Pulmonary regurgitation studied with the ultrasonic pulsed Doppler technique

Right-sided valvular regurgitation in normal children determined by combined colour-coded and continuous-wave Doppler echocardiography

Using Doppler echocardiography, the prevalence of tricuspid and pulmonary valve regurgitation was determined prospectively in 173 normal children, aged 8.3 +/- 2.7 (range 5-14) years. Pulmonary regurgitation was defined as a red-yellow or mosaic coloured regurgitant flow, continuing to end-diastole with continuous-wave Doppler. It was found in 84% of the children. Tricuspid regurgitation was defined as a blue-green or mosaic coloured regurgitant flow from the tricuspid valve into the right atrium lasting > 0.5 systole, as determined by continuous-wave Doppler. Tricuspid regurgitation was present in only 8% of the children. Tricuspid regurgitation flow of very short duration, considered to be due to valve closure, was found in 75%. No effect of age, presence of a vibratory innocent heart murmur or gender on the prevalence of right-sided valvular regurgitation could be demonstrated. All regurgitations were haemodynamically insignificant. Thus right-sided valvular regurgitation in normal schoolchildren is a normal physiological finding with relatively high prevalence. In the absence of functional reasons for these regurgitations and in the absence of structural pulmonary or tricuspid valve disease, these signals should be considered physiological in order to avoid iatrogenic heart disease.

Echocardiographic evaluation of isolated pulmonary valve disease in adolescents and adults

Congenital pulmonary valve disease is often not discovered until adolescence or adulthood. Transthoracic two-dimensional echocardiography can provide detailed information regarding right ventricular outflow anatomy, although images are often less satisfactory than those obtained in infants and children. The more recent addition of biplanar transesophageal echocardiography has enhanced our ability to image the right ventricular outflow tract, pulmonary valve, and pulmonary artery noninvasively. Pulsed and continuous-wave Doppler estimates of subvalvular and transvalvular gradients have proved to be accurate. Doppler color flow mapping has proved useful in determining the location and direction of stenotic and regurgitant flow. With no accepted standard for comparison, quantification of regurgitation remains problematic. In many cases, echocardiography has replaced catheterization and angiography in the evaluation and long-term follow-up of congenital pulmonary valve disease before and after intervention.

Isolated pulmonary valvular regurgitation: current perspectives

IPVR is a rare clinical entity that was first diagnosed during life in 1955. In the past 35 years, only 69 patients have been reported. With increasing clinical awareness, as well as use of PDE, the confirmation of its clinical diagnosis has become easier and more accurate without having to take recourse to invasive cardiac studies as in the past. For this reason, it is becoming increasingly apparent that IPVR is not so rare as has been suggested in the past. IPVR is more common in men than in women, in whites than blacks, and in the young than the elderly. The mean age of IPVR patients is 27 years (range, 4 to 85). The majority of the patients are asymptomatic and the diagnosis is usually suspected upon the discovery of a crescendo-decrescendo, low-pitched, early to mid diastolic murmur in the second and third left intercostal space, which increases during inspiration, particularly in the presence of a hyperdynamic right ventricle and in the absence of peripheral circulatory phenomenon of aortic regurgitation. The ECG often shows right axis deviation, incomplete right bundle branch block, and rarely, right ventricular hypertrophy and strain. However, a normal ECG does not preclude its diagnosis. Approximately 30% of the IPVR patients have normal 12-lead ECGs. The diagnosis may be further suggested by the posteroanterior chest roentgenogram when dilated and large central pulmonary arteries are noted to pulsate vigorously (hilar dance) on chest fluoroscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

The echo Doppler spectrum of valvular abnormalities in the hospitalized octogenarian

Cardiac valves thicken and become more opaque with advancing age. As more individuals live longer and as more treatment modalities such as valvuloplasty evolve, the presence and significance of these valvular abnormalities become important. We retrospectively studied 628 octogenarian patients to try and define further the presence and significance of these abnormalities detected by Doppler echocardiography. A group of 547 patients were suitable for analysis. Age ranged from 80 to 96 years (mean 84.4). The female:male ratio was 1.9:1. Mitral, aortic, and tricuspid regurgitation (MR, AR, and TR) were significant if the jet moved greater than 2 cm from the plane of the valve away or toward the transducer, depending on transducer position. Mitral regurgitation was detected in 331 patients (60.5%) and was significant in 82 patients (15%). Aortic regurgitation was detected in 276 patients (50.5%) and was significant in 70 patients (12.8%). Tricuspid regurgitation was detected in 131 patients (23.9%) and was significant in 30 patients (5.5%). Regurgitant lesions were detected in two valves in 150 patients (27.4%) three valves in 57 patients (10.4%), in all four valves in 17 patients (3.1%). Aortic stenosis was detected in 160 patients (29.3%). The gradient range was 16-156 mmHg (mean 47.8). Significant aortic stenosis was present in 70 patients (12.8%) (gradient greater than 50 mmHg), of whom 54 had isolated pure aortic stenosis and 16 had mixed lesion. In 40% of these patients, significant aortic stenosis was an unexpected finding at two-dimensional echocardiography. Valvular pathology is common in the octogenarian population.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical implications of pulmonary regurgitation in healthy individuals: detection by cross sectional pulsed Doppler echocardiography

Pulsed Doppler echocardiography in healthy individuals often shows a disturbance of diastolic flow in the right ventricular outflow tract just below the pulmonary valve that suggests regurgitation. This disturbance of diastolic flow was studied in 50 healthy individuals and 40 patients with cardiopulmonary disease, some of whom had a pulmonary regurgitant murmur. Diastolic flow was disturbed in 39 of the 50 healthy individuals. In 32, cross sectional echocardiography gave a satisfactory image of the pulmonary valve. The characteristic Doppler signals usually lasted throughout diastole, were directed toward the right ventricular cavity, and gradually waned towards end diastole; they formed a spindle shaped area of abnormal signals that extended to within 10 mm of the coaptation of the pulmonary valve towards the right ventricular cavity and the pressure difference estimated from the signals by the modified Bernoulli equation seemed to be proportional to the normal retrograde transpulmonary pressure difference. In all 40 patients with cardiopulmonary disease, signals indicating pulmonary regurgitation were found whether or not a regurgitant murmur was present. When it was present, however, the spindle was longer than 20 mm and in patients with pulmonary hypertension the velocity of abnormal diastolic flow was higher than in healthy individuals. The Doppler signals registering disturbed flow in the healthy individuals resembled the signals caused by pulmonary regurgitation in the patients in terms of location, orientation, and configuration. These results show that healthy individuals usually have trivial pulmonary regurgitation. In practice the distance that the flow disturbance extends from the valve and estimated pressure difference across the valve are probably the most important variables for assessing the clinical significance of pulmonary valve regurgitation.

Right atrial flow topography in healthy subjects studied with real-time two-dimensional Doppler flow imaging technique

The pattern of normal blood flow in the right atrial cavity was studied using the newly developed real-time two-dimensional Doppler flow imaging technique as a standard reference for the Doppler diagnosis of heart diseases with intracardiac shunts at the atrial level. The study was performed primarily with use of the apical four chamber and the parasternal right ventricular inflow tract views in 21 healthy subjects. The following patterns were observed: blood from the inferior vena cava flowed up along the posterior wall of the right atrium and joined with blood from the superior vena cava in the posterocranial part of the right atrial cavity; the flow then coursed along the roof of the right atrium toward the tricuspid valve in the atrial relaxation phase. This flow was always noted along the interatrial septum in the four chamber view. During and after mid-systole of the right ventricle, additional blood flow away from the tricuspid valve appeared, moving from the valve to the central part of the right atrial cavity, that is, at the lower right of the preceding inflow; this flow was interpreted as arising from eddy currents caused by the preceding inflow. In early diastole of the right ventricle, the flow signal area along the interatrial septum and the roof of the right atrium extended into the right ventricular cavity through the tricuspid valve. In the atrial contraction phase only the blood near the tricuspid valve in the right atrial cavity appeared to flow into the right ventricular cavity. Inflow from the coronary sinus was almost undetectable.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler echocardiography: theory, instrumentation, technique, and application

A Doppler examination is a valuable adjunct to a complete echocardiographic examination. It has the capability of measuring normal and abnormal velocities of blood flow noninvasively. For the first time, this procedure allows noninvasive quantitation of stenotic gradients, intracardiac pressures, and blood flow as well as semiquantitative assessment of regurgitant lesions. With this procedure, the operator must progress through a learning curve in order to gain a complete understanding of the examination techniques, the limitations of the instruments, and the Doppler physics principles before applications can be made to clinical practice. Evaluation of other aspects of Doppler echocardiography, such as color-flow mapping and assessment of diastolic events, portends great promise for the role of this procedure in the future.

Doppler echocardiographic diagnosis and quantification of valvular heart disease

Doppler echocardiography is a logical companion to ultrasound imaging in the diagnosis and quantification of valvular heart disease. Accurate noninvasive identification and quantification of valvular heart disease is now possible if both techniques are utilized together. The continued application of our knowledge of hemodynamics should extend our current uses of Doppler echocardiography to allow more intelligent management of patients with known or suspected valvular heart disease.

Experience with qualitative and quantitative applications of Doppler echocardiography in congenital heart disease

The increasing popularity of Doppler echocardiography in recent years has stemmed from the combination of Doppler with two-dimensional echocardiography, and from the Doppler capability for flow velocity measurement. In the past decade, Doppler instrumentation has evolved from single probe A- and M-mode systems with non-quantitative Doppler output, into multi-faceted instruments combining two-dimensional echo, M-mode echo, with both pulsed and continuous wave Doppler. In the field of pediatric cardiology, quantitative Doppler applications have proven most useful in noninvasive measurement of the severity of obstruction at aortic and pulmonic valves, and across pulmonary artery bands. High accuracy is enjoyed using either continuous wave, or high pulse repetition pulsed wave, Doppler. Additional quantitative applications include estimation of volume aortic flow (cardiac output), and comparison with volume pulmonic flow (pulmonary to systemic flow ratio). Through evaluation of specific disturbances of blood flow (timing, location, direction, duration), qualitative aspects of Doppler continue to provide sensitive and specific diagnosis of valvular disease, as well as shunt lesions such as atrial and ventricular septal defect, and patent ductus arteriosus. Qualitative Doppler offers 'semi-quantitation' of the severity of lesions based on demonstration of breadth and extent of the individual flow disturbances. The addition of Doppler flow information to the information available from conventional M-mode and two-dimensional echo has led to a comprehensive cardiac ultrasound capability. Information previously available only from invasive study (severity of gradient, shunt, regurgitation) is now available noninvasively; the impact upon current and long-term aspects of patient care should prove considerable.

Analysis of blood flow in pulmonary hypertension with the pulsed Doppler flowmeter combined with cross sectional echocardiography

Blood flow patterns were analysed at nine points in the pulmonary area using the pulsed Doppler technique combined with cross-sectional echocardiography in 53 patients with heart disease and 10 healthy subjects. In subjects with a normal pulmonary artery pressure the blood flow pattern in systole showed a gradual acceleration and deceleration with a rounded summit in mid systole, designated the round type. In patients with pulmonary hypertension it showed a rapid acceleration and early deceleration with a sharp peak in early systole, designated the triangular type. The acceleration time index, defined as the ratio of the time interval from the beginning to the peak of ejection to the ejection time, showed a significant inverse correlation with mean pulmonary artery pressure. In pulmonary hypertension a prominent reverse flow occurred in the right posterior part of the pulmonary trunk during mid-systole and early diastole, indicating the presence of a vortex. Similar flow patterns were also seen in patients with idiopathic pulmonary artery dilatation. The factors responsible for the triangular type were principally the reduced capacitance and increased impedance of the pulmonary vascular tree. Those responsible for the reverse flow were the curved path of the blood flow and dilatation of the pulmonary artery.