Multiparametric assessment of right ventricular function in heart transplant recipients by echocardiography and relations with pulmonary hemodynamics.

OBJECTIVE: Right ventricular (RV) dilatation and dysfunction are usually present in heart transplant (HTx) patients and worsened with residual pulmonary hypertension (PH). We aimed to determine the ability of different echocardiographic modalities to evaluate RV function in comparison with cardiac magnetic resonance (CMR) and their relations with pulmonary hemodynamics in HTx patients. METHODS: A total of 62 data sets [echocardiographic, hemodynamic, and CMR] were acquired from 35 HTx patients. Comprehensive echocardiography, including two-dimensional (2D) transthoracic echocardiography, speckle tracking echocardiography, and three-dimensional (3D) echocardiography, was performed. Mean pulmonary artery pressure (mPAP) was obtained invasively from right heart catheterization. The correlations between all echocardiographic parameters and CMR imaging data and the differences between patients with and without residual PH were evaluated. RESULTS: Diastolic and systolic RV volumes and RV ejection fraction (RVEF) by 3D echocardiography correlated strongly with CMR-derived volumes and RVEF (r = .91, r = .79, r = .64; p < .0001 for each, respectively). Among other parameters, RV fractional area change (r = .439; p < .001) and RV free wall longitudinal strain (RVFW-LS) (r = -.34; p < .05) correlated moderately with CMR-RVEF, whereas tricuspid annulus S' velocity (r = .29; p < .05) and tricuspid annular systolic plane excursion (r = .27; p < .05) correlated weakly with CMR-RVEF. Additionally, 3D-RVEF and RVFW-LS were significantly decreased in studies with mPAP ≥ 20 mm Hg in comparison to those with mPAP < 20 mm Hg (47.7 ± 3.7 vs. 50.9 ± 5.3, p = .04 and -15.5 ± 3.1 vs. -17.5 ± 3, p = .03, respectively). CONCLUSION: The best method for the evaluation of RV function in HTx recipients is 3D echocardiography. Besides, the subclinical impact of residual PH on RV function can be best determined by RVFW-LS and 3D-RVEF in these patients.

Approach to optimal assessment of right ventricular remodelling in heart transplant recipients: insights from myocardial work index, T1 mapping, and endomyocardial biopsy.

AIMS: Right ventricular (RV) dysfunction is an important cause of graft failure after heart transplantation (HTx). We sought to investigate relative merits of echocardiographic tools and cardiac magnetic resonance (CMR) with T1 mapping for the assessment of functional adaptation and remodelling of the RV in HTx recipients. METHODS AND RESULTS: Sixty-one complete data set of echocardiography, CMR, right heart catheterization, and biopsy were obtained. Myocardial work index (MWI) was quantified by integrating longitudinal strain (LS) with invasively measured pulmonary artery pressure. CMR derived RV volumes, T1 time, and extracellular volume (ECV) were quantified. Endomyocardial biopsy findings were used as the reference standard for myocardial microstructural changes. In HTx recipients who never had a previous allograft rejection, longitudinal function parameters were lower than healthy organ donors, while ejection fraction (EF) (52.0 ± 8.7%) and MWI (403.2 ± 77.2 mmHg%) were preserved. Rejection was characterized by significantly reduced LS, MWI, longer T1 time, and increased ECV that improved after recovery, whereas RV volumes and EF did not change MWI was the strongest determinant of rejection related myocardial damage (area under curve: 0.812, P < 0.0001, 95% CI: 0.69-0.94) with good specificity (77%), albeit modest sensitivity. In contrast, T1 time and ECV were sensitive (84%, both) but not specific to detect subclinical RV damage. CONCLUSION: Subclinical adaptive RV remodelling is characterized by preserved RV EF despite longitudinal function abnormalities, except for MWI. While ultrastructural damage is reflected by MWI, ECV, and T1 time, only MWI has the capability to discriminate functional adaptation from transition to subclinical structural damage.

Role of myocardial strain and rotation for predicting prosthetic aortic valve stenosis.

Pressure overload due to aortic stenosis leads to subclinical left ventricular (LV) dysfunction and global longitudinal strain (GLS) impairment even if ejection fraction is preserved. However, little is known about LV mechanics in aortic prosthetic valve (APV) stenosis. The study aimed to determine the role of myocardial strain and rotation in predicting prosthetic valve stenosis in mechanical APV patients. 60 patients with mechanical APV and 30 healthy individuals were evaluated. APV patients were analyzed in two groups; aortic valve mean gradient < 20 mmHg (27 normal gradient patients) and ≥ 20 mmHg (33 high gradient patients). Strain, rotation, and twist values were assessed using the speckle tracking method, and brain natriuretic peptide (BNP) levels were measured. Four-chamber (p < 0.001) and two-chamber (p = 0.008) longitudinal strain (LS) were higher in the control group. GLS was lower in the high gradient group than control and normal gradient groups (p < 0.001, p = 0.022). LS of lateral wall's basal and mid segments were lower in normal and high gradient groups than the control group (p = 0.003, p = 0.008). While basal rotation was lower in the high gradient group than the control group (p = 0.048), there was no difference between the groups in terms of apical rotation, and twist. BNP levels were significantly different between the groups (p = 0.048). No correlation was found between aortic valve mean gradient and GLS, basal rotation, and BNP. In conclusions, LV GLS and basal rotation are depressed in high APV gradient patients; however, these parameters are not independent predictors of gradient increment.

Longitudinal Strain and Strain Rate for Estimating Left Ventricular Filling Pressure in Heart Transplant Recipients.

Traditional parameters have limited value to estimate left ventricular filling pressure (LVFP) in orthotropic heart transplant (OHT) recipients. We hypothesized that global longitudinal strain (GLS), diastolic, and systolic strain rate (SR) would be depressed in OHT recipients with elevated LVFP and could overcome the limitations of traditional parameters. We studied consecutively OHT patients at the time of endomyocardial biopsies and retrospectively pretransplantation studies conforming to the same protocol. Comprehensive echocardiography with strain measurements was performed. Results were compared with pulmonary capillary wedge pressure (PCWP) obtained from right heart catheterization that was performed just after the echocardiography study. In all, 74 studies were performed in 50 OHT recipients. Mean PWCP was 11.8 ± 4.3 mm Hg (range: 4 to 25 mm Hg). Several parameters, but not left atrial volume index, mitral inflow velocities, annular velocities, and their ratio (E/e'), were different between studies with normal (n = 47) and elevated PCWP (n = 27). Area Under Curve for GLS (0.932*), E/e'SR (0.849*), and systolic SR (0.848*) (*p <0.0001) were more accurate than traditional parameters for predicting PCWP>12 mm Hg. GLS, systolic SR and E/e'SR remained accurate regardless of LV ejection fraction and allograft vasculopathy. Meanwhile, E/e' was accurate to predict PWCP in native failing hearts before transplantation. Changes in GLS and E/e'SR tracked accurately changes in PCWP. In conclusion, traditional indices of diastolic function perform poorly in OHT recipients, whereas GLS and E/e'SR provide reliable means of LVFP, irrespective of ejection fraction and allograft vasculopathy. These parameters also track reasonably well the changes in LVFP.

[Turkish Cardiology Association Consensus Report: COVID-19 Pandemic and Cardiovascular Diseases (May 13, 2020)]. / Türk Kardiyoloji Dernegi Uzlasi Raporu: COVID-19 Pandemisi ve Kardiyovasküler Hastaliklar Konusunda Bilinmesi Gerekenler (13 Mayis 2020).

In December 2019, in the city of Wuhan, in the Hubei province of China, treatment-resistant cases of pneumonia emerged and spread rapidly for reasons unknown. A new strain of coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) was identified and caused the first pandemic of the 21st century. The virus was officially detected in our country on March 11, 2020, and the number of cases increased rapidly; the virus was isolated in 670 patients within 10 days. The rapid increase in the number of patients has required our physicians to learn to protect both the public and themselves when treating patients with this highly infectious disease. The group most affected by the outbreak and with the highest mortality rate is elderly patients with known cardiovascular disease. Therefore, it is necessary for cardiology specialists to take an active role in combating the epidemic. The aim of this article is to make a brief assessment of current information regarding the management of cardiovascular patients affected by COVID-19 and to provide practical suggestions to cardiology specialists about problems and questions they have frequently encountered.

Risk factors for left atrial appendage thrombus.

Background: Atrial fibrillation (AF) is the most common persistent rhythm disorder that has been shown to be associated with a significant increase in stroke risk. Left atrial appendage (LAA) thrombi are responsible for most of strokes of cardiac origin. CHA2DS2-VASc is a risk scoring system to identify patients' indications for anticoagulation in nonvalvular AF patients. The aim of our study was to investigate CHA2DS2-VASc score, the other risk factors, echocardiographic data and blood parameters for LAA thrombus.Methods: Two hundred and sixty-four patients who were admitted to our adult cardiology outpatient clinic and who underwent a transesophageal echocardiography procedure between June 2017 and June 2019 included in our study. Patient's demographic data, transthoracic echocardiographic examinations, and laboratory results were recorded retrospectively.Results: LAA thrombus was detected in 39 (14.7%) patients. The rates of coronary artery disease and systolic dysfunction were significantly higher in patients with LAA thrombus (p = .017, p = .016, respectively). When AF subtypes were examined in detail, thrombus rate was significantly higher in persistent AF (51 vs. 25.7%, p = .002). Although the CHA2DS2-VASc score was slightly higher in the thrombus group, there was no statistically significant difference between the two groups (3.0 ± 1.65 vs. 2.78 ± 1.66).Conclusions: In conclusion, CHA2DS2-VASc score system itself was not informative about LAA thrombus formation although some of its components were related with LAA thrombus formation. According to a multiple regression analysis, the independent determinants of LAA thrombus were the presence of AF and coronary artery disease.

[Consensus Report from Turkish Society of Cardiology: COVID-19 and Cardiovascular Diseases. What cardiologists should know. (25th March 2020)]. / Türk Kardiyoloji Dernegi Uzlasi Raporu: COVID-19 Pandemisi ve Kardiyovasküler Hastaliklar Konusunda Bilinmesi Gerekenler (25 Mart 2020).

In December 2019, in the city of Wuhan, in the Hubei province of China, treatment-resistant cases of pneumonia emerged and spread rapidly for reasons unknown. A new strain of coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) was identified and caused the first pandemic of the 21st century. The virus was officially detected in our country on March 11, 2020, and the number of cases increased rapidly; the virus was isolated in 670 patients within 10 days. The rapid increase in the number of patients has required our physicians to learn to protect both the public and themselves when treating patients with this highly infectious disease. The group most affected by the outbreak and with the highest mortality rate is elderly patients with known cardiovascular disease. Therefore, it is necessary for cardiology specialists to take an active role in combating the epidemic. The aim of this article is to make a brief assessment of current information regarding the management of cardiovascular patients affected by COVID-19 and to provide practical suggestions to cardiology specialists about problems and questions they have frequently encountered.

Subclinical myocardial dysfunction in liver transplant candidates determined using speckle tracking imaging.

OBJECTIVE: There are various cardiovascular abnormalities in end-stage liver disease (ESLD). In these patients, left ventricular (LV) systolic function is normal at rest but deteriorates during stress. This deterioration may be due to subclinical myocardial dysfunction. This study evaluated global LV and right ventricular (RV) functions using 2-dimensional (2D) speckle tracking in patients with ESLD. METHODS: Forty liver transplant candidates with ESLD and 26 healthy individuals were included in the study. All of the patients underwent conventional echocardiographic measurement. Longitudinal, circumferential, and radial strain measurements, as well as apical and parasternal short-axis image recordings were obtained. All 2D strain measurements were measured with offline analysis using velocity vector imaging (VVI) software. RESULTS: In the apical 4- and 2-chamber measurements, the LV mean longitudinal strain was significantly lower in the patient group compared with that of the control group (-16.0±3.2% versus -17.6±2.2%, -16.7±3.3% versus -18.7 ±2.1 ± 2.1 %; p=0.002, respectively). The LV mean circumfe-rential strain did not differ between groups. The LV mean radial strain and RV longitudinal strain were significantly lower in the patient group (45.4±10.7 vs. 52.7±10.8%; p=0.01 and -19.2±3.5% versus -21.5±3.6%; p=0.03, respectively). CONCLUSION: Subclinical impairment of global LV and RV systolic functions was determined in liver transplantation candidates using VVI. This deterioration was detected in longitudinal and radial deformation rather than circumferential deformation mechanics, which is consistent with early-stage LV myocardial dysfunction.

T1 Mapping by Cardiac Magnetic Resonance and Multidimensional Speckle-Tracking Strain by Echocardiography for the Detection of Acute Cellular Rejection in Cardiac Allograft Recipients.

OBJECTIVES: The aim of this study was to test the hypothesis that echocardiographic strain imaging, by tracking subtle alterations in myocardial function, and cardiac magnetic resonance T1 mapping, by quantifying tissue properties, are useful and complement each other to detect acute cellular rejection in heart transplant recipients. BACKGROUND: Noninvasive alternatives to endomyocardial biopsy are highly desirable to monitor acute cellular rejection. METHODS: Surveillance endomyocardial biopsies, catheterizations, and echocardiograms performed serially according to institutional protocol since transplantation were retrospectively reviewed. Sixteen-segment global longitudinal strain (GLS) and circumferential strain were measured before, during, and after the first rejection and at 2 time points for patients without rejection using Velocity Vector Imaging for the first part of the study. The second part, with cardiac magnetic resonance added to the protocol, served to validate previously derived strain cutoffs, examine the progression of strain over time, and to determine the accuracy of strain and T1 measurements to define acute cellular rejection. All tests were performed within 48 h. RESULTS: Median time to first rejection (16 grade 1 rejection, 15 grade ≥2 rejection) was 3 months (interquartile range: 3 to 36 months) in 49 patients. GLS and global circumferential strain worsened significantly during grade 1 rejection and ≥2 rejection and were independent predictors of any rejection. In the second part of the study, T1 time ≥1,090 ms, extracellular volume ≥32%, GLS >-14%, and global circumferential strain ≥-24% had 100% sensitivity and 100% negative predictive value to define grade ≥2 rejection with 70%, 63%, 55%, and 35% positive predictive values, respectively. The combination of GLS >-16% and T1 time ≥1,060 ms defined grade 1 rejection with 91% sensitivity and 92% negative predictive value. After successful treatment, T1 times decreased significantly. CONCLUSIONS: T1 mapping and echocardiographic GLS can serve to guide endomyocardial biopsy selectively.

Three-Dimensional Right Ventricular Strain Versus Volume Quantification in Heart Transplant Recipients in Relation to Pulmonary Artery Pressure.

OBJECTIVES: Residual pulmonary hypertension challenges the right ventricular function and worsens the prognosis in heart transplant recipients. The complex geometry of the right ventricle complicates estimation of its function with conventional transthoracic echocardiography. We evaluated right ventricular function in heart transplant recipients with the use of 3-dimensional echocardiography in relation to systolic pulmonary artery pressure. MATERIALS AND METHODS: We performed 32 studies in 26 heart transplant patients, with 6 patients having 2 studies at different time points with different pressures and thus included. Right atrial volume, tricuspid annular plane systolic excursion, peak systolic annular velocity, fractional area change, and 2-dimensional speckle tracking longitudinal strain were obtained by 2-dimensional and tissue Doppler imaging. Three-dimensional right ventricular volumes, ejection fraction, and 3-dimensional right ventricular strain were obtained from the 3-dimensional data set by echocardiographers. Systolic pulmonary artery pressure was obtained during right heart catheterization. RESULTS: Overall mean systolic pulmonary artery pressure was 26 ± 7 mm Hg (range, 14-44 mmHg). Three-dimensional end-diastolic (r = 0.75; P < .001) and end-systolic volumes (r = 0.55; P = .001)correlated well with systolic pulmonary artery pressure. Right ventricular ejection fraction and right atrium volume also significantly correlated with systolic pulmonary artery pressure (r = 0.49 and P = .01 for both). However, right ventricular 2- and 3-dimensional strain, tricuspid annular plane systolic excursion, and tricuspid annular velocity did not. CONCLUSIONS: The effects of pulmonary hemodynamic burden on right ventricular function are better estimated by a 3-dimensional volume evaluation than with 3-dimensional longitudinal strain and other 2-dimensional and tissue Doppler measurements. These results suggest that the peculiar anatomy of the right ventricle necessitates 3-dimensional volume quantification in heart transplant recipients in relation to residual pulmonary hypertension.

Treatment-associated change in apelin concentration in patients with hypertension and its relationship with left ventricular diastolic function.

OBJECTIVE: We examined the change in apelin concentration and its relationship with left ventricular diastolic function in patients treated for hypertension. METHODS: Ninety treatment-naive patients with newly diagnosed hypertension and 33 age- and sex-matched control subjects were prospectively enrolled. Patients with hypertension were randomized to treatment either with telmisartan 80 mg or amlodipine 10 mg. Apelin concentration was measured and echocardiography was performed at baseline and after 1 month of treatment. RESULTS: The data of 77 patients and 33 controls were analyzed. Mean age, gender, baseline blood pressure, apelin levels, and echocardiographic measurements were similar between the treatment groups (p>0.05 for all). Apelin concentration was significantly lower in patients with hypertension than in controls. There was a significant increase in apelin level after 1 month of treatment in both groups (0.32±0.17 vs. 0.38±0.17 ng/dL in telmisartan group, p=0.009, and 0.27±0.13 vs. 0.34±0.18 ng/dL in amlodipine group, p=0.013). Diastolic function improved significantly in both groups (p<0.05) but was not significantly associated with change in apelin concentration. CONCLUSION: Apelin concentration increased significantly after 1 month of effective treatment with telmisartan or amlodipine to a similar extent. Change in apelin concentration was not associated with improvement in diastolic function.

Assessment of myocardial mechanics in patients with end-stage renal disease and renal transplant recipients using speckle tracking echocardiography.

OBJECTIVES: Velocity vector imaging allows quantitation of myocardial strain and strain rate from 2-dimensional images based on speckle tracking echocardiography. The aim of this study was to analyze the changes in myocardial strain and strain rate patterns in patients with end-stage renal disease and renal transplant recipients. MATERIALS AND METHODS: We studied 33 patients with end-stage renal disease on hemodialysis (19 men; mean age, 36 ± 8 y), 24 renal transplant recipients with functional grafts (21 men; mean age, 36 ± 7 y) and 26 age- and sex-matched control subjects. Longitudinal peak systolic strain and strain rate for basal, mid, and apical segments of the left ventricular wall were determined by velocity vector imaging from apical 4- and 2-chamber views. The average longitudinal strain and strain rate for the left ventricle were noted. From short-axis views at the level of papillary muscles, average circumferential, and radial strain, and strain rate were assessed. RESULTS: Mean heart rate and systolic and diastolic blood pressure during imaging were similar between the groups. Longitudinal peak systolic strain and strain rate at basal and mid-segments of the lateral wall were significantly higher in renal transplant recipients and control groups than endstage renal disease patients. Average longitudinal systolic strain from the 4-chamber view was highest in control subjects (-14.5% ± 2.9%) and was higher in renal transplant recipients (-12.5% ± 3.0%) than end-stage renal disease patients (-10.2% ± 1.6%; P ≤ .001). Radial and circumferential strain and strain rate at the level of the papillary muscle were lower in patients with end-stage renal disease than other groups. CONCLUSIONS: Differences in myocardial function in patients with end-stage renal disease, renal transplant recipients, and normal controls can be quantified by strain imaging. Myocardial function is improved in renal transplant recipients compared with end-stage renal disease patients.

Follow-up of heart transplant recipients with serial echocardiographic coronary flow reserve and dobutamine stress echocardiography to detect cardiac allograft vasculopathy.

BACKGROUND: Implementation of reliable noninvasive testing for screening cardiac allograft vasculopathy (CAV) is of critical importance. The most widely used modality, dobutamine stress echocardiography (DSE), has moderate sensitivity and specificity. The aim of this study was to assess the potential role of serial coronary flow reserve (CFR) assessment together with DSE for predicting CAV. METHODS: A total of 90 studies were performed prospectively over 5 years in 23 consecutive heart transplant recipients who survived >1 year after transplantation. Assessment of CFR with transthoracic Doppler echocardiography, DSE, coronary angiography, and endomyocardial biopsy was performed annually. Results of CFR assessment and DSE were compared with angiographic findings of CAV. RESULTS: Acute cellular rejections were excluded by endomyocardial biopsies. CAV was detected in 17 of 90 angiograms. Mean CFR was similarly lower in both mild (CAV grade 1) and more severe (CAV grades 2 and 3) vasculopathy, but wall motion score index became higher in parallel with increasing grades of vasculopathy. Any CAV by angiography was detected either simultaneously with or later than CFR impairment, yielding 100% sensitivity for CFR. The combination of CFR and DSE increased the specificity of the latter from 64.3% to 87.2% without compromising sensitivity (77.8%). CONCLUSIONS: CFR is very sensitive for detecting CAV and increases the diagnostic accuracy of DSE, raising the potential for patient management tailored to risk modification and to avoid unnecessary angiographic procedures.

Flow in the left anterior descending coronary artery in patients with migraine headache.

Migraine is a common neurovascular disorder characterized by attacks of severe headache, autonomic and neurologic symptoms. Migraine can affect many systems in the body, yet its effects on cardiovascular system are unclear. We hypothesized that migraine and coronary microvascular angina may be manifestations of a common systemic microvascular dysfunction and clinically associated. Forty patients with migraine and 35 healthy volunteers were included into the study. Using transthoracic Doppler echocardiography, coronary flow was visualized in the middle or distal part of the left anterior descending artery. Coronary diastolic peak flow velocities were measured with pulse wave Doppler at baseline and after dipyridamole infusion (0.56 mg/kg/4 min). Coronary flow reserve of <2 was considered normal. In addition, thorough 2-dimensional and Doppler echocardiographic examinations were also performed. Fifty-two women and 23 men were included. Coronary flow reserve was significantly lesser in the migraine group than in the control group (1.99 ± 0.3 vs 2.90 ± 0.5, p <0.05). In addition, mitral annular velocities were lower and the ratio of early mitral inflow velocity to early mitral annular velocity (E/E' lateral and E/E' septal) was higher in migraineurs than in the control group (p <0.05 for all), indicating diastolic function abnormalities in the migraine group. In conclusion, these findings suggest that there is an association between coronary microvascular dysfunction and migraine independently of the metabolic state of the patients. A common pathophysiologic pathway of impaired endothelial vasodilatation, vasomotor dysfunction, and increased systemic inflammatory factors may play a role in these 2 clinical conditions and could be the underlying cause of subclinical systolic and diastolic left ventricular dysfunction in migraineurs.

Coronary microvascular function in patients with isolated systolic and combined systolic/diastolic hypertension.

Isolated systolic hypertension (ISH) is a common condition in the elderly that is associated with endothelial dysfunction. Concerning the effect of type of hypertension on coronary microvascular function, coronary flow reserve (CFR) in patients with ISH was evaluated and the results were compared with patients with combined systolic/diastolic hypertension (SDH). Seventy-six elderly patients (older than 60 years) who were free of coronary artery disease and diabetes mellitus were enrolled in the study (38 with ISH and 38 with combined SDH). Using transthoracic Doppler echocardiography, CFR was calculated as the ratio of hyperemic to baseline diastolic peak flow velocities. A CFR value of >2 was accepted as normal. The mean age was 68.6±6.3 years and the groups had similar features with regard to demographic and clinical characteristics. Patients with ISH had significantly lower CFR values compared with those with combined SDH (2.22±0.51 vs 2.49±0.56, respectively; P=.03). On multivariate regression analysis, ISH (ß=-0.40, P=.004) and dyslipidemia (ß=-0.29, P=.04) were the independent predictors of CFR. These findings indicate that CFR, an indicator of coronary microvascular/endothelial function, is impaired more profoundly in patients with ISH than in patients with combined SDH.

A Rare Cause of Endocarditis: Streptococcus pyogenes.

Although group A ß-hemolytic streptococcus is an uncommon cause of infective endocarditis, an increase in the incidence of invasive group A streptococcus infections including bacteremia has been reported in the last two decades. Herein we report Streptococcus pyogenes endocarditis in a previously healthy adult patient who was hospitalized to investigate the etiology of fever. Because of a suspicion of a new vegetation appeared in the second (aortic) valve in the 14(th) day of high dose penicillin G treatment, the mitral and aortic valves were replaced by mechanical prosthesis on the 22(nd) day of treatment. He was discharged from hospital after the 6 week course of antibiotic treatment.

Direct measurement of proximal isovelocity surface area by real-time three-dimensional color Doppler for quantitation of aortic regurgitant volume: an in vitro validation.

OBJECTIVE: The proximal isovelocity surface area (PISA) method is useful in the quantitation of aortic regurgitation (AR). We hypothesized that actual measurement of PISA provided with real-time 3-dimensional (3D) color Doppler yields more accurate regurgitant volumes than those estimated by 2-dimensional (2D) color Doppler PISA. METHODS: We developed a pulsatile flow model for AR with an imaging chamber in which interchangeable regurgitant orifices with defined shapes and areas were incorporated. An ultrasonic flow meter was used to calculate the reference regurgitant volumes. A total of 29 different flow conditions for 5 orifices with different shapes were tested at a rate of 72 beats/min. 2D PISA was calculated as 2pi r(2), and 3D PISA was measured from 8 equidistant radial planes of the 3D PISA. Regurgitant volume was derived as PISA x aliasing velocity x time velocity integral of AR/peak AR velocity. RESULTS: Regurgitant volumes by flow meter ranged between 12.6 and 30.6 mL/beat (mean 21.4 +/- 5.5 mL/beat). Regurgitant volumes estimated by 2D PISA correlated well with volumes measured by flow meter (r = 0.69); however, a significant underestimation was observed (y = 0.5x + 0.6). Correlation with flow meter volumes was stronger for 3D PISA-derived regurgitant volumes (r = 0.83); significantly less underestimation of regurgitant volumes was seen, with a regression line close to identity (y = 0.9x + 3.9). CONCLUSION: Direct measurement of PISA is feasible, without geometric assumptions, using real-time 3D color Doppler. Calculation of aortic regurgitant volumes with 3D color Doppler using this methodology is more accurate than conventional 2D method with hemispheric PISA assumption.