Improved differential diagnosis of intracardiac and extracardiac shunts using acoustic intensity mapping of saline contrast studies.

AIMS: The aim of this study was to test the hypothesis that temporal patterns of saline contrast entry into, and exit from the left heart are significantly different in intra- and extra-cardiac shunts and can be used to differentiate the shunt mechanism when Valsalva manoeuvre cannot be performed, or is of uncertain quality. We propose a novel approach of mapping the temporal changes in acoustic intensity (AI) within the left and right heart to identify and define these unique patterns. METHODS AND RESULTS: We screened cases of right to left shunting on resting agitated saline contrast echocardiograms with clinical criteria that identified the origin of shunting as either a patent foramen ovale or pulmonary arteriovenous malformation. Acoustic time-intensity curves were generated from the right and left heart chambers that reflected the change in saline contrast density over time. Several novel pre-specified parameters were measured from these curves, in addition to the standard heartbeat counting method, to characterize the entrance (wash-in) and exit (wash-out) patterns of saline contrast in the left heart. Statistical analysis showed that AI mapping provided superior differentiation of the two populations than did the traditional beat counting method. CONCLUSION: Diagnosis of shunt mechanism from saline contrast studies can be improved over current methods through the use of AI mapping to define the rapidity that peak contrast effect develops, the speed that the contrast effect decays, and the contrast intensity late in the recording.

An alternative isovelocity surface model for quantitation of effective regurgitant orifice area in mitral regurgitation with an elongated orifice application to functional mitral regurgitation.

OBJECTIVES: The purpose of this study was to develop and test a simple, clinically practical alternative isovelocity surface (ISVS) model for calculating effective regurgitant orifice area (EROA) in mitral regurgitation (MR) when the regurgitant orifice is elongated, such as in functional MR. BACKGROUND: Clinical experience and 3-dimensional imaging suggest that the traditional hemispheric ISVS model used in the conventional proximal isovelocity surface area (PISA) calculation is invalid in certain MR cases and can cause erroneous EROA values. METHODS: Our ISVS model consisted of 3 sections of equal radius (R): a cylindrical midsection of length (L) positioned between 2 hemispheroidal end sections. Total ISVS area (T(S)) is equal to 2πR(2) + πLR and EROA is equal to (V(N/)V(CW))T(S), where V(N) is the flow velocity crossing perpendicular to the ISVS, and V(CW) is the peak MR jet velocity by continuous-wave Doppler. This EROA was corrected for any obtuse angle, θ formed by tented leaflets, by multiplying T(S) by a planar factor, (θ/180) or a combination of this planar factor for the cylindrical midsection and the solid-angle factor, 1-cos(θ/2), for the 2 spheroidal end sections. In 24 cases of severe or 3+ functional MR, we calculated EROA using 3 traditional hemispheric surfaces and 3 alternative ISVS models that differed in the leaflet angle correction applied. Results were compared with continuity-based EROA using the standard mitral valve - aortic valve stroke volume method and with predictions based upon theoretical geometric considerations. RESULTS: The mean differences between continuity EROA and ISVS area-based EROA for no angle correction, planar correction, or combined angle correction were, respectively, 0.38, 0.32, and 0.28 cm(2) for the 3 spherical surface models and 0.17, 0.018, and -0.012 cm(2) for the 3 alternative 3-section ISVS models. The empiric EROA results with both the traditional spherical and alternative ISVS models agreed well with theoretical geometric predictions. CONCLUSIONS: The traditional spherical PISA model underestimates EROA in functional MR. For elongated MR orifices, an ISVS model that mirrors orifice shape yields more accurate EROA values. Correction to the ISVS area for obtuse leaflet angulation improves accuracy of EROA estimation.

Quantitative estimation of left ventricular ejection fraction from mitral valve E-point to septal separation and comparison to magnetic resonance imaging.

This study tested the hypothesis that the mitral valve E point-to-septal separation (EPSS) can be used to quantify the left ventricular (LV) ejection fraction (EF) on a continuous scale rather than simply as "normal" or "reduced." After excluding 5 patients with mitral valve prostheses, asymmetric septal hypertrophy, or significant aortic insufficiency, EPSS was measured in 42 patients by 3 independent observers on a cardiac magnetic resonance image identical to the echocardiographic parasternal long-axis view. In each patient, the reference standard LVEF was calculated from the magnetic resonance short-axis cross-sectional stack images by Simpson's rule and ranged from 11% to 72%. For all 42 patients, linear regression revealed the relation magnetic resonance imaging (MRI) LVEF = 75.5 - 2.5. EPSS (millimeters). Correlation between EPSS and the MRI LVEF for the 3 observers agreed closely, ranging from r = 0.78 to r = 0.82 (SEE 9 to 10), with similar regression coefficients. After blinded segmental wall motion scoring of the gated magnetic resonance cine images of the left ventricle in each patient, correlations, SEEs, and regression coefficients were found to be very similar in the 21 patients with the most homogenous wall motion, compared with the 21 patients with the most heterogenous wall motion. In conclusion, clinically useful quantitative prediction of the LVEF as a continuous variable can be obtained from the EPSS with a simple linear regression equation in a substantial portion of patients and may be a useful adjunct for assessment of LV function.

Noninvasive evaluation of pericardial effusion composition by computed tomography.

BACKGROUND: Measurement of the hematocrit (HCT) and total protein (TP) of pericardial fluid can be of critical importance in the management of pericardial effusion (PE) but requires pericardiocentesis. There has been no systematic study of computed tomography (ct) hounsfield density (hd) measurement for the noninvasive evaluation of pe composition. METHODS: We performed CT-guided pericardiocentesis in 53 patients to obtain simultaneous measurement of the PE HD, HCT, and TP. We determined the relationship of PE HCT to the following variables: (1) the average of the mean HD in 5 regions of interest (ROIs) within the PE; (2) the maximum PE HD; (3) the difference between the average effusion region of interest HD and the ventricular blood pool HD. We also correlated PE HD with PE HCT and TP to assess their contribution to the PE CT HD. RESULTS: The average of the HD measured in up to 5 regions within the PE was the best predictor of PE HCT ( r = 0.84). Addition of ventricular blood pool HD and venous HCT to the regression did not improve prediction of PE HCT over average PE HD alone. Pericardial effusion HD was unrelated to PE TP. There was a statistically significant difference in the PE HD among 8 categories of underlying disease etiology in the population. Excluding postcardiotomy cases (n = 22) in which PE etiology is known before pericardiocentesis, visceral or vascular rupture was associated with the highest HD values. Hounsfield density >30 HU had a sensitivity of 100%, specificity 70%, and predictive value 33% for this condition in the remaining cases (n = 31). CONCLUSIONS: Computed tomography is a rapid and accurate method for noninvasive estimation of pericardial fluid HCT and may be helpful in guiding both the acute management and differential diagnosis of PE.

Diagnosis of Partial Anomalous Pulmonary Venous Connection with Intact Interatrial Septum by Echocardiography.

This case illustrates the complementary use of transthoracic echocardiography and transesophageal echocardiography in the diagnosis of partial anomalous pulmonary venous connection. The transthoracic echocardiogram suggested the presence of anomalous pulmonary venous return by demonstrating right heart volume overload and evidence of an intact atrial septum. Transesophageal echocardiography was required to confirm these findings and provide a firm anatomic diagnosis before surgery. This case also emphasizes that a high degree of clinical suspicion for this condition should occur in situations in which apparent right heart volume overload is otherwise unexplained.

Survival in Infarct Related Intramyocardial Dissection Importance of Early Echocardiography and Prompt Surgery.

Infarct related intramyocardial dissection, an unusual mechanical complication associated with recent inferior/inferoposterior myocardial infarction, is characterized by a septal defect and a dissection tract that originates on the left side of the interventricular septum, extends beyond the septum into the right ventricular free wall, and subsequently re-enters the right ventricle. The utility of echocardiography for diagnosis has been described. Despite aggressive therapy, the prognosis of intramyocardial dissection is reported to be dismal. We describe the use of prompt echocardiography in two patients, which established the diagnosis of infarct related intramyocardial dissection allowing early definitive surgery and long-term survival.

Echocardiographic Findings in Rupture of Long False Tendons: Report of Two Cases.

Long left ventricular false tendons, which connect distant sites on the ventricular endocardium, are common incidental echocardiographic findings. We describe two cases in which rupture of such long false tendons produced unusual, highly mobile, intracavitary echo densities that could be mistaken for other important pathologies, such as thrombus or vegetation. The differentiation of ruptured long false tendons and intact short apical false tendons from other entities they may mimic is described. (ECHOCARDIOGRAPHY, Volume 13, September 1996)