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PubMed2004

Angiographic right and left ventricular function in arrhythmogenic right ventricular dysplasia.

We prospectively documented right ventricular (RV) and left ventricular (LV) volumes and ejection fractions in a large series of patients with arrhythmogenic RV dysplasia/cardiomyopathy (ARVD/C). Eighty-five patients with ARVD/C and 11 controls underwent 2 successive orthogonal right and left monoplane x-ray-digitized cineangiographies. Volumes were calculated using the hemielliptical RV and ellipsoidal LV models. All controls and 58 of 85 patients (ARVD/C-I) had a RV ejection fraction > or =35% and 27 patients had a RV ejection fraction <35% (ARVD/C-II). Tricuspid annulus plane systolic excursion (TAPSE) was lower in ARVD/C-II than in ARVD/C-I patients (6 +/- 3 vs 14 +/- 3 mm) and controls (16 +/- 2 mm) (each p <0.001). In patients with ARVD/C, TAPSE was positively related to RV ejection fraction (r = 0.79) and to crista supraventricularis shortening (r = 0.81) (each p <0.001). Sensitivity and specificity of TAPSE <12 mm in identifying patients with RV ejection fraction <35% were 96% and 78%, respectively. LV ejection fraction was > or =50% in 68 patients, 40% to 49% in 10, and <40% in 7. Diffuse RV outflow tract aneurysm was observed in 9 patients, all belonging to ARVD/C-II, and this sign identified patients with LV ejection fraction <40% with 86% sensitivity and 96% specificity. In conclusion, 68% of ARVD/C patients had normal RV ejection fraction and RV volumes, and 80% of ARVD/C patients had normal LV ejection fraction. Decreased TAPSE <12 mm and a diffuse RV outflow tract aneurysm were sensitive and specific indicators of RV ejection fraction <35% and LV ejection fraction <40%, respectively.

Adult↗
PubMed1996

Hepatic blood flow and right ventricular function during cardiac surgery assessed by transesophageal echocardiography.

OBJECTIVE: To determine the effect of cardiopulmonary bypass (CPB) on hepatic blood flow (HBF) and the hepatic venous flow pattern. DESIGN: Single-arm prospective study. SETTING: University hospital operating room and intensive care unit. PARTICIPANTS: Eight patients ranging in age from 57 to 73 years undergoing cardiac surgery. INTERVENTIONS: Transesophageal echocardiography (TEE) was used to assess HBF before, during, and after CPB by pulsed-wave Doppler ultrasound recordings of hepatic venous flow velocity and two-dimensional recordings of the hepatic vein diameter. Hepatic vein oxygenation was monitored by hepatic vein catheterization, and gastric intramucosal pH (pHi) was followed by tonometry. MEASUREMENTS AND MAIN RESULTS: The HBF was unchanged after the start of CPB but was reduced from the baseline value 415 (standard error of the mean 40) mL/min to 225 (25) mL/min during hypothermic CPB (p < 0.05). Cardiac index, right ventricular ejection fraction, and arterial and tonometric pH were essentially unchanged during the study period. Hepatic vein and mixed venous saturation were unchanged compared to control during CPB and were reduced at 2 and 3 hours after CPB (p < 0.01). Six of the patients had a normal predominant systolic flow pattern before surgery. In the postoperative period, seven patients showed an abnormal predominant diastolic filling pattern. CONCLUSIONS: TEE represents a useful tool in assessing changes in the hepatic blood flow. The HBF was reduced during hypothermic CPB, but this was not accompanied by a reduced pHi. The changes in the venous flow pattern with a reduction in systolic flow could be explained by impaired atrial relaxation.

Aged↗
PubMed1999

Reduced heart rate variability following repair of tetralogy of Fallot.

OBJECTIVE: To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices. METHODS: Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was performed to assess left ventricular size and function, right ventricular size and pressure, and any proximal pulmonary arterial stenosis. Right ventricular function was evaluated by radionuclide scan. QRS duration, QT interval, and QT dispersion were measured on a standard 12 lead ECG. Measurements of heart rate variability were compared with values from 28 age matched healthy controls (mean age 19.9 years). Interrelations between variables were assessed using Pearson correlation coefficients and stepwise regression analysis. RESULTS: Heart rate variability was reduced, compared with values for age matched normal controls, in 12 of the 28 patients. Reduced heart rate variability was associated with increased age, increased right ventricular size and pressure, and widening of the QRS complex. CONCLUSIONS: Reduced heart rate variability is a feature following repair of tetralogy of Fallot. It is associated with increasing age, impaired right ventricular haemodynamics, and widening of the QRS complex. Under these circumstances, reduced heart rate variability may be a marker for deteriorating right ventricular function. Increased QRS duration has been identified as a risk factor for sudden death following repair of tetralogy of Fallot, and impaired cardiac autonomic control may be one of the mechanisms involved.

Adolescent↗
PubMed1982

Radionuclide assessment of sequential changes in left and right ventricular function following first acute transmural myocardial infarction.

The purpose of this study was to define the sequential changes in left and right ventricular ejection fraction (LVEF, RVEF) and regional LV wall motion following first transmural acute myocardial infarction (AMI). Fifty-four patients with either anterior (n = 28) or inferior (n = 26) infarction underwent radionuclide ventriculography (RNV) within 48 hours of onset of chest pain (study 1), between days 3 and 6 (study 2), and again between days 7 and 25 (study 3). Twenty-six of the patients with anterior MI (93%) had initial LVEF less than 0.54, compared with 13 of 26 patients (50%) with inferior MI (p less than 0.01). Eleven of 26 patients (42.3%) with inferior MI had initial RVEF less than 0.39, compared with 8 of 27 patients (29.6%) with anterior MI (p less than 0.01). There were no overall significant serial changes in mean LVEF or mean RVEF in patients with either anterior or inferior MI. From study 1 to study 2, LVEF did not change in 24 patients (44%), improved in 13 (24%), and worsened in 17 (31%). From study 1 to study 3, LVEF remained unchanged in 15 patients (35%), improved in 17 (39%), and worsened in 11 (26%). From study 1 to study 2, RVEF did not change in 25 of 51 patients (49%), improved in 17 (31%), and worsened in 9 (17%). From study 1 to study 3, RVEF remained unchanged in 14 (38%), improved in 18 (48%), and worsened in five (14%). Changes in EF tended to occur early in the hospital course, with little subsequent changes. Serial changes in EF could not be predicted by clinical or demographic variables or by location of infarction. Significant changes in LVEF typically occurred without concurrent change in regional LV wall motion, suggesting alteration in ventricular loading rather than change in intrinsic myocardial performance. Initial depression of LVEF correlated with in-hospital mortality as well as with development of congestive heart failure and conduction defects. However, sequential changes in LVEF did not correlate with short-term prognosis. We conclude that sequential changes in LVEF and RVEF occur frequently following AMI, appear to reflect ventricular loading conditions rather than intrinsic change in myocardial performance, and do not correlate well with short-term prognosis.

Adult↗
PubMed1998

ST-segment elevation in right precordial leads implies depressed right ventricular function after acute inferior myocardial infarction.

BACKGROUND: The prognosis of acute inferior myocardial infarction is worse when it is complicated by right ventricular infarction. ST elevation in the right precordial leads is one of the reliable methods for detecting acute right ventricular infarction. The purpose of the study was to examine the relation between ST elevation in the right precordial electrocardiographic leads during acute inferior infarction and the severity of right ventricular systolic dysfunction. METHODS: This study analyzed the relation between ST elevation > or = 0.1 mV in V4R and the severity of right ventricular systolic dysfunction in 43 consecutive patients (men/women: 35/8; average age 62+/-9 years) with acute inferior myocardial infarction with a rapid-response Swan-Ganz catheter to measure the right ventricular ejection fraction (RVEF). RESULTS: RVEF was significantly lower in patients with ST elevation (n = 18) than in those without (n = 25) (33%+/-6% vs 40%+/-9%, p = 0.010). If the infarct-related lesion was located in the proximal right coronary artery, RVEF tended to be lower than if the lesion was located in the distal right coronary artery or the left circumflex coronary artery (33%+/-10% vs 37%+/-9% vs 42%+/-9%, p = 0.101). Logistic regression analysis demonstrated that ST elevation in V4R was the only independent predictor of depressed RVEF (odds ratio = 5.31, 95% confidence interval = 1.28 to 22.1, p = 0.022). CONCLUSION: ST elevation in lead V4R during acute inferior myocardial infarction predicts right ventricular systolic dysfunction.

Adult↗
PubMed1986

Preliminary study of the effects of low flow oxygen on oxygen delivery and right ventricular function in chronic lung disease.

This study was designed to test the feasibility of using the noninvasive radionuclide measurement of the right ventricular ejection fraction (RVEF) to identify which patients with chronic lung disease objectively benefit from low flow oxygen therapy. Two categories of benefit, pulmonary artery pressure/resistance and peripheral oxygen delivery, were examined in 19 patients. Fourteen subjects returned after at least 3 wk of continuous low flow oxygen therapy for restudy; 12 patients had complete radionuclide and hemodynamic data. The change in RVEF, in response to continuous oxygen, correlated significantly with the change in coefficient of oxygen delivery (r = 0.59, p less than 0.05) and the change in cardiac output (r = 0.62, p less than 0.05). The change in RVEF did not correlate significantly with the change in pulmonary artery pressure (r = 0.06) or the change in total pulmonary resistance (r = -0.35). The change in coefficient of oxygen delivery, representing oxygen delivery corrected for oxygen consumption, correlated positively with change in cardiac output (r = 0.58, p less than 0.05) and negatively with change in oxygen consumption (r = -0.63, p less than 0.05), arterial oxygen content (r = -0.63, p less than 0.05), and arterial oxygen tension (r = -0.61, p less than 0.05). That is, the fall in hemoglobin in these patients more than compensated for any increase in Pao2 so that improved oxygen delivery frequently occurred despite a decrease in arterial oxygen content, and improved oxygen delivery occurred for the most part among patients with smaller improvement in Pao2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Scintigraphic assessment of patients with pulmonary thromboembolism by extent of perfusion defect and right ventricular function].

In 36 cases, severity of pulmonary thromboembolism (PTE) were determined with extent of perfusion defect (%PD) from pulmonary perfusion scintigraphy combined right ventricular ejection fraction (RVEF) from radionuclide angiocardiography. In 27 cases, follow-up scintigraphy was also done. After medical therapy, delta PD (= initial %PD-follow up %PD) was significant improved in patients with normal RVEF (greater than 38%) (19.40 +/- 15.58%: n = 15) than that in those with reduced RVEF (less than or equal to 38%) (0.00 +/- 3.9%). In follow-up studies, patients with larger %PD (greater than or equal to 40) showed poor prognosis than those with moderate or less %PD (less than 40). In conclusion, these both non-invasive indicators were proved to be useful for the evaluation not only the clinical severity but the prognosis of pulmonary thromboembolism.

Female↗
PubMed1988

Pulmonary hypertension and right ventricular function in patients with COPD.

In 100 patients with chronic obstructive pulmonary disease (COPD), we found no significant correlation between simultaneous measurements of right ventricular ejection fraction, using radionuclide ventriculography, and pulmonary arterial pressure. There was, however, a weak but significant correlation between right ventricular ejection fraction and the pulmonary vascular resistance (r = 0.40, p less than 0.005). In 52 of these patients, 37 with pulmonary hypertension, right ventricular end-systolic volume index was 53 +/- 21 ml.m-2 and end-diastolic volume index was 86 +/- 27 ml.m-2, compared with a calculated mean of 33 ml.m-2 and 79 ml.m-2, respectively, for normal subjects. In 24 of these patients where the measurements were made at rest and on exercise, the mean right ventricular end-systolic volume increased from 66 +/- 20 ml.m-2 to 87 +/- 32 ml.m-2, with an increase in right ventricular systolic pressure from 28 +/- 9 mm Hg to 55 +/- 15 mm Hg. Analysis of the slope of the right ventricular end-systolic pressure volume relationship at rest and on exercise suggested relatively normal right ventricular contractility in the majority of patients. Thus, in these patients with stable COPD, despite the presence of pulmonary hypertension, right ventricular contractility remained relatively normal.

Blood Pressure↗
PubMed1998

Association between right ventricular function and perfusion abnormalities in hemodynamically stable patients with acute pulmonary embolism.

BACKGROUND/OBJECTIVES: Patients presenting with acute pulmonary embolism associated with hemodynamic compromise exhibit right ventricular enlargement and dysfunction on transthoracic echocardiogram. However, the degree of echocardiographic abnormalities among hemodynamically stable patients without preexisting cardiopulmonary disease during the acute stage of pulmonary embolism, and following treatment, is unknown. Therefore, this study was designed to assess the extent of right ventricular abnormalities detected on transthoracic echocardiogram in patients following acute pulmonary embolism and during treatment with anticoagulation or vena caval interruption. The extent of pulmonary vascular obstruction and complication rate on follow-up were also assessed. DESIGN/INTERVENTIONS: Sixty-four consecutive hemodynamically stable patients without preexisting known cardiopulmonary disorder presenting with acute pulmonary embolism and undergoing treatment with anticoagulation or inferior vena caval interruption were studied. All subjects underwent a two-dimensional transthoracic echocardiogram within 24 h of diagnosis. The degree of perfusion abnormality on lung scan was quantified. Twenty-six patients underwent follow-up echocardiogram and lung scan at 6 weeks. The echocardiographic findings were compared with those obtained from a group of normal control subjects matched for gender and age. RESULTS: Although the mean right ventricular end-diastolic areas did not differ (21.9+/-5.2 cm2 vs 20.1+/-2.9 cm2 for control subjects; p=not significant), the right ventricular end-systolic area was larger in comparison to our series of control subjects (14.6+/-5.1 cm2 vs 11.7+/-2.0 cm2; p=0.025). Fractional right ventricular area change was reduced in the patient group compared with the control subjects (34.3+/-9.0% vs 41.3+/-7.0%; p=0.003). The extent of right ventricular end-systolic area enlargement and decrease in fractional area change did not correlate with the degree of pulmonary vascular obstruction. Patients who were restudied at 6 weeks showed minimal improvement in echocardiographic findings, despite almost complete resolution of perfusion defects on lung scan. CONCLUSIONS: The extent of right ventricular dysfunction in hemodynamically stable, previously normal patients with acute pulmonary embolism does not reflect the extent of the perfusion abnormalities. Further, right ventricular enlargement and systolic dysfunction are present and persistent despite treatment with heparin and warfarin therapy or vena caval interruption.

Acute Disease↗
PubMed1983

Assessment of right ventricular function and anatomy using peripheral vein infusion of krypton 81m.

A method for imaging the right side of the heart (atrium, ventricle and main pulmonary artery) and for assessment of RV systolic function (ejection fraction and ejection rate) is described. An ultra-short-lived isotope (81Krm) is continuously eluted in 5% dextrose and infused into an ante-cubital arm vein; standard multigated images are acquired using a gamma camera and commercially available software. Preliminary evaluation of the method in 55 subjects (20 with repaired tetralogy of Fallot, 14 with dilated cardiomyopathy and 21 normal volunteers) showed that the technical success rate was 100%; that RV boundaries free from LV overlap can be clearly visualised due to efficient exhalation of 81Krm through the lungs and that 81Krm measurements of RVEF are reproducible. The technique offers considerable potential for serial non-invasive assessment of RV function.

Cardiomyopathy, Hypertrophic↗
PubMed1987

Right ventricular function: a comparison between blood and crystalloid cardioplegia.

Blood cardioplegia resulted in better left ventricular (LV) function than crystalloid cardioplegia after elective coronary artery bypass operations. However, most methods of cardioplegic delivery may not adequately cool and protect the right ventricle, and right ventricular (RV) dysfunction may limit hemodynamic recovery. Therefore, RV and LV temperatures were measured intraoperatively and RV and LV function were evaluated postoperatively in 80 patients with double-vessel or triple-vessel coronary artery disease who were randomized to receive either blood cardioplegia or crystalloid cardioplegia. Myocardial performance, systolic function, and diastolic function were assessed with nuclear ventriculography by evaluating the response to volume loading. Preoperatively the groups were similar. Intraoperatively, blood cardioplegia resulted in significantly warmer LV and RV temperatures (left ventricle: 15.5 degrees +/- 0.2 degrees C with blood cardioplegia and 12.6 degrees +/- 0.3 degrees C with crystalloid cardioplegia [p less than .0001]; right ventricle: 18.3 degrees +/- 0.3 degrees C with blood cardioplegia and 15.1 degrees +/- 0.3 degrees C with crystalloid cardioplegia [p less than .0001]). Postoperatively, blood cardioplegia resulted in better LV performance (higher LV stroke work index at a similar LV end-diastolic volume index [EDVI]) (p = .01), better LV systolic function (similar systolic blood pressures at smaller LV end-systolic volume indexes [ESVI]), (p = .04), and improved LV diastolic function (lower left atrial pressures at similar LVEDVIs) (p = .03).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1989

[Evaluation of right ventricular function using radioisotope angiography in patients with chronic obstructive pulmonary disease].

The aim of the study was the evaluation of equilibrium gated blood pool angiography in noninvasive assessment of right ventricular ejection fraction in 50 patients with chronic obstructive pulmonary disease. The degree of ventilatory disturbances was measured using plethysmography to calculate air flow indexes--FEV1, MEF50 and Rt and gasometric values of arterialized capillary blood--PaO2, PaCO2, pH. The used method allowed calculation of RVEF in 41 patients, which were divided into three groups according to presence of symptoms of right ventricular failure and RVEF values. In 12 patients free of RV failure symptoms RVEF was decreased (below 40%). Basing on results of this study the authors believe that this method is useful in diagnosing subclinical states of RV failure.

Aged↗
PubMed1984

Right ventricular function evaluated by radionuclide angiography in acute myocardial infarction.

Radionuclide angiographic studies were performed in 26 patients with a first myocardial infarction, 11 with anterior and 15 with an inferior location. Right ventricular (RV) and left ventricular (LV) ejection fractions (EF) were determined. Mean LVEF in anterior infarctions (33.2 +/- 7.3) was lower than in inferior myocardial infarctions (59.9 +/- 10.2) (p less than 0.001). Mean RVEF in the anterior infarct group was 41.3 +/- 15.1 and in the inferior myocardial infarction group 33.7 +/- 12.8 (p = NS). RVEF was less than 40% in 11 of 15 (73%) with inferior and 7 of 11 (66%) with anterior myocardial infarction. The ratio of LVEF:RVEF was 0.84 +/- 0.19 in the anterior and 2.13 +/- 1.28 in the inferior myocardial infarction group (p less than 0.001). LVEF correlated with RVEF in patients with anterior infarcts (r = 0.77; p less than 0.05) but not in those with inferior myocardial infarction (r = 0.14). RV regional wall motion abnormalities were observed in the inferolateral zones in 10 of 15 (66%) with inferior and in none of the 11 patients with anterior myocardial infarctions (p less than 0.001). Inferoseptal wall motion abnormalities were observed in 3 of 15 (20%) with inferior and 6 of 11 (56%) with anterior myocardial infarctions (p = NS). RV dysfunction in the inferior infarctions is probably an expression of primary RV dysfunction rather than secondary to LV dysfunction. RV dysfunction was proportional to LV dysfunction in the anterior infarction group and was often accompanied by RV septal contraction abnormalities.

Aged↗
PubMed1995

[The postinfarct prognostic value of right ventricular systolic function].

BACKGROUND: Right ventricular extension of inferior myocardial infarction has been shown to be a predictor of poor prognosis during the acute phase. However, it is not known whether right ventricular dysfunction predicts long term complications. The aim of the present study was to assess whether right ventricular ejection fraction is also a predictor of poor prognosis during the first five follow-up years. METHODS: Ninety-eight consecutive patients (age < or = 65 years) with acute noncomplicated myocardial infarction (49 anterior and 49 inferior) were evaluated before hospital discharge. In all of them the ejection fraction of both ventricles was evaluated with radionuclide ventriculography at rest and during submaximal exercise. All patients were clinically followed up for at least 5 years. The prognostic relevance of right and left ventricular function for the prediction of all complications and severe complications was assessed using univariate and multivariate analysis. RESULTS: After 5 years, 66 patients had 94 complications (angina in 44, heart failure in 21, reinfarction in 10, revascularization procedures in 11, death in 6). In the univariate analysis, resting right ventricular ejection fraction was significantly lower in patients with inferior infarction and severe complications at one year (32 +/- 12% vs 38 +/- 6%, p = 0.03). However, in multivariate analysis only resting left ventricular ejection fraction was predictive of complications at 5 years (odds ratio 5.93, 95% confidence interval = 1.32-26.6). Statistical results did not change when the ejection fraction of both ventricles during submaximal exercise was considered. CONCLUSIONS: Although right ventricular ejection fraction, measured before hospital discharge, is predictive of complications at five years in inferior infarctions, multivariate analysis shows that it does not add prognostic information to the measurement of left ventricular ejection fraction in patients with uncomplicated acute myocardial infarction, either anterior or inferior.

Chi-Square Distribution↗
PubMed1978

[Analysis of the right ventricular function by simulation (author's transl)].

In the previous experiments it was reported that either the interventricular septum of the free wall of the right ventricle was replaceable with a non-contractile prosthesis. It was also reported that a new chamber constructed on the epicardium had capability of producing a pulsatile pressure. This study was to determine contribution of the septum and the free wall on performance of the right ventricle by using a simulator. Left-ward shift of the interventricular groove was not found along the basal half of the long axis and was limited only along the apical half. Bulging of the septum toward the right ventricular cavity did not occur at all, but on contrary the septum moved toward left, denying contribution of the septal movement to pump action of the right ventricle.

Animals↗
PubMed1984

Effect of successful thrombolytic therapy on right ventricular function in acute inferior wall myocardial infarction.

In 19 patients undergoing intracoronary fibrinolytic therapy for acute myocardial infarction, the site of coronary obstruction was in the proximal right coronary artery. Time between onset of symptoms and hospitalization was less than 4 hours. These patients were studied prospectively by radionuclide techniques immediately after admission, 48 hours and 4 weeks after AMI. Right and left ventricular (RV and LV) ejection fractions (EF) were calculated from gated blood pool scintigrams and the size of the LV perfusion defect was assessed by thallium-201 scintigraphy. Before the intervention, RV performance was significantly lower (RVEF 29 +/- 8%) than normal (53 +/- 7%). The size of the LV perfusion defect was relatively small (less than 25% of LV circumference), and as a consequence, LV pump function was only marginally impaired (LVEF 54 +/- 11%). Recanalization of the infarct artery was achieved in 12 patients (group A); in 7 patients the infarct artery remained occluded (group B). Early after the intervention (48 hours), RV performance in group A recovered significantly (RVEF: 30 +/- 9% vs 39 +/- 7%, p less than 0.01), and further improvement was noted at 4 weeks (RVEF 43 +/- 5%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Ellipsoidal shell subtraction model of right ventricular volume. Comparison with regional free wall dimensions as indexes of right ventricular function.

Pulse-transit sonomicrometry was used to measure the base-apex (a), anteroposterior (b), and septal-free wall (c) diameters of the left ventricle and the septal-free wall diameter of the right ventricle (d) in eight excised and three isolated, pump-perfused canine heart preparations, as well as in nine conscious dogs. In the three perfused hearts and in four of the excised hearts, right ventricular free wall regional segment lengths and segment area also were assessed. Biventricular volumes were measured directly with intracavitary balloons in all isolated hearts. When left ventricular balloon volume was held constant, relations between right ventricular free wall dimensions and right ventricular balloon volume were highly linear. With increments in left ventricular volume, however, these relations remained linear but shifted progressively upward, indicating an independent relation between right ventricular free wall dimensions and left ventricular cavitary volume. An ellipsoidal shell subtraction model (pi/6.abd minus right ventricular free wall volume) was developed to estimate right ventricular cavitary volume from cardiac dimensions. With this method, a highly linear relation was observed between calculated right ventricular volume and right ventricular balloon volume (mean r = 0.99 +/- 0.01). Moreover, this relation appeared to be independent of changes in left ventricular balloon volume. With the shell subtraction model, dynamic right ventricular volume was computed in nine conscious dogs, and in four, stroke volume derived from dimensions was compared with right ventricular stroke volume measured with ultrasonic flow probes. A highly linear relation was observed, suggesting the accuracy of the shell subtraction method in vivo. Right ventricular end-systolic pressure-volume and stroke work/end-diastolic volume relations then were evaluated, and both proved to be highly linear in the right ventricle (both mean r = 0.99 +/- 0.01). Thus, the shell subtraction model allows a simple estimate of dynamic right ventricular volume in the intact heart and facilitates assessment of right ventricular performance in vivo.

Animals↗