Cross sectional echocardiographic identification of hypoplastic left heart syndrome and differentiation from other causes of right ventricular overload

To identify the echocardiographic features that can be used to distinguish between hypoplastic left heart syndrome and other causes of right ventricular overload in the sick neonate cross sectional echocardiographic studies of 10 neonates with hypoplastic left heart syndrome were analysed and compared with those in 15 neonates with other causes of right ventricular overload and 15 normal controls. Left ventricular and right ventricular cavity dimensions and the shape and size of the mitral valve annulus and aortic root were recorded and presented both as absolute values (mm) and corrected for body surface area (mm/m2). Logistic regression was used to produce a classification rule to estimate the probability of a neonate having hypoplastic left heart syndrome. The diameter of the mitral valve annulus was the single most discriminative variable. There was, however, considerable overlap of all the calculated features between neonates with hypoplastic left heart syndrome and those with other causes of right ventricular overload. The diagnosis of hypoplastic left heart syndrome should not be based on any one single echocardiographic feature but the general appearance of abnormal left heart valves, small cavity dimensions, and the size of the mitral valve annulus.     

Echocardiographic spectrum of the hypoplastic left heart syndrome: A clinicopathologic correlation in 19 newborns

Ultrasonic studies were performed in 19 neonates with the hypoplastic left heart syndrome whose diagnosis was confirmed at angiography or autopsy, or both. The patients were classified in two echocardiographic groups: Group I, 10 infants whose ventricular septum could be recorded, and Group II, 9 infants whose septum could not be recorded. The findings in these groups were compared with those in 60 neonates without congenital heart disease also studied with ultrasound. Two additional neonates who presented with signs of shock were also studied.The diagnostic echocardiographic features of hypoplastic left heart syndrome were: (1) a left ventricular end-diastolic dimension of less than 9 mm; (2) an aortic root diameter of less than 6 mm; (3) a ratio of left ventricular end-diastolic to right ventricular end-diastolic dimension of less than 0.6; and (4) a mitral valve echo that is absent or greatly distorted and of small amplitude. These echocardiographic criteria differed significantly from findings in the normal group (P < 0.01). Echocardiography proved valuable in neonates with shock. It is a safe, reliable technique that can be used to delineate the intracardiac anatomy in sick neonates with the hypoplastic left heart syndrome.     

Comparison of M mode echocardiography and pathologic findings in the hypoplastic left heart syndrome

The M mode echocardiograms and pathologic specimens from 18 infants with the hypoplastic left heart syndrome were compared to determine the accuracy with which the echocardiogram reflects the state of the mitral valve, left ventricle and aortic valve, and its limitations in establishing this diagnosis. Mitral valve echoes were recorded in 7 of the 11 cases with an anatomic mitral valve orifice diameter greater than 3 mm. Ventricular septal echoes were found only in the seven cases in which the mitral valve was recorded. Differences between echocardiographic and anatomic left ventricular internal dimensions were not statistically significant in this small group. When aortic valve echoes were recorded, this valve was always patent in the anatomic specimen. The aortic valve was atretic in 9 of the 11 cases in which no aortic valve echoes were present. The echocardiographic and anatomic aortic root dimensions had a statistically significant correlation (p < 0.05), but there was considerable scatter in the data.None of the 18 infants met all of the previously proposed criteria for the echocardiographic diagnosis of hypoplastic left heart syndrome. An echocardiographic left ventricular dimension of 10 mm or greater was present in five cases (28 percent), and an aortic root dimension of 10 mm or greater in six (33 percent). The most reliable echocardiographic finding was excursion of 5 mm or less of the anterior leaflet of the mitral valve or inability to detect the mitral valve. Noninvasive findings are not always sufficient to establish the diagnosis of hypoplastic left heart syndrome, and further studies may be necessary in some patients.     

Left ventricular dysfunction in the fetus: relation to aortic valve anomalies and endocardial fibroelastosis.

OBJECTIVE--To examine the relation between a characteristic form of left ventricular dysfunction in the fetus and abnormalities of the aortic valve and endocardial fibroelastosis of the left ventricle. DESIGN--A retrospective study to examine the correlation between echocardiographic findings in the fetus and postnatal or necropsy findings. SETTING--Tertiary referral centre for fetal echocardiography. PATIENTS--Thirty fetuses showing a characteristic echocardiographic picture of left ventricular dysfunction. MAIN OUTCOME MEASURES--The relation between the prenatal echocardiographic features and the postnatal and necropsy findings. RESULTS--At presentation the size of the left ventricular cavity was normal or enlarged in all cases. The measurements of the orifice of the aortic root and mitral valve were either normal or small for the gestational age. The echocardiographic diagnosis made at presentation was critical aortic stenosis in all cases. At necropsy or postnatal examination the aortic valve was dysplastic and stenotic in 15 cases and the left ventricle had become hypoplastic in one of these. Aortic atresia was present in seven patients, three of whom had a hypoplastic left ventricle. In six patients the aortic valve was bicuspid although not obstructive. One of these patients had hypoplasia of the aortic arch and one had a hypoplastic left ventricle but in the remaining four patients endocardial fibroelastosis of the left ventricle was the only abnormality found. No follow up information was available in two. Of 26 patients for whom there was postmortem information, 24 had evidence of some degree of endocardial fibroelastosis of the left ventricle. Sequential observations showed that five cases developed into the hypoplastic left heart syndrome. CONCLUSIONS--This type of left ventricular dysfunction in the fetus is the result of an overlap of diseases, including primary left ventricular endocardial fibroelastosis, critical aortic stenosis, and the hypoplastic left heart syndrome.     

Left ventricular dysfunction in the fetus: relation to aortic valve anomalies and endocardial fibroelastosis.

OBJECTIVE--To examine the relation between a characteristic form of left ventricular dysfunction in the fetus and abnormalities of the aortic valve and endocardial fibroelastosis of the left ventricle. DESIGN--A retrospective study to examine the correlation between echocardiographic findings in the fetus and postnatal or necropsy findings. SETTING--Tertiary referral centre for fetal echocardiography. PATIENTS--Thirty fetuses showing a characteristic echocardiographic picture of left ventricular dysfunction. MAIN OUTCOME MEASURES--The relation between the prenatal echocardiographic features and the postnatal and necropsy findings. RESULTS--At presentation the size of the left ventricular cavity was normal or enlarged in all cases. The measurements of the orifice of the aortic root and mitral valve were either normal or small for the gestational age. The echocardiographic diagnosis made at presentation was critical aortic stenosis in all cases. At necropsy or postnatal examination the aortic valve was dysplastic and stenotic in 15 cases and the left ventricle had become hypoplastic in one of these. Aortic atresia was present in seven patients, three of whom had a hypoplastic left ventricle. In six patients the aortic valve was bicuspid although not obstructive. One of these patients had hypoplasia of the aortic arch and one had a hypoplastic left ventricle but in the remaining four patients endocardial fibroelastosis of the left ventricle was the only abnormality found. No follow up information was available in two. Of 26 patients for whom there was postmortem information, 24 had evidence of some degree of endocardial fibroelastosis of the left ventricle. Sequential observations showed that five cases developed into the hypoplastic left heart syndrome. CONCLUSIONS--This type of left ventricular dysfunction in the fetus is the result of an overlap of diseases, including primary left ventricular endocardial fibroelastosis, critical aortic stenosis, and the hypoplastic left heart syndrome.     

Absence of the aortic valve associated with hypoplastic left-sided heart syndrome

In this report we describe the twelfth case in the literature of absence of the aortic valve cusps, associated with hypoplastic left-sided heart syndrome in a neonate. Clinical and hemodynamic conditions in our patient resemble the classical features of this syndrome except for a greater development of the ascending aorta and the left ventricular cavity, due to aortic insufficiency. A patch was unsuccessfully inserted at the aortic annulus to exclude the left ventricle from the circulation. In addition the Norwood operation was performed.     

The tricuspid valve in carcinoid cardiopathy: characteristic echocardiographic aspects

Cardiac involvement is commonly seen in the carcinoid syndrome (C.S.). However echocardiographic observations in this condition are still very scanty. In two patients with the C.S. and clinical signs of tricuspid insufficiency (plus mild pulmonic stenosis in one case) two-dimensional echocardiography showed: 1) right ventricular overload with normal left heart valves and chambers; 2) a peculiar aspect of the tricuspid valve, whose three leaflets were markedly thickened and retracted. The anterior leaflet was almost fixed in a semi-open position while the septal and posterior leaflets appeared as rigid structures fixed in an open position, extending from the annulus into the right ventricular cavity. In both cases only the posterior cusp of the pulmonary valve could be visualized. The afore-mentioned changes exactly reproduce the pathological features of the tricuspid valve in the carcinoid heart disease and so far, have not been observed in other conditions.     

Coronary artery abnormalities and right ventricular histology in hypoplastic left heart syndrome.

OBJECTIVES. To determine whether right ventricular preservation is compromised in any anatomic subgroup of hypoplastic left heart syndrome, we assessed the coronary artery anatomy and myocardial histologic features of 151 postmortem specimens with hypoplastic left heart syndrome. BACKGROUND. Although previous studies have shown that coronary artery abnormalities are more prominent in the subgroup of patients who have a patent mitral valve and obstructed aortic valve, it has not been established that these abnormalities compromise right ventricular perfusion. METHODS. Eighty-nine specimens with a patent mitral valve and aortic atresia, 52 with mitral and aortic atresia and 10 with patent mitral and aortic valves were examined. Histologic sections of the right ventricle, left ventricle and coronary arteries were obtained from 64 study hearts and 5 control hearts. RESULTS. Gross coronary anomalies included coronary-cameral communications (n = 29), single left coronary artery (n = 2), single right coronary artery (n = 1) and tortuosity (n = 19). Coronary-cameral communications and tortuosity were significantly associated with the subgroup that had mitral hypoplasia and aortic atresia. Coronary artery wall thickness relative to lumen diameter was not different among the subgroups. No areas of coronary artery stenosis or interruption were discovered. Although endocardial fibroelastosis of the left ventricle was strongly associated with the mitral hypoplasia and aortic atresia group, the right ventricular histologic findings were similar in all subgroups and were not differentially affected by older age. CONCLUSIONS. Although the incidence of coronary abnormalities is greater in patients with mitral hypoplasia and aortic atresia, in this study there was no apparent difference in perfusion of the right ventricle among the anatomic subgroups of hearts with hypoplastic left heart syndrome.     

Selective aortic root angiography in the hypoplastic left heart syndrome.

Selective aortic root angiography was performed in 18 patients with the clinical diagnosis of hypoplastic left heart syndrome in order to allow more precise correlation with echocardiography. Aortic valve atresia and severe hypoplasia of the left heart chambers subsequently were substaniated at necropsy in each instance. Wide variation in the size and shape of the aortic root and ascending aorta was demonstrated angiographically in these patients. In some patients, despite aortic valve atresia, the dimensions of the aortic root and sinuses of Valsalva at angiography were almost normal. In addition, this technique allowed the demonstration of primitive vascular communications between the coronary artery and left ventricular cavity in 1 patient (coronary-cameral fistula). The realization that the aortic root may approach nearly normal size in some patients with the hypoplastic left heart syndrome is essential to the echocardiographic diagnosis of this disease and to the differential diagnosis from other cardiac and noncardiac causes of severe neonatal congestive heart failure.     

Hypoplastic left heart syndrome: is echocardiography accurate enough to guide surgical palliation?

Two-dimensional echocardiography can diagnose hypoplastic left heart syndrome. However, with the advent of the possibility of palliative open heart surgery, complete anatomic diagnosis is necessary. The anatomic findings of 15 neonates with hypoplastic left heart syndrome (age 1 to 10 days, mean 4.1) who had two-dimensional Doppler echocardiographic studies were compared with the results obtained by angiography (6 cases), surgery (11 cases) and autopsy (8 cases). Complete two-dimensional echocardiographic examination of the aortic arch, pulmonary and systemic venous return, atrial septum, ductus arteriosus and proximal coronary arteries was possible in all 15 neonates and correctly diagnosed hypoplastic left heart syndrome in each. Anatomic two-dimensional echocardiographic assessment was accurate in 13 (86%) of the 15 neonates and there were no false positive results. Undiagnosed associated abnormalities were hypoplasia of a left pulmonary artery in one patient and left superior vena cava in another. Accurate quantitation of the size of the tricuspid valve anulus, ascending aorta, pulmonary anulus and right and left pulmonary arteries was possible. Doppler examination was performed in seven patients and confirmed retrograde aortic arch flow and right to left systolic shunting in the patent ductus arteriosus. In selected neonates, surgical palliation can be attempted without angiography.     

Fistulous communications with the coronary arteries in the setting of hypoplastic ventricles

Neonates born with hypoplastic left heart syndrome now have a remarkably improved prognosis compared with the situation existing before the development of the Norwood sequence of operative procedures. Some of those born with hypoplastic right ventricles in the setting of pulmonary atresia with an intact ventricular septum, however, still have a relatively poor prognosis. In part this reflects the presence of fistulous communication between the cavity of the right hypoplastic right ventricle and the coronary arterial tree. Such fistulous communications are now increasingly recognised as being important in the setting of hypoplastic left heart syndrome. In this brief review, we describe the anatomy of the communications. Those found with hypoplastic right ventricles are seen most frequently when the cavity of the ventricle effectively represents only the inlet, this in turn reflecting mural overgrowth of the apical trabecular and outlet components during foetal development. This almost certainly reflects an earlier appearance of the pulmonary valvar lesion that promotes the cavitary hypoplasia. In those with hypoplastic left ventricles, the key feature differentiating those with fistulous communications is the presence of a patent mitral valve, since the left ventricle is typically no more than a virtual slit in postero-inferior ventricular wall in the setting of mitral valvar atresia or absence of the left atrioventricular connection.     

Extensive left ventricular to coronary artery connections in hypoplastic left heart syndrome

We demonstrate the echocardiographic features of a rare case of very extensive left ventricular to coronary arterial connections (VCC) to both the right and left coronary arteries in a fetus and subsequent neonate with hypoplastic left heart syndrome (HLH). The right coronary artery, after receiving multiple VCC supplied the only antegrade ascending aortic flow. The left main coronary artery was very hypoplastic and the left anterior descending coronary artery was dilated and tortuous with multiple large VCC. The left circumflex coronary artery arose exclusively from its own VCC. To our knowledge this is the first such echocardiographic demonstration of HLH with extensive bilateral VCC and coronary artery stenosis and interruption.     

Left Ventricular Shape Deformation and Mitral Valve Prolapse in Chronic Pulmonary Hypertension

Mitral valve prolapse (MVP) has been described in patients with right ventricular pressure or volume overload. The frequency of this phenomenon and its relationship to left ventricular shape and mitral valve annulus size, as well as its reversibility in chronic pulmonary hypertension, are poorly understood. We have observed an increased frequency of MVP in a patient population with chronic thromboembolic pulmonary hypertension that often resolves after thromboendarterectomy and reduction of pulmonary hypertension. To further evaluate the relationship between MVP and left ventricular shape in pulmonary hypertension, we studied 51 consecutive patients undergoing surgery for thromboembolic pulmonary hypertension. Echocardiographic features including interventricular septal position, as measured by an eccentricity index, left ventricular size, and several mitral valve annulus dimensions were evaluated prior to surgery and during the postoperative hospitalization period. The pulmonary artery systolic pressure was elevated for all patients prior to surgery, 87 ± 21 mmHg (mean ± SD). Twelve patients (23.5%) had MVP before surgery, which resolved in ten patients postoperatively. In addition, one patient whose pulmonary hypertension improved little, developed MVP postoperatively. Those patients with MVP had a greater pulmonary artery pressure preoperatively than those without MVP (102 ±19 vs 84 ±21 mmHg). The eccentricity index for those patients with MVP (1.68±0.2) was greater than for those with no MVP (1.53 ± 0.37). No significant differences were noted between groups with MVP and without MVP according to all mitral annulus dimensions or left ventricular chamber areas. Postoperatively, eccentricity index decreased significantly in both those with MVP and without MVP (1.29 ± 0.18 and 1.20 ± 0.15, respectively) as did pulmonary artery systolic pressure (67± 22 and 47 ± 13 mmHg, respectively). Mitral valve prolapse in chronic pulmonary hypertension occurs frequently and is noted particularly in those patients with the most severe pulmonary hypertension. It appears that deformation of the left ventricle is associated with echocardiographic MVP and that reduction of pulmonary hypertension reverses this deformation and allows for resolution of MVP.     

Clinical and echocardiographic features of isolated severe pure mitral regurgitation

Recent studies have shown that rheumatic heart disease is no longer the main cause of isolated severe pure mitral regurgitation. In this study, we evaluated various clinical and echocardiographic features found in the syndrome of mitral regurgitation. Our data is consistent with recent reports that mitral valve prolapse and coronary artery disease are now the predominant causes of mitral regurgitation and that rheumatic heart disease is a much less common etiology. In addition, our data suggest that clinical evaluation alone is usually very accurate in identifying the correct etiology. Various clinical and echocardiographic features found in the subsets of acute and chronic mitral regurgitation are described. Specifically, patients with acute mitral regurgitation were more likely to have echocardiographic evidence of segmental left ventricular dysfunction and flail mitral valve leaflet. In chronic mitral regurgitation, atrial fibrillation and left atrial dilatation were more commonly present. Echocardiography was found to be more useful in the detection of the complications of coronary artery disease rather than in identifying its presence. Patients with a New York Heart Association classification of IV and those with echocardiographic evidence of an increased left ventricular end-systolic dimension or left ventricular hypertrophy had a worse prognosis.     

Values for Mitral Valve Annulus Dimensions in Normals and Patients with Mitral Regurgitation

Objectives. The present study was designed to investigate the dimensions of mitral valve annulus in the presence of mitral regurgitation. Method. Fifty-four patients were examined. On transthoracic echocardiographic images, we performed linear measurements in the parasternal plane in order to define the size of the left ventricle, left atrium, and mitral valve annulus. We compared these findings with those obtained in 16 control subjects. Results. Twenty-one patients with mild or moderate mitral regurgitation demonstrated no significant change of the mitral valve annulus compared with the control group (P > 0.05). Seventeen patients with severe mitral regurgitation (grade of 4) had a significant increase of the dimensions of the mitral valve annulus, left ventricle, and left atrium (P < 0.05). The etiology of mitral regurgitation was degenerative in 32 patients, rheumatic in 2 patients, and mitral valve prolapse in 4 patients. All patients had normal left ventricular systolic function. Thirty-one patients were in normal sinus rhythm, and seven were in atrial fibrillation. Conclusions. The measurement of the diameter of the mitral valve annulus is feasible with transthoracic echo-cardiography. In addition to the evaluation of mitral valve leaflets and subvalvular apparatus, the measurement of the mitral valve annulus is important in the evaluation of mitral regurgitation, as its enlargement is indicative for severe mitral regurgitation .     

Intracardiac M-mode echocardiography for continuous left ventricular monitoring: method and potential application.

Because no accurate and readily applied method exists for continuous recording of left ventricular cavity dimensions and wall motion in man, we designed a catheter-mounted echocardiographic probe. The purpose of this report is to describe the instrumentation, technique, limitations, complications and preliminary observations employing the probe in humans. The echo transducer built into a cardiac allowed positioning in the right heart under fluoroscopy. The echo signals permitted continuous left ventricular cavity measurements at rest and during maneuvers. Our results suggest that intracardiac echo may be able to provide clear definition of motion patterns of the mitral valve and left ventricular walls. The ultrasonic catheter is an instrument that potentially offers a new technique for continuous monitoring of left ventricular size and motion.     

Intracardiac M-mode echocardiography for continuous left ventricular monitoring: Method and potential application

Because no accurate and readily applied method exists for continuous recording of left ventricular cavity dimensions and wall motion in man, we designed a catheter-mounted echocardiographic probe. The purpose of this report is to describe the instrumentation, technique, limitations, complications and preliminary observations employing the probe in humans. The echo transducer built into a cardiac catheter allowed positioning in the right heart under fluoroscopy. The echo signals permitted continuous left ventricular cavity measurements at rest and during maneuvers. Our results suggest that intracardiac echo may be able to provide clear definition of motion patterns of the mitral valve and left ventricular walls. The ultrasonic catheter is an instrument that potentially offers a new technique for continuous monitoring of left ventricular size and motion.     

Beurteilung der diastolischen Herzinsuffizienz

Diastolic heart failure, also known as heart failure with preserved left ventricular ejection fraction (HF-pEF), is responsible for approximately 50 % of all heart failure cases. According to current guidelines the diagnosis HF-pEF requires three criteria: (1) signs or symptoms of heart failure, (2) presence of a normal left ventricular ejection fraction and (3) evidence of diastolic dysfunction. Echocardiography is the diagnostic modality of choice, especially after ruling out other causes of dyspnea, such as pulmonary diseases, heart rhythm disturbances and volume overload. Important echocardiographic parameters for the assessment of diastolic function are atrial dimensions, myocardial mass, mitral inflow pattern, pulmonary vein flow, propagation velocity of mitral inflow and the tissue Doppler of the mitral annulus. Nevertheless, a complete echocardiographic examination should be performed in every patient with heart failure. In general, diastolic dysfunction is frequently associated with increased atrial diameter and left ventricular hypertrophy. In advanced stages pulmonary hypertension can be present. A robust method for evaluation of systolic function in patients with diastolic dysfunction is crucial. The mitral inflow pattern provides various parameters to describe diastolic function (E/A ratio, deceleration time, isovolumetric relaxation time). In case of difficulties to separate a normal from a pseudonormal mitral inflow pattern the Valsalva maneuver can be used. Another valuable parameter for this differentiation is the duration of the backward flow in the pulmonary veins in contrast to forward flow over the mitral valve. Tachycardia or atrial fibrillation is a major problem for grading of diastolic function; however, in patients with atrial fibrillation E/e’ is a well-established parameter. In summary, this review provides a detailed overview and discussion of the established and newer echocardiography techniques for the evaluation of diastolic function and provides an algorithm for the assessment of diastolic dysfunction in everyday routine.     

Catheter Intervention for Congenital Heart Disease at Risk of Circulatory Failure

Percutaneous interventions complement other therapeutic modalities in the management of patients with heart failure secondary to congenital heart disease. The systemic left ventricle can fail when submitted to excessive afterload as seen with critical aortic stenosis or coarctation. Balloon dilation of the aortic valve is safe and effective in establishing adequate forward flow and improving myocardial function in neonates. A large left-to-right shunt caused by a ventricular septal defect or a patent ductus arteriosus can lead to left ventricular failure. In selected infants, device closure of these defects is a therapeutic option. The postoperative right ventricle burdened by chronic residual obstruction and volume overload is at risk of failure. Balloon dilation of the pulmonary valve, pulmonary artery angioplasty with or without stent implantation, and pulmonary conduit stenting are effective in minimizing afterload to the right ventricle. More recently, percutaneously implantable pulmonary valves have become an option, in selected patients, for full rehabilitation of dysfunctional pulmonary conduits. Patients with single ventricle physiology have a fragile physiology, justifying an aggressive catheter interventional approach to optimize hemodynamic characteristics. The hybrid approach to palliation of hypoplastic left heart syndrome has become a viable option in selected centres.     

Asynchronous atrioventricular valve opening as it relates to right to left interatrial shunting in the normal newborn

The opening of the tricuspid valve and the onset of right ventricular filling precede the opening of the mitral valve and the onset of flow in the normal adult. Sixty-five studies of atrioventricular flow with range-gated pulsed Doppler echocardiography, performed on 32 normal neonates, consistently demonstrated the reverse sequence. Further investigation showed that at the time of mitral valve opening, while the tricuspid valve was still closed, the valve of the foramen ovale began to bow posteriorly into the left atrium and remained posteriorly bowed for most of diastole. The magnitude of posterior bowing varied among the neonates but, concomitant with the more prominent grades of posterior bowing, right to left shunting across the foramen ovale was demonstrated on color flow mapping. Ultrasound studies in the normal fetus also revealed earlier opening of the mitral valve, bowing of the valve of the foramen ovale into the left atrium and right to left shunting across the foramen ovale. These findings indicate that in the normal immature heart isovolumic ventricular relaxation is completed earlier on the left than on the right side and that left ventricular compliance appears to be greater than right ventricular compliance. The relation of left and right ventricular compliance in the adult is different from that in the normal immature heart. Whereas systemic and pulmonary vascular resistance and pressure levels change rapidly in the newborn period, ventricular compliance matures over a longer period of time. As a result of the differential maturity, for a variable period of time in the normal neonate, a left to right ductal shunt coexists with a right to left atrial shunt.