Frederick Helmcke

Color Doppler assessment of mitral regurgitation with orthogonal planes.

We evaluated 147 patients with adequate color Doppler and angiographic studies for mitral regurgitation. Sixty-five patients had no mitral regurgitation by both color Doppler and angiography and 82 patients had mitral regurgitation by both techniques. Thus the sensitivity and specificity of color Doppler for the detection of mitral regurgitation was 100%. Three two-dimensional echocardiographic planes (parasternal long and short axis, apical four-chamber view) were used to analyze variables of the mitral regurgitant jet signals in the left atrium. The best correlation with angiography was obtained when the regurgitant jet area (RJA) (maximum or average from three planes) expressed as a percentage of the left atrial area (LAA) obtained in the same plane as the maximum regurgitant area was considered. The maximum RJA/LAA was under 20% in 34 of 36 patients with angiographic grade I mitral regurgitation, between 20% and 40% in 17 of 18 patients with grade II mitral regurgitation, and over 40% in 26 of 28 patients with severe mitral regurgitation. Maximum RJA/LAA also correlated with angiographic regurgitant fractions (r = .78) obtained in 21 of 40 patients in normal sinus rhythm and with no evidence of associated aortic regurgitation. Other variables of the regurgitant jet such as maximal linear and transverse dimensions, maximal area, or maximal area expressed as a percentage of the LAA in one or two planes correlated less well with angiography. Color Doppler is a useful noninvasive technique that is not only highly sensitive and specific in the identification of mitral regurgitation but also provides accurate estimation of its severity.

Evaluation of aortic insufficiency by Doppler color flow mapping

The color Doppler echocardiographic studies and aortic angiograms of all patients who had these procedures performed within 2 weeks of each other between October 1984 and August 1985 were reviewed to determine whether any parameters of the regurgitant jet visualized by color Doppler study predicted the severity of aortic insufficiency as assessed by angiographic grading. Patients with an aortic valve prosthesis were excluded. Twenty-nine patients had aortic insufficiency and had adequate color Doppler studies for analysis. The mean time between color Doppler examination and angiography was 2.3 days (range 0 to 12). The maximal length and area of the regurgitant jet were poorly predictive of the angiographic grade of aortic insufficiency. The short-axis area of the regurgitant jet from the parasternal short-axis view at the level of the high left ventricular outflow tract relative to the short-axis area of the left ventricular outflow tract at the same location best predicted angiographic grade, correctly classifying 23 of 24 patients. However, the jet could be seen from this view in only 24 of the 29 patients. The height of the regurgitant jet relative to left ventricular outflow tract height measured from the parasternal long-axis view just beneath the aortic valve correctly classified 23 of the 29 patients. Mitral stenosis or valve prosthesis, which was present in 10 patients, did not interfere with the diagnosis or quantitation of aortic insufficiency by these methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Uses and limitations of transthoracic echocardiography in the assessment of atrial septal defect in the adult

Two-dimensional and color Doppler echocardiography accurately detected the presence of an atrial septal defect (ASD) in 47 of 50 adults (mean age 40 years) confirmed by surgery or cardiac catheterization, or both. It correctly categorized all patients with ostium secundum and ostium primum ASD but misdiagnosed 3 of 5 patients with surgically proven sinus venosus ASD. The shunt flow volume across the ASD was calculated with the standard Doppler equation, and assuming the ASD to be circular correlated with shunt flow volume obtained by cardiac catheterization (r = 0.74). The maximum width of the color flow signals moving across the ASD was taken as its diameter. Mean flow velocity was determined either by placing a pulsed Doppler sample volume parallel to the flow across the ASD as visualized by color Doppler or by color M-mode examination, which allowed determination of flow velocities using a previously validated method that incorporates a computer analysis of pixel color intensity. The pulmonary to systemic blood flow ratio obtained by color-guided conventional Doppler interrogation of the left and right ventricular outflow tracts correlated poorly with cardiac catheterization results (r = 0.38). In patients with associated tricuspid regurgitation, the peak systolic pulmonary artery pressure obtained by color Doppler-guided continuous-wave Doppler correlated well with that obtained at cardiac catheterization (r = 0.89). The maximum color Doppler jet width of the flow across the ASD poorly correlated with ASD size estimated at surgery (r = 0.50).

Transesophageal doppler color flow mapping assessment of atrial septal defect

Transesophageal Doppler color flow imaging was performed in 19 adult patients (mean age 35 years) with an atrial septal defect demonstrated by cardiac catheterization or at surgery, or both. The transesophageal study correctly identified and classified 19 of 19 shunts in contrast to 16 of 18 shunts identified by the transthoracic approach. The area of the atrial septal defect was calculated by assuming it to be circular and taking the maximal Doppler color flow jet width at the defect site as its diameter. The pulsed Doppler sample volume was placed parallel to the shunt flow direction at the defect site to obtain the mean velocity and flow duration. From these values, the shunt volume was calculated as a product of the defect area, mean velocity, flow duration and heart rate. The calculated shunt flow volume obtained by transesophageal study showed a good correlation with shunt flow volume (r = 0.91, p less than 0.001) and pulmonary to systemic blood flow ratio (r = 0.84, p less than 0.001) obtained at cardiac catheterization. The size of the defect by transesophageal Doppler color flow mapping correlated fairly well with the size estimated at surgery (r = 0.73, p = 0.004). It is concluded that transesophageal Doppler color flow imaging is useful in the detection and classification of atrial septal defects and in the assessment of shunt volumes.

Two-dimensional and color doppler assessment of ventricular septal defect of congenital origin

Two-dimensional echocardiography and color Doppler examinations were performed in 53 patients with 58 ventricular septal defects (VSD) proven surgically or anatomically. All patients also had angiocardiograms. Two-dimensional echocardiography/color Doppler examination detected all VSDs and correctly categorized the site and extension of VSDs in 50 of 58 (86%). All 40 perimembranous VSDs were diagnosed in the left ventricular outflow tract short-axis plane as an area of discontinuity adjacent to septal tricuspid valve leaflet attachment. Fourteen of 16 VSDs with inlet extension showed initial color flow signals along the septal tricuspid leaflet and along the ventricular septum. Of 23 perimembranous VSDs with outlet extension, 19 had flow signals moving directly toward the right ventricular outflow tract. One perimembranous VSD with trabecular extension showed flow signals directed anterolaterally toward the right ventricular free wall. Eleven of 13 muscular VSDs were similarly categorized correctly by color Doppler as inlet, outlet and trabecular. All 5 doubly committed VSDs were correctly diagnosed as an area of discontinuity adjacent to the pulmonary valve in the short-axis view with flow signals directly moving through VSD into right ventricular outflow and pulmonary artery. Angiography correctly detected all VSDs and correctly classified their site and extension in 45 of 58 (77.5%). It misclassified 8 of 40 perimembranous, 3 of 13 muscular and 2 of 5 doubly committed VSDs. Color Doppler compares favorably with angiocardiography in the detection and localization of VSDs.

Amplitude information from Doppler color flow mapping systems: A preliminary study of the power mode

The flow of a saline-glycerin solution with sand particles through a continuous in vitro flow system was imaged by using two commercially available Doppler color flow mapping systems in a power mode (Toshiba SSH-160A and Advanced Technology Laboratories [ATL] Ultramark 9). The images generated from seven solutions with particle concentrations ranging from 0.0001 x 10(12) to 6 x 10(12) particles/liter and a mean velocity of 30 cm/s measured with use of pulsed Doppler ultrasound were used to examine the dependence of the power mode on particle concentration. To examine the velocity dependence, 20 mean velocities ranging from 0.1 to 0.53 m/s (3 to 30 liters/min) and three particle concentrations (1, 3 and 6 x 10(12) particles/liter) in the solution were used. The recorded images were digitized and analyzed off-line. The SUM values, or the adjusted color intensity levels in delineated areas of interest in the displayed flow, were compared. In general, the power mode was sensitive in displaying slower velocity flows; in the selected particle concentration and velocity ranges, it was both velocity and concentration dependent. The specific dependence differed for the two color flow mapping systems.

Value and limitations of color doppler echocardiography in the evaluation of percutaneous balloon mitral valvuloplasty for isolated mitral stenosis

The limitations of 2-dimensional and pulsed Doppler echocardiography in patients undergoing mitral valvuloplasty are well known. This study was undertaken to assess the value of color Doppler flow imaging in 36 symptomatic mitral stenosis patients who subsequently underwent successful balloon mitral valvuloplasty by comparing the results to those obtained at cardiac catheterization. Color Doppler-guided conventional Doppler assessment agreed well with cardiac catheterization results in classifying mitral stenosis as mild, moderately severe and severe, both before and after valvuloplasty. Color Doppler was also useful in identifying patients who had moderate to severe mitral regurgitation before and after valvuloplasty. Color Doppler flow mapping was more sensitive than oximetry in the detection of iatrogenic atrial septal defects, which were noted in 25 patients. The defects of those patients with smaller defects by color Doppler (diameter less than 0.7 cm) or echocardiographic shunt volume less than 0.7 liters/min tended to close, usually within 6 months, as opposed to those with larger defects or higher shunt volumes, which tended to persist. Echocardiographic shunt volumes revealed a fair correlation with oximetric results.

Color Velocity Determination Using Pixel Color Intensity in Doppler Color Flow Mapping

Quantitating flow velocities in the heart can be easily accomplished using conventional continuousand pulsed-wave Doppler echocardiography. These techniques, which are based on the principles of wave phenomenon, use either a Fast Fourier Transform or Chirp-Z technique to analyze the frequency differences between the transmitted and returning sound waves at the transducer. This analysis generates information about direction, velocity and/or direction, amplitude or strength, and variance or velocity variation of the flow. Pulsed Doppler, specifically, provides this information with regards to a small sample of flow selected by the examiner moving the sample volume to a desired location. This technique, however, is limited by the maximum velocity that it can display and by the blind positioning of the cursor in the area of the flow causing the maximum velocities in the flow possibly to be missed and, thus, the severity of the regurgitation possibly misdiagnosed. Conventional continuous-wave Doppler is not limited to the maximum velocity that it can measure, but it provides flow information along the entire scanline causing the exact velocities in a particular flow to be undefined. Doppler color flow mapping or color Doppler is an accepted technique in providing qualitative flow information and in supplementing conventional continuous and pulsed Doppler. It displays flow information in terms of the primary colors: red, blue, and green, and their properties: hue, saturation, and intensity, in conjunction with a two-dimensional image. A spectral analysis technique such as autocorrelation is used to generate this flow information about direction, velocity, variance, and amplitude from the phase differences between the transmitted and received sound waves. A vertical calibration bar is displayed on each image to show the examiner the information being depicted and the color properties used to display this information. Often, color Doppler is referred to as multigated pulsed Doppler because several sample volumes along the scan line are analyzed to provide flow information. Also, color Doppler, like pulsed Doppler, has a maximum measurable velocity or Nyquist limit. The flow with velocities greater than the Nyquist limit are easy to differentiate for a trained examiner because this aliased flow is displayed with the color indicating the opposite flow direction. Quantitating color Doppler information has just begun to be One technique of quantitating the color may possibly include using the color intensity level assigned to a pixel, the smallest picture element used to display the flow, to determine the velocity of the flow being examined. We have conducted a study on using this quantitating technique by measuring the velocities in vitro and in vivo in the left ventricle and by comparing our results to the velocities measured using conventional pulsed Doppler and color M-mode.

Commonly used respiratory and pharmacologic interventions in the echocardiography laboratory.

Respiratory and pharmacologic interventions are used during auscultation of heart sounds. These same principles may be utilized in the echocardiography laboratory to aid diagnosis. Four physical maneuvers and one pharmacologic intervention performed in the echocardiography laboratory are described. A brief discussion of applications in specific clinical situations is then presented. The Valsalva maneuver involves having the patient inspire deeply followed by a forceful exhalation against a closed glottis for approximately 10 seconds. Placing the hand on the patient’s abdomen by the examiner provides a force for the patient to strain against and ensures that the abdominal muscles are tightening.1 Some patients who have difficulty with this may find it best to insert their index finger in the mouth and attempt to blow out with lips sealed. Alternatively, the patient may blow into a manometer to maintain 40 mmHg or more.2 The Valsalva maneuver involves the following four phases:

AN UNUSUAL CAUSE OF CONSTRICTIVE PERICARDITIS AFTER CORONARY BYPASS SURGERY

Classic constrictive pericarditis is characterized by impaired cardiac filling secondary to a calcified pericardium from chronic inflammation. Constrictive physiology may also occur without chronic pericardial calcification and display an atypical presentation. We describe an unusual case of