Thomas Riggs

Assessment of the pulmonary vascular bed by echocardiographic right ventricular systolic time intervals.

SUMMARY Echocardiography was used to measure right ventricular systolic time intervals (RVSTI) in 85 normal children (group I) and in 229 patients undergoing cardiac catheterization (group II). Corrected right ventricular pre-ejection period (RPEPC) and right ventricular ejection time (RVETC) (based on regression analysis of group I) and RPEP/RVET were each correlated with pulmonary artery (PA) diastolic and mean pressures and pulmonary vascular resistance (PVR). The best correlation (0.83) was between a second degree polynomial of the RPEP/RVET and PA diastolic pressure. The RPEP/RVET allowed prediction of PA diastolic pressure within 10 mm Hg in 85% of the patients. The utility of RPEP/RVET was confirmed in sequential data of 22 patients, in whom alteration in RPEP/RVET accurately reflected the changing PA diastolic pressure. The RPEP/RVET could not be used to assess PA pressure in six patients with congestive cardiomyopathy nor in 18 patients with complete right bundle branch block (CRBBB).

Echocardiographic abnormalities in infants of diabetic mothers

In order to evaluate the presence of myocardial hypertrophy and/or abnormalities of postnatal cardiovascular adaptation, echocardiograms were performed on 34 infants of diabetic mothers. Based on cardiopulmonary assessment, the IDM were divided into three groups: Group I with congestive heart failure predominating: Group II with respiratory distress predominating: Group III asymptomatic. Hypertrophy of the interventricular septum and of the walls of left and right ventricles was frequently present in IDM: this change was most notable in association with clinical CHF. Six IDM, four of whom were found to have CHF, had additional echocardiographic signs of subaortic stenosis. All IDM had normal indices of left ventricular performance, despite the presence of CHE. In IDM with respiratory distress, the right ventricular pre-ejection period to ventricular ejection time ratio was elevated, suggesting an abnormality of the transitional pulmonary circulation. Poor maternal diabetes control and maternal systemic hypertension were closely correlated with evidence of myocardial hypertrophy in the infants.

Persistence of fetal circulation syndrome: an echocardiographic study.

Serial echocardiograms were performed on 17 infants with persistence of fetal circulation syndrome to measure right ventricular systolic time intervals from pulmonic valve echograms and left ventricular systolic time intervals from aortic valve echograms. Right ventricular pre-ejection period/right ventricular ejection time ratio was prolonged in PFCS when compared to that in normal newborn infants, and diminished with clinical improvement. Left ventricular pre-ejection period/left ventricular ejection time ratio was prolonged in infants with PFCS. Echographic RPEP/RVET was consistent with the elevated pulmonary artery pressure and pulmonary vascular resistance of PFCS; elevated LPEP/LVET suggested left ventricular dysfunction.

Cardiomyopathy and pulmonary emboli in terminal Duchenne's muscular dystrophy

should raise the possibi l i ty of a t raumat ic fistula. 1 This case was unusual in tha t prolonged survival such as this is uncommon and probably occurred because of local tamponade and occlusion of the wound by extensive thrombus. Per iphera l emboli are also an uncommon event and should alert the physician to the possibil i ty of a bul let embolus. 4 The repeated emboli in this pa t ien t reflect the friable nature of the aortic thrombus and the extensive damage tha t bul let wounds may cause to the vessel wall. 5 Angiography has been the t rad i t ional method of evaluating pathologic condit ions of the aorta, but because of the hemodynamic instabi l i ty associated with penetra t ing wounds of the aorta, it may not be safe and may cause undue delay in management of the patient . T E E is a safe bedside technique tha t has been shown to be as reliable as angiography in the evaluat ion of thoracic aortic dissections and aneurysms and superior to computed tomography scanning, s This case highlights the usefulness of TEE and also shows the advantages of recently developed biplane imaging. Longaxis scanning provided a much greater appreciat ion of the three-dimensional nature of the aortic clot and allowed the use of color flow mapping and Doppler quantif icat ion of the obstruction. T E E may reduce the need for extensive angiography and hence permi t more rapid definitive t reatment.

Echocardiographic estimation of ventricular hypoplasia in complete atrioventricular canal.

Echocardiograms from 10 patients with complete atrioventricular canal (CAVC) were compared with autopsy specimens to determine the capabilities of echocardiography in identifying patients with ventricular hypoplasia. On the basis of echographic ventricular size, patients could be divided into three groups: 1) “balanced” CAVC patients had both increased right left ventricular end-diastolic dimensions (RVED LVED) an increased RVED/LVED ratio; 2) “dominant left ventricular” CAVC patients had an increased LVED small or normal RVED a diminished RVED/LVED ratio; 3) “dominant right ventricular” CAVC patients had an increased RVED, but small LVED, increased RVED/LVED. There was complete agreement between echographic ventricular dominance pathologic findings. This study demonstrates that echocardiography may be valuable in assessing ventricular dominance in the presence of CAVS.

Ventricular septal defect in infancy: a combined vectorgraphic and echocardiographic study.

Echocardiograms (echo) and vectorcardiograms (VCG) from 40 infants with ventricular septal defects (VSD) were compared with cardiac catheterization data to assess noninvasively the hemodynamics of VSD. The specific aim was to use VCG parameters of right ventricular hypertrophy and echo parameters which reflect pulmonary artery pressure to identify all patients with a nonrestrictive VSD. The configuration of the QRS vector in the horizontal plane was more reliable than individual voltages in assessing right ventricular systolic pre-ssure. Among patients older than 2 months with a clockwise or anterior two-main-vector horizontal loop, 73% (eight of 11) had a nonrestrictive VSD. However, a counterclockwise or posterior two-main-vector loop was also frequently found (43%, six of 14) in infants with a nonrestrictive VSD. The most useful echo parameter was the ratio of right ventricular preejection period-to-right ventricular ejection time (RPEP/RVET), which closely (r = 0.74) reflected the pulmonary artery diastolic pressure. An elevated RPEP/RVET to greater than 0.30 was always associated with a nonrestrictive VSD, although many patients (36%, five of 14) with a nonrestrictive VSD had a normal ratio. By combining both echo and VCG parameters, a nonrestrictive VSD was correctly identified in all patients, while a restrictive VSD was correctly identified in 81% (21 of 26

Respiratory variation in Frank vectorcardiography and echocardiography in children.

Forty pediatric patients underwent echocardiographic and Frank vectorcardiographic studies during normal respiration. The right ventricular minor axis (RVEDD) increased significantly with inspiration (p less than 0.005), while the left ventricular minor axis did not significantly change. The distance from the anterior chest wall to the center of the left ventricle did significantly increase with inspiration (p less than 0.005). Some vectorcardiographic parameters changed with inspiration, also. Both the maximal spatial vector to the left (MSVL) and the X to the left (X-L) significantly decreased with inspiration. Although the average magnitude of these changes was small (10-15%), there was wide variation. Five of twenty-one patients with left ventricular hypertrophy during expiration had a clearly normal Frank VCG during inspiration. It is suggested that phases of respiration should be monitored when evaluating the Frank VCG in pediatric patients.

The pediatric spectrum of dynamic left ventricular obstruction

Twenty-one pediatric patients with echocardiographic and/or hemodynamic evidence of dynamic left ventricular obstruction are presented in order to examine the pathophysiologic mechanisms of this disorder. Neonates commonly had transient hypertrophic cardiomyopathy related to hypertension or to being infants of diabetic mothers. Infants with D-transposition of the great arteries sometimes developed signs of subpulmonic dynamic obstruction. Older children and adolescents had either classic findings of IHSS or concentric left ventricular hypertrophy. The spectrum of hypertrophic cardiomyopathy appears to be broader in pediatric patients than in adults.

Echocardiographic assessment of the adequacy of pulmonary arterial banding.

Thirty-one echocardiograms of 21 patients who had pumonary arterial banding were analyzed to assess the aequacy of surgery. In 5 patients the echocardiograms were obtained before and after banding and in 16 patients only after surgery. Right and left ventricular systolic time intervals were measured echographically. The ratios of the right ventricular preejection period to right ventricular ejection time (RPEP/RVET) were correlated with both diastolic (r = 0.94) and systolic (r = 0.86) pulmonary arterial pressures distal to the band. The analysis of right ventriclar systolic time intervals, especially the RPEP/RVET ratio, clearly differentiated patients with an adequate band (distal pulmonary arterial diastolic pressure less than 15 mm Hg) from patients with an inadequate band (distal pulmonary arterial diastolic pressure equal to or greater than 30 mm Hg). The results indicate that echocardiography is a useful noninvasive tool in evaluating the adequacy of the pulmonary arterial band and facilitates the follow-up of patients after banding.