Mean End-diastolic Volume Research Articles

Unfavourable Left Ventricular Remodelling in Patients with Dobutamine-Inducible Ischaemia after Acute Myocardial Infarction

Aims: Aim of the study was to assess the role of early inducible ischaemia for determining left ventricular remodelling in patients with acute myocardial infarction. Methods and Results: In 179 consecutive patients with first myocardial infarction the occurrence of new wall motion abnormalities during dobutamine stress echocardiography at discharge was related to the left ventricular volume changes at 6 months. Left ventricular end-diastolic and end-systolic index volumes (mL/m2) were echocardiographically detected at discharge and at 6 months and the relative changes were calculated. The study population consisted of 105 patients without and 74 patients with inducible ischaemia; of these, 46 patients had ≥4 ischaemic segments. At 6 months, the end-diastolic index volume increased in patients with inducible ischaemia compared to patients without (+7·5±11·2 vs −0·1±10·2 mL/m2; P =0·0049) and final mean end-diastolic volume was greater in patients with inducible ischaemia than without (70·8±16.0 vs 61·1±17.0 mL/m2; P =0·0012). The end-systolic volume increased at 6 months in patients with inducible ischaemia and it decreased in patients without (+2·8±8·6 vs −1·4±7·8 mL/m2; P =0·021). At the multivariate analysis, inducible ischaemia in ≥4 segments (odds ratio=6·43), the wall motion score index at the peak of dobutamine infusion (odds ratio=1·14) and the end-systolic index volume at discharge (odds ratio=1·06) were independent predictors of subsequent left ventricular end-diastolic index volume increase ≥15 mL/m2. Conclusion: In patients with first myocardial infarction the presence and the severity of inducible ischaemia, as detected by dobutamine stress echocardiography at discharge, indicates an unfavourable left ventricular remodelling. Copyright 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved .

Myocardial revascularization in patients with severe ischemic left ventricular dysfunction. Long term follow-up in 141 patients.

The present study evaluates our experience with coronary bypass grafting in patients with EF < or =25%. Myocardial revascularization in this setting remains controversial because of concerns over operative mortality and morbidity and lack of functional and survival benefit. One hundred and forty-one patients with coronary artery disease and left ventricular ejection fraction < or =25% underwent coronary artery bypass graft between January 1988 and December 1998. Mean age at operation was 63.3 years and 81.4% were male. The major indication for surgery was angina (114 patients, 80.8%). Ejection fraction (EF), left ventricular end diastolic pressure (LVEDP) and cardiac index (CI) were used to assess left ventricular function. The number of graft was 2.7+/-1.6/patient. Internal mammary artery was used in 119 patients (84.3%). Intra aortic balloon pump was placed preoperatively in 25 patients (17.7%). Five operative risk factors were associated with a higher mortality: emergency, female sex, LVEDP, CI and NYHA class IV. The operative mortality was 7% (10 patients). Left ventricular ejection fraction (assessed post operatively in 83 patients) improved from 22.2% preoperatively to 33.5% post operatively (P<0.001), mean end diastolic volume index fell from 98 to 83 ml/m(2) following surgery. Survival at 2, 5 and 7 years was respectively 84+/-3%, 70+/-4% and 50+/-5%. Two variables were associated with increased long term survival: congestive heart failure (NYHA class lower than IV (P=0.035) and cardiomegaly (P=0.04) In patients with left ventricular dysfunction, myocardial revascularization can be performed relatively safely with good medium term survival and improvement in quality of life and in left ventricular function. Coronary artery bypass graft may be offered to patients with impaired ventricular function, but careful patient selection and management when considering these patients for operation should assess potentially reversible dysfunction.

Mid-term results of partial left ventriculectomy in end-stage heart disease.

Immediate and mid-term effectiveness of partial left ventriculectomy (PLV) is assessed in 27 idiopathic dilated cardiomyopathy patients. All patients were in New York Heart Association (NYHA) class III (17) or IV (ten). The average left ventricular ejection fraction (LVEF) was 19+/-4% by MUGA, and 23+/-4% by digital echocardiography. The mean end-systolic volume (LVESV) was 259+/-66 ml and the mean end-diastolic volume (LVEDV) was 342+/-83 ml. Mitral valve replacement was a routine part of the procedure. Operative mortality was 18.5%, a LVEDP>25 mmHg, left atrial diameter>55 mm, pulmonary artery systolic pressure>40 mmHg, congestive hepatomegaly and NYHA class IV being the mortality predictors. Three-year Kaplan-Meier survival was 64+/-10%, including operative mortality; freedom from congestive heart failure was 65+/-11%. Functional status improved from 3.2+/-0.4 to 1.5+/-0.6 (P=0.0003). The mean LVEF was dramatically increased after PLV (to 40+/-4%, P=0.0001); LVESV was decreased to 90+/-30 ml (P<0.0001) and LVEDV to 160+/-49ml (P<0.0001). This improvement was sustained during the first 30 months. PLV is a reasonable approach for end-stage patients, providing sustained dramatic changes in ventricular geometry and functional capacity, especially in the absence of compromised right and diastolic left heart functions. Routine replacement of the mitral valve allows a more liberal ventriculectomy and eliminates mitral regurgitation, and this may help minimize ventricular distention.

Ventricular dilation after anterior ST-elevation myocardial infarction in the thrombolytic era

Background The aim of this work was to study changes in end-diastolic volume 6 months after Q-wave and non-Q-wave anterior ST-elevation myocardial infarction by echocardiography. Ventricular dilation after anterior Q-wave myocardial infarction is well-recognized. However, there is a dearth of information about the natural history of ventricular volumes after non-Q-wave myocardial infarction. Methods One hundred ninety patients receiving thrombolytic therapy after anterior ST-elevation myocardial infarction were studied. All patients had 2D echocardiograms and 12-lead electrocardiograms recorded within 24 hours of symptoms and at 3, 42, and 180 days later. In addition, a further electrocardiogram was recorded on day 7 to assess patients for the presence of Q waves. Peak creatine kinase over the first 3 days of admission was recorded. End-diastolic volume index was the study end point. Results Peak creatine kinase was strongly associated with ventricular dilation in both groups (P < .001). Mean end-diastolic volume in the Q-wave group increased significantly from day 1 to 6 months (P < .05) but did not alter after non-Q-wave infarction. However, when patients were selected on predefined criteria for significant change in ventricular dilation (>10 mL/m2), then 35% of those with and 15% of those without Q waves fell into this category. Within this group, the increase in end-diastolic volume followed a similar pattern, with the maximum percentage increase occurring between day 1 and 6 weeks. Conclusions In the postthrombolytic group of anterior ST-elevation myocardial infarction, a minority of patients without Q-wave development also undergo significant ventricular dilation. (Am Heart J 2000;140:611-6.)

Comparison of two three-dimensional gated SPECT methods with thallium in patients with large myocardial infarction

Background. Two different commercially available gated single photon emission computed tomography (GSPECT) methods were compared in a population of patients with a major myocardial infarction. Methods. Rest thallium GSPECT was performed with a 90-degree dual-detector camera, 4 hours after injection of thallium-201 (Tl-201; 185 MBq) in 43 patients (mean age, 62 ± 12 years) with a large myocardial infarction (mean defect size, 33% ± 16%). End-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF) were calculated by using QGS (Cedars Sinai) and MultiDim (Sopha Medical Vision International, Buc, France). Images were reconstructed by using a 2.5 zoom and a Butterworth filter (order, 5; cut-off frequency, 0.20). LVEF was calculated in all patients by using equilibrium radionuclide angiocardiography (ERNA). EDV, ESV, and LVEF were also measured by using left ventriculography (LVG). Results. Compared with LVG, QGS underestimated LVEF by means of an underestimation of mean EDV. MultiDim overestimated EDV and ESV. GSPECT EDV and ESV overestimation was demonstrated by means of Bland-Altman analysis to increase with left ventricular volume size ( P < .05). The difference between LVG and GSPECT volumes was demonstrated by means of regression analysis to be correlated with infarction size. This effect was particularly important with MultiDim ( P < .0001). Conclusion. In Tl-201 GSPECT, LVEF and volume measurements will vary according to the type of software used. (J Nucl Cardiol 2000;7:312–19.)

Predicting Feasibility of Biventricular Repair of Right-Dominant Unbalanced Atrioventricular Canal

Background. In right-dominant unbalanced atrioventricular (AV) canal, there are no criteria to judge adequacy of the left ventricle for biventricular repair. The purpose of this study was to test the hypothesis that right ventricular volume overload in this condition results in right-to-left septal bowing and contributes to the appearance of a small left ventricle.Methods. Five consecutive neonates and young infants (age range, 23 days to 5 months; median age, 3 months) with right-dominant unbalanced complete AV canal underwent biventricular repair. Preoperative and postoperative echocardiographic measurements of left (LV) and right ventricular size and AV valve component size were made. Potential LV volume was assessed preoperatively using a theoretic model that assumed a normalization of septal bowing.Results. There was no perioperative mortality; 1 patient died 71 days postoperatively of problems related to the left AV valve. Preoperatively, all patients had severe LV hypoplasia, with a mean end-diastolic indexed true LV volume of 14.8 ± 9.1 mL/m2, indexed potential LV volume of 32.0 ± 18.8 mL/m2, left AV valve to total AV valve ratio of 0.30 ± 0.06, and LV to right ventricular long-dimension ratio of 0.65 ± 0.1. Postoperatively, all patients had indexed true LV volumes greater than 30 mL/m2 (mean volume, 35.6 ± 3.9 mL/m2), and the left AV valve to total AV valve ratio and the LV to right ventricular long-dimension ratio increased to 0.42 ± 0.03 and 0.88 ± 0.11, respectively. Both preoperative potential and true LV volumes correlated well with postoperative true LV volumes: r = 0.90 (p = 0.040) and r = 0.93 (p = 0.023), respectively. Increases in LV length and left AV annulus size indicated contributions of volume loading and surgical patching to the right of the ventricular crest to the increase in LV size.Conclusions. In our small series, preoperative indexed potential LV volume of 15 mL/m2 or greater (present in all patients) allowed biventricular repair of right-dominant unbalanced AV canal. Any previous criteria for LV hypoplasia in this condition need to be reconsidered. This study also has implications for other right-sided volume-loaded lesions in which the left ventricle initially is judged to be hypoplastic but in which biventricular repair may be feasible.(Ann Thorac Surg 1997;63:1657–63)

Left ventricular volume determination using colour superpositioning of contrast echocardiograms

Objective: To delineate the endocardium, selective colouring of contrast regions in left ventricular contrast echocardiograms was performed using digital image processing. Methods: Volume determinations were performed in end-diastolic and end-systolic frames before and after the injection of contrast agent into the left ventricle and were compared to cineventriculograms in 30 patients by two independent investigators. Results: The mean end-diastolic volume measured was 114 ± 44 ml in the native, 235 ± 79 ml in the contrast, 175 ± 70 ml in the color-superimposed (observer 1), and 187 ± 79 ml in the cineventriculographic images. Thus, native echocardiograms underestimated angiographic volumes by 39%, contrast echocardiographic pictures overestimated angiographic volumes by 26%, and color-superimposed pictures underestimated angiographic volumes by 6%. The mean end-systolic volume measured was 61 ± 34 ml in the native, 126 ± 51 ml in the contrast, 88 ± 47 in the color-superimposed (observer 1) and 93 ± 53 in the cineventriculographic images. Ejection fractions were identical in the color-superimposed and angiographic images. In a two-factor cross classified analysis of variance the factor methodology showed significant differences for end-diastolic (P = 0.0001) and end-systolic volumes (P = 0.0001) and the ejection fraction (P = 0.0003), while the factor observer did not show significant differences (P = 0.046, 0.70 and 0.0435). Inter-observer variability was significantly lower for end-diastolic, end-systolic volumes and the ejection fraction (P = 0.0060, 0.0006 and 0.0001, F-test) in the color-superimposed images when compared to native echocardiographic images. Conclusion: Color superpositioning of contrast echocardiograms allows improved volume determination due to better left ventricular endocardial delineation.

Use of the 21-mm Björk-Shiley Monostrut valve in patients with a narrow aortic root.

Technical considerations regarding the insertion of 21-mm Björk-Shiley Monostrut valves, particularly regarding decalcification of a calcified annulus with an ultrasonic surgical dissector, in patients with aortic stenosis and a narrow aortic root are described. Short-term follow-up (mean(s.d.) 37(10) months) is also presented. Ten adults whose body surface area ranged from 1.26 to 1.47 m2 underwent implantation of a 21-mm valve without outflow patch or annuloplasty. One operative death occurred; there were no other complications. The New York Heart Association functional class decreased from a mean of 3.2 before surgery to 1 in all cases. The mean(s.d.) end-diastolic volume decreased from 129(44) ml to 80(21) ml, and the end-systolic volume from 41(21) ml to 27(10) ml (P < 0.01). The mean(s.d.) maximum velocity, as measured by Doppler echocardiography in the aortic position, decreased from 4.35(0.55) m/s to 2.42(0.59) m/s (P < 0.01). This degree of improvement was not meaningfully different from that of the 23-mm valve. However, there was a negative correlation between the reduction in left ventricular mass and body surface area (r = -0.72, P < 0.03). It is concluded that the 21-mm Björk-Shiley Monostrut valve can be inserted using a modified technique in most patients with a narrow aortic root. This size valve is satisfactory when the patient's body surface area is < 1.45 m2.

R peak time prolongation and R peak delay in leads I, V 5, or V 6: Diagnostic values as signs of myocardial dysfunction in chronic mitral incompetence

On the assumption that maximum R peak time prolongation in the left-sided leads I, V 5, or V 6 and its time relationship to the S peak time of the maximum S amplitude in leads V 1, V 2, or V 3 (representing dorsally directed forces of ventricular depolarization) could indicate the extent of left ventricular volume overloading and possibly left ventricular systolic function, these variables and the preoperative findings of angiocardiography were compared between patients with chronic mitral incompetence who, late after corrective valve surgery, had either well-preserved radionuclide left ventricular ejection fraction (group 1, n = 36) or radionuclide left ventricular ejection fraction below 50% (group 2, n = 30). Before surgery, group 2 patients had a highly significant lower mean left ventricular ejection fraction, a highly significant greater mean end-systolic volume index, a significantly greater mean end-diastolic volume index, a significantly greater mean maximum R peak time in leads I, V 5, or V 6, and a significantly greater prolongation of the maximum R peak time above the S peak time in the right precordial leads, as compared with group 1. R peak times greater than 50 ms or the presence of R peak delay (maximum R peak time greater than the S peak time of the maximum right precordial S amplitude) yields less sensitive but highly reliable results in predicting radionuclide left ventricular ejection fraction below 50% with both specificity and positive predictive values of 100%. Thus, in chronic mitral regurgitation surgery should not be delayed if patients present these signs because they are specific markers of irreversibly impaired chamber function.

Reversible left ventricular dysfunction secondary to rapid atrial fibrillation

We present the cases of four patients with reversible left ventricular dysfunction associated with severe congestive heart failure presumably induced by rapid atrial fibrillation. The mean heart rate was 159 beats/min and the mean left ventricular end-diastolic dimension was 58.5 mm with diffusely impaired left ventricular motion. None of the patients had a history of preceding upper respiratory infection before the acute episode and no signs of inflammation at onset, and all patients were New York Heart Association Class I or II before the acute episode. Left ventriculography, done about 1 month when congestive heart failure and ventricular rate were controlled with digitalis and diuretics, still showed diffusely decreased left ventricular motion; the mean end-diastolic volume was 165 ml and the mean ejection fraction was 30%. Coronary angiography was normal in three patients and one showed moderate left anterior descending artery stenosis. Right ventricular biopsy, done in three patients showed no evidence of myocarditis. Left ventricular wall motion normalized in 5–36 months on follow-up echocardiography. These findings suggest that persistent rapid atrial fibrillation can cause reversible left ventricular dysfunction which can take a considerable period of time to normalize.

Left ventricular function under stress before and after myocardial revascularization

To compare left ventricular responses to stress during exercise-induced myocardial ischemia and after myocardial revascularization, 35 patients (mean age 55 ± 7 years, class III angina) with three-vessel coronary artery disease underwent a rest and exercise initial-transit radionuclide angiocardiography before aortocoronary bypass grafting. Left ventricular ejection fraction decreased during exercise ( p < 0.01), but cardiac output was augmented with an increased heart rate ( p < 0.0001) and left ventricular end-diastolic volume ( p < 0.001). Group A ( n = 15) underwent six serial resting studies at different volume loads during the first 24 hours after operation while heart rate and blood pressure were held constant. These data revealed no significant change in left ventricular ejection fraction, but preload varied in all patients because of bleeding and fluid administration, with a mean end-diastolic volume change of 115 to 176 ml. This range of end-diastolic volume was similar to that defined with rest and exercise testing before operation. Group B ( n = 20) underwent a repeat rest and exercise test 3 months after operation that demonstrated no change in resting function. However, exercise ejection fraction and peak systolic pressure/end-systolic volume ratio increased ( p < 0.001 and p < 0.05, respectively) while end-diastolic volume decreased ( p < 0.05) compared with the values before operation. These data indicate that patients with coronary artery disease have chronically adapted cardiac function that makes use of both rapid heart rate and a wide range in preload to augment cardiac function under stress. This adaptation is present early after revascularization, but by 3 months after operation an increased contractile force replaces preload reserve as the secondary mechanism for augmenting function under stress.

Left ventricular aneurysm: Clinical and hemodynamic data

Clinical and hemodynamic data of 30 patients with left ventricular aneurysm (27 men, 3 women, mean age 54.9 years) were compared with those of 30 patients with previous myocardial infarction and segmental hypo- or akinesis (28 men, 2 women, mean age 51 years). In each group, 10 patients were affected by one-, two-, or three-vessel disease. A semiquantitative evaluation of collateral coronary circulation showed no significant differences between the two groups. Mean end-diastolic volume was higher in patients with left ventricular aneurysm (p less than .025, less than .05, and less than .001 in 1-, 2-, and 3-vessel disease, respectively) and ejection fraction was lower only in patients with one-, (p less than .001) and two- (p less than .05) vessel disease in comparison with patients without left ventricular aneurysm. No significant difference was evidenced in basal or isometric exercise end-diastolic pressure. The incidence of thrombosis detected by ventriculography was higher in patients with left ventricular aneurysm (33.3 vs. 6.6%). The mean duration of follow-up was 20.7 months in patients with left ventricular aneurysm and 20.6 in the control group. No significant difference was found either in mortality or in reinfarction rate as far as incidence and severity of angina. The incidence of congestive heart failure was more evident, but not significant in patients with left ventricular aneurysm. One embolic episode was present in one patient with aneurysm and intraventricular thrombosis. Left ventricular performance is influenced by an aneurysm when a limited coronary compromise is present (one- and two-vessel disease) while it is not affected in the case of a coexisting three-vessel disease.

Diagnostic accuracy of right ventriculography in arrhythmogenic right ventricular cardiomyopathy

Diagnostic sensitivity and specificity of cineangiography were evaluated by multivariate logistic discriminant analysis in 32 patients with arrhythmogenic right ventricular (RV) cardiomyopathy, 27 patients with biventricular dilated cardiomyopathy, 28 patients with atrial septal defect and 18 normal subjects. In patients with arrhythmogenic RV cardiomyopathy and biventricular dilated cardiomyopathy, the diagnosis was confirmed by endomyocardial biopsy. All RV values overlapped for the diagnosis of atrial septal defect and arrhythmogenic RV cardiomyopathy; overlapping extended to dilated cardiomyopathy for end-diastolic volume and infundibular dimensions. RV ejection fraction appeared reduced in all the diseases; in particular, mean values in dilated cardiomyopathy and arrhythmogenic RV cardiomyopathy were 38 and 53%, respectively (p < 0.05). Left ventricular quantitative studies showed a significant difference between dilated and arrhythmogenic RV cardiomyopathy, both in terms of pumping indexes (mean end-diastolic volumes 180 vs 91 ml/m 2 and mean ejection fraction 33 vs 60%), and indexes of contractility (stress/end-diastolic volume 3.7 vs 6.7). Multivariate analysis disclosed that transversally arranged hypertrophic trabeculae, separated by deep fissures, were associated with the highest probability of arrhythmogenic RV cardiomyopathy (p < 0.001). Posterior subtricuspid and anterior infundibular wall bulgings were the only other independently significant variables. Coexistence of these signs was associated with 96% specificity and 87.5% sensitivity. Thus, arrhythmogenic RV cardiomyopathy presents quantitative volumetric and hemodynamic as well as qualitative features that clearly distinguish it from dilated cardiomyopathy and confirm its nosographic autonomy among the primary diseases of the myocardium.

Relative myocardial depression in normotensive sepsis

To assess biventricular performance in normotensive sepsis, the measurements of cardiovascular function in 69 septic patients were compared with those in 18 similarly hyperdynamic patients who had sustained multisystem trauma. All studies were performed following initial resuscitation, during a period in which the blood pressure was stable and no sympathomimetics were required. Although the two study groups demonstrated a similar increase in the mean cardiac index (CI), and similar levels of systemic oxygen transport and consumption, the machanisms by which these groups maintained the high Cl were dissimilar. Mean ejection fractions were significantly lower in the septic group than in the trauma group for both the left ventricles (0.49 ± 0.13 v 0.62 ± 0.10; P < .001) and right ventricles (0.41 ± 0.10 v 0.50 ± 0.10; P < .005). Concurrently, mean end-diastolic volume indexes were significantly greater in the septic group for both the left ventricles (97 ± 31 v 74 ± 18 mL/m 2; P < .005) and right ventricles(117 ± 45 v 91 ± 25 mL/m 2; P < .05). Thus, indexes of myocardial performance influenced by ventricular contractility were not augmented in septic patients to the same degree as was found in a similarly hyperdynamic reference group. This study suggests that normotensive, hyperdynamic sepsis is associated with a “relative” depression in biventricular contractile performance when compared with a reference group of similarly hypermetabolic, but nonseptic, patients.

Long-term stepwise sustained improvement in left ventricular ejection fraction after myocardial infarction

Radionuclide left ventricular ejection fraction, end-diastolic volume, and exercise capacity were determined in 34 selected patients who survived a first Q wave anterior infarction. Patients were included in the study if they had no subsequent cardiac events (unstable angina or myocardial infarction) during the average follow-up period of 47 months (range = 36 to 70 months); none was treated with thrombolysis, coronary angioplasty, or bypass grafting. Overall, mean left ventricular ejection fraction increased from 28 ± 10% 1 month after infarction to 33 ± 10% at 3 years ( p < 0.01); mean end-diastolic volume decreased from 217 ± 99 ml to 171 ± 80 ml ( p < 0.002). Stepwise improvement in left ventricular ejection fraction occurred in 15 of these patients (group B) and was associated with a significant increase in exercise capacity. Mean ejection fraction in group B was 26 ± 7% at 1 month and 41 ± 10% at 3 years ( p < 0.001). In all of these patients there was improved regional wall motion in the noninfarct zone, whereas five patients also showed improvement in the infarct zone. The results indicate a progressive improvement in left ventricular function that occurs over time in some patients after first Q wave anterior infarction, independent of intervention.

Left ventricular systolic and diastolic function after two-stage anatomic correction of transposition of the great arteries

Anatomic repair of transposition of the great arteries (TGA) has been developed because of concerns about right ventricular function after atrial repair by the Mustard or the Senning technique. This study assessed left ventricular systolic and diastolic function in three patients after two-stage anatomic repair. Two patients had a ventricular septal defect (one with coarctation), and the third patient had right ventricular dysfunction precluding atrial repair. All had pulmonary artery banding. The mean ages at the time of repair and catheterization were 2.75 and 4.9 years, respectively. The control group included 10 patients with insignificant or no cardiac disease. At cardiac catheterization the group with TGA had a higher mean end-diastolic volume index (110.9 ± 4.74 ml/m 2) compared to normal subjects (79.1 ± 14.55; p < 0.001), mean end-systolic volume index (37.3 ± 3.69 vs 22.7 ± 4.42; p < 0.001), mass index (101.0 ± 16.9 vs 68.2 ± 12.34; p = 0.038), and stroke volume index (73.6 ± 3.52 vs 56.5 ± 12.1; p = 0.0027). The ejection fractions, end-diastolic and peak systolic pressures, and stresses were not different. There was no difference in the relationship between the mean rate-corrected velocity of circumferential fiber shortening and end-systolic stress for the group with TGA, but myocardial stiffness was markedly elevated (29.5 ± 1.84 vs 10.8 ± 2.20; p < 0.001). Thus, this study found abnormalities of left ventricular size after two-stage anatomic repair of TGA in this group of patients with TGA. Contractile function was within normal limits, but at the lower end of normal, and myocardial stiffness was increased.

Characterisation of the normal right ventricular pressure-volume relation by biplane angiography and simultaneous micromanometer pressure measurements.

The normal right ventricular pressure-volume relation was studied by recording biplane right ventriculograms with simultaneous high fidelity pressure recordings in 10 adults found to have normal coronary arteries and haemodynamic function at diagnostic cardiac catheterisation. Right ventricular volume was measured frame by frame from digitised ventriculograms by a modification of Simpson's rule. The accuracy of this method was tested in a study of 22 human and animal right ventricular casts. There was excellent agreement between calculated volumes and those measured by fluid displacement. The derived regression equations were used to correct right ventricular volumes calculated from in vivo studies. The mean (SD) end diastolic volume index for the group was 62 (13) ml/m2, the stroke volume index was 43 (8) ml/m2, and the ejection fraction was 62 (6)%. Right ventricular pressure-volume loops were generated by combining simultaneous volume and pressure curves. The normal right ventricular pressure-volume loop was triangular, departing significantly from the square or rectangle of the normal left ventricular pressure-volume loop. Ejection from the right ventricle began early during the pressure rise and continued as right ventricular pressure fell. As a result phases of isovolumic contraction and relaxation were difficult to define. These observations show that normal right ventricular pressure-volume relations differ considerably from those of the normal left ventricle, presumably reflecting the different loading conditions of the two ventricles.

Left ventricular systolic and diastolic function after total correction of tetralogy of Fallot

Left ventricular (LV) systolic and diastolic function was assessed in 12 patients after total correction of tetralogy of Fallot (age range 5 to 18 years, mean 10) and compared with 10 control patients. Only 1 patient had a shunt before total correction that was performed at a mean age of 3.5 years, (range 0.3 to 8). At cardiac catheterization the following indexed LV parameters were measured: end-diastolic and end-systolic volumes, wall mass, ejection fraction, stroke volume and end-diastolic and end-systolic pressures and stresses. The rate-corrected mean velocity of fiber shortening was calculated. LV diastolic operant chamber stiffness and myocardial stiffness were calculated from simultaneous diastolic pressures and volumes in mid- and late diastole using monoexponential formulas. The 2 groups were compared by unpaired t tests. The tetralogy group had higher mean end-diastolic (93 vs 74 ml/m 2), end-systolic (29 vs 19 ml/m 2) and stroke (64 vs 55 ml/m 2) volumes than controls. Rate-corrected mean velocity of fiber shortening was lower in the tetralogy group (1.07 vs 1.24). Myocardial stiffness was higher in the tetralogy group (16 vs 11). Other indexes were not significantly different. Thus, LV function after total correction of tetralogy of Fallot may be abnormal with larger than normal LV size, decreased contractile function and increased myocardial stiffness.

Longitudinal changes in left ventricular architecture and function in peripartum cardiomyopathy

Left ventricular (LV) function was quantitated in 14 patients with peripartum cardiomyopathy, in 10 using 2-dimensional (2-D) echocardiography and in 4 radionuclide ventriculography, and values were compared with those in 11 normal women in the immediate postpartum period. LV end-diastolic and end-systolic volume indexes, LV wall mass index and ejection fraction were calculated during the acute phase of the illness and serially through long-term follow-up (mean 24 months). During the acute phase of illness there was marked LV dilatation: mean end-diastolic volume index was 95 ± 22 MI/M 2, vs 67 ± 9 ml/m 2 in control subjects (p <0.005), and mean end-systolic volume index was 66 ± 18 ml/m 2, compared to 27 ± 5 ml/m 2 in control subjects (p <0.001). Mean heart rates and mean systolic pressures in the patients with peripartum cardiomyopathy and the control subjects were similar, 91 ± 24 vs 79 ± 14 beats/min and 120 ± 14 vs 117 ± 10 mm Hg, respectively. LV wall mass index was higher, 139 ± 38 vs 96 ± 8 g/m 2 (p <0.005), and ejection fraction much lower, 29 ± 5% vs 67 ± 5% (p <0.001), in control subjects. Five patients underwent endomyocardial biopsy during the acute illness, which showed interstitial fibrosis but no evidence of active inflammation. There was rapid and early improvement in LV function in 13 of 14 patients. Changes in LV volume, mass and ejection fraction all followed an exponential time course during LV remodeling. By late follow-up, LV size and function had returned to normal in more than half the patients. The severity of early compromise in LV function did not predict long-term functional outcome.

Exercise testing and hemodynamic performance in healthy elderly persons

To determine the effect of age on cardiovascular performance, 39 healthy elderly men and women, 70 to 83 years old, underwent treadmill thallium-201 exercise perfusion imaging and radionuclide equilibrium angiography at rest and during supine bicycle exercise. Five volunteers who had a positive exercise thallium test response were excluded from the study. Radionuclide left ventricular ejection fraction, regional wall abnormalities, relative cardiac output, stroke volume, end-diastolic volume and end-systolic volume were measured. Seventy-four percent of the subjects maintained or increased their ejection fraction with exercise. With peak exercise, mean end-diastolic volume did not change, end-systolic volume decreased and cardiac output and stroke volume increased. Moreover, in 35% of the subjects, minor regional wall motion abnormalities developed during exercise. There was no significant difference in the response of men and women with regard to these variables. However, more women than men had difficulty performing bicycle ergometry because they had never bicycled before. Subjects who walked daily performed the exercise tests with less anxiety and with a smaller increase in heart rate and systolic blood pressure.