heart disease. Doppler-derived transmitral flow and hemodynamic parameters were simultaneously assessed in 26 patients with pulmonary hypertension (primary pulmonary hypertension = 11; chronic thromboembolism = 15). Transmitral Doppler variables including DT were correlated with hemodynamics and LV deformity index measured in early diastole with 2-dimensional echocardiography. DT significantly correlated with the total pulmonary resistance (r = −0.70, p <0.001). Multivariate analysis revealed that DT was independently determined by total pulmonary resistance, but not by pulmonary arterial wedge pressure, heart rate, or patient's age in our study population. DT showed a correlation with LV deformity index (r = −0.74, p <0.001). These results indicate that DT may shorten in association with the severity of pulmonary hypertension and that the shortened DT in pulmonary hypertension may be attributable to right ventricular pressure overload which causes geometric changes.To determine if deceleration time (DT) of the early transmitral flow velocity may be influenced by the severity of pulmonary hypertension in patients without left-sided heart disease, Doppler-derived transmitral flow and hemodynamic parameters were simultaneously assessed in 26 patients with pulmonary hypertension. DT showed significant inverse correlations with the total pulmonary resistance and left ventricular deformity index, suggesting that DT shortens in association with the severity of pulmonary hypertension, and that the shortened DT in pulmonary hypertension may be attributable to right ventricular pressure overload which causes geometric changes.

Early Diagnosis and Estimation of Pulmonary Congestion and Edema in Patients With Left-Sided Heart Diseases From Histogram of Pulmonary CT Number

To establish an early diagnosis and have a quantitative estimation of congestion or edema, pulmonary CT scans were performed to detect the increase of regional lung water volume of patients with congestive heart failure. CT scanning of the upper, middle, and lower lung fields at maximum inspiration and hemodynamic analysis to ensure a hemodynamically chronic stable condition after the heart failure therapy for 5 weeks by cardiac catheterization within 2 weeks before CT scanning were performed in 10 normal subjects and 25 patients with left-sided heart failure. Patients were divided into two groups according to the presence or absence of pulmonary congestion or edema on chest radiographs, and the mean pulmonary wedge pressure (mPWP). The pulmonary congestion group (14 patients) had pulmonary congestion or edema, and mPWP was greater than 13 mm Hg despite the heart failure therapy. The nonpulmonary congestion group (11 patients) had no pulmonary congestion or edema, and mPWP was lower than 10 mm Hg. Histograms of pulmonary CT numbers were graphed to a set region of interest (ROI) on transverse CT images in all subjects; then changes of pulmonary CT numbers when pulmonary congestion or edema occurred were estimated from those histograms. We found that when severe pulmonary congestion or edema occurred in 6 patients with severe left heart failure, the pulmonary CT numbers within the ROI rapidly increased from -650 to -750 Hounsfield units (HU). We defined the amount ratio between the pixels (pixel counts between -650 and -750 HU within these R0Is) and the pixels (pixel counts between -300 and -950 HU) of the CT number (which were all pixels composing these R0Is) x100(%) as "%PXL." %PXL showed a linear correlation with mPWP. Compared with the %PXL in the normal group, the %PXL in the pulmonary congestion group was significantly higher than that in the normal group (p<0.05, p<0.01, p<0.001) in all lung fields. Similarly, compared with the %PXL in the normal group, %PXL in the nonpulmonary congestion group was significantly higher than that in the normal group in the middle and lower lung fields (p<0.05, p<0.01) in the posterior field. From these results, we concluded that %PXL was a good index to identify abnormal water content usually not recognizable by routine chest radiograph in the lungs.

Abnormal diastoiic unopacified blood front: A useful marker of mitral stenosis

The left ventriculograms of 113 patients, divided into seven groups, were reviewed for the detection of unopacified front (UOF) of blood entering the left ventricle (LV) during diastole. Normal UOF was detected in all the patients without left-sided valvular heart disease (regardless of the existence of coronary artery disease), constrictive pericarditis, aortic stenosis, and mitral regurgitation, although in the last group the UOF faded after several beats in 70% of cases. Only 5% of the patients with isolated mitral stenosis (MS) had an UOF, 75% had an abnormal UOF (< 60% of LV inflow tract), and 20% (with the greatest degree of MS) had only a dilution effect. A dilution effect was found in 62.5% of the patients with severe (> or = 3 degrees) aortic regurgitation (AR). An abnormal UOF is a sensitive and specific marker of significant MS. A dilution effect is indicative of either a significant MS or severe AR.

Anesthesia for Aortic and Mitral Valve Replacement in a Patient with Carcinoid Heart Disease

Anesthesia for Aortic and Mitral Valve Replacement in a Patient with Carcinoid Heart Disease

Extravascular lung water measured with 99mTc-RBC and 99mTc-DTPA is increased in left-sided heart failure.

Extravascular lung water (EVLW) was quantitatively measured in 81 patients consisting of 10 subjects with normal cardiac function and 71 patients with left-sided heart diseases, using 99mTc-RBC as a non-diffusible indicator and 99mTc-DTPA as a diffusible indicator in the equilibrium phase. EVLW averaged 3.0 +/- 1.4 (ml/kg, mean +/- SD) in subjects with normal cardiac function (n = 10), 4.3 +/- 1.7 in New York Heart Association functional class I patients (n = 30), 4.8 +/- 2.4 in NYHA functional class II patients (n = 33) and 9.4 +/- 5.4 in NYHA functional class III (n = 8) patients. EVLW was greater in NYHA class III than in normal controls or NYHA classes I or II (p < 0.01). Lung thermal volume (LTV) was also measured in 31 of the 81 patients using a double indicator dilution technique with sodium and heat. LTV averaged 6.0 +/- 1.2 (ml/kg) in normal subjects (n = 4), 8.6 +/- 2.0 in NYHA functional class I patients (n = 11), 9.7 +/- 3.0 in NYHA functional class II patients (n = 13), and 15.9 +/- 8.2 in NYHA functional class III patients (n = 3). The correlation between EVLW and LTV was significant (EVLW = 0.79 x LTV - 72.8, r = 0.80, p < 0.01). There were significant differences in EVLW/LTV ratio between NYHA class III (0.93 +/- 0.16) and NYHA class I (0.62 +/- 0.22). Thus, it was shown that EVLW was increased in left-sided heart failure and that LTV overestimated the EVLW.

第13回 心臓核医学研究会 左心不全患者における肺静脈還流曲線

第13回 心臓核医学研究会 左心不全患者における肺静脈還流曲線

Significance of left-sided heart disease for the detection of patent foramen ovale by transesophageal contrast echocardiography

Detection of patent foramen ovale by contrast echocardiography is based on transient inversion (right atrial pressure higher than left atrial pressure) of the interatrial pressure gradient. Therefore, the presence of left-sided heart disease with potential elevation of left atrial pressure might obscure the diagnosis of patent foramen ovale. Accordingly, 150 patients (88 men, 62 women; mean age 51.7 ± 15.2 years) were evaluated for a patent foramen ovale by transesophageal contrast echocardiography. Additionally, atrial septal motion during normal respiration and during the Valsalva maneuver was analyzed.Patency of the foramen ovale was observed in 20 (27%) of 74 patients without left-sided heart disease and with previous arterial embolism, in none (0%) of 25 patients with left-sided heart disease and embolism, in 7 (39%) of 18 patients without left-sided heart disease and without embolism and in 3 (9%) of 33 patients with left-sided heart disease and without embolism. The detection rate of patent foramen ovale was lower in patients with than without left-sided heart disease (5% vs. 29%, p = 0.0007) but was similar in patients with and without embolism (20% vs. 19.5%, p = NS). Abnormal atrial septal motion was more frequently observed in patients with left-sided heart disease (p = 0.0003) and was inversely correlated to detection of patent foramen ovale (p = 0.0003).Multivariate analysis revealed an independent association between the absence of left-sided heart disease and the detection of patent foramen ovale (p = 0.0003). These data suggest that in patients with left-sided heart disease, patency of the foramen ovale may be missed even by transesophageal contrast echocardiography.

Lack of correlation between P pulmonale and right atrial overload in chronic obstructive airways disease.

The correlation between P pulmonale and right atrial overload in chronic lung disease was studied. Right atrial pressure, pulmonary artery pressure, and cardiac output were measured with a Swan-Ganz catheter in nine patients with chronic lung disease and P pulmonale on the electrocardiogram (P wave amplitude of greater than or equal to 2.5 mm (0.25 mV) in leads II, III, and a VF. The results were compared with those in six patients with an atrial septal defect (left to right shunt greater than or equal to 50%) and six patients with pulmonary hypertension (mean pressure greater than or equal to 30 mm Hg without left sided heart disease). Right atrial volume and wall thickness were measured in 10 cases of P pulmonale among 1000 necropsy cases and compared with 141 normal hearts from the same series. The patients with P pulmonale did not show a significant increase in right atrial or pulmonary artery pressures. None of the patients with an atrial septal defect or pulmonary hypertension had P pulmonale on the electrocardiogram. In the necropsy cases of P pulmonale mean (1 SD) in right atrial volume (32 (12) ml) and wall thickness (1.5 (0.7) mm) were not significantly increased (40 (14) ml and 1.4 (0.5) mm in the normal hearts). There was a significant inverse relation between the presence of P pulmonale and the cardiothoracic ratio. In all the patients with P pulmonale chest x ray showed a low cardiothoracic ratio, a considerably depressed diaphragm, and a pendulous heart. This study showed no correlation between P pulmonale and right atrial overload in chronic lung disease. A more vertical anatomical position of the heart, particularly of the right atrium, seems to be the major factor responsible for generation of P pulmonale in chronic airways disease.

Bronchial neuroendocrine (carcinoid) tumor causing unilateral left-sided carcinoid heart disease

A female patient suffering from a bronchial neuroendocrine tumor with unilateral left-sided carcinoid heart disease is reported. Repeated x-ray films of the chest showed a slowly growing lung tumor in the left lower lobe. The patient refused any diagnostic or therapeutic procedure to define the type of the tumor. During the follow-up of 24 years she developed severe mitral and moderate to severe aortic insufficiency, both invasively quantified by thermodilution techniques. During surgery for double valve replacement the patient died from left ventricular heart failure. Necropsy revealed the typical pattern of a bronchial neuroendocrine tumor without metastases. Examination of the heart disclosed the characteristic deposits of fibrous tissue on the cusps of both the mitral and the aortic valves whereas the right heart showed no abnormalities. Review of the literature suggests the unilateral left-sided carcinoid heart disease to be a very rare finding, its pathogenesis remains to be elucidated.

Physiological manometric tested tricuspid valvuloplasty.

Tricuspid insufficiency associated with severe left-sided valvular heart disease carries a poor prognosis. Twenty-two patients with severe pulmonary hypertension and tricuspid insufficiency underwent a tricuspid valvuloplasty in addition to left-sided single or double valve replacement. The tricuspid valvuloplasty was performed after weaning the patient from cardiopulmonary bypass. The efficacy of the tricuspid valvuloplasty was gauged by continuous right atrial pressure recordings as the annuloplasty was completed. Obliteration of the peak of the V wave of the right atrial pressure recordings indicated that the tricuspid annuloplasty was secured. Twenty-one patients were long-term survivors, and 19 patients are in good condition for an average follow-up of 6.1 years (1 to 12 years postoperatively).

Role of right and left atrial dimensions for release of atrial natriuretic peptide in left-sided valvular heart disease and idiopathic dilated cardiomyopathy

To evaluate the role of atrial dimensions for release of atrial natriuretic peptide (ANP), right and left atrial dimensions (cross-sections) were determined by 2-dimensional echocardiography in 50 patients with left-sided valvular heart disease or idiopathic dilated cardiomyopathy. All patients underwent right- and left-sided heart catheterization with measurement of central hemodynamics. Plasma samples for ANP were withdrawn from femoral vein (ANPv) and ascending aorta. An estimate of right and left meridional atrial wall stress was derived by multiplying cross-sectional areas with pressures of the respective atria. As expected ANPv was closely related to mean right (r = 0.63; p < 0.001; n = 50) and left atrial pressures (r = 0.61; p < 0.001; n = 47). Furthermore, a positive correlation between ANPv and right (r = 0.56; p < 0.001; n = 48) and left (r = 0.30; p < 0.05; n = 48) atrial cross-sections was obtained. Finally, an excellent relation was found between ANPv and right (r = 0.73; p < 0.001; n = 48) as well as left (r = 0.58; p < 0.001; n = 44) meridional atrial wall stress, indicating that atrial wall stress rather than atrial pressures or dimensions alone determines plasma ANP concentrations. However, for identical right and left meridional atrial wall stress 3- to 4-times higher plasma ANPv levels were obtained in patients with idiopathic dilated cardiomyopathy than in patients with left-sided valvular heart disease. This indicates that release of ANP to the same stimulus may be modulated by the nature of the underlying heart disease.

Response of peripheral venous pressure and plasma catecholamine concentration to supine leg exercise--a study in patients with mild congestive heart failure.

We measured the peripheral venous pressure (VP) in supine leg exercise in 25 "normal" subjects and 122 patients with primarily left-sided heart diseases (NYHA class I = 68, class II = 54 cases) to determine whether or not plasma catecholamine concentration would increase in patients with mild congestive heart failure, in response to dynamic exercise. Cardiac patients (n = 122) were divided into 2 groups on the basis of VP increment (delta VP): Group N had 60 patients with delta VP less than 35 mmH2O, and Group H had 62 patients with delta VP in excess of 35 mmH2O. Plasma concentrations of noradrenaline (NA) and adrenaline (A) were measured before and during leg exercise. The relation between delta VP, NA and A, and the relation between delta VP and increments of NA (delta NA) and of A (delta A) by leg exercise were studied in both the cardiac patients and the "normal" subjects (Group C). (1) NA at rest was 0.225 +/- 0.016 ng/ml (mean +/- SE) in Group C and 0.216 +/- 0.009 ng/ml in Group N. It was 0.468 +/- 0.026 ng/ml in Group H, which was significantly higher than in Group C (p less than 0.001), or Group N (p less than 0.001). (2) delta NA was 0.051 +/- 0.009 ng/ml (mean +/- SE) in Group C, 0.067 +/- 0.007 ng/ml in Group N, and 0.249 +/- 0.019 ng/ml in Group H. There was a statistically significant difference in delta NA between Groups C and H (p less than 0.001) and between Groups N and H (p less than 0.001). (3) There was no significant difference between the three groups in A at rest, or in delta A. (4) There was a correlation between delta VP and NA at rest (r = 0.614, p less than 0.001) and between delta VP and delta NA (r = 0.708, p less than 0.001). These data suggest that sympathetic nervous activity increased in the patients with high delta VP but without overt heart failure, and that the constriction of the capacitance vessels caused by an increase in NA could be at least one of the mechanisms involved in raising the delta VP in those patients.

Plasma amino acids in interrupted aortic arch and the hypoplastic left heart syndrome.

Plasma amino acids were measured in 8 babies with left-sided congenital heart disease, 3 interrupted aortic arch (IAA) and 5 hypoplastic left heart syndrome (HLH), at 1-6 days of age. There was an increase in total amino acid levels when compared with 40 control infants of similar gestational age and birth weight. Both branched-chain and aromatic amino acids were raised although there were differences between the babies with IAA and HLH. Babies with HLH had higher total amino acid levels than babies with IAA, the difference being due to raised branched-chain amino acids. Apart from the anatomical differences babies with HLH had metabolic acidosis at the time of sampling whereas babies with IAA had normal pH. It is possible that the increase in amino acid levels in babies with obstructed left-sided congenital heart disease is due to hepatic congestion and hypoperfusion, although altered acid base states may also be important.

Effects of phentolamine on response to supine leg exercise of peripheral venous pressure and plasma catecholamine concentration--a study in patients with mild congestive heart failure.

The present study examined the effects of phentolamine (PH) on the increments in peripheral venous pressure (delta VP), and of plasma noradrenaline (delta NA) and adrenaline (delta A) concentration, in response to supine leg exercise. Peripheral venous pressure and plasma catecholamine concentrations were measured at rest and during exercise, before and after intravenous injection of PH (0.1 mg/kg) in 10 healthy volunteers (Group C), and in 42 patients with primarily left-sided heart diseases but without apparent right-sided or left-sided heart failure (NYHA class I, II). These cardiac patients were divided into 2 groups on the basis of delta VP. Those with delta VP below 35 mmH2O comprised the normal group (Group N), and those with delta VP more than 35 mmH2O the abnormally high group (Group H). 1) In Group C, delta VP changed only slightly from 11.1 +/- 2.8 (mean +/- SE) to 4.9 +/- 1.7 mmH2O with an intravenous injection of PH. On the other hand, PH caused a significant decrease in delta VP from 22.2 +/- 2.3 to 10.4 +/- 2.3 mmH2O in Group N (p less than 0.001), and from 52.7 +/- 3.4 to 17.0 +/- 12.4 mmH2O in Group H (p less than 0.001). It was suggested that PH blocked the alpha-receptors of the systemic capacitance vessels, thereby inhibiting the constriction of these vessels. 2) Both NA at rest and delta NA before PH were significantly higher in Group H than those in Groups C or N. delta NA increased significantly after the PH injection in all 3 groups, i.e., from 0.038 +/- 0.013 (mean +/- SE) to 0.282 +/- 0.051 ng/ml in Group C, from 0.056 +/- 0.013 to 0.279 +/- 0.034 ng/ml in Group N and from 0.279 +/- 0.034 to 0.839 +/- 0.103 ng/ml in Group H. The increase in delta NA after PH was especially marked in Group H. It was suggested that the "sympathetic nervous activity" was increased in the patients with an impaired left ventricular pumping function. 3) PH caused a slight increase in delta A in all groups, but there was no significant difference in delta A before and after PH in the 3 groups.

Left-to-Right Shunt via Left Superior Vena Cava Communication with Left Atrium

The findings in a 22-year-old man with Ebstein's anomaly of the tricuspid valve, Wolff-Parkinson-White syndrome, and a persistent left superior vena cava are reported. This is the first reported case of this combination of anomalies in which the atrial septum was intact and the left superior vena cava communicated with the left atrium. Uniquely, blood was shunted left to right via the left superior vena cava from the left atrium. Only one previous case of left-to-right shunting via a left superior vena cava (in the absence of mitral valvular disease or cor triatriatum) has been reported (associated with aortic coarctation). Angiograms demonstrated the left atrial connection of the left superior vena cava to be at the entrance of the right superior pulmonary vein into the left atrium. In the absence of demonstrable left-sided heart disease, this anatomic juxtaposition is suggested as a possible explanation for the direction of shunting.

Assessment of left ventricular contractility during supine exercise in children with left-sided cardiac disease.

Exercise stresses the cardiovascular system and causes it to use its reserve capacities. Exercise assessment may unmask abnormalities of left ventricular contractility not suspected from or detected by resting measurements. We have studied the following indices of left ventricular contractility in 21 children with left-sided congenital heart disease: maximum dP/dt, Vmax, Vpm, Vcf, and peak meridional wall stress. Studies were performed in the supine posture at rest, and at 25 per cent, and 50 per cent of a predetermined maximal upright workload on a bicycle ergometer. The method of measurement used simultaneous high fidelity catheter pressure tracings and M-mode echocardiography. There were no complications and the technique appeared practical and safe. The measurements of contractility differentiated patients with left ventricular volume or pressure overload from each other and from patients with either volume plus pressure overload, or myocardial dysfunction. These measurements can be used to measure the functional reserve capacity of patients with left-sided lesions, and may be useful in follow-up studies, especially before and after operation.

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 ± 0.09∗ 0.24 ± 0.06∗ Group 4 0.51 ± 0.06∗ 0.44 ± 0.09∗ 0.20 ± 0.03∗ ∗ 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.

Pulsatile Varicose Veins in Tricuspid Insufficiency

To the Editor.— The diagnosis of tricuspid insufficiency, which is often functional in nature and secondary to primary left-sided heart disease or severe lung disease, is not infrequently difficult to diagnose clinically. The accentuated V-waves in the neck veins may be missed if there is severe right-sided failure and the upper limit of the venous column cannot be seen to pulsate. The classical sign of the pulsating liver may be misinterpreted as pulsation being transmitted from the abdominal aorta. Recently, three patients with known left- and right-sided failure were suspected of having functional tricuspid insufficiency. In addition to the classical findings of pulsatile jugular veins and a pulsatile liver, it was noted in these patients that the veins in the upper part of their thighs were also pulsating with ventricular systoles. The fact that the patients had prominent varicose veins probably facilitated the propagation of these pulsations. In one of

Non-invasive assessment of the performance of the right heart during dynamic exercise, a study of left-sided heart disease.

A simplified, non-invasive method for assessment of the performance of the right heart during supine leg exercise was described, which necessitated no more than a bicycle "ergometer" for leg exercise, a radiocardiograph for recording cardiac index (CI) and a "water" manometer for measuring cubital venous pressure (VP). Because the use of a cardiac catheter was omitted, right atrial pressure (RA), right ventricular diastolic pressure (RVd) or pulmonary arterial pressure (PA) were not measured. In 11 healthy subjects and 25 patients with primarily left-sided valvular disease and hypertension, the observed shift of CI-VP plot with exercise was similar to the published records of exercise-induced shift of CI-RA plot or CI-RVd plot in normal subjects and the same types of heart disease. With levels of load used in this study, a dividing line separating normal from abnormal elevation of VP during supine leg exercise (deltaVP) could be drawn at deltaVP = 35 mm H2O, because (1) none of the healthy subjects had deltaVP in excess of 35 mm H2O and (2) in these types of heart disease, deltaVP in excess of 35 mm H2O was always associated with a "subnormal" increase in CI (deltaCI less than 0.8 lit. min-1. M-2) with exercise, except in a few cases who appeared, clinically, to be in what may be termed "latent heart failure". Factors probably responsible for an impaired pumping ability of the right heart during exercise in left-sided heart disease were discussed, in relation to deltaVP.