Echo Indices Research Articles

Pulsed and Tissue Doppler Echocardiographic Changes in Hypertensive Crisis with and without End Organ Damage.

BackgroundHypertensive crisis (HC) is a common medical emergency associated with acute rise in arterial blood pressure that leads to end-organ damage (EOD). Therefore, it is imperative to find markers that may help in the prediction of EOD in acute hypertensive crisis.AimTo assess the clinical presentations on admission; echocardiographic changes of pulsed and tissue Doppler changes in EOD patients compared with no EOD; and the risk of developing end organ damage for clinical and biochemical variables in hypertension crisis.Material and MethodsThe data of 241 patients with hypertensive crisis with systolic blood pressure (SBP) of >180 mmHg or diastolic blood pressure (DBP) >120 mmHg were extracted from patients files. Patients divided into hypertensive emergency (HE) with EOD, n = 62 and hypertensive urgency (HU) without EOD, n = 179. LV hypertrophy on ECG, echo parameters for wall thickness, left Ventricular mass index (LVMI), Body mass index (BMI), pulse Doppler ratio of early filling velocity E wave to late A wave (E/A) and ratio of E wave velocity to tissue Doppler Em to E wave (E/Em) were evaluated. Serum creatinine, hemoglobin, age, gender, body mass Index (BMI), history of diabetes mellitus, smoking, hypertension, stroke and hyperlipidemia were recorded. Multiple logistic regression analysis was applied for risk prediction of end organ damage of clinical variables.ResultsPatients with HE compared with HU were significantly older, with a significantly higher SBP on admission, high BMI and LVMI. Further there were significantly higher E/A ratio on Doppler echo and higher E/Em ratio on tissue Doppler echocardiogram. Multiple regression analysis with adjustment for age and sex shows positive predictive value with odds ratio of SBP on admission >220 mmHg of 1.98, serum creatinine > 120 µg/L of 1.43, older age > 60 year of 1.304, obesity (BMI ≥ 30) of 1.9, male gender of 2.26 and left ventricle hypertrophy on ECG of 1.92. The hemoglobin level, history of smoking, hyperlipidemia and DM were with no significant predictive value. The pulsed Doppler E/A ratio was ≥1.6, E/Em > 15, LVMI > 125 gm/m2 in patients with EOD compared with those without.ConclusionIn patients presented with hypertensive crisis, the echo indices of E/A ratio and E/Em ratio of tissue Doppler are significantly higher in patients with hypertensive emergency compared to hypertensive urgency. The left ventricle hypertrophy on ECG, high LV mass index of >125 gm/m2, BMI > 30, old age > 60 year, male gender and history of hypertension and stroke were positive predictors of poor outcome and end organ damage.

Echocardiographic Assessment of Diastolic Heart Failure

A normal ejection fraction (EF) is present in >50% of patients with clinical features of heart failure (HF). This entity has been referred to as HF with normal EF (HFNEF), or diastolic HF. The underlying pathophysiology of HFNEF is still under debate and this is reflected in the unsatisfactory results of pharmacological treatment and in the high mortality and morbidity rates, which are similar to those for systolic HF. By providing evidence of left ventricular (LV) diastolic dysfunction in patients with clinical features of HF and normal LVEF, echocardiography, the most practical and widely available diagnostic modality, can offer two of the three current diagnostic criteria for HFNEF. Moreover, abnormalities in LV myocardial deformation and torsional dynamics at rest and during exercise were recently demonstrated in HFNEF patients by echocardiography. Newer echocardiographic parameters may improve the understanding of this complex entity, but further studies are needed before using them in clinical practice for the diagnostic and therapeutic approach of patients with HFNEF. This article discusses the current echocardiographic approach to the diagnosis of diastolic HF, as well as the potential role of newer echo indices and modalities.

Two-dimensional strain analysis in patients with hypertrophic cardiomyopathy and normal systolic function: A 12-month follow-up study

Although left ventricular (LV) and left atrial (LA) echo indices may reliably reflect loading conditions in patients with hypertrophic cardiomyopathy (HCM), little is known about 2-dimensional strain imaging. We evaluated LV and LA 2-dimensional strain imaging in relation to long-term outcome in patients with HCM. Fifty consecutive patients (58% men, aged 51 +/- 18 years) with familial HCM and normal LV ejection fraction underwent 2-dimensional LV and LA strain imaging; total LA strain was defined as the sum of maximum positive and maximum negative atrial strain. Patients were followed up for 12 months for cardiovascular events, defined as death or hospitalization for cardiovascular causes. Twenty patients (40%) experienced an event after a median time of 98 days: 2 (4%) died and 18 (36%) were hospitalized. In multivariate analysis, total LA strain was the strongest predictor of 12-month outcome (odds ratio 0.858, 95% CI 0.771-0.954, P = .005); a cutoff of 21% predicted events with 90% sensitivity and 86% specificity. Total LA strain was also an independent predictor of atrial fibrillation requiring hospitalization (odds ratio 0.853, 95% CI 0.748-0.972, P = .017). In patients with HCM and normal systolic function, total LA strain predicts 12-month outcome in terms of death and/or hospitalization.

Echocardiographic Predictors of Pulmonary Embolism in Patients Referred for Helical CT

Transthoracic echocardiography (TTE) is ordered frequently in patients with suspected pulmonary embolism (PE). Multiple indices have been suggested to play a useful diagnostic role. We sought to determine the relative predictive accuracy of suggested quantitative indices among patients referred for CT scanning for exclusion of PE. We retrospectively identified 67 consecutive patients who underwent CT for the exclusion of PE, and had a TTE within 48 hours of CT. Echo indices suggested to play a role in the diagnosis of PE were measured RV/LV area ratio, RV/LV end diastolic dimension ratio, the "McConnell" sign, interventricular septal shift ("D-sign"), Pulmonary artery diameter, tricuspid regurgitation velocity, and "60/60 sign" (TR velocity < 3.9 m/sec plus pulmonary artery acceleration time < 60 msec). CT confirmed PE in 41 (61%). Mean age was 58 (18-92). Forty-five were female. Subjects with PE were younger, and more likely to be tachycardic and require ICU admission. Of the echocardiographic indices, RV/LV EDD ratio > 0.7 was the most accurate predictor (sensitivity 66%, specificity 77%). The McConnell sign was the most specific (96%), however, with poor sensitivity (16%). Mean TR velocities did not differ between those with and without PE (270 +/- 74 vs. 294 +/- 83, P = 0.25). RV/LV EDD ratio > 0.7 has good accuracy for the diagnosis of acute PE. RV/LV area ratio > 0.7 and McConnell sign are specific but not sensitive indicators of acute pulmonary embolism. The presence of these findings should prompt further diagnostic testing for PE.

Abstract 3289: Vortex Formation Index in Heart Failure: Novel Non-invasive Assessment Of Fluid Dynamics using Transthoracic Echocardiography

Background: In clinical heart failure (HF), inefficient propagation of blood through the left ventricle (LV) may result from suboptimal vortex formation (VF) ability of the LV during early diastole. We aim to validate echocardiographic-derived VF index (VFI) in normal subjects and examine its utility in both systolic and diastolic HF. Method: Echocardiography was performed in 100 normals and 155 pts admitted with HF (110, systolic and 45, isolated diastolic failure). In additon to biplane LV ejection fraction (EF) and conventional parameters, the Tei index and tissue Doppler (TD) indices were measured. VFI was obtained using: 4 X (1-β) / πX α 3 X LVEF where β is the fraction of total transmitral diastolic stroke volume contributed by atrial contraction (assessed by time velocity integral of the mitral E and A waves) and α is the biplane end diastolic volume (EDV) 1/3 divided by mitral annular diameter during early diastole. Results: Mean VFI was 2.75 ± 0.7 in control subjects; reduced in heart failure, diastolic, 2.21 ± 0.8; systolic, 1.24 ± 0.5 (P&lt;0.001, Fig 1 ). It correlated positively with TD early diastolic myocardial velocities (E, septal, r =0.58; lateral, r =0.58), inversely with LV filling pressure (E/E’ septal, r =−0.42; lateral, r =−0.41) and the Tei index (r =−0.57, curvilinear relation, Fig 2 ); all Ps &lt;0.001. In comparison with age, sex and LVEF-matched controls, only VFI, but not all other echo indices, remained significantly different (attenuated) in diastolic HF patients (2.01 ± 0.7 vs 2.74 ± 0.8, P=0.005). Conclusion: VFI, a novel, dimensionless index, incorporating LV geometry, systolic and diastolic contributions to fluid dynamics, may be useful in heart failure.

Abstract 3336: Fractional and Coronary Flow Reserve in Prediction of Functional Recovery of Myocardium in Patients with Previous Myocardial Infarction

Background: Fractional flow reserve (FFR) may provide clinically useful diagnostic information both in patients (pts) with normal left ventricular (LV) function as well as in pts with previous myocardial infarction (MI). However, the question remains to the relation between improvement of FFR and improvement of LV function in pts with previous MI undergoing percutaneous coronary intervention (PCI). Aim: The aim of the study was to evaluate the relation between FFR and simultaneously evaluated coronary flow reserve by thermodilution (CFRthermo), with functional improvement of LV function in pts with previous MI undergoing PCI. Methods: Study population consisted of 50 pts (mean age 53±8 years; 40 male) with previous MI and significant coronary stenosis in one-vessel CAD (33 LAD, 4 Cx, 13 RCA) undergoing PCI of infarct-related coronary artery. In all pts we have evaluated by single pressure/thermo wire FFR and CFRthermo before and immediately after PCI. In all pts, we have evaluated LV ejection fraction by echo and wall motion score index (WMSI) before and 3 months after PCI. Results: Coronary lesions were successfully treated in all pts with decrease of diameter stenosis from 63±7% to 18±9% (p&lt;0.001). FFR increased significantly (p&lt;0.001) from 0.62±0.15 to 0.91±0.06 after PCI, whereas CFRthermo increased significantly (p&lt;0.01) from 1.5±0.3 to 2.5±0.7. LV ejection fraction increased from 49±6% to 55±8% (p&lt;0.0001), and WMSI decreased from 1.44±0.24 to 1.29±0.29 (p&lt;0.0001). LV functional improvement was observed in 33/50 (66%) of pts. In pts with LV functional recovery in comparison to pts with no recovery there was significant difference in FFR before PCI (0.57±0.15 vs. 0.71±0.11, p=0.001), improvement of FFR during PCI (0.34±0.15 vs. 0.21±0.13, p=0.004), improvement of CFRthermo during PCI (1.2±0.6 vs. 0.6±0.5, p=0.001) and CFRthermo after PCI (2.7±0.7 vs. 2.1±0.6, p=0.008), respectively. Conclusion: Evaluation of FFR and CFRthermo provide significant prognostic information on LV functional recovery in pts with previous MI undergoing PCI. Lower FFR before PCI, higher CFRthermo after PCI, as well as higher improvement of FFR and CFRthermo during PCI are indicative of left ventricular functional improvement in pts with previous MI.

Differentiation of Systolic and Diastolic Heart Failure using Strain and Strain Rate Echocardiography

Background and Objectives:Diastolic heart failure (DHF) is defined as clinical evidences of heart failure, with a normal ejection fraction (EF) and abnormal diastolic function. However, the distinction between DHF and SHF is often difficult. Strain (S) and strain rate (SR) echocardiography can measure the regional myocardial function as a magnitude and rate of deformation. The hypothesis“myocardial velocity (Vel), S & SR can provide additional information for differentiation DHF from SHF”was assessed. Subjects and Methods: 30 patients with symptomatic HF and low EF (SHF group) and 27 with symptomatic HF, and normal EF and diastolic dysfunction (DHF group) were enrolled. 37 age-and sex-matched control subjects were recruited. Conventional echo and regional indices (Vel, S and SR), measured at the mid septum and posterior wall, were obtained. Results:Almost all clinical and echo indices of control were different between the two HF groups. The EF, LV mass, S’ and DT in DHF were greater than those with SHF. The LA size, diastolic dysfunction grades; E, A, E/A, E’, A’ and E/E’, were not different between the two HF groups. In the regional indices, the peak S (long axis: 12.0±5.4 vs. 17.6±5.9%, radial axis: 26.4±12.7 vs. 46.0±16.7%) and systolic Vel (long axis: 2.6±0.8 vs. 3.6±0.9 cm/s, radial axis: 2.1 (1.2 vs. 3.7±1.4 cm/s) with SHF were significantly lower than those with DHF. However, the SR of the two groups was not different. The best cutoff values of peak S were 13.7% (long axis) and 32.9% (radial axis), and the systolic Vel were 3.0 cm/s (long axis) and 2.8 cm/s (radial axis). Conclusion:The peak S and systolic Vel may be useful indices for differentiating DHF from SHF. A similarly decreased SR in the two HF groups suggests that DHF has decreased myocardial contractility, despite the normal EF. (Korean Circulation J 2004; 34(11):1090-1098)

Echocardiographic evaluation of the ductal morphology in patients with refractoriness to lipo-prostaglandin E1 therapy

Lipo-prostaglandin (PG)E1 is effective at lower doses and has fewer side effects than PGE1-cyclodextrin (CD). Previous studies, however, have suggested that some patients show refractoriness to lipo-PGE1 in the course of treatment. The present paper examines: (i) whether such cases can be predicted by examining the ductal morphology before and 24 h after the start of lipo-PGE1 infusion; and (ii) whether PGE1-CD dilates the ductus arteriosus in patients with refractoriness to lipo-PGE1. The ductal morphology was evaluated with two echo indices, such as minimal and minimal plus maximal intraluminal diameters of the ductus. Two-dimensional echocardiography was performed in 24 patients with ductus-dependent congenital heart disease. The two echo indices were measured before and 24 h after lipo-PGE1 infusion and also at least twice per week until surgery. In 19 of 24 patients, ductal patency was maintained until surgical treatment (group A). The remaining five patients (21%) showed ductal closure during the course of the lipo-PGE1 therapy (group B). There were no significant differences between the two groups, in either the maximal or minimal diameters, which were examined before and 24 h after treatment. In the five patients of group B, lipo-PGE1 was replaced with a relatively high dosage of PGE1-CD (50-100 ng/kg per min), resulting in good ductal patency until surgery. Patients with refractoriness to lipo-PGE1 therapy could not be predicted from initial intraluminal diameters of the ductus using echocardiography. Therefore, serial echocardiographic examinations are important to detect early findings of ductal closure. In addition, PGE1-CD is still useful as back-up therapy in such patients.

Long-term prognostic significance of M mode echocardiography in young men after myocardial infarction.

To evaluate the power of measurements of left ventricular size and function for predicting long term (82 month) mortality by performing echocardiography in 97 men who had survived an acute myocardial infarction. University hospital specialising in cardiology. 97 consecutive male patients who had survived a myocardial infarction. The additive prognostic value of functional measurements to that provided by primary risk factors (smoking habits and lipoprotein levels), radiological heart size, exercise capacity, and number of major coronary arteries with haemodynamically significant stenoses was evaluated. An echo index was calculated from three echocardiographic variables (yielding one score point each if: left ventricular diameter at the end of diastole (LVDD) > or = 5.7 cm, left ventricular fractional shortening < or = 24%, and E point-separation (EPSS) > or = 10 mm). 17 cardiac deaths occurred during follow up. Univariate analysis showed that treatment with loop diuretics for heart failure (P < 0.01), LVDD (P < 0.01), left ventricular diameter at the end of systole (LVDS) (P < 0.001), left atrial diameter (P < 0.001), fractional shortening (P < 0.05), and echo index (P < 0.001) were all associated with cardiac death. Angiographically determined regional wall motion disturbances (P < 0.005) and angiographic ejection fraction (P < 0.001) were also associated with cardiac death, as was the number of major coronary arteries with significant stenosis (P < 0.05). When all significant echocardiographic variables from univariate analysis were entered into Cox proportional hazards survival analysis, LVDS and left atrial diameter contributed independently to the prediction of cardiac death. If angiographic data were also entered into the model, the echo index made an independent contribution to the prediction of cardiac death. Among young male patients with a previous myocardial infarction, a simple M mode echocardiographic examination can identify high and low risk patients and improve the prediction of cardiac death made from clinical information, exercise test, chest x ray and angiographically determined ejection fraction.

949–98 Do Doppler Indices of Diastolic Dysfunction Provide Prognostic Information in Elderly Patients with Congestive Heart Failure?

Congestive heart failure (CHF) due to left ventricular diastolic dysfunction (DDFXN) is common in the elderly, and Doppler echo indices are frequently used to characterize DDFXN, but the relationship between these parameters and clinical outcomes has not been well studied. We analyzed the relationship between echo indices of systolic and DDFXN and clinic outcomes (3-mo mortality and readmission rates) in 130 PTS ≥ 70 yrs of age with CHF (mean age 79 yrs, 35% male, 47% white). Overall, neither deceleration time (DT) nor E:A ratio (E:A) COrrelated with 3-mo survival or readmissions. However, in PTS with reduced LV systolic function (ejection fraction &lt;45% , N = 67). DT was significantly lower in PTS who died within 3 months than in survivors (129 ± 27 msec vs. 186 ± 67 msec, p &lt; 0.001). Moreover, on multivariate analysis, DT remained an independent predictor of 3-month mortality after adjusting for age. sex. ejection fraction. and NYHA class (p = 0.05). OT was not a significant predictor of readmission in PTS with reduced LV function. or of readmission or survival in PTS with normal LV function. The E:A ratio provided no prognostic information in any subgroup. In elderly patients with CHF due to LV systolic dysfunction, DT provides important independent prognostic information. In particular, a shorter DT, suggestive of restrictive physiology, appears to be associated with a worse prognosis. These findings may have therapeutic implications for these PTS.

Humoral Determinants of the Left Ventricular Function in Pheochromocytoma Patients

In an attempt to characterize the hemodynamic diversity of adaptation to chronic catecholamine exposure and to determine a possible link between the tumor humoral activity and left ventricular (LV) systolic and diastolic function, mitral flow Doppler, and echo indexes were calculated and urinary adrenaline, noradrenaline (NA), and dopamine levels determined in 25 patients with pheochromocytoma. Pheochromocytoma patients had higher LV contractility quantified by the ratio of systolic blood pressure to endsystolic LV volume/body surface area (8.2 ± 3.2 vs. 5.5 ± 1.5 mm Hg•m^2/ml; p < 0.001) and LV mass index (113.4 ± 41.4 vs. 88.9 ± 15 g/m^2, p < 0.01) than healthy controls of similar age and sex distribution. End-systolic LV wall stress showed wide scatter, with some very high values not compensated by LV hypertrophy. Mitral flow Doppler indicated impaired early LV filling in pheochromocytoma patients vs. controls: lower early-to-late mitral flow velocity integral ratio (1.9 ± 0.9 vs. 2.7 ± 0.9, p < 0.001) and maximal early-to-late mitral flow velocity ratio (Ev/Av; 1.2 ± 0.6 vs. 1.7 ± 0.4, p < 0.005). Dopamine correlated inversely with LV mass (r = -0.44, p < 0.05) and blood pressure (systolic r = -0.39, p < 0.05; diastolic r = -0.57, p < 0.05). NA correlated with Er/Ar (r = 0.44, p < 0.05). In patients with pheochromocytoma the mitral inflow profile indicates impaired LV relaxation, but NA may play a role in enhancing early LV filling.

Influence of left ventricular cavity dimension on electrocardiographic estimation of the extent of wall motion abnormalities.

To estimate the influence of left ventricular cavity dimension on the electrocardiographic estimation of the extent of wall motion abnormalities, two-dimensional echocardiograms and standard 12-lead electrocardiograms (ECG) were carried out on 221 patients within 3 months after acute myocardial infarction (MI). Among the patients with anterior MI (96 patients; 43.4%) both the extent of asynergy (% of asynergic segments, an echo index taking into account the type of asynergy) and the electrocardiographic signs of necrosis (number of Q waves greater than or equal to 40 ms, Wagner's score) were significantly greater (p less than 0.001) in those with left ventricular dilatation (60 patients) than in those with normal ventricular size (36 patients); within the latter group, the ECG-asynergy correlations were good (r value 0.67-0.79). In patients with left ventricular dilatation no correlation was found. In inferior MI (108 patients, 48.9%), asynergy was more extensive in patients with left ventricular dilatation (p less than 0.001) than in those with normal left ventricle. However, the electrocardiographic extent of necrosis was similar in the two groups and no significant ECG-asynergy correlation was found. Likewise, in anteroinferior MI (17 patients; 7.7%), the ECG-asynergy correlations were statistically insignificant in both groups. In conclusion, the electrocardiographic patterns of necrosis are poorly related to the extent of asynergy and are greatly influenced by left ventricular dimensions.

Precordial contrast echocardiographic detection of patent ductus arteriosus in small preterm infants.

Clinical detection of patent ductus arteriosus (PDA) remains an important and challenging problem in the small preterm infant with respiratory distress. In this study, PDA was diagnosed in 28 small preterms using an improved contrast echocardiographic method. In these infants, the injection of saline into the aorta generated echoes which were imaged at the pulmonary valve. This was accomplished using a conventional M-mode ultrasound transducer applied at the usual precordial position. Contrast echo studies were compared with the degree of ductal patency shown by single film aortography. Ductal patency was detected by contrast echo in 29 of 31 instances of aortographically proven PDA. Indirect echo indices commonly used for detection of PDA (cardiac chamber enlargement) may be limited since factors other than left-to-right shunt can cause cardiac enlargement in distressed small preterms. This direct contrast echo technique is an easily performed, sensitive, qualitative method for confirmation of the diagnosis of PDA in small preterm infants.

The cardiovascular effects of dopamine in the severely asphyxiated neonate

The cardiovascular effects of dopamine were evaluated in 14 severely asphyxiated neonates. After a period of stabilization, either dopamine 2.5 micrograms/kg/minute or placebo was infused in a randomized double-blind protocol. In seven dopamine-treated infants, echocardiographically determined shortening fraction and mean velocity of circumferential fiber shortening increased when compared to preinfusion values (P less than 0.05). There was no significant change in these echo indices of cardiac function in the placebo-treated group. Systolic blood pressure rose in the dopamine group when compared to predopamine infusion values and to the postinfusion values of the placebo group (P less than 0.001 and 0.025, respectively). Diastolic blood pressure increased to a small degree in the dopamine group. There was no significant change in heart rate or echocardiographically measured systolic time intervals. Low doses of dopamine increase cardiac performance and raise systolic blood pressure in the severely asphyxiated neonate.

SERIAL EVALUATION OF CARDIAC FUNCTION IN CHILDREN UNDERGOING DIALYSIS

Serial echocardiographic (echo) evaluation of cardiac performance in children undergoing chronic dialysis is currently not feasible due to significant dialysis induced changes of heart rate (HR), preload and afterload which alter selected echo indices in the absence of true dysfunction. To eliminate this problem the effect of the independent variables heart rate (HR), preload index (PI) (represented by left ventricular end diastolic dimension (LVED)/a matched control LVED) and afterload (represented by a simultaneously recorded aortic diastolic pressure (DP)) upon pre-ejection period (PEP), ejection time (ET), PEP/ET, shortening fraction (SF), mean circumferential fiber shortening (Vcf), isovolumic contraction time (ICT), maximum posterior wall velocity (PWV) and cardiac output (CO) was evaluated on 92 echograms obtained from four children undergoing chronic dialysis. Multiple linear regression analysis of the data was performed for each patient and for the entire group in order to express each echo index as a function of HR, DP, and PI. Few significant regressions were obtained for the group as a whole but were obtained (r>0.77,P<0.05) in all individuals for ET, CO, and SVR; in three for Vcf and PEP/ET; in one for ICT and SF but in none for PEP. For each echo index except CO, the independent variables differed among children. We conclude that these regressions should significantly improve the ability to interpret selected echo indices in some patients with frequent alterations of HR, preload, and afterload.

Echocardiographic Indices of Left Ventricular Function: A Comparison

Multiple M-mode echocardiographic indices of left ventricular function are currently in use, but their reliability is disputed. Therefore, we correlated echo ejection fraction (EF) using quadratic (Q) and cubic (C) formulae, percentage of minor axis shortening (%S), mean velocity of circumferential fiber shortening (mVCF), and peak VCF with angiographic EF in 37 subjects, including 10 normal subjects. None had echocardiographic segmental wall motion abnormalities. Significant linear correlations were found between angiographic EF and EFc (r = 0.78), %S (r = 0.77), EFQ(r = 0.68), peak VCF (r = 0.68), and mVCF (r = 0.58). However, for all indices, the scatter was too great to permit reliable quantitative estimations of angiographic EF based on echo date. Peak VCF was qualitatively the most reliable predictor of ventricular function, being greater than or equal to 2.00 circumference per second in 23 of 25 patients with angio EF greater than or equal to 55 percent and less than 2.00 circumferences per second in 11 of 12 with EF less than 55 (sensitivity [sens] 92 percent, specificity [spec] 92 percent). Mean VCF (sens 83 percent, spec 80 percent), %S (sens 50 percent, spec 96 percent), EFC (senc 58 percent, spec 96 percent), and EFQ (sens 58 percent, spec 92 percent) were less satisfactory. We conclude that echo indices are reliable only as qualitative parameters of ventricular function. Peak VCF appears to be the most sensitive and specific qualitative index now available.

ECHOCARDIOGRAPHIC PITFALLS IN THE PREMATURE WITH LARGE PATENT DUCTUS ARTERIOSUS

The ultrasound-derived ratio of left atrial to aortic root dimensions (LA/Ao) is used commonly to assess the presence and magnitude of left to right shunting through the PDA in prematures. The results of the present study emphasize the hazards of overreliance on this echo index. Thus, seven of thirty-one consecutive premature infants with severe respiratory distress syndrome and clinical and radiographic evidence of significant ductal left to right shunting were found to have normal LA/Ao ratios, as well as normal absolute left atrial dimensions. The LA/Ao ratios remained normal in these respirator-bound infants despite clinical signs of severe cardiac decompensation. In four of these infants the PDA was ligated surgically, while in two indomethacin was effective. The remaining infant responded to digitalis, diuretics, and fluid restriction, and ultimately closed her PDA spontaneously. Abolition of ductal left to right shunting did not consistently change the LA/Ao ratios or absolute left atrial dimensions in this group. A major finding in these infants was the detection of abnormally enlarged left ventricular end diastolic dimensions in the presence of normal left atrial dimensions. Thus, maximum diagnostic accuracy can be achieved only by a comprehensive echocardiographic evaluation that combines analysis of both atrial and ventricular dimensions since the former, when used alone, may be misleading.